**OH-58 A, A+, and C**

**Helicopters**

**INSPECTION PLANNING GUIDE**

![](media/image1.wmf){width="1.575in" height="1.51875in"}

INTERAGENCY COMMITTEE for AVIATION POLICY (ICAP)

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

# Updated 1 March 2002

**Table of Contents**

**\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

**[Chapter/ Section]{.underline} Page**

Record of Revisions . . . . . . . . 2

List of Effective Pages . . . . . . . . 7

Definitions . . . . . . . . . . 8

Points of Contact . . . . . . . . . 13 \|

C hapter 1 Introduction . . . . . . . 15

1-1. General . . . . . . . 15 \|

1-2. Warnings, Cautions, and Notes Defined . . 16

1-3. Aircraft, Aircraft Engines, and

Appliances Documents/Records Review . . . . 16

1-4. Format Defined . . . . . . 17

Chapter 2 Inspection Descriptions . . . . . . 18

2-1. Chapter 3 Preventive Maintenance Inspection (P.M.I.) 18 \|

2-2. Chapter 4 Intermediate Inspection (25 Hour) . 18 \|

2-3. Chapter 5 Periodic Inspection (300 Hour) . . 18 \|

2-4. Chapter 6 Special Inspections . . . . 18 \|

2-5. Chapter 7 Conditional Inspections . . . 18 \|

Inspection Schedules . . . . . 19 \|

Chapter 3 Preventive Maintenance Inspection (P.M.I**.**). . . 20

Chapter 4 Intermediate Inspection (25 Hour) . . . . 28 \|

Chapter 5 Periodic Inspection (300 Hour). . . . . 31 \|

Chapter 6 Special Inspections . . . . . . 35

Special Inspections Index . . . . . 35 \|

Chapter 7 Conditional Inspections . . . . . . 50

Conditional Inspections Index . . . . . 50 \|

APPENDIX Letter from Bell Textron

Ref: Overhaul and Retirement Schedule,

Manuals and Technical Assistance 65 \|

**Record of Revisions**

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

As originally submitted to the FAA for

acceptance on January 17, 1997. Revisions posted as of:\|

+-----------------+-----------------+-----------------+-----------------+
| **Posted:**     |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| Date            | By:             | Revision Number | Page Number (s) |
|                 |                 |                 |                 |
|                 |                 |                 | (Page numbers   |
|                 |                 |                 | are as they     |
|                 |                 |                 | appeared in the |
|                 |                 |                 | January 17,     |
|                 |                 |                 | 1997 version.)  |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | TOC revised to  |
|                 |                 |                 | reflect         |
|                 |                 |                 | changes. Page   |
|                 |                 |                 | numbers in      |
|                 |                 |                 | Revision 1 were |
|                 |                 |                 | changed as      |
|                 |                 |                 | needed.         |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Cover page date |
|                 |                 |                 | "January 17,    |
|                 |                 |                 | 1997"           |
|                 |                 |                 |                 |
|                 |                 |                 | Changed to "1   |
|                 |                 |                 | March 2002"     |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | TOC changed to  |
|                 |                 |                 | include "Points |
|                 |                 |                 | of Contact" in  |
|                 |                 |                 | Chapter 1 and   |
|                 |                 |                 | an              |
|                 |                 |                 |                 |
|                 |                 |                 | "Appendix"      |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 4 "List of |
|                 |                 |                 | Effective       |
|                 |                 |                 | Pages" Changed  |
|                 |                 |                 | to reflect      |
|                 |                 |                 | "Revision 1"    |
|                 |                 |                 | changes.        |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 5 Change   |
|                 |                 |                 | to "Civil       |
|                 |                 |                 | Aircraft"       |
|                 |                 |                 | definition.     |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 7 Change   |
|                 |                 |                 | to "Public      |
|                 |                 |                 | Aircraft"       |
|                 |                 |                 | definition.     |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 8 Changed  |
|                 |                 |                 | to include      |
|                 |                 |                 | "Safety of      |
|                 |                 |                 | Flight"         |
|                 |                 |                 | definition      |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | "Point of       |
|                 |                 |                 | Contact"        |
|                 |                 |                 | information     |
|                 |                 |                 | added.          |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 13 Changed |
|                 |                 |                 | last "NOTE" to  |
|                 |                 |                 | state           |
|                 |                 |                 | "emphasize"     |
|                 |                 |                 | instead of      |
|                 |                 |                 | "highlight".    |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 11, 10.1,  |
|                 |                 |                 | a., changed     |
|                 |                 |                 | "Main" to       |
|                 |                 |                 | "Tail".         |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | # Page          |
|                 |                 |                 |  22, Chapter 4, |
|                 |                 |                 |  Section III, 3 |
|                 |                 |                 | .2, changed to  |
|                 |                 |                 | read, "Inspect  |
|                 |                 |                 | cross tube atta |
|                 |                 |                 | chment points." |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 26,        |
|                 |                 |                 | Chapter 5,      |
|                 |                 |                 | Section III,    |
|                 |                 |                 | 3.7, b.,        |
|                 |                 |                 | changed to read |
|                 |                 |                 | "Install cap    |
|                 |                 |                 | plug."          |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 26,        |
|                 |                 |                 | Chapter 5,      |
|                 |                 |                 | Section III,    |
|                 |                 |                 | 3.7, c.,        |
|                 |                 |                 | changed to      |
|                 |                 |                 | read, "Lightly  |
|                 |                 |                 | coat mast nut   |
|                 |                 |                 | threads with    |
|                 |                 |                 | corrosion       |
|                 |                 |                 | preventive      |
|                 |                 |                 | compound (C53), |
|                 |                 |                 | install mast    |
|                 |                 |                 | nut, torque to  |
|                 |                 |                 | 250 to 275 inch |
|                 |                 |                 | pounds and      |
|                 |                 |                 | install         |
|                 |                 |                 | lockwire."      |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 33,        |
|                 |                 |                 | Chapter 6,      |
|                 |                 |                 | "Special        |
|                 |                 |                 | Inspections",   |
|                 |                 |                 | now states,     |
|                 |                 |                 | "Special        |
|                 |                 |                 | Inspection      |
|                 |                 |                 | Index"          |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | # Page 3        |
|                 |                 |                 | 3, Special Insp |
|                 |                 |                 | ection, 6-6, b. |
|                 |                 |                 | , changed to re |
|                 |                 |                 | ad, "Start airc |
|                 |                 |                 | raft and run fo |
|                 |                 |                 | r 15 minutes at |
|                 |                 |                 |  full RPM then  |
|                 |                 |                 | rapidly reduce  |
|                 |                 |                 | throttle to gro |
|                 |                 |                 | und idle and ob |
|                 |                 |                 | serve a momenta |
|                 |                 |                 | ry split of the |
|                 |                 |                 |  NR and N2 need |
|                 |                 |                 | le and then con |
|                 |                 |                 | firm that the n |
|                 |                 |                 | eedles rejoin." |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 33,        |
|                 |                 |                 | Special         |
|                 |                 |                 | Inspections,    |
|                 |                 |                 | 6-6, c.,        |
|                 |                 |                 | changed to      |
|                 |                 |                 | read, "Fly      |
|                 |                 |                 | helicopter in   |
|                 |                 |                 | vicinity of a   |
|                 |                 |                 | safe landing    |
|                 |                 |                 | area for 15     |
|                 |                 |                 | minutes, and    |
|                 |                 |                 | [th             |
|                 |                 |                 | en]{.underline} |
|                 |                 |                 | perform a power |
|                 |                 |                 | recovery        |
|                 |                 |                 | autorotation."  |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 33,        |
|                 |                 |                 | Special         |
|                 |                 |                 | Inspections,    |
|                 |                 |                 | 6-9, a.,        |
|                 |                 |                 | changed to      |
|                 |                 |                 | read, "Verify   |
|                 |                 |                 | torque on tail  |
|                 |                 |                 | rotor gearbox   |
|                 |                 |                 | attaching       |
|                 |                 |                 | hardware 50-70  |
|                 |                 |                 | inch pounds     |
|                 |                 |                 | plus drag       |
|                 |                 |                 | torque."        |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 36,        |
|                 |                 |                 | Special         |
|                 |                 |                 | Inspections,    |
|                 |                 |                 | 6-22, "NOTE"    |
|                 |                 |                 | has been        |
|                 |                 |                 | removed.        |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 38,        |
|                 |                 |                 | Special         |
|                 |                 |                 | Inspections     |
|                 |                 |                 | 6-26, "NOTE"    |
|                 |                 |                 | has been        |
|                 |                 |                 | removed.        |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 40,        |
|                 |                 |                 | Special         |
|                 |                 |                 | Inspections,    |
|                 |                 |                 | 6-39, c, 1.,    |
|                 |                 |                 | "NOTE" has been |
|                 |                 |                 | removed.        |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 42,        |
|                 |                 |                 | Special         |
|                 |                 |                 | Inspections,    |
|                 |                 |                 | 6-47 a.,        |
|                 |                 |                 | changed to      |
|                 |                 |                 | read, "Every    |
|                 |                 |                 | [               |
|                 |                 |                 | 14]{.underline} |
|                 |                 |                 | Days."          |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 42,        |
|                 |                 |                 | Special         |
|                 |                 |                 | Inspections,    |
|                 |                 |                 | 6-47 a., 1.,    |
|                 |                 |                 | changed to      |
|                 |                 |                 | read, "If the   |
|                 |                 |                 | idle time of    |
|                 |                 |                 | the helicopter  |
|                 |                 |                 | has been for a  |
|                 |                 |                 | period of       |
|                 |                 |                 | [               |
|                 |                 |                 | 14]{.underline} |
|                 |                 |                 | days following  |
|                 |                 |                 | the last        |
|                 |                 |                 | flight, it is   |
|                 |                 |                 | required that a |
|                 |                 |                 | ground run of 5 |
|                 |                 |                 | to 10 minutes   |
|                 |                 |                 | be performed    |
|                 |                 |                 | (attainment of  |
|                 |                 |                 | the operating   |
|                 |                 |                 | temperature)."  |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 42,        |
|                 |                 |                 | Special         |
|                 |                 |                 | Inspections,    |
|                 |                 |                 | 6-47, a., 2.,   |
|                 |                 |                 | changed to      |
|                 |                 |                 | read, "If a     |
|                 |                 |                 | ground run is   |
|                 |                 |                 | not possible    |
|                 |                 |                 | every           |
|                 |                 |                 | [               |
|                 |                 |                 | 14]{.underline} |
|                 |                 |                 | days the        |
|                 |                 |                 | helicopter and  |
|                 |                 |                 | especially the  |
|                 |                 |                 | engine          |
|                 |                 |                 | [shou           |
|                 |                 |                 | ld]{.underline} |
|                 |                 |                 | be preserved in |
|                 |                 |                 | accordance with |
|                 |                 |                 | the current     |
|                 |                 |                 | military        |
|                 |                 |                 | document.       |
|                 |                 |                 | Engine          |
|                 |                 |                 | preservation    |
|                 |                 |                 | requirements    |
|                 |                 |                 | and             |
|                 |                 |                 | instructions    |
|                 |                 |                 | are in Allison  |
|                 |                 |                 | publication 5W2 |
|                 |                 |                 | or 10W2."       |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 44,        |
|                 |                 |                 | Chapter 7       |
|                 |                 |                 | Conditional     |
|                 |                 |                 | Inspections,    |
|                 |                 |                 | now state       |
|                 |                 |                 | "Conditional    |
|                 |                 |                 | Inspection      |
|                 |                 |                 | Index".         |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 46,        |
|                 |                 |                 | Conditional     |
|                 |                 |                 | Inspections,    |
|                 |                 |                 | 7-1., i., 5.,   |
|                 |                 |                 | "NOTE" has been |
|                 |                 |                 | removed.        |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 49,        |
|                 |                 |                 | Conditional     |
|                 |                 |                 | Inspections,    |
|                 |                 |                 | 7-4., c.,       |
|                 |                 |                 | "NOTE"          |
|                 |                 |                 | ("Wrinkles of   |
|                 |                 |                 | this nature .") |
|                 |                 |                 | has been        |
|                 |                 |                 | removed.        |
+-----------------+-----------------+-----------------+-----------------+
| March 1, 2002   |                 | Revision 1      | Page 52,        |
|                 |                 |                 | Conditional     |
|                 |                 |                 | Inspections,    |
|                 |                 |                 | 7-6., e., 6.,   |
|                 |                 |                 | changed to      |
|                 |                 |                 | read, "Tail     |
|                 |                 |                 | rotor           |
|                 |                 |                 | driveshafts for |
|                 |                 |                 | concentricity   |
|                 |                 |                 | and cracks.     |
|                 |                 |                 | [Dye            |
|                 |                 |                 | penetrate/NDI   |
|                 |                 |                 | is              |
|                 |                 |                 | required        |
|                 |                 |                 | ".]{.underline} |
+-----------------+-----------------+-----------------+-----------------+

1\. All personnel to whom this IPG is furnished shall keep it up to date

with the changes and additions furnished to them.

2\. Each IPG shall have the date of the last revision on each page.

## List of Effective Pages

**\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

This listing contains all current pages, with effective dates, of the
OH-58 A, A+, and C Helicopters INSPECTION PLANNING GUIDE (IPG). It
should be used after posting changes to insure the IPG is complete and
up-to-date.

**[Chapter/Section]{.underline}** **[Status]{.underline}**
**[Date]{.underline}**

**Record of** **Revisions** **.** **.** **Revision 1** **.** **.**
**March 1, 2002**

**List of** **Definitions** **.** **.** **Revision 1** **.** **.**
**March 1, 2002**

**Points of Contact Revision 1 March 1, 2002**

### Chapter 1 . . . . Revision 1 . . March 1, 2002

### Chapter 2 . . . . Revision 1 . . March 1, 2002

**Chapter 3** **.** **.** **.** **.** **Revision 1** **.** **.** **March
1, 2002**

**Chapter 4** **.** **.** **.** **.** **Revision 1** **.** **.** **March
1, 2002**

**Chapter 5** **.** **.** **.** **.** **Revision 0** **.** **.** **March
1, 2002**

**Chapter 6** **.** **.** **.** **.** **Revision 1** **.** **.** **March
1, 2002**

**Chapter 7** **.** **.** **.** **.** **Revision 1** **.** **.** **March
1, 2002**

**Definitions**

**\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

**[AIRCRAFT]{.underline}** means a device that is used or intended to be
used for flight.

**[AIRCRAFT ENGINE]{.underline}** means an engine that is used or
intended to be used for propelling aircraft. It includes
turbo-superchargers, appurtenances, and accessories necessary for its
functioning, but does not include propellers.

**[AIRFRAME]{.underline}** means the fuselage, booms, nacelles,
cowlings, fairings, airfoil surfaces (including rotors but excluding
propellers and rotating airfoils of engines), and landing gear of an
aircraft and their accessories and controls.

**[AIRCRAFT MAINTENANCE]{.underline}** means that work which is required
to be performed by an appropriately certificated and qualified
person(s).

**[AIRWORTHINESS DIRECTIVE]{.underline}** means a maintenance procedure
dictated by the Federal Aviation Administration that must be performed
on an aircraft in order to remain airworthy.

**[APPROVED]{.underline}** unless used with reference to another person,
means approved by the FAA Administrator.

**[APPLIANCE]{.underline}** means any instrument, mechanism, equipment,
part, apparatus, appurtenance, or accessory, including communications
equipment, that is used or intended to be used in operating or
controlling an aircraft in flight, is installed in or attached to the
aircraft, and is not part of an airframe, engine, or propeller.

**[CALIBRATION]{.underline}** means making precise measurements and
adjustments to equipment or systems in order to obtain optimum
performance and to certify that output data falls within prescribed
tolerances.

**[CAUTION]{.underline}** means a maintenance or inspection procedure,
practice, etc., which, if not strictly observed, could result in damage
to or destruction of equipment.

**[CHECK]{.underline}** means an action taken to examine and verify, in
accordance with established procedures and requirements, the condition
or status of an aircraft, its systems, components, and/or accessories.

**[CIVIL AIRCRAFT]{.underline}** means aircraft other than "public
aircraft". \|

**[COMPONENT]{.underline}** any self-contained part, combination of
parts, subassemblies or units, which perform a distinctive function
necessary to the operation of the airframe, powerplant or propeller.

**[CONDITIONAL INSPECTION]{.underline}** means an inspection which is
contingent upon specific conditions or incidents that arise, and only
because of these conditions or incidents. Examples of these conditions
or incidents are hard landings, overspeed, and sudden stoppage. An
inspection is required in such cases before further flight.

**[(ENGINE)]{.underline}** **[CYCLE]{.underline}** means an engine start
and shutdown procedure to be counted as "1". For the purposes of this
document (2 cycles per flight hour plus 25%) is the method recommended
to determine the number of cycles on engines that have not been logging
cycles. After that, 1 cycle per flight hour. \|

**[DMWR]{.underline}** (pronounced dimwar) means Depot Maintenance Work
Requirement. It is a document that details maintenance and inspection
criteria for specific components.

**[FOREIGN OBJECT DAMAGE]{.underline}** (FOD) means damage to an
aircraft, airframe. or engine caused by a foreign object that is not
part of the aircraft, or has broken loose of the aircraft and caused
damage.

**[GROUND RUN (see RUN-UP)]{.underline}** means operating the aircraft
on the ground, with no intention of taking off, from a normal start thru
flight idle, as a minimum.

[**HARD LANDING**]{.underline} means any accident or incident in which
ground impact of the helicopter causes severe pitching of main rotor,
allowing hard contact of hub with mast, or results in yielding or
noticeable cracking of fuselage pylon support structure or landing gear.

**[HARD-TIME]{.underline}** means a primary maintenance process that
requires an appliance or part be periodically overhaul in accordance
with the Agency's maintenance manual or that it be removed from service.

**[HEALTH INDICATOR]{.underline}** **[(ENGINE) TEST]{.underline}** (HIT)
means a method for engine trend monitoring to evaluate engine health and
performance.

**[INSPECT]{.underline}** means a method of qualifying the condition or
status of the aircraft, its systems, components, and/or accessories to
specific standards and requirements.

**[INTERMEDIATE INSPECTION]{.underline}** means an inspection that is
performed each 25 hours.

**[MAINTENANCE INSPECTIONS]{.underline}** include daily/preflight,
segment, safety, service, special, and numbered inspections. These
inspections vary in scope and frequency of performance according to
types of aircraft.

**[MODIFICATION WORK ORDER]{.underline}** (MWO) means an authorization
to perform a modification on an aircraft to correct or enhance an
existing condition. This is a military term and is similar to a
commercial model service instruction.

**[MAJOR ALTERATIONS]{.underline}** means an alteration not listed in
the aircraft, or aircraft engine/rotor specifications that (1) might
appreciably affect weight, balance, structural strength, performance,
powerplant operation, flight characteristics, or other qualities
affecting airworthiness; or (2) is not done according to accepted
practices, or cannot be done by elementary operations (refer to

Part 43).

**[MAJOR REPAIR]{.underline}** means a repair that (1) if improperly
done, might appreciably affect weight, balance, structural strength,
performance, powerplant operations, flight characteristics, or other
qualities of airworthiness; or (2) is not done according to accepted
practices, or cannot be done by elementary operations (refer to Part
43).

**[MAST BUMPING]{.underline}** or flapping-stop contact means the
condition which occurs when the main yoke contacts the mast and may
result in a fractured mast and rotor seperation. It usually occurs
during; slope landings, rotor startup/coastdown, or when the flight
envelope is exceeded.

**[MINIMUM EQUIPMENT LIST]{.underline}** (MEL) means a regulatory
authorization to continue to operate an aircraft with inoperable
instruments or equipment. The aircraft may be operated under all
applicable conditions and limitations contained in the minimum equipment
list.

**[MINOR]{.underline}** **[ALTERATION]{.underline}** means a
modification that is an alteration other than a major alteration.

**[MINOR REPAIR]{.underline}** means a repair that is other than a major
repair.

**[NOTE]{.underline}** means an inspection or maintenance procedure,
condition, et**c.**, which is essential to highlight

**[ON CONDITION ITEM]{.underline}** (OC) means an item of equipment that
must be restricted to one on which a determination of continued
airworthiness may be made by a visual check, measurement, test, or other
means.

**[OPERATIONAL CHECK]{.underline}** means an \"in motion\" or \"power
on\" test for determining that an item of equipment will operate at a
specified performance level.

**[OVERHAUL]{.underline}** means the complete disassembly, cleaning,
inspection, necessary replacement or repair of parts, reassembly,
adjustment, and testing of an item or equipment in accordance with
recommended procedures.

**[PERIODIC INSPECTION]{.underline}** means an inspection that is
performed each 300 hours or 12 calendar months whichever comes first.

**[PREVENTIVE MAINTENANCE]{.underline}** means simple or minor
preservation operations and the replacement of small standard parts not
involving complex assembly operations. It is corrective action taken
before it becomes necessary to make a major repair.

**[PREVENTIVE MAINTENANCE INSPECTION]{.underline}** (P.M.I.) means an
inspection which is accomplished each 12 1/2 flight hours or every 14
calendar days, whichever occurs first.

**[PUBLIC AIRCRAFT]{.underline}** means an aircraft used only for the
United States Government, \|

an aircraft owned by the Government and operated by any person for
purposes \|

related to crew training, equipment development, or demonstration, an
aircraft \|

owned and operated by the government of a State, the District of
Columbia, or a \|

territory or possession of the United States or a political subdivision
of one \|

of these governments, an aircraft exclusively leased for at least 90
continuous \|

days by the government of a State, the District of Columbia, or a
territory or \|

possession of the United States or a political subdivision of one of
these \|

governments, an aircraft owned or operated by the armed forces or
chartered to \|

provide transportation to the armed forces. In this definition, the
following \|

definitions apply: \|

\(1\) COMMERCIAL PURPOSES means the transportation of persons or
property for \|

compensation or hire, but does not include the operation of an aircraft
by the \|

armed forces for reimbursement when that reimbursement is required by
any \|

Federal statute, regulation, or directive, in effect on November 1,
1999, or by \|

one government on behalf of another government under a cost
reimbursement \|

agreement if the government on whose behalf the operation is conducted
certifies\|

to the Administrator of the Federal Aviation Administration that the
operation \|

is necessary to respond to a significant and imminent threat to life or
property\|

(including natural resources) and that no service by a private operator
is \|

reasonably available to meet the threat. \|

\(2\) GOVERNMENTAL FUNCTION means an activity undertaken by a
government, such as \|

national defense, intelligence missions, firefighting, search and
rescue, law \|

enforcement (including transport of prisoners, detainees, and illegal
aliens), \|

aeronautical research, or biological or geological resource management.
\|

\(3\) QUALIFIED NON-CREWMEMBER means an individual, other than a member
of the \|

crew, aboard an aircraft\-- \|

\(A\) operated by the armed forces or an intelligence agency of the
United \|

States Government; or

\(B\) whose presence is required to perform, or is associated with the
\|

performance of, a governmental function. \|

\(4\) ARMED FORCES has the meaning given such term by section 101 of
title 10. \|

An aircraft does not qualify as a public aircraft when the aircraft is
used for \|

commercial purposes or to carry an individual other than a crewmember or
a \|

qualified non-crewmember. \|

AIRCRAFT OWNED OR OPERATED BY THE ARMED FORCES qualifies as a public
aircraft \|

if: \|

\(A\) the aircraft is operated in accordance with title 10; \|

\(B\) the aircraft is operated in the performance of a governmental
function \|

under title 14, 31, 32, or 50 and the aircraft is not used for
commercial \|

purposes; or \|

\(C\) the aircraft is chartered to provide transportation to the armed
forces \|

and the Secretary of Defense (or the Secretary of the department in
which the \|

Coast Guard is operating) designates the operation of the aircraft as
being \|

required in the national interest. \|

LIMITATION An aircraft that is owned or operated by the National Guard
of a \|

State, the District of Columbia, or any territory or possession of the
United \|

States, qualifies as a public aircraft only to the extent that it is
operated \|

under the direct control of the Department of Defense. \|

**[PYLON WHIRL (see SPIKE KNOCK)]{.underline}** means a condition which
occurs after blade flapping and mast bumping. The resultant motion of
the pylon is elliptical, and spike knock is apt to occur.

**[REPAIR]{.underline}** means the restoration of an item of equipment
to a serviceable condition after fault detection.

**[RUN UP (see GROUND RUN)]{.underline}** means operation of the
aircraft from normal start thru flight idle. Flight of the aircraft may
be planned.

**[SPECIAL INSPECTION]{.underline}** means an inspection, in addition to
the P.M.I., Intermediate and Periodic Inspections, that are inspections
performed on a calendar basis, a cycle basis, a combination of
hourly/calendar basis, or following the installation of a major
component such as a gearbox installation.

**[TIME CONTROLLED COMPONENT]{.underline}** means a part or component
which has an established service life, at which time certain maintenance
must be performed or the item disposed of as unserviceable. The service
life may be based on operating hours, cycles, landings, calendar time,
or combinations of these.

**[UNSALVAGEABLE]{.underline}** means an aircraft part that should not
be returned to aviation use as defined by Federal Aviation
Administration (FAA) Advisory Circular

(AC) No. 21-38 "Disposition of Unsalvageable Aircraft Parts and
Materials

(7-5-94).". Persons disposing of unsalvageable aircraft parts and
materials should, when appropriate, mutilate those parts and materials
prior to release. Mutilation should be accomplished in such a manner
that the parts become unusable for their original intended use (see AC
No. 21-38).

**[VISUAL]{.underline}** **[INSPECTION]{.underline}** means an
inspection of an item of equipment for cleanliness, and deterioration of
parts or materials by visual means.

**[WARNING]{.underline}** means a maintenance or inspection procedure,
practice, etc., which if not correctly followed,could result in personal
injury or loss of life.

**[WIRE STRIKE]{.underline}** Protection System (WSPS) means a basic
system consisting of an upper cutter assembly, a windshield
deflector/cutter assembly, and a lower cutter assembly that provides
protection against frontal impacts with horizontally strung mechanical
and power transmission wires.

**[SAFETY OF FLIGHT MESSAGE]{.underline}** means an Army issued message
that details a method to \|

inspect, maintain, repair, or replace a component of a U.S. Army
aircraft, in \|

this case an OH-58 or UH-1 helicopter. SOF could also apply to flight \|

procedures, operating limits, or operational policy. \|

**[SPIKE KNOCK]{.underline}** means a condition which occurs when the
round pin in the drag-pin fitting contacts the side of the square hole
of the pylon stop, which is mounted to the roof. A loud noise will be
heard and will occur during a rocking of the pylon. Spike Knock usually
occurs during; low rotor RPM, extreme asymmetric loading, poor execution
of an autorotational landing and low G maneuvers below +.5 G's.

**Points Of Contact**

**\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

[www.gsa.gov/aircraftpolicy](http://www.gsa.gov/aircraftpolicy) Web Site
for the General Services Administration Aircraft Management Policy
Division. The 'caretaker' of the Inspection Planning Guides.

Charlie Elkins

\(256\) 955-0773 ATCOM UH-1 contact.

Susan Lewis

\(256\) 955-0773 ATCOM OH-58 contact.

Paul Elliott

\(602\) 231-3077

<paul.Elliott@honeywell.com>

Russ Smith

\(602\) 231-3599

<russ.smith@honeywell.com>

Dan Grady

\(602\) 231-3348

<dan.grady@honeywell.com> Honeywell contacts for T53 engines. Technical
publications.

National Technical Information Service

1 800 553-6847

\(703\) 605-6000

5285 Port Royal Raod

Springfield, VA 22161 Maintenance manuals for Army helicopters.

Randy Stewart

Department of Energy

Senior Aviation Policy Officer, MA-10

Office of Aviation Management

1000 Independence Ave., SW,

Rm 9H-063

Washington, DC 20585

\(202\) 586-6171 IPG Work Group

Andrew L. Kelley

Product Support Engineer

Bell Helicopter Textron

PO Box 482

Fort Worth, TX 76101

\(817\) 280-4074 IPG Work Group

Richard Thomas

Federal Aviation Administration

FTW-Aircraft Evaluation Group (AEG)

3601 MEACHAM BLVD.

Fort Worth, Texas 76193-0270

\(817\) 222-5272 IPG Work Group

Mike Miles

General Services Administration

1800 F Street, NW Rm 1221A

Washington, DC 20405

\(202\) 219-1356 IPG Work Group and

IPG Custodian

**Chapter 1**

**Introduction**

[\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_]{.underline}

**1-1. GENERAL**

This document, the OH-58A, A+, and C Helicopters Inspection Planning
Guide (IPG), is available to operators of OH-58A, A+, and C Helicopters
for the purpose of providing operators with an alternative inspection
program. The IPG has been developed as a reasonable basis for the
inspection program development.

The owner/operator conducting public use operations may use this
document as an alternative of an inspection program to assure an
adequate level of safety.

***WARNING***

***Unless specifically designated herein, standards for***

***serviceability for the airframe maintenance and inspection
contained***

***in this document are found in the applicable military maintenance
document***

***for these specific make and models of aircraft, OH-58A, A+, C
aircraft.***

***Unless specifically designated herein standards for serviceability***

***for the engine maintenance and inspection contained in this document
are***

***found in the Allison Operation and Maintenance Manual; Allison
publication***

***5W2 or 10W2 for these specific models of engine, Allison 250-series
engines.***

This document contains the requirements for the Preventive Maintenance
Inspection (P.M.I**.**), Intermediate Inspection, Periodic Inspection,
and Special Inspections that shall be performed on the OH-58A, A+, and C
helicopters.

Inspections required herein shall be performed by an appropriately
certificated person (under 14 Code of Federal Regulations, Part 65) or a
Federal Aviation Administration certified Airframe and Powerplant
mechanic.

An owner/operator shall develop a checklist for each inspection outlined
in this document.

Maintenance functions and definitions of terms shall be in accordance
with applicable military maintenance manual for the OH-58A, A+, and C
unless otherwise stipulated in this document.

The IPG is applicable to an OH-58A, A+, and C helicopters operating in a
flight profile similar to the U.S. Military.

**NOTE**

OH-58A, A+, and C helicopters used for **repetitive** lift operations

(logging,water bucket, long line, etc**.**), shall require additional

and/or more frequent inspections as deemed necessary based on

operational experience and/or Alert Service Bulletins and/or
airworthiness Directives. OH-58A, A+, and C helicopters modified through
incorporation

of Supplemental Type certificates or equipped with special mission kits

shall require additional inspections as deemed necessary.

The IPG is presented for OH-58A, A+, and C model helicopters. The IPG is
also presented for the Allison 250 series engines. The engine should be
maintained and inspected in accordance with the manufacturer's Operation
and Maintenance Manual; Allison publication 5W2 or 10W2 and the
appropriate manufacturer's service bulletins.

**NOTE**

An engine Health Indicator Test (HIT) is normally a pre-flight

function performed by the pilot and has not been included in the
IPG**.**

However, the operator should establish a method for engine trend
monitoring

to evaluate engine health and performance**.** A suggested method for
engine

trend monitoring is found in the Allison Operations and Maintenance
Manual.

**1-2. WARNING, CAUTIONS, AND NOTES DEFINED.**

***WARNING***

***An inspection procedure, practice, etc., which if not***

***correctly followed,could result in personal injury or loss of
life.***

**CAUTION**

**An inspection procedure, practice, etc., which, if not strictly**

**observed, could result in damage to or destruction of equipment.**

**NOTE**

An inspection procedure, condition, et**c.**, which is essential to
emphasize.

**1-3. AIRCRAFT, AIRCRAFT** **ENGINES, AND APPLIANCES DOCUMENTS/RECORDS
REVIEW:**

**Review aircraft, aircraft engines, appliances,** **forms and records
for any recorded discrepancies and for any applicable Airworthiness
Directives or Department of Defense** **Safety of Flight Messages.**

**1-4. FORMAT DEFINED**

[The IPG is divided into]{.underline}: [Example:]{.underline}

Chapters, **CHAPTER 7 Special Inspections**

Sections, **SECTION V. LOWER PYLON**

Headings, **8-1. HARD LANDING**

Paragraphs, **10.** Tail rotor gearbox.

and subparagraphs. **10.1** Remove tail rotor gearbox. Check

for cracks. Etc.

**a.** Main rotor blades.

**1.** Bolt contact etc.

**(a)** Remove spline etc.

**(1)** Tighten bolt etc.

**Chapter 2**

**Inspection Descriptions**

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

**NOTE**

Prior to placing an aircraft on this program,

a P.M.I**.**, Intermediate, Periodic and any Special

Inspections that may be required, should be accomplished**.**

**2-1. PREVENTIVE MAINTENANCE INSPECTION (P.M.I.) Chapter 3**

A P.M.I. is accomplished each 12 1/2 flight hours or every 14 calendar
days, whichever occurs first.

**2-2. INTERMEDIATE INSPECTION (25 Hour) Chapter 4**

An inspection that is performed each 25 hours.

**2-3. PERIODIC INSPECTION (300 Hour) Chapter 5**

> An inspection that is performed each 300 hours or 12 calendar months
> whichever comes first.

**2-4. SPECIAL INSPECTIONS Chapter 6**

In addition to the P.M.I., Intermediate and Periodic Inspections,
required Special Inspections are performed on a calendar basis, a cycle
basis, a combination of hourly/calendar basis, or following the
installation of a major component such as a gearbox installation.

Special Inspections performed on the engine are required at periodic
intervals to maintain proper operation and performance of the engine to
assure airworthiness.

Refer to applicable Allison publication 5W2 or 10W2, commercial engine
bulletins, commercial service letters, etc., for specific or
supplemental information and instructions.

**2-5. CONDITIONAL INSPECTIONS Chapter 7**

An inspection which is contingent upon specific conditions or incidents
that arise and only because of these conditions or incidents. Examples
of these conditions or incidents are hard landings, overspeed, and
sudden stoppage. **An** **inspection is required in such cases before
further** **flight.** Refer to the applicable military aircraft
operations manual, aircraft technical manual, and DMWRs for limitations
and inspection criteria.

**Inspection Schedules**

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

**[Flight Hours]{.underline}**

[25 50 75 100 125 150 175 200 225 250 275 300]{.underline}

**[Inspections]{.underline}**

P.M.I. Every 12 1/2 Flight Hours or 14 Days, whichever comes first.

INTERMEDIATE X X X X X X X X X X X X

PERIODIC X

SPECIAL *As required*

CONDITIONAL *As required*

**NOTE**

1\. If an aircraft will be out of service more than 30 days, a P.M.I.
shall be performed prior to returning the aircraft to service.

2\. If an aircraft is out of service more than 14 days, a run-up in
accordance with appropriate manuals is strongly recommended.

3\. The complete aircraft must be inspected within 12 calendar months,
which means a P.M.I., Intermediate inspection, and Periodic inspection,
and any required special inspections must have been performed.
Therefore, if an aircraft flies less than 300 hours in 12 calendar
months, the next Intermediate and a Periodic inspection must be
performed. If an aircraft flies greater than 300 hours, the inspection
cycle is continued and no additional inspections are required. See
inspection schedules chart above.

4\. Engine overhaul and retirement life limited intervals
(hours/cycles) - refer to the Allison Operations and Maintenance Manual;
Allison publication 5W2 or 10W2.

5\. Airframe retirement life intervals (hours/calendar), refer to
appropriate military technical manuals.

**Chapter 3**

**Preventive Maintenance Inspection (P.M.I.)**

**\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

**NOTE**

Refer to applicable OH-58 lubrication chart and

review aircraft, aircraft engines, appliances, forms and

records for any recorded discrepancies and for any applicable

Airworthiness Directives or Department of Defense Safety of Flight
Messages.

**SECTION I NOSE AREA**

**1.1** Inspect nose section exterior for visible damage.

**1.2** Check pitot tube and static ports for obstructions, cleanliness,
and pitot static drains for damage.

**1.3** Inspect landing/search lights, brackets, terminals and wiring
for condition and security.

**1.4** Inspect vent system drain for obstructions, condition.

**1.5** Check windshields, windows and chin bubbles for cracks or damage
and cleanliness.

**1.6** Check WSPS windshield deflector, upper and lower cutters for
damage and security. Check breakaway tip for looseness.

**SECTION II CABIN AND LANDING GEAR AREA (RIGHT SIDE)**

**2.1** Check cabin exterior for damage.

**2.2** Inspect antennas for condition and security.

**2.3** Check crew and cabin doors for positive latching and operation.
Inspect door posts for cracks and safeties properly installed on
jettison handles.

**2.4** Check cabin and nose section interior for cleanliness, proper
stowage of equipment, loose connections and visible damage.

**2.5** Inspect anti-torque pedals for freedom of operation and
security.

**2.6** Check current compass correction card.

**2.7** Inspect instrument panel and instruments for security,condition
and range markings.

**2.8** Inspect Outside Air Temperature (OAT) indicator for condition
and security.

**2.9** Check fuel valve handle for binding and condition. Check full
range of travel, leave in \"ON\" position.

**2.10** Inspect overhead console for condition and security.

**2.11** Inspect utility light and heater control for condition,
security and mounting.

**2.12** Check collective and power controls for freedom of operation,
boots for condition and throttle set screw.

**2.13** Inspect cyclic control for freedom of operation, boots and
grips for condition and security of electrical connectors.

**2.14** Inspect shoulder harness, seat belts, seat backs and bottoms
for condition, security and proper installation. Inspect and check
inertia reels for damage, security, and positive locking. Check seat
belt mounting hinges and brackets for cracks. Check retarder springs for
proper operation. Check armor plates for cracks, delamination and
security if installed.

**2.15** Check fire extinguisher for designated location, inspection tag
and seal.

**2.16** Inspect first aid kits, for security and completeness of
contents.

**2.17** Inspect passenger seat backs, cushions and retainer loops for
condition, security and proper installation. Inspect and check
sound-proofing for condition, security and cleanliness.

**2.18** Inspect aft electrical equipment shelf for unauthorized or
foreign objects, cleanliness and security of components.

**SECTION III ENGINE AREA (RIGHT SIDE)**

**3.1** Inspect induction fairing for proper seal at firewall and
particle separator.

**3.2** Inspect engine air intake ducts and plenum for obstructions or
damage. Inspect air induction fairing for seal security, conditions, and
bond voids along the seals complete length. Inspect sand and dust
separator for damage and particle ejection opening for freedom of
obstructions.

**3.3** Inspect engine cowling and fairing for damage and security of
fasteners and hinges.

**3.4** Check anti-collision light for condition and security.

**3.5** Inspect engine mounts and fittings for cracks, damage and
security.

**3.6** Inspect fuel control linkage for damage and security.

**3.7** Check compressor bleed valve for condition and security.

**3.8** Inspect engine accessories and connections for damage, corrosion
and security.

**3.9** Inspect exhaust stack and clamps for condition, corrosion and
cracks and engine combustion chamber housing, turbine support and
exhaust ducts for cracks, dents, burned or buckled areas.

**3.10** Check starter generator and exhaust duct for condition,
security and obstructions.

**3.11** Inspect engine to transmission driveshaft for condition and
evidence of grease leakage and over-heating. If engine to transmission
driveshaft

P/N 206-040-371-111 is used, inspect for damage and fastener security.

**SECTION IV AFT FUSELAGE AREA (RIGHT SIDE)**

**4.1** Check fuel filler cap for proper locking, condition of seal and
lanyard.

**4.2** Inspect rubber pad below fuel receiver for debonding.

**4.3** Inspect battery and fuel vents for condition and security,
proper positioning and obstructions.

**4.4** Check air ducts for condition and security.

**4.5** Check Ground Power Unit (GPU) access door for condition and
security.

**SECTION V AFT FAIRING AND OIL COOLER (RIGHT SIDE)**

**5.1** Inspect engine oil tank for condition and security and oil
level. Inspect oil lines for leaks and damage.

**5.2** Inspect oil filler access door for condition, marking and
placard, and security.

**5.3** Inspect engine scavenge oil filter for security, leaks and
indication of bypass (if installed).

**SECTION VI TAIL BOOM AREA**

**6.1** Inspect tail boom exterior and driveshaft cover for visible
damage and condition of fasteners.

**6.2** Inspect long tail rotor drive shaft and bearings for evidence of
overheat, splinded adapters for freedom of movement and slippage marks.

**NOTE**

Do not wipe grease from seal area

(not required after compliance with MWO 55-1520-228-50-25).

**6.3** Inspect segmented driveshaft for condition and security,
coupling disc for distortion, cracks and security. Check splined adapter
for freedom of movement and bearing and driveshaft for evidence of
overheating.

**NOTE**

Do not wipe grease from seal area

(not required after compliance with MWO 55-1520-228-50-25).

**6.4** Inspect horizontal stabilizer and navigational lights for
condition and security.

**6.5** Inspect vertical stabilizer, tail skid, tail light and support
and antenna leads for damage and security.

**6.6** Inspect ballast installation for security and condition.

7.  Inspect tail rotor controls for damage and security of attachment
    bolts.

**NOTE**

Suspected crack will be confirmed by penetrate inspection.

**6.8** Inspect tail rotor gearbox for security, oil level and vent for
obstruction. Inspect sight glass for damage or stains that might give a
false indication of oil level. Inspect tail rotor gearbox casing and
support rivets for cracks, damage or evidence of 'working' rivets.

**6.9** Inspect tail rotor hub and blade assembly for security and
damage. Check blades for cleanliness.

***WARNING***

***Tail rotor blades P/N 206-010-750 are not authorized for use.***

**6.10** Inspect all self-locking nuts on the hub and blade assembly for
cracks and security.

**6.11** Following check not required after compliance with MWO
55-1520-228-50-25. Inspect tail rotor blades for cracks on both sides in
the area approximately 7 inches outboard from the butt end and l.5
inches aft of the leading edge.

***WARNING***

***If cracks are revealed blade must be removed*** ***prior to
furtherflight.***

**NOTE**

Tail rotor blades SN TLL-8000 and below require ten power

magnification for this check and careful inspection for corrosion and
deterioration of clear coating on the areas left clear for this
inspection.

**6.12.** Inspect tail rotor blade tip blocks for cracks, debonding and
loose, missing or corroded rivets.

**SECTION VII AFT FAIRING AND OIL COOLER AREA (LEFT SIDE)**

**7.1** Inspect engine oil tank for damage, access door for security.

**7.2** Inspect oil cooler blower, ducts and driveshaft for damage,
cracks and foreign material.

**7.3** Inspect aft fairing assembly for damage.

**SECTION VIII AVIONICS AND AFT FUSELAGE AREA (LEFT SIDE)**

**8.1** Inspect avionics compartment for security of items and door for
condition and operation.

**8.2** Inspect antennas for damage, debonding and security.

**8.3** Check battery for leakage and security. Check foam pad for
condition and security.

**8.4** Inspect external power receptacle for condition and security.

**SECTION IX ENGINE AREA (LEFT SIDE)**

**9.1** Inspect engine cowling and fairing for damage, security and
condition of fasteners.

**9.2** Inspect engine mounts and fittings for cracks and security.

**9.3** Check airframe mounted fuel filter for leaks and security.

**9.4** Inspect engine accessories and connections for damage and
security.

**9.5** Check linear actuator, linkage and electrical lead for condition
and security.

**9.6** Inspect exhaust stack and clamps for condition, corrosion and
cracks and engine combustion chamber housing, turbine support and
exhaust ducts for cracks, dents, burned or buckled areas.

**9.7** Check drain valve for leakage, security and evidence of contact
with driveshaft.

**9.8** Check fuel nozzle and lines for leaks, condition and security.

**9.9** Inspect forward tail rotor driveshaft for corrosion, freedom of
movement on the splined adapters and cleanliness.

**9.10** Inspect particle separator for damage.

**9.11** Inspect engine air inlet air bellmouth for damage, obstructions
and plenum area for loose or foreign objects.

**SECTION X TRANSMISSION AND PYLON AREA**

**10.1** Inspect main rotor hub assembly for leakage, damage, security
and proper oil level.

**10.2** Check pillow blocks for condition and security of mounting
hardware and slippage marks.

**CAUTION**

**If slippage has occurred, replace hardware.**

**10.3** Inspect static stops for damage and security.

**10.4** Inspect main rotor yoke assembly for cracks and evidence of
corrosion between the pillow block bores and the lower flange on inboard
surfaces. Wipe clean the yoke web section and outer surfaces.

**NOTE**

If inspection by flashlight reveals indication of crack, validate by

fluorescent penetrant. If crack is confirmed remove hub assembly for
evaluation.

**10.5** Inspect main rotor blades for cleanliness, damage, condition,
corrosion and security. Check for condition of protective coating.

**10.6** Inspect visible areas of the mast for damage.

**NOTE**

Assure swashplate is level for inspection of outer

ring self aligning bearings for main rotor push-pull tubes.

**10.7** Inspect swashplate, lever and sleeve, and connecting linkage
for security and damage. Check swashplate support base drain holes are
open and free of foreign matter. Inspect swashplate support for evidence
of damage.

**10.8** Check cyclic and collective control linkage for security and
condition. Check security of attachment bolts by attempting to turn nuts
with fingers

**CAUTION**

**Do not remove cotter pin.**

**10.9** Inspect main rotor pitch links for damage and security of
attachment, tubes for corrosion and cracks.

**NOTE**

Pay particular attention to swaged ends at the jam nut.

**10.10** Inspect hydraulic system components and lines for security,
chaffing, leaks, damage and reservoir for oil level. Check collective
actuator bellcrank cover for missing rubber flipper or bond failure.
Check for proper security of reservoir cap and pin assembly.

**10.11** Inspect hydraulic filter element for indication of filter by
pass.

**10.12** Check power turbine governor (N2) linkage for freedom of
operation, condition and security.

**10.13** Check hydraulic pump, rotor tach generator for condition and
security.

**10.14** Inspect transmission oil cooler ducting, filter head and
filter for damage, condition and security

**10.15** Inspect pylon isolation mount, cover, drag pin assembly and
cabin roof for damage and condition.

**10.16** Visually inspect clevis area and mount for cracks or other
damage. Inspect entire area for loose, broken or missing hardware.

**10.17** Check area under drag pin for oil or water. Inspect
transmission deck area for dents, cracks, holes and overall condition.

**10.18** Inspect pylon support links for cracks, condition and security
of hardware.

**10.19** Inspect main transmission case assembly and all electrical
connections for damage, condition and security. Check transmission fluid
level and service if required. Inspect sight glass for condition and
leakage.

**10.20** Inspect particle separator intake and swirl tubes for damage
and security.

**10.21** Check security of engine cleaning tube and cap assembly.

**10.22** Inspect cowling and cabin roof mounted antennas and
connections for serviceability and security.

**SECTION XI CABIN AND LANDING GEAR AREA (LEFT SIDE)**

**11.1** Inspect landing gear for condition of skid tubes, cross tubes
attachment fittings and skid shoes for damage or evidence of hard
landing and security.

**11.2** Check crew and cabin doors for positive latching and operation,
vents and hinges for operation and security.

**11.3** Inspect seats for damage and security. Inspect cushions for
cleanliness and proper installation. Inspect armor plates for cracks,
delamination and security if installed.

**11.4** Check crew and cabin door jettison handles for proper operation
and safeties.

**SECTION XII LUBRICATION (ALL AREAS)**

**12.1** Service in accordance with TM 55-1520-228-23, applicable to
daily and 25 hour requirements.

**SECTION XIII ELECTRICAL** **POWER ON**

**13.1** Check pitot heater for proper operation.

**13.2** Check all panel mounted warning, caution and segmented panel
lights illuminate properly.

**13.3** Check operation of all cockpit and cabin lighting.

***WARNING***

***Assure defog blower motors are free of debris prior to checking
operation.***

**13.4** Operate defogging blower motors for a minimum of 15 seconds for
proper function check.

**13.5** Operate all exterior lights and check for illumination.

**Chapter 4**

**Intermediate Inspection (25 Hour)**

**\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

**SECTION I GENERAL**

**NOTE**

Refer to applicable OH-58 lubrication chart.

**1.1** Perform a P.M.I. inspection.

**SECTION II NOSE AREA**

**2.1** Drain moisture from pressure and static ports (if required).

**2.2** Check attached optional equipment for condition and security.

**SECTION III CABIN, ELECTRICAL EQUIPMENT SHELF AND LANDING GEAR AREA**

**3.1** Check radio antenna, masts, and insulators for condition and
security.

**3.2** Inspect cross tube attachment points. \|

**3.3** Check radio switches and knobs for condition and security.

**3.4** Check radio headsets, microphones, leads, plugs and jacks for
operation and general condition and security.

**3.5** Inspect visible pitot and static tubes for damage, security and
freedom from obstruction.

**3.6** Inspect visible wiring, insulating tubing, and retaining clamps
for general condition and security.

**3.7** Check ventilating system controls for operation. Inspect air
ducts for condition and security and check drains for obstruction.

**SECTION IV TRANSMISSION AND PYLON AREA**

**4.1** Inspect main rotor hub for condition and security of hardware.
Inspect flapping bearings for freedom of operation by tipping hub
assembly spanwise**.** Inspect main rotor retaining nut for security and
safety. Inspect pillow blocks for mounting condition, security of
mounting bolts and slippage marks.

**4.2** Inspect blade bolts and latch retainer and nut for security.

**4.3** Inspect main rotor control tubes and links for condition and
security.

**4.4** Inspect swashplate and control for condition and security.
Inspect inner and outer swashplate arms for cracks. Check bearings for
freedom of movement.

**4.5** Inspect fuselage upper and intermediate structure and cowling
for damage, cracks, and condition.

**4.6** Inspect hydraulic servo actuator control linkage and bolts for
condition and security. Check actuator valve linkage for freedom of
movement.

**4.7** Inspect hydraulic reservoir for damage, leakage and correct oil
level. Check reservoir cover for proper locking and security. Check
groove area of reservoir cover tab for cracks.

**SECTION V ENGINE AREA**

**5.1** Inspect engine and engine area for loose or missing nuts and
bolts, loose or broken wires and connectors. Check accessories for
security or broken, missing, or improper safety.

**5.2** Inspect engine and accessible area for obvious damage and
evidence of fuel or oil leakage.

**5.3** Check engine mount and support bolts for condition, security,
and proper safety.

**5.4** Check engine firewall and cowling for condition and security.

**5.5** Check fuel system components and lines for security and leakage.
Inspect filter for security and leakage.

**NOTE**

If leakage is evidenced refer to Allison publication 5W2 or 10W2.

**5.6** Check governor and fuel control linkage for freedom of
operation, proper rigging, and security.

**5.7** Tachometer generator (power turbine): Inspect mounting flange
for cracks. Check paint marks for slippage**.**

**5.8** Tachometer generator (gas producer): Inspect mounting flange for
cracks. Check paint marks for slippage.

**SECTION VI AFT FUSELAGE AREA AND AVIONICS COMPARTMENT**

**6.1** Inspect Fuselage for signs of damage, cracks, and general
condition.

**6.2** Check lower anti-collision light for condition and security.

**6.3** Inspect voltage regulator and associated components for
condition and security. Inspect wiring for chafing, condition, security,
and proper connection. Inspect terminals for security or corrosion.

**6.4** Check lead acid battery electrolyte for proper level. Check vent
tube for freedom from obstruction.

**6.5** Check nickel cadium (nicad) battery in accordance with
manufacturer's instructions.

**SECTION VII TAIL BOOM AREA**

**7.1** Inspect tail rotor flapping bearings for freedom of movement.

**7.2** Inspect tail rotor pitch change linkage for wear, security and
freedom of operation and tail rotor pitch change (PC) links for cracks
with ten power magnification.

**NOTE**

Suspected cracks will be confirmed by dye penetrant inspection.

**7.3** Inspect tail rotor pitch change bearings and rod end bearings
for looseness.

**SECTION VIII POWER ON**

**8.1** Check all switches and circuit breakers for proper operation.

**8.2** Check airframe fuel filter bypass warning system for proper
operation.

**SECTION IX AVIONICS**

**9.1** Perform avionics inspections, and check, and/or test avionics
equipment as required.

**SECTION X POWER OFF**

**10.1** Check all fixed equipment is refitted and properly secured.

**10.2** Check that tools, rags, and foreign objects are removed from
aircraft.

**10.3** Check all inspection doors and access panels are properly
closed or installed.

**Chapter 5**

**Periodic Inspection (300 Hour)**

**\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

**SECTION I GENERAL**

**NOTE**

Refer to applicable OH-58 lubrication chart.

**1.1** Perform a P.M.I. and an Intermediate Inspection in addition to
the following items.

**SECTION II CABIN, ELECTRICAL EQUIPMENT SHELF AND LANDING GEAR AREA**

**2.1** Remove access panel above electrical shelf and inspect fuel
shutoff valve and linkage for condition, proper operation, security and
evidence of leaks.

**2.2** Check seat cushions. seat belts, inertia reels, and shoulder
harnesses for security, cleanliness, and general condition.

**2.3** Check door jettison mechanism for proper operation.

**2.4** Check cyclic, collective, and directional controls for general
installation and freedom of movement through full range of operation and
correct response to control movement.

**2.5** Check all control friction adjustments for correct control
operation and general condition.

**2.6** With vertical post cover and pilot and copilot seat panels
removed, inspect cyclic, collective, anti-torque and throttle control
linkage and cable for damage, operation, binding and interference.

**2.7** Inspect control linkage and bellcranks for cracks, security, and
general condition.

**2.8** Remove access panel from instrument console and inspect
instrument wiring and plumbing for damage, security, deterioration and
proper connection.

**2.9** Inspect radio cables, plugs, and associated fittings for damage,
security. and general condition. Inspect bonding straps for condition
and security.

**2.10** Check removable radio units for condition and security.

**2.11** Check radio equipment for cleanliness from dust and foreign
material.

12. Check torque meter for accuracy during run-up.

**2.13** Check turbine outlet temperature indicator for accuracy using
electronic test equipment (Barfield).

**SECTION III TRANSMISSION AND PYLON AREA**

**3.1** Check swashplate duplex bearing for smoothness by disconnecting
idler link and rotor pitch links (do not allow rotor blades and grips to
rotate on the yoke), free lower end of boot, and rotate outer ring in
both directions.

**3.2** Check swashplate uniball for proper friction, adjust as
required.

**3.3** Check swashplate support pivot sleeve bearing slot sidewalls and
Teflon sleeve and bolts for condition and security.

**3.4** Inspect hydraulic servo-cylinder supports for cracks.

**3.5** Inspect main rotor system flight control bolts.

**3.6** Remove particle separator and induction cowling. Inspect engine
inlet for foreign object damage. Inspect separator and cowling for
damage.

**3.7** Inspect mast assembly as follows:

**a.** Remove mast nut and cap plug. Inspect internal surface (ID) of
mast for corrosion and condition of protective coating by using a bright
light.

**b.** Install cap plug. \|

**c.** Lightly coat mast nut threads with corrosion preventive compound
\|

> (C53), install mast nut, torque to 250 to 275 inch pounds and \|
>
> install lockwire. \|

**d.** Check mast nut torque after 25 operating hours as outlined in
**SPECIAL INSPECTION 6-22.**

**3.8** Inspect longeron and engine pan interface as follows:

**a.** Remove access panel from access hole through canted web**.**

**b.** Open engine compartment cowling.

**c.** Use bright light and mirror to expose upper and lower edges of
the joints and fastener between the aluminum longeron and titanium
engine pan. The edge of the Proseal 890 fraying surface coating should
be visible.

**CAUTION**

**No indications of corrosion such as corrosion pits, finish blisters**

**or surface stains by corrosion material from joint should be
detected.**

**3.9** Inspect airframe fuel filter elements. Using a 0.020 inch wire,
pass the wire through the outlet bleed port to check that the bleed port
is not clogged**.** Replace with new fuel filter element.

**3.10** Drain hydraulic reservoir and system and inspect inside bottom
of reservoir for corrosion and pitting. Re-service hydraulic reservoir.

**SECTION IV ENGINE AREA**

**4.1** Inspect particle separator and engine inlet bellmouth for
damage, obstructions and plenum area for loose or foreign objects.
Inspect exhaust stack clamp as follows:

**CAUTION**

**Do not bend clamps during removal, inspection or installation.**

**a.** Remove both right hand and left hand exhaust stack clamp, by
removing nuts on both \"T\" bolts.

**b.** Inspect both sides of each clamp for any evidence of cracking
around rivets, particularly at the gaps between the V band sections.

**NOTE**

Cracks will most likely begin at the edge of a rivet and

run radially to the edge or to the next rivet. Look for cracks

or corrosion tracks which indicate an imminent crack. Any clamp that

displays evidence of cracking shall be condemned and replaced with a
like,

serviceable item. Clamps that exhibit surface corrosion only, may be
reinstalled on exhaust stacks. Replace corroded clamps as soon as new
ones become available.

**4.2** With freewheeling unit drained, check magnetic plug for metal
particles.

**4.3** Refer to Allison publication 5W2 or 10W2 for all inspection
requirements and recommended maintenance procedures regarding engine
operations.

**SECTION V FUSELAGE AREA**

**5.1** Check fuel cell for leakage and check torque of access opening
bar and cover bolts

**NOTE**

If MWO 55-1520-228-30-32 has not been complied with, re-torque

upper clamp on fuel support hose inside fuel cell (refer to applicable
TM).

**5.2** Check air ducts, heater, and access panel for condition and
security.

**5.3** Inspect tail rotor control tubes located under engine for
security, condition, chafing or binding.

**5.4** Inspect engine deck longeron for condition.

**SECTION VI TAIL BOOM AREA**

**6.1** Inspect tail rotor driveshaft bonded fittings for security.

**6.2** With tail rotor control tube assembly removed, inspect for wear
at five areas where tube may contact fairleads.

**SECTION VII ELECTRICAL** **POWER ON**

**7.1** Inspect transmission, tail rotor and engine chip detector
circuit for continuity. With power on, ground detector plug to airframe
and short across magnet, light should illuminate.

**SECTION VIII RUN-UP**

**8.1** Test all electrical systems and lights for proper operation.

**8.2** Wash compressor in accordance with Allison publication 5W2 or
10W2.

**8.3** Ground run aircraft and check for leaks, vibrations in tail,
fuel and oil pressures, anti-ice valve operation and engine performance
(HIT).

**8.4** Check heater for proper operation and fuel odor.

**8.5** Check voltage and adjust voltage regulator if required.

**8.6** Check idle RPM and governor beep range.

**8.7** Check compressor bleed control valve for proper operation.

**8.8** Check turn and slip indicator for proper operation.

**8.9** Check attitude indicator for proper operation.

**8.10** Check engine oil pressure indicator for proper operation.

**8.11** Check engine oil temperature indicator for proper operation.

**8.12.** Check tachometer indicator, rotor and power turbine, for
proper operation.

**8.13** Check tachometer indicator, gas producer, for proper operation.

**8.14** Check free air temperature indicator for proper operation.

**8.15** Check on board clock for proper operation.

**8.16** Check operation of any optional equipment.

**8.17** Check oil and hydraulic fluid levels after run-up and engine
shutdown.

**Chapter 6**

**Special Inspections**

**\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

In addition to the P.M.I., Intermediate, and Periodic Inspections
required Special Inspections are performed on a calendar basis, a cycle
basis, a combination of hourly/calendar basis, or following the
installation of a major component such as a gearbox installation.

Special Inspections performed on the engine are required at periodic
intervals to maintain proper operation and performance of the engine to
assure airworthiness. Refer to applicable Allison publication 5W2 or
10W2, commercial engine bulletins, commercial service letters, etc., for
specific or supplemental information and instructions.

**[Special Inspections Index]{.underline} Page**

**6-1. ANY TIME ENGINE ASSEMBLY IS REPLACED . . . . 39**

**DUE TO METAL CONTAMINATION**

**6-2. ANY TIME THE TRANSMISSION IS REMOVED . . . . 39**

**6-3. ANY TIME MAIN ROTOR MAST ASSEMBLY IS**

**TRANSFERRED TO ANOTHER AIRCRAFT . . . . . 39**

**6-4. ANY TIME TRANSMISSION IS REMOVED AS A**

**RESULT OF METAL PARTICLES . .** **. . . . 39**

**6-5. AFTER INSTALLING AN ENGINE OR ENGINE**

**COMPONENT . . . . . . . . 39**

**6-6. AFTER INSTALLING A REPAIRED FREEWHEELING UNIT . . . 39**

**6-7. AFTER EACH ENGINE CHANGE . . . . . .** **40**

**6-8. ANYTIME MAIN DRIVESHAFT IS REMOVED . . . . . 40**

**6-9. AFTER INITIAL RUN-UP FOLLOWING TAIL ROTOR**

**GEARBOX INSTALLATION . . . . . . . 40**

**6-10. ANYTIME AIR IN THE FUEL LINE IS SUSPECTED . . . . 40**

**6-11. ANY TIME MAIN ROTOR HUB AND BLADE ASSEMBLY**

**IS TRANSFERRED TO ANOTHER HELICOPTER . . . . 40**

**6-12. AFTER THE HELICOPTER HAS BEEN SUBJECTED TO**

**SALT WATER OR SALT WATER SPRAY . . . . . 40**

**[Special Inspections Index Continued.]{.underline} Page**

**6-13. WHEN OPERATING FROM A BASE WITHIN 10 MILES**

**OF SALT WATER OR WHEN HELICOPTER IS FLOWN**

**BELOW 500 FEET OVER SALT WATER . . . . . 40**

**6-14. AFTER WASHING HELICOPTER . . . . . . 40**

**6-15. WHEN MAJOR MODIFICATIONS OR MAJOR AIRFRAME**

**REPAIRS ARE ACCOMPLISHED, ANY SPECIAL**

**EQUIPMENT HAS BEEN ADDED TO OR REMOVED FROM**

**THE BASIC AIRFRAME, OR WHEN WEIGHT AND BALANCE**

**DATA ARE SUSPECTED TO BE IN ERROR . . . . . 41**

**6-16. AT EACH ENGINE OIL CHANGE . . . . . . 41**

**6-17. AT EACH TIME MAIN ROTOR PITCH LINKS AND THE**

**IDLER LINK ARE DISCONNECTED . . . . . . 41**

**6-18. AFTER EACH ENGINE CHANGE, ELECTRICAL EQUIPMENT**

**CHANGE, OR MAJOR STRUCTURAL CHANGE LIKELY**

**TO AFFECT THE COMPASS . . . . . . . 41**

**6-19. AFTER INSTALLATION OF ENGINE MOUNT**

**TO AIRFRAME BOLTS . . . . . . . 41**

**6-20. AFTER INSTALLATION OF TAIL BOOM . . . . . 41**

**6-21. FIVE TO TEN HOURS AFTER INSTALLATION OF**

**PILLOW BLOCK HARDWARE . . . . . . . 41**

**6-22. 25 HOURS AFTER MAIN ROTOR MAST NUT INSTALLATION . . . 42**

**6-23. 25 [HOURS]{.smallcaps} AFTER INSTALLATION OF SWASHPLATE . . . .
42**

**6-24. EVERY 50 HOURS . . . . . . . . 42**

**6-25. EVERY 100 HOURS . . . . . . . . 42**

**6-26. AT FIRST 100 HOUR INSPECTION FOLLOWING**

**MAST NUT INSTALLATION . . . . . . . 44**

**6-27. AT FIRST 100 HOURS AFTER INSTALLATION**

**OF TAIL BOOM . . . . . . . . 44**

**6-28. EVERY 100 HOURS OR 120 CALENDAR DAYS**

**WHICHEVER OCCURS FIRST . . . . . . . 44**

**6-29. 100 HOURS AFTER INSTALLATION OF PILLOW**

**BLOCK RETENTION BOLTS AND NUTS OR**

**INSTALLATION OF A NEW OR OVERHAULED**

**MAIN ROTOR HUB ASSEMBLY . . . . . . . 44**

**6-30. 100 HOURS AFTER SERVO ACTUATOR INSTALLATION . . . 44**

**[Special Inspections Index Continued.]{.underline} Page**

**6-31. 100 HOURS OF OPERATION AFTER THE TAIL ROTOR**

**GEARBOX HAS BEEN INSTALLED OR HARDWARE ADJUSTED . . . 44**

**6-32. EVERY 150 HOURS OR 6 CALENDAR MONTHS WHICHEVER OCCURS FIRST .
44**

**6-33. EVERY 200 HOURS . . . . . . . . 45**

**6-34. AFTER 200 HOURS OR WHEN RED BUTTON (IMPENDING**

**BYPASS INDICATOR) IS SHOWING . . . . . . 45**

**6-35. EVERY 500 HOURS OR 12 CALENDAR MONTHS. . . . . 45**

**6-36. EVERY 600 HOURS . . . . . . . . 45**

**6-37. AFTER 600 HOURS AND 900 HOURS OF OPERATION**

**OF NEW RETENTION STRAP . . . . . . . 45**

**6-38. EVERY 1000 HOURS . . . . . . . . 45**

**6-39. [EVERY 1200 HOURS . . . . . . . . 45]{.smallcaps}**

**6-40. EVERY 100 HOURS AFTER THE 1200 HOUR INSPECTION**

**OF SWASHPLATE DUPLEX BALL BEARING UNTIL THE 2400**

**HOUR OVERHAUL OF THE SWASHPLATE . . . . . 46**

**6-41. AFTER 1200 HOURS OPERATION OF NEW OR**

**OVERHAULED MAIN ROTOR HUB ASSEMBLY . . . . . 46**

**6-42. AFTER 1200 HOURS OPERATION OF NEW OR**

**OVERHAULED MAIN TRANSMISSION . . . . . . 47**

**6-43. AFTER 1200 HOURS OPERATION OF NEW OR**

**OVERHAULED MAIN TRANSMISSION MAST ASSEMBLY . . . 47**

**6-44. AFTER 1500 HOURS OPERATION OF NEW OR**

**OVERHAULED FREEWHEELING ASSEMBLY . . . . . 48**

**6-45. EVERY 1500 HOURS . . . . . . . . 48**

**6-46. EVERY** **12 CALENDAR** **CALENDAR MONTHS . . . . . 48**

**6-47. AFTER** **12 CALENDAR** **MONTHS: OR WHENEVER HELICOPTER IS**

**TRANSFERRED, RECEIVED, PLACED IN STORAGE,**

**OR REMOVED FROM STORAGE . . . . . . . 48**

**6-48. EVERY 24 CALENDAR MONTHS . . . . . . 48**

**6-49. AFTER 1550 HOURS OPERATION OF NEW OR OVERHAULED**

**ENGINE WITH PRODUCT IMPROVED TURBINE FOR T63-A-700**

**AND AFTER 1775 HOURS OR 3000 CYCLES OPERATION OF**

**NEW OR OVERHAULED ENGINE WITH PRODUCT IMPROVED**

**TURBINE FOR T63-A-720 . . . . . . . 49**

**[Special Inspections Index Continued.]{.underline} Page**

**6-50. EVERY 1750 HOURS . . . . . . . . 49**

**6-51. AFTER 2400 HOURS OF OPERATION OF NEW OR**

**OVERHAULED MAIN TRANSMISSION . . . . . . 49**

**6-52 AFTER 2400 HOURS OF OPERATION OF NEW OR**

**OVERHAULED MAIN TRANSMISSION MAST ASSEMBLY . . . 49**

**6-53 AFTER 2400 HOURS OF OPERATION OF NEW OR**

**OVERHAULED TAIL ROTOR GEARBOX ASSEMBLY . . . . 49**

**6-54 AFTER 3000 HOURS OF OPERATION OF NEW OR**

**OVERHAULED FREEWHEELING ASSEMBLY . . . . . 49**

**Special Inspections**

**\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

**6-1. ANY TIME ENGINE ASSEMBLY IS REPLACED DUE TO METAL CONTAMINATION**

**a.** Refer to Allison publication 5W2 or 10W2 for instruction
regarding the necessary actions required.

**b.** Replace engine oil cooler.

**6-2. ANY TIME THE TRANSMISSION IS REMOVED**

**a.** Remove and inspect the pylon support links and the isolation
mount.

**6-3. ANY TIME MAIN ROTOR MAST ASSEMBLY IS TRANSFERRED TO ANOTHER
AIRCRAFT**

**a.** Disassemble and inspect for corrosion and condition of parts.

**6-4. ANY TIME TRANSMISSION IS REMOVED AS A RESULT OF METAL PARTICLES**

**a.** Disassemble as required and inspect main rotor mast bearing for
corrosion.

**b.** Replace transmission oil cooler and filter.

**c.** Inspect external transmission oil lines for contamination.

**6-5. AFTER INSTALLING AN ENGINE OR ENGINE COMPONENT**

**a.** Refer to Allison publication 5W2 or 10W2 for instruction
regarding:

**1.** Engine operations and check for leaks.

**2.** Performance of engine post installation inspection.

**6-6. AFTER INSTALLING A REPAIRED FREEWHEELING UNIT**

**a.** Refer to Allison publication 5W2 or 10W2 for instruction
regarding the necessary actions required.

**b.** Start aircraft and run for 15 minutes at full RPM then rapidly
reduce throttle to ground idle and observe a momentary split of the NR
and \| N2 needle and then confirm that the needles rejoin. \|

**c.** Fly helicopter in vicinity of a safe landing area for 15 minutes,
and then perform a power recovery autorotation. \|

**d.** Remove freewheeling unit magnetic plug and drain oil into a clean
container.

**e.** Check magnetic plug and oil for metal chips.

**6-7. AFTER EACH ENGINE CHANGE**

**a.** Refer to Allison publication 5W2 or 10W2 for instruction
regarding: check of turbine outlet temperature system.

**6-8. ANY TIME MAIN DRIVESHAFT IS REMOVED**

**a.** Inspect for condition.

**6-9. AFTER INITIAL RUN-UP FOLLOWING TAIL ROTOR GEARBOX INSTALLATION**

**a.** Verify torque on tail rotor gearbox attaching hardware 50-70 inch
\| pounds plus drag torque. \|

**6-10.** **ANYTIME AIR IN THE FUEL LINE IS SUSPECTED**

**a.** Disconnect the battery and ground the aircraft.

**b.** If the helicopter has full fuel, it may be necessary to remove
approximately two gallons of fuel in order to perform the inspection.

**c.** Remove the cap and adapter. Ascertain that the upper clamp is
radial. Re-tighten the upper clamp on the self sealing hose finger tight
plus two and one half turns.

**d.** When re-installing the receiver assembly or cap and adapter, use
a new packing and torque bolts (refer to applicable TM).

**e.** After the inspection, bleed the engine fuel system in accordance
with Allison publication 5W2 or 10W2.

**6-11.** **ANY TIME MAIN ROTOR HUB AND BLADE ASSEMBLY IS TRANSFERRED TO
ANOTHER HELICOPTER**

**a.** Verify mast nut torque after first flight and after 25 hours of
operation (refer to applicable TM).

**6-12. AFTER THE HELICOPTER HAS BEEN SUBJECTED TO SALT WATER OR SALT
WATER SPRAY**

**a.** Wash entire helicopter with fresh water, particularly inside of
engine compartment doors. Wash all components which were exposed to salt
water and make a detailed check of all surfaces for corrosion. Apply
corrosion preventive compound to exposed non-painted, anodized, or
cadmium plated assemblies. Refer to TM 55-1500-204-25/1.

**6-13. WHEN OPERATING FROM A BASE WITHIN 10 MILES OF SALT WATER OR WHEN
HELICOPTER IS FLOWN BELOW 500 FEET OVER SALT WATER**

**a.** Rinse engine compressor after the last flight of each day. Refer
to Allison publication 5W2 or 10W2.

**6-14.** **AFTER WASHING HELICOPTER**

**a.** Inspect pitot-static system for moisture.

**b.** Check fuselage and tail boom attachment fittings for accumulation
of water.

**6-15.** **WHEN MAJOR MODIFICATIONS OR MAJOR AIRFRAME REPAIRS ARE
ACCOMPLISHED, ANY SPECIAL EQUIPMENT HAS BEEN ADDED TO OR REMOVED FROM
THE BASIC AIRFRAME, OR WHEN WEIGHT AND BALANCE DATA ARE SUSPECTED TO BE
IN ERROR**

**a.** Weigh aircraft and perform weight and balance records check.

**b.** Re-compute empty weight and center of gravity and revise weight
and balance record (refer to applicable TM)

**6-16. AT EACH ENGINE OIL CHANGE**

**a.** Refer to Allison publication 5W2 or 10W2 for instruction
regarding engine oil change.

**b.** Change external oil filter if installed.

**6-17. AT EACH TIME MAIN ROTOR PITCH LINKS AND THE IDLER LINK ARE
DISCONNECTED**

**a.** Inspect swashplate duplex ball bearing by rotating swashplate
outer ring.

**NOTE**

Replace bearing if rough.

**6-18. AFTER EACH ENGINE CHANGE, ELECTRICAL EQUIPMENT CHANGE, OR MAJOR
STRUCTURAL CHANGE LIKELY TO AFFECT THE COMPASS**

**a.** Check magnetic standby and remote compass indicators for
accuracy.

**NOTE**

Compensate when necessary. Refer to applicable TM.

**6-19. AFTER INSTALLATION OF ENGINE MOUNT TO AIRFRAME BOLTS**

**a.** Verify torque on attachment bolts and nut (refer to applicable
TM) and secure with cotter pin.

**6-20. AFTER INSTALLATION OF TAIL BOOM**

**a.** Verify torque on tail boom attachment bolts after maintenance
test flight (refer to applicable TM).

**6-21. FIVE TO TEN HOURS AFTER INSTALLATION OF PILLOW BLOCK HARDWARE.**

**a.** Inspect pillow block retention bolts and nut for slippage.

**b.** Verify torque on nuts (refer to applicable TM).

**CAUTION**

**If slippage has occured, replace the bolt.**

**6-22. 25 HOURS AFTER MAIN ROTOR MAST NUT INSTALLATION**

**a.** Re-torque mast nut (refer to applicable TM).

**6-23. 25 [HOURS]{.smallcaps} AFTER INSTALLATION OF SWASHPLATE**

**a.** Check tilt friction after first 25 flight hours.

**6-24. EVERY 50 HOURS**

**a.** Verify torque (refer to the applicable TM) of upper clamp of fuel
hose inside fuel tank.

**NOTE**

No longer required after completion of MWO 55-1520-228-30-32.

**1.** Disconnect the battery and electrically ground the helicopter.

**2.** If helicopter fuel cell is full, remove approximately two gallons
of fuel.

**3.** Remove the cap and adapter. Inspect upper clamp. If the clamp is
not radial, install a radial clamp. Tighten the upper clamp assembly on
self-sealing hose finger tight plus two and one half turns.

**4.** Install cap and adapter with new packing and torque bolts (refer
to applicable TM).

**b.** Clean engine compressor. Refer to Allison publication 5W2 or
10W2.

**6-25. EVERY 100 HOURS**

a.  Refer to Allison publication 5W2 or 10W2 for all inspection
    requirements and recommended maintenance procedures regarding engine
    operations.

**NOTE**

The below special inspection is not required on those

servo cylinders having an "A" suffix after the serial number.

**b.** Servo actuators serial numbers 8383 through and including serial
number 9318, inspect for cracking on aft end of piston rod between jam
nut on rod end and valve housing.

**c.** Rotating control inspection.

**1.** Inspect main rotor pitch links for damage and security of
attachment.

**2.** Inspect tubes for corrosion and cracks, pay particular attention
to swaged ends at jam nut.

**3.** Inspect pitch horn trunnion bearing for evidence of wear.

**d.** Inspect bearing clearance of collar set.

**e.** Inspect main rotor yoke as follows:

**1.** Yoke for evidence of corrosion.

**NOTE**

If corrosion is evident, remove with scotch brite

fine abrasive pads. If corrosion cannot be removed with

pads, or is excessive, dissemble hub and inspect and repair.

**2.** Yoke center section inboard and outboard surfaces from pillow
block bores and tooling holes to lower web section for nicks, scratches
tool marks, and cracks.

**3.** Inspect to insure no sealant voids are evident around shields.

**NOTE**

Re-coat with bead of sealing compound as required.

Coat the remaining exposed fillet radii and repaired

surfaces with a film of corrosion prevention compound.

**f.** Inspect tail boom attachment fittings by:

**1.** Opening access panel on the right side of the aft fuselage and
inspect the four tail boom attachment fittings on fuselage aft bulkhead
and tail boom forward bulkhead for cracks.

**NOTE**

Give special attention to the tail boom attach fittings and

bolts and to the fasteners between the fittings and intercostals.

Particular attention must be given to inspection of the upper left
fittings.

**CAUTION**

**Any cracks, corrosion, loose or sheared**

**rivets, is cause for** **immediate corrective maintenance.**

**g.** Check engine air intake ducts and plenum for obstructions or
damage. Check air induction fairing for seal security, conditions, and
bond voids along the seals complete length. Check sand and dust
separator for damage and particle ejection opening for freedom of
obstruction.

**h.** Check voltage regulator for proper operation.

**i.** Inspect tail rotor for proper dynamic balance.

**6-26. AT FIRST 100 HOUR INSPECTION FOLLOWING MAST NUT INSTALLATION**

**a.** Re-torque mast nut (refer to applicable TM).

**6-27. AT FIRST 100 HOURS AFTER INSTALLATION OF TAIL BOOM**

**a.** Verify torque of tail boom attachment bolts (refer to applicable
TM).

**6-28. EVERY 100 HOURS OR 120 CALENDAR DAYS WHICHEVER OCCURS FIRST.**

**a.** Perform preventive battery maintenance checks and services on the
nickel-cadmium battery (refer to battery maintenance and instruction
manual or TM). After battery removal, check area around battery for
cleanliness, corrosion, paint and condition.

**b.** Remove transmission oil cooler duct and inspect radiator for
foreign objects blocking air flow.

**6-29. 100 HOURS AFTER INSTALLATION OF PILLOW BLOCK RETENTION BOLTS AND
NUTS OR INSTALLATION OF A NEW OR OVERHAULED MAIN ROTOR HUB ASSEMBLY.**

**a.** Verify torque of pillow block retention bolts and nuts (refer to

applicable TM).

**NOTE**

Paint a slippage mark across bolt heads to pillow block

surfaces and across nuts to yoke surfaces including washers.

**6-30. 100 HOURS AFTER SERVO ACTUATOR INSTALLATION**

**a.** Verify torque of trunnion plate nuts.

**b.** Verify torque of bearing plate nuts.

**NOTE**

Refer to applicable TM for proper torque.

**6-31. 100 HOURS OF OPERATION AFTER THE TAIL ROTOR GEARBOX HAS BEEN
INSTALLED OR HARDWARE ADJUSTED**

**a.** Verify torque of the tail rotor gearbox retaining hardware (refer
to applicable TM).

**6-32. EVERY 150 HOURS OR 6 CALENDAR MONTHS WHICHEVER OCCURS FIRST**

**a.** Remove, disassemble, clean, inspect, reassemble and lubricate
engine to transmission main input driveshaft assembly.

**NOTE**

This inspection does not apply to P/N 206-040-3171-111.

**6-33. EVERY 150 HOURS**

**a.** Inspect tail rotor gearbox chip detector for metal particles and
contamination. Change tail rotor gearbox oil.

**6-34. EVERY 300 HOURS OR WHEN RED BUTTON (IMPENDING BYPASS INDICATOR)
ON TRANSMISSION OIL FILTER IS SHOWING**

**a.** Replace transmission oil filter and reset impending by-pass
indicator.

**b.** Inspect transmission oil for contamination and metal particles.

**NOTE**

Cut filter open (do not saw) to inspect pleated element.

**c.** Inspect transmission oil sump screen and chip detectors for
contamination and metal particles. Change transmission oil.

**6-35. EVERY 500 HOURS OR EVERY 12 CALENDAR MONTHS**

Refer to Allison publication 5W2 or 10W2 for all inspection requirements
and recommended maintenance procedures regarding engine operations.

**6-36. EVERY 600 HOURS**

Refer to Allison publication 5W2 or 10W2 for all inspection requirements
and recommended maintenance procedures regarding engine operations.

**6-37. AFTER 600 HOURS AND 900 HOURS OF OPERATION OF NEW RETENTION
STRAP**

**a.** Retention straps inspection (refer to applicable TM).

**6-38. [EVERY 1000 HOURS ]{.smallcaps}**

Refer to Allison publication 5W2 or 10W2 for all inspection requirements
and recommended maintenance procedures regarding engine operations.

**6-39. [EVERY 1200 HOURS ]{.smallcaps}**

**NOTE**

For the following inspection refer to the applicable TM.

**a.** Check the tail rotor gearbox attaching hardware for proper torque
(refer to applicable TM).

**b.** Remove transmission isolation mount and inspect absorber plate
for cracks and wear. Inspect metal parts for, dents, notches, or other
damage. Inspect rubber parts for separation and cracks.

**c.** Inspect the main rotor control components listed below for
damage, wear, and cracks.

**1.** Inspect spherical bearings in these parts for damage and
looseness.

**2.** Inspect Teflon lined bearings in these parts for loose fabric,
damaged Teflon, and for exposed fiberglass base.

**3.** Inspect metal bushings in these parts for damage and looseness.

**[Name]{.underline}** **[Part Number]{.underline}**

Swashplate Idler Lever 206-010-335-1

Idler link 206-010-336-5

Main rotor pitch link 206-010-360-3

assemblies

Collective lever link 206-010-407-1

assembly

Collective lever assembly 206-010-467-1

Collar set 206-011-005-1

**6-40. EVERY 100 HOURS AFTER THE 1200 HOUR INSPECTION OF SWASHPLATE
DUPLEX BALL BEARING UNTIL THE 2400 HOUR OVERHAUL OF THE SWASHPLATE.**

**a.** Disconnect main rotor pitch links and the idler link. Inspect
swashplate duplex ball bearing for roughness by rotating swashplate
outer ring**.**

**6-41. AFTER 1200 HOURS OPERATION OF NEW OR OVERHAULED MAIN ROTOR HUB
ASSEMBLY.**

**a.** Inspect main rotor grips per following:

**1.** Remove grips from hub and inspect for wear and corrosion in
excess of limits.

**2.** Clean paint from grips and pitch horns with paint remover,
MIL-R-46116.

**3.** Prepare grips and pitch horns for inspection by procedures
outlined by fluorescent penetrant manufacturer.

**4.** Inspect pitch horns and grips for cracks.

**5.** After inspection is complete, assemble main rotor hub**.**

**6.** Paint main rotor hub as follows:

**(a)** Touch up all exposed steel surfaces with brush cadmium plate LHE
Solution, MIL-STD-865.

**(b)** Touch up all exposed aluminum surfaces with chemical conversion
coating (Alodine), MIL-C-81706.

**(c)** Paint main rotor hub.

**6-42. AFTER 1200 HOURS OPERATION OF NEW OR OVERHAULED MAIN
TRANSMISSION**

**a.** Inspect transmission as follows:

***WARNING***

***The inspection of this transmission must be***

***accomplished by an appropriately certificated and qualified
person.***

**1.** Inspect top case for cracks. Use fluorescent penetrant method. It
is not necessary to strip paint from the top case. Do not use dye-check
method to make this inspection. Check ring gear carefully around area of
roots of splines. If any cracks are detected, reject the top case.

**2.** Inspect splines in top case for wear. Place O**.**1200 inch
diameter pins in splines and measure distance between pins. If dimension
is greater than 11.8840 inches, reject the top case.

**3.** Inspect planetary sun gear as follows:

**(a)** Visually inspect for general condition.

**(b)** Place two 0.1600 inch diameter pins, not longer than 0.250 inch
in splines. Measure dimension over the pins in area of greatest wear. If
dimension over pins is 2.7290 inches or greater, inspect sun gear and
planetary gear teeth for evidence of interference. If gears are
satisfactory, the sun gear may be reinstalled.

**(c)** If dimensions over pins is less than 2.7290 inches, reject the
sun gear.

**4.** Inspect planetary bearings and gear assemblies as follows:

**(a)** Visually inspect gears for chipped, broken and worn teeth.

**(b)** Check bearing surfaces of rollers, inner race and outer race for
chips, cracks, nicks, brinnelling, spalling and corrosion.

**6-43. AFTER 1200 HOURS OPERATION OF NEW OR OVERHAULED MAIN
TRANSMISSION MAST ASSEMBLY**

**a.** Inspect as follows:

**1.** Mast splines for burrs, nicks, cracks and wear.

**2.** Mast inner and outer surfaces for corrosion. Inspect surface
protective coatings for condition.

**3.** Bearing for pits, erosion, spalling and brinelling.

**6-44. AFTER 1500 HOURS OPERATION OF NEW OR OVERHAULED FREEWHEELING
ASSEMBLY.**

**a.** Inspect shafts, bearing and clutch P/N CL 41742-1 or CL 42250-1
visually for wear and damage.

**b.** Conduct magnetic particle inspection of shafts in accordance with
the applicable TM.

**6-45. EVERY 1500 HOURS**

Refer to Allison publication 5W2 or 10W2 for all inspection requirements
and recommended maintenance procedures regarding engine operations.

**6-46. EVERY** **12 CALENDAR** **MONTHS**

**a.** Inspect portable fire extinguisher in accordance with the
manufacturer's instructions and check for hydro static test date and
life limit.

**b.** First Aid kit inspection in accordance with the manufacturer's
instructions.

**c.** Calibrate (swing) magnetic (standby) compass in accordance with
applicable TM.

**d.** Check current magnetic compass and gyro-compass correction cards
for availability and legibility.

**6-47. EVERY** **12 CALENDAR** **MONTHS: OR WHENEVER HELICOPTER IS
TRANSFERRED, RECEIVED, PLACED IN** **STORAGE, OR REMOVED FROM STORAGE.**

**a.** Every 14 Days \|

1.  If the idle time of the helicopter has been for a period of \|

> 14 days following the last flight, it is required that a \|
>
> ground run of 5 to 10 minutes be performed (attainment of the \|
> operating temperature). \|

**2.** If a ground run is not possible every 14 days the helicopter \|
and especially the engine should be preserved in accordance \| with the
current military document. Engine preservation requirements and
instructions are in Allison publication 5W2 or 10W2.

**6-48. EVERY 24 CALENDAR** **MONTHS**

**a.** Perform test on pitot static system in accordance with applicable
Federal Aviation Regulations and TM.

**b.** Inspect fuel tank for condition, contamination.

**c.** Check fuel quantity indicator for accuracy.

**6-49. AFTER 1550 HOURS OPERATION OF NEW OR OVERHAULED ENGINE WITH
PRODUCT IMPROVED TURBINE FOR T63-A-700 AND AFTER 1775 HOURS OR 3000
CYCLES OPERATION OF NEW OR OVERHAULED ENGINE WITH PRODUCT IMPROVED
TURBINE FOR T63-720.**

**a.** Refer to Allison publication 5W2 or 10W2 for engine component P/N
applicability, retirement life schedule, and special notes regarding
differing turbine module operating configurations.

**6-50. EVERY 1750 HOURS**

Refer to Allison publication 5W2 or 10W2 for all inspection requirements
and recommended maintenance procedures regarding engine operations.

**6-51. AFTER 2400 HOURS OF OPERATION OF NEW OR OVERHAULED MAIN
TRANSMISSION**

**a.** Overhaul and inspect main transmission per DMWR 55-1615-157.

**6-52. AFTER 2400 HOURS OF OPERATION OF NEW OR OVERHAULED MAIN
TRANSMISSION MAST ASSEMBLY**

**a.** Inspect mast assembly per applicable TM.

**6-53. AFTER 2400 HOURS OF OPERATION OF NEW OR OVERHAULED TAIL ROTOR
GEARBOX ASSEMBLY**

**a.** Overhaul and inspect tail rotor gearbox assembly per DMWR
55-1615-159 or DMWR 55-1615-298.

**6-54. AFTER 3000 HOURS OF OPERATION OF NEW OR OVERHAULED FREEWHEELING
ASSEMBLY**

**a.** Overhaul and inspect freewheeling assembly per DMWR 55-1615-161.

**Chapter 7**

**Conditional Inspections**

**\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

Inspections which are contingent upon specific conditions or incidents
that arise, and only because of these conditions or incidents. Examples
of these conditions or incidents are hard landings, overspeed, and
sudden stoppage. **An immediate inspection is required in such cases to
ensure safe flight.** Refer to the applicable military aircraft
operations manual, aircraft technical manual, and DMWR's for limitations
and inspection criteria**.**

**[Conditional Inspections Index (Airframe)]{.underline} Page**

**7-1. AFTER A HARD LANDING . . . . . . . 51**

**7-2. AFTER LOWER WSPS GROUND CONTACT . . . . . 54**

**7-3. AFTER WIRE STRIKE . . . . . . . . 55**

**7-4. AFTER PYLON WHIRL . . . . . . . . 55**

**7-5. AFTER SPIKE KNOCK . . . . . . . . 56**

**7-6. AFTER SUDDEN STOPPAGE-MAIN ROTOR . . . . . 56**

**7-7. AFTER SUDDEN STOPPAGE-TAIL ROTOR . . . . . 58**

**7-8. AFTER MAIN ROTOR OVERSPEED . . . . . . 59**

**7-9. AFTER AIRFRAME OVERTORQUE OPERATION . . . . . 60**

**7-10. ANY TIME FUEL FILTER LIGHT COMES ON . . . . . 61**

**7-11. ANY TIME TRANSMISSION OR TAIL ROTOR MAGNETIC**

**CHIP LIGHT COMES ON . . . . . . . 61**

**7-12.** **LIGHTING STRIKE** **.** **.** **.** **.** **.** **.** **.**
**.** **62**

**[Conditional Inspections Index (Engine)]{.underline}**

**7-13. SUSPECTED FOREIGN OBJECT DAMAGE . . . . . 63**

**7-14. AFTER ENGINE OVERTEMPERATURE OPERATION . . . . 64**

**7-15. AFTER ENGINE OVERSPEED OPERATION . . . . . 64**

**7-16. ANY TIME ENGINE MAGNETIC CHIP LIGHT COMES ON . . . 64**

**7-17. IF ENGINE OIL TEMPERATURE EXCEEDS 107 DEGREES**

**CELSIUS WITH A CHANGE IN NORMAL OIL PRESSURE . . . 64**

**7-18. EMERGENCY FUEL USAGE . . . . . . . 64**

**Conditional Inspections**

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

**7-1. AFTER A HARD LANDING**

Definition: Hard landing is defined as any accident or incident in which
ground impact of the helicopter causes severe pitching of main rotor,
allowing hard contact of hub with mast, or results in yielding or
noticeable cracking of fuselage pylon support structure or landing gear.
This definition is confined only to those accidents not involving sudden
stoppage of main rotor or tail rotor. When a probable hard landing
incident has occurred, proceed as follows:

Refer to Allison publication 5W2 or 10W2 for instruction regarding the
necessary actions required for engine inspection.

**a.** Check all cowling and doors for proper fit and alignment. Mis-
aligned cowling may indicate a distorted fuselage, resulting in major
stresses and damage. Remove center post cover assembly and inspect cap
angles for buckling and bending.

**b.** Remove all cowling as necessary to perform a complete visual
inspection.

**c.** Inspect landing gear skid tubes and crosstubes for damage and
deflection. Inspect crosstube attachment points for damage or
distortion.

**d.** Inspect structure with a ten-power magnifying glass around the
transmission mounting points. Particular attention should be given to
the isolation mount and pylon support mounts.

**e.** Inspect upper longerons and adjacent skin near the aft engine
firewall (Station 167.00) for loose rivets, cracks, distortion and
structural damage.

**f.** Inspect tail skid tube and mounting for damage. Inspect tail boom
internally and externally for cracks, distortion, and loose rivets.
Inspect the tail boom attachment points for elongated bolts and damaged
structure. Inspect external skin of tail boom for cracks in area of
attachment of the horizontal stabilizer.

**g.** Inspect flight control system from pilot's controls to rotor head
for bent or damaged tubes, bellcranks, and supports, and for damaged
bearings. Particular attention should be given to the mast control rods
and collective sleeve assembly.

**h.** Check for leaks in the hydraulic system and interference or
binding, and for satisfactory operation.

**i.** Inspect transmission and mast assembly for the following:

**1.** Mast for indentation caused by hard contact with static stops.

**2.** Mast outside diameter for out-of-round condition as follows:

**NOTE**

Cadmium plating on the outside diameter (O.D.) of mast

is 0.0003 to 0.0004 inch. When measuring mast O.D. at six places

for out-of-round, ensure that 0.0003 to 0.0004 inch surface differential
is considered when measuring plated surfaces or where plating may have
been removed.

**(a)** Using a suitable micrometer, measure the mast O.D., at a minimum
of six places for out-of-round condition; two opposing measurements
under the collar set and above the swashplate, two opposing measurements
midway between the collar set and the static stop contact area, two
opposing measurements approximately two inches below the static stop
contact area on the mast.

**(b)** If any set of opposing measurements vary in excess of 0.002
inch, the mast is suspected of bending and a run- out check must be
performed.

**3.** Structure supporting the transmission mount points for cracks or
deformation.

**4.** Transmission drag pin for security of attachment. Replace adapter
mount studs as required.

**5.** Transmission-drag pin-transmission mount support on cabin roof
for deformation and/or loss of attachment bolt torque. Supporting
structure for damage and loose or sheared rivets.

**(a)** The transmission to engine coupling will be removed and a
detailed inspection performed.

**(b)** The transmission assembly will be removed and returned to
authorized overhaul or repair facility for evaluation.

**j.** If no major damage is found in the inspections listed above,
start engine and check main rotor (while in a flat pitch condition) for
any evidence of a 1/rev. vibration.

**k.** Inspect main rotor blades for contact with tail boom.

**NOTE**

If damage is found, refer to **7-6** **AFTER SUDDEN STOPPAGE - MAIN
ROTOR.**

**l.** Inspect tail rotor blades for damage.

**NOTE**

If damage is found, refer to **7-7** **AFTER SUDDEN STOPPAGE - TAIL
ROTOR.**

**m.** Inspect fuel and oil systems for damage. Before flight, check
fuel and oil systems for leaks. Inspect the crashworthy fuel system for
the following:

**1.** Sump retainer and surrounding airframe for cracks and/or
distortion.

**2.** Sump area for leaks.

**3.** Sump drain valve for proper operation.

**4.** Fuel boost pump wiring for broken leads.

**5.** Retainer at filler cap and adapter for cracks and/or sheared
rivets.

**6.** Relation of fuel cell fitting with airframe fuel opening.

**7.** Fuel feed hose for clamping security inside fuel cell.

**8.** Cover assembly to ensure no pullout has occurred at screws
attaching cover assembly to seat back panel.

**9.** Fuel feed valve at top right side of fuel tank for cracks.

**10.** Boost pump pressure available to engine and that no leakage
occurs.

**11.** Manual shutoff valve for binding.

**12.** Fuel quantity indicator for proper operation and probe leads or
broken wires.

**13.** All hoses for chafing and broken or distorted clamps.

**n.** Inspect engine mounts and fuselage attachment points for cracks
and damage.

**o.** Check power and accessory gearbox for cracked flanges.

**p.** Inspect magnetic chip detectors for metal accumulation.

**q.** Check engine mounting pads for cracks.

**r.** Check air, oil and fuel hose connections for tightness.

**s.** Check all engine accessories for cracked flanges, loose bolts and
nuts, connections and general condition.

**t**. After a hard landing: If damage or misalignment to fuselage
structure, skid gear, or tail boom is such that a major repair,
replacement or alignment is necessary, remove the following components
and conduct a major overhaul inspection in accordance with instructions
in the appropriate TM:

**1.** Main rotor blades and attachments.

**2.** Main rotor hub.

**3.** Swashplate and controls.

**4.** All control bolts.

**5.** Transmission and mast assembly.

**6.** Transmission to engine coupling assembly.

**7.** Tail rotor shafts and bearings.

**8.** Tail rotor gearbox.

**9.** Tail rotor hub and blades.

**10.** Isolation mount.

**11.** Freewheeling assembly.

**u.** If misalignment is indicated as a result of excessively hard
contact of main rotor hub static stop against mast, remove the following
components and conduct a major overhaul inspection in accordance with
instructions in the appropriate TM.

**1.** Main rotor blades and attachments.

**2.** Main rotor hub.

**3.** Transmission and mast assembly.

**4.** Transmission-to-engine coupling assembly.

**5.** Isolation mount.

**6.** Freewheeling assembly.

**v.** If damage is found in rotating controls, accomplish the following
steps:

**1.** Replace all control rods and bolts.

**2.** Remove and overhaul the following components.

**(a)** Main rotor hub assembly.

**(b)** Swashplate and controls.

**7-2. AFTER LOWER WSPS GROUND CONTACT**

**NOTE**

Loss of breakaway tip or damage not affecting structural integrity

of installation are not causes for grounding of aircraft. However,

replacement of tip damage repair shall be accomplished as soon as
practical.

**a.** Inspect lower WSPS for obvious damage.

**b**. Inspect attachment area for damage.

**c.** Remove panel and inspect structure and directional control tubes
and bellcranks for damage.

**7-3. AFTER WIRE STRIKE**

**a.** Windshield deflector-upper and lower WSPS.

**1.** Inspect for obvious damage.

**2.** Inspect attachment areas for damage.

**7-4. AFTER PYLON WHIRL**

Definition: A combination of very low rotor speeds and high collective
blade angles which results in excessive flapping of the main rotor hub,
which in turn causes bumping and rotation of the pylon in an elliptical
pattern. Pylon Whirl will usually include spike knocking and swashplate
to cowling contact.

**NOTE**

Oil canning and some wrinkling occurring aft of the

avionics compartment door below WL 61.76 is normal on the helicopter.

**a.** Inspect tail boom in the area aft of the tail boom attach point
to the elevator. Check for bending, buckling or creasing, especially on
the top and bottom of the tail boom.

**b.** Inspect fiberglass fairing under the tail boom assembly on the
aft section assembly for cracking.

**c.** Inspect aft section assembly of the helicopter forward of the
tail boom attach point for approximately 36 inches both sides of
aircraft. Check for skin wrinkling above WL 61.76 which is characterized
by permanent creasing and abrupt changes in profile.

**NOTE**

If the fiberglass fairing has been cracked, or if the aft

section assembly skin is wrinkled above WL 61**.**76, the longerons

and stiffeners must also be inspected for bending, cracking or tearing.

**d.** Inspect transmission cowling for swashplate to cowling contact.
Check for loose jam nuts on swashplate control tubes.

**e.** Inspect transmission drag pin assembly and its static stop for
permanent deformation and security of attachment.

**NOTE**

If the preceding inspections reveal no damage as a result of

pylon whirl, or suspected pylon whirl, the helicopter may be released

for flight. Otherwise, a complete hard landing inspection is required.

**7-5. AFTER SPIKE KNOCK**

**a.** If spike knocking occurred as a result of ground impact, or
sudden stoppage of the helicopter in sand or mud, the **7-1 AFTER A
HARD** **LANDING** inspection is required.

**b.** If spike knocking occurred during flight, but did not involve
rotor RPM's below 330 RPM and high collective blade angles, only the
transmission adapter mount (drag link) and isolation mount must be
inspected. If spike knocking was accompanied by severe vibrations
(shuddering), the **7-4 AFTER PYLON WHIRL** inspection is applicable.

**c.** If spike knocking occurred during ground run-up, but was induced
by lateral movement to the cyclic, rather than full up collective and
rotor speed below 225 RPM only the transmission adapter mount (drag
link) and isolation mount must be inspected.

***WARNING***

***If swashplate to cowling or main driveshaft to***

***isolation mount contact occurs, the following inspections***

***must be complied with: 7-1*** ***HARD LANDING INSPECTION, 7-4***
***PYLON WHIRL***

***INSPECTION to include special inspection of main driveshaft
assembly.***

***The drag pin assembly must be removed from transmission assembly for
a***

***detailed inspection. The four drag pin assembly mounting studs will
be replaced.***

**d.** If spike knocking occurred during ground run up with full up
collective and rotor speed below 225 RPM, the **7-4** **AFTER PYLON
WHIRL** will be accomplished.

**7-6. AFTER SUDDEN STOPPAGE-MAIN ROTOR**

Definition: Sudden stoppage is defined as an abnormal deceleration of
the drive system caused by internal seizure of the transmission or by
the main rotor or tail rotor blades striking something which causes
rapid deceleration.

Refer to Allison publication 5W2 or 10W2 for instruction regarding
Engine Sudden Stoppage and the necessary actions required.

**a.** If visible damage to either one or both of the blades (other than
tip cap fairing damage) is evident, remove the following components for
major overhaul inspections:

**1.** Main rotor blades and attachments.

**2.** Main rotor hub.

**3.** Mast.

**4.** Swashplate and controls.

**5.** Transmission.

**6.** Freewheeling unit.

**7.** Main driveshaft.

**b.** After Sudden Stoppage with no visible damage. Inspect the
exterior of blades for security of all bonds and visible damage. Remove
tip cover plate.

**NOTE**

If tip weight has moved, blade shall be disposed of as unsalvageable.

**c.** Engine and transmission mounts at fuselage attachment points for
cracks.

**d.** After sudden stoppage with minor damage to main rotor, inspect
the following components. If any damage is found proceed to category of
major damage.

**1.** Main rotor hub pillow block bearings and grip bearings for
freedom and security.

**2.** Flight control system from the rotor to hydraulic boost cylinder
for bent or damaged tubes. Bell cranks and supports for damaged
bearings.

**3.** Swashplate idler links and lever for damage.

**4.** Swashplate pivot for damage.

**5.** Structure at transmission mounting points for cracks (use ten
power magnifying glass).

**6.** Isolation mount and pylon supports for damage, security, and
distortion.

**e.** If main rotor has major damage, inspect the following components:

**1.** Flight control system from the rotor to hydraulic boost cylinder
for bent or damaged tubes. Bell cranks and supports for damaged
bearings.

**2.** Swashplate idler links and lever for damage.

**3.** Swashplate pivot for damage.

**4.** Isolation mount and pylon support for damage, security and
distortion.

**5.** Tail rotor driveshaft adapters and disk assemblies for cracks
using magnetic particle process.

**6.** Tail rotor driveshafts for concentricity and cracks. Dye \|
penetrate/NDI is required. \|

**f.** If more than minor damage is found on any component, remove and
perform a major overhaul inspection in accordance with instructions in
the applicable TM.

**7-7. AFTER SUDDEN STOPPAGE-TAIL ROTOR**

Refer to Allison publication 5W2 or 10W2 for instruction regarding the
necessary actions required.

**a.** Remove and replace tail rotor hub and blade assembly.

**b.** Inspect the following tail rotor driveshaft system components for
damage.

**1.** Flexible couplings, driveshaft, and adapters for cracks, use
magnaflux or zyglo method.

**2.** All components dimensionally in accordance with applicable TM.

**3.** Bonds between tail rotor driveshaft and adapters for failure.

**CAUTION**

**This requirement also applies to tail rotor blades which**

**may have contacted water during float operation.** **Damage to the
hub**

**and blade could be present although it may not be readily detected
by**

**standard visual, dimensional, magnaflux or zyglo methods of
inspection.**

**4.** Driveshaft support hangers for cracks and distortion.

**c.** If tail rotor driveshaft is damaged, remove the following
components and perform a major overhaul in accordance with instructions
in the overhaul sections of the applicable TM:

**1.** Tail rotor gearbox.

**2.** Freewheeling unit.

**3.** Replace all tail rotor driveshaft hangers.

**d.** Inspect tail boom in the area of the tail rotor gearbox mounting
studs, using a ten-power magnifying glass.

**e.** Inspect four tail boom attachment points for cracks, distortion,
damage and security. Check torque on nuts of attachment bolts (refer to
applicable TM).

**f.** Inspect tail boom internally for cracks, distortion and loose or
missing rivets. Check external skin of tail boom for cracks in area of
the attachment of the horizontal stabilizer.

**g.** Inspect horizontal stabilizer for skin cracks and looseness in
mounting.

**h.** Inspect vertical fin for security and overall condition. Check
the tail skid for condition and security. Check anti-collision light for
condition and security.

**NOTE**

Known or suspected contact of tail rotor blades

with loose earth, snow, water, or vegetation does not

require removal and replacement of the tail rotor gearbox unless

inspection as required by this section, **d**. through **h**. (above),
reveals

an obvious defect, and provided the hub assembly can be dynamically
balanced.

**CAUTION**

**Sudden stoppage may result in a tail rotor out of balance condition**

**which could be detrimental to the structure. Perform the following:**

**i.** If sudden stoppage originated at the main rotor, the tail rotor
hub and blade assembly may remain in service providing no visual
external damage is noted.

**NOTE**

Obvious damage noted to the tail rotor hub and blade

assembly is cause for detailed inspection and/or repair.

**j.** If sudden stoppage originated at the main transmission, the
transmission, input driveshaft and freewheeling assembly will be removed
and subjected to a major overhaul. If sudden stoppage originated at the
tail rotor gearbox, the tail rotor gearbox and tail rotor driveshafts
will be removed and subjected to a major overhaul. Tail rotor hub and
blade will be inspected for damage.

**7-8. AFTER MAIN ROTOR OVERSPEED**

If main rotor overspeeds in excess of 390 RPM, 110%, perform the
following inspections:

Refer to Allison publication 5W2 or 10W2 for instruction regarding the
necessary actions required.

**a.** Main rotor blades. Inspect for the following:

1.  Main retention bolt hole for elongation or deformation.

**NOTE**

Elongation in excess of 0.0015 inches is cause to replace blade.

**2.** Main retention bolt bushings for looseness. Replace blade if
bushing is loose.

**3.** Tip cap screws and matching holes. Replace blade if screws or
holes are deformed**.**

**4.** Blade skin for wrinkles or deformation. Replace blade if skin is
deformed or wrinkled.

**5.** Inertia weight retaining screws for damage or looseness. Replace
blade if screws or holes are deformed.

**6.** Replace grip retention strap assemblies.

**7.** Replace inboard strap fittings and pins.

**8.** Replace outboard strap latch bolts.

**b.** Tail rotor blades. Inspect for the following:

**1.** If one of the blades of a pair has been damaged badly enough that
metal has been torn or any bond lines have separated, the hub and blade
assembly should be disposed of as unsalvageable.

**2.** If one of the blades contour has been damaged slightly, the hub
and blade assembly should be disposed of as unsalvageable.

**3.** If any movement of the tip end or root end balance weights has
occurred, the hub and blade assembly should be disposed of as
unsalvageable.

**4.** If the tip block is cracked, the hub and blade assembly should be
disposed of as unsalvageable.

**c.** Inspect tail rotor driveshaft bearing hanger brackets for
security of attachment and for cracks or bends.

**d.** Inspect oil cooler blower fan for visible distortion or cracks of
the brazed vane joints.

**e.** Conduct a major overhaul inspection of main and tail rotor hub
assemblies. Refer to DMWR 55-1615-158 for the Main Rotor Hub Assembly,
and DMWR 55-1615-162 for the Tail Rotor Hub Assembly.

**7-9. AFTER AIRFRAME OVERTORQUE OPERATION**

**a.** Refer to the appropriate military operating manual for the
definition of overtorque condition applicable to the make and model.

**b.** If engine overtorque occurs, perform a P.M.I. Conduct an
inspection of the following components for evidence of damage,
deformation, yielding, etc:

**1.** Main rotor hub**.**

**2.** Main rotor mast.

**3.** Transmission top case.

**4.** Pylon mount arm attachment fittings, upper and lower.

**5.** Cabin roof at pylon mount fittings.

**6.** Isolation mount attachment.

**7.** Transmission chip detectors.

**8.** Main driveshaft couplings for overheating. If main rotor
driveshaft 206-040-371 is used, check for damage and fastener security.

**9.** Tail rotor hub and attachments.

**10.** For engine overtorque inspection requirement refer to Allison
publication 5W2 or 10W2 for instruction regarding the necessary actions
required.

**c.** After 25 flight hours following overtorque, inspect the
following:

**1.** Main rotor hub.

**2.** Main rotor mast.

**3.** Transmission top case**.**

**4.** Pylon mount arm attachment fittings, upper and lower.

**5.** Cabin roof at pylon mount fittings.

**6.** Isolation mount attachment.

**7.** Transmission chip detector.

**8.** Tail rotor hub, blades, and attachments.

**7-10. ANY TIME FUEL FILTER LIGHT COMES ON**

**a.** Refer to Allison publication 5W2 or 10W2 for instruction
regarding the necessary actions required.

**b.** Inspect air frame fuel system.

**7-11. ANY TIME TRANSMISSION OR TAIL ROTOR MAGNETIC CHIP LIGHT COMES
ON**

**a.** Remove chip detector leads (one at a time), to determine which
magnetic plug caused the light.

**b.** Remove and inspect the applicable magnetic plug for metal
accumulation, determine if accumulation is acceptable.

**c.** Clean or replace oil and/or filter of component if acceptable.

**d.** Remove component for inspection or overhaul if accumulated
material is considered unacceptable

**7-12. LIGHTNING STRIKE INSPECTION**

**a.** General requirements when helicopter is struck by lightning:

**1.** Inspect fuselage interior and exterior, landing gear, rotor
system, and static ground wire for burn marks, cracks, pitting, or signs
of high temperature stress; to determine lightning entry and exit
points.

**2.** Trace path of lightning strike to extent possible using a
magnetometer.

**3.** Check magnetic compass for accuracy (degree of inaccuracy may
serve as an indicator of severity of strike).

**4.** Inspect wiring in tunnel areas and exposed areas for burns.

**5.** Inspect antennas for burns and pitting.

**6.** Inspect all electrically operated components and lighting systems
for damage.

**7.** Inspect communications and navigation equipment for damage.

**8.** If the preceeding steps **1** through **7** (above) reveal major
damage has occured, proceed as follows:

**9.** Bench test all avionics and electrical systems and components.

**10.** Perform a continuity check on all wiring cables.

**11.** Perform a Voltage Standing Wave Ration (VSWR) check on all
antennas, antenna cables, and connectors.

**12.** Perform specific inspection/replacements as required.

**13.** Perform a ground run operational check on the aircraft.
Functionally check the flight control system, and all avionics,
electrical, lighting, communication, and navigation systems.

**14.** Repair any damage and replace damaged components as required
using standard maintenance pratices.

**b**. Specific requirements whenever lightning strike is evident on
main rotor system:

**1.** Inspect blades for damage such as burns, pitting, skin
seperation, etc. If damage is evident, dispose of as unsalvageable.

**2.** Remove hub assembly and return for overhaul.

**3**. Replace all bearings (or next higher assembly if required) in the
fixed and rotating control system located above the servo- cylinders.

**4.** Remove swashplate assembly, mast assembly and transmission
assembly, and return for overhaul.

**5.** Check driveshafts for residual magnetism. If magnetized or
damaged replace driveshafts and remove engine and return for overhaul.

**c.** Specific requirements when lightning strike is evident on tail
rotor system:

**1.** Inspect blades for damage such as burns, pitting, skin
seperation, etc. If damage is evident, dispose of as unsalvageable.

**2.** Tail rotor hub, dispose of as unsalvageable.

**3.** Remove and condem pitch change links, and crosshead bearings.

**4.** Inspect crosshead and control rod for any indications of aging.
Replace if necessary.

**5.** Remove 90 degree gearbox and return for overhaul.

**6.** Replace any magnetized tail rotor driveshaft hanger bearings.

**7.** Check disc assembly, blower assembly, splined adapter,
freewheeling assembly, main driveshaft and tail rotor driveshaft
couplings for residual magnetism. Replace as necessary.

**8.** Inspect oil cooler and oil cooler filter assembly for damage.
Replace as necessary.

**9.** If previous drive train items show magnetism, remove transmission
and return for overhaul.

**10.** If freewheeling assembly shows magnetism remove engine assembly
and return for overhaul.

**11.** Inspect engine mounts, support installation, pylon, and mount
installation, isolation pylon for damage. Replace if necessary.

**[Conditional Inspections (Engine)]{.underline}**

All Conditional Inspections (Engine) are to be performed in accordance
with the Allison publication 5W2 or 10W2. Refer to these publications
for instruction regarding the necessary actions required.

**7-13. SUSPECTED FOREIGN OBJECT DAMAGE**

**a.** Refer to Allison publication 5W2 or 10W2 for instruction
regarding foreign object damage inspection.

**7-14. AFTER ENGINE OVERTEMPERATURE OPERATION**

**a.** Refer to Allison publication 5W2 or 10W2 for instruction
regarding overtemperature operation inspection.

**7-15. AFTER ENGINE OVERSPEED OPERATION**

**a.** Refer to Allison publication 5W2 or 10W2 for instruction
regarding overspeed limits and maintenance actions.

**b.** Inspect transmission for obvious damage.

**7-16. ANY TIME ENGINE MAGNETIC CHIP LIGHT COMES ON**

**a.** Refer to Allison publication 5W2 or 10W2 for instruction
regarding the necessary actions required.

**7-17. IF ENGINE OIL TEMPERATURE EXCEEDS 107 DEGREES C WITH A CHANGE IN
NORMAL OIL PRESSURE**

**a.** Refer to Allison publication 5W2 or 10W2 for instruction
regarding the necessary actions required.

**7-18. AFTER** **EMERGENCY FUEL USAGE**

**a.** Emergency fuel usage is limited to an accumulation of 6 hours per
overhaul period. Refer to Allison publication 5W2 or 10W2 for

instruction regarding the necessary actions required.

**APPENDIX**

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

**Letter from Bell Textron**

**Ref: Overhaul and Retirement Schedule, Manuals, and Technical
assistance.**

***B**e**ll Helicopter*** Post Office Box 482

> A Textron Company Fort Worth, Texas 76101

Dear Bell Helicopter Excess/Surplus Aircraft Operators:

Bell Helicopter is aware of several situations in which many operators
need technical assistance in maintaining their OH-58A/C Helicopters.
When the helicopters are surplused by the Defense Logistics Agency
(DLA), many operators do not receive the appropriate Technical Manuals
to maintain their helicopters.

The military Technical Manuals (TM\'s) required to maintain the OH-58A/C
are:

TM 55-1520-228-23P PARTS MANUAL

TM 55-1520-228-10 OPERATORS MANUAL

TM 55-1520-228-23-1/-2 MAINTENANCE MANUAL

TM 55-1520-228-CL CHECKLIST, OPERATOR

TM 55-1520-228-PMD PREVENTIVE MAINTENANCE DAILY

TM 55-1520-228-PM PHASE MAINTENANCE

These are not Bell Helicopter manuals, Bell Helicopter doesn\'t
maintain, update or distribute these manuals. These manuals are
available for purchase at:

NTIS- National Technical Information Service

Military Publications Department

5285 Port Royal Road

Springfield, V A 22161

[PHONE]{.underline}: 703-605-6000

800-553-6847

FAX: 703-605-6900

Email <ORDERS@NTIS.GOV>

In order to assist operators operating in the Public Use, Bell
Helicopter has developed and recommends the Overhaul and Retirement
Schedule. Unfortunately Bell Helicopter cannot assist operators in Type
Certified Restricted Category. These operators are obligated to maintain
their aircraft in accordance with the Type Certificate Holder
requirements.

The rationale behind Bell Helicopter developing this recommended
Overhaul and Retirement Schedule is to remove the Gearboxes out of a
\"On-Condition\": Airworthy Limitation. In compliance with the TM\'s an
operator is required to take an oil analysis every 25 hours and submit
for a lab analysis. Bell Helicopter is aware that all operators are not
performing this maintenance task and therefore Bell Helicopter has
developed a recommend Overhaul/Retirement schedule, it\'s only provided
to assist Public Use operators.

Regards

/Andrew L. Kelley/

Product Support Engineer

4/18/2002

**OH-58A/C Retirement/Overhaul Schedule 4/18/2002**

**OVERHAUL RETIREMENT ITEM PART NUMBER**

**INTERVAL INTERVAL**

**(HOURS) (HOURS)**

> 24 Months PILOT AND CO-PILOT 602COO01-8
>
> SEAT COVERS

# MAIN ROTOR 

> 4800 Grip Assembly 206-010-102-009
>
> 4800 Grip Assembly 206-010-102-013
>
> 4800 Grip Assembly 206-010-102-121
>
> 400 Pin Strap Retainer 206-010-123-001
>
> 1200 Pin Strap Retainer 206-010-123-003
>
> 400 Fitting Assembly 206-010-155-007
>
> 1200 Fitting Assembly 206-010-155-015
>
> 1200 Fitting Assembly 206-011-140-001

1200 Hub Assembly 206-011-100-001

1200 Hub Assemb!y 206-011-100-005

1200 Hub Assembly 206-011-100-023

> Hub Assembly 206-011-100-131
>
> (Note 1)
>
> Hub Assembly 206-011-100-143
>
> (Note 1)
>
> 2400 Trunnion Assembly 206-011-113-001
>
> (Note2)
>
> 4800 Trunnion Assembly 206-011-113-103
>
> 1200/24 months Strap Assembly 206-011-147-001
>
> 1200/24 months Strap Assembly. 206-011-147-005
>
> 1200/24 months Strap Assembly 206-011-154-101
>
> 1200/24 months Strap Assembly. 206-011-154-105
>
> 3600 Blade Assembly 206-011-250-003
>
> (Note 3)
>
> 3600 Blade Assembly 206-011-250-113
>
> (Note 3)
>
> 3600 Blade Assembly 206-011-250-119

3000 Mast 206-040-003-007

> (OH-58A)

3000 Mast 206-040-003-025

> (OH-58C)

# 

# MAIN ROTOR CONTROLS 

> 4800 Control Tube 206-001-194-001
>
> 4800 Control Tube 206-001-194-005
>
> 4800 Collective Idler Link 206-010-407-001
>
> Assembly
>
> 4800 Swashplate and Support 206-010-450-005
>
> Assembly
>
> 4800 Swashplate and Support 206-010-450-007
>
> Assembly
>
> 4800 Swashplate and Support 206-010-450-009
>
> Assembly
>
> 4800 Support Swashplate 206-010-452-001
>
> Assembly
>
> 4800 Support Swashplate 206-010-452-005
>
> Assembly
>
> 4800 Support Swashplate 206-010-452-109
>
> Assembly
>
> 4800 Sleeve Swashplate 206-010-454-001
>
> Assembly
>
> 1

**OH-58A/C Retirement/Overhaul Schedule 4/18/2002**

**OVERHAUL RETIREMENT ITEM PART NUMBER**

**INTERVAL INTERVAL**

**(HOURS) (HOURS)**

# 

# 

# MAIN ROTOR CONTROLS (continued)

> 4800 Sleeve Swashplate 206-010-454-005
>
> Assembly

4800. Sleeve Swashplate 206-010-454-109

> Assembly
>
> 4800 Collective Lever 206-010-467-001
>
> Assembly

**MAIN ROTOR DRIVE \|**

2400 Main Transmission 206-040-003-005 \|

206-040-003-023 \|

**TAIL ROTOR DRIVE SYSTEM**

> ON CONDITION Blower Assembly Oil 206-061-432-001
>
> Cooler (OH-58 A)
>
> ON CONDITION Blower Assembly Oil 206-061-432-039
>
> Cooler (OH-58 C)
>
> 1200 Blade Assembly 206-010-750-005
>
> 900 Blade Assembly (Serial 206-010-750-005
>
> Numbers TLL8000 and
>
> below only)
>
> 1200 Blade Assembly 206-010-750-109
>
> 2400 Blade Assembly 206-016-201-111
>
> 2500 Blade Assembly 206-016-201-131
>
> (Note 4)
>
> 2400 Trunnion Assembly 206-011-803-005
>
> Unlimited Trunnion Assembly 206-011-812-005
>
> 4800 Yoke Assembly 206-011-819-101

2400 Gearbox Assembly 206-040-400-007

2400 Gearbox Assembly 206-040-400-009

2400 Gearbox Assembly 206-040-402-003

> 3000 Freewheeling Unit Clutch CL42250-1

3000 Freewheeling Unit 206-040-230-025

> 5000 Main Driveshaft 206-040-371-111
>
> Assembly (SKCP2348-5)

2

**Notes:**

All retirement components will have a Demil code of \"L\" and be
mutilated.

#1. The complete -131 and -143 Hub Assembly has no overhaul or
retirement interval. It

does contain retirement items listed on this schedule. For record
keeping purposes the -131 and -143 hub assembly will be treated as a
time change component. Hub Assemblies will be recorded on the aircraft
time change DA Form 2408-16, with the lowest retirement life components
as the driver for time change requirements.

#2. Main Rotor Hub Assemblies PIN 206-011-100-131 or earlier may contain
the 206-011- 113-001 or -103 Trunnion. The 206-011-100-143 Hub Assembly
should only have the -103 Trunnion. Replacement of Main Rotor Trunnion
PIN 206-011-113-001 has been controlled at overhaul of the Main Rotor
Hub. When operating time of the -001 Trunnion is unknown due to no
records, field units may replace the Trunnion on PIN 206-011-100-131
Hubs at 1200 hours since last Main Rotor Hub overhaul. The PIN
206-011-100-023 or earlier Hubs may be operated to next scheduled Main
Rotor overhaul. When part number or serial number of the installed
Trunnion cannot be determined, the unit may be operated to next required
special (magnetic particle) Trunnion inspection.

#3. Reference BHT Technical Bulletin SU-OH-2. Main Rotor Blade PIN
206-011-250-0031- 113, Increase in Retirement Life. This bulletin is not
applicable to Type Certified Helicopters.

#4. Reference BHT Technical Bulletin SU-OH-01, Alternate Spare Part;
Tail Rotor Blade Assembly, PIN 206-016-201-131. This bulletin is not
applicable to Type Certified Helicopters.

#5. Applies to any engine having the Letter B as part of the suffix.

3