[Federal Register Volume 62, Number 52 (Tuesday, March 18, 1997)]
[Proposed Rules]
[Pages 12771-12774]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-6716]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-CE-53-AD]
RIN 2120-AA64


Airworthiness Directives; Jetstream Aircraft Limited HP137 Mk1, 
Jetstream Series 200, and Jetstream Model 3101 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to supersede Airworthiness Directive 
(AD) 82-20-04 R1, which currently requires repetitively inspecting the 
main landing gear (MLG) hinge fitting, support angles, and attachment 
bolts on British Aerospace (currently known as Jetstream Aircraft 
Limited (JAL)) HP137 Mk1 and Jetstream series 200 airplanes, and 
repairing or replacing any part that is cracked beyond certain limits. 
The Federal Aviation Administration's policy on aging commuter-class 
aircraft is to eliminate or, in certain instances, reduce the number of 
certain repetitive short-interval inspections when improved parts or 
modifications are available. The proposed action would require 
installing improved design MLG fittings, as terminating action for the 
repetitive inspections that are currently required by AD 82-20-04 R1, 
and would incorporate the Jetstream Model 3101 airplanes into the 
Applicability of the AD. The actions specified in the proposed AD are 
intended to prevent structural failure of the MLG caused by fatigue 
cracking, which could result in loss of control of the airplane during 
landing operations.

DATES: Comments must be received on or before June 6, 1997.

ADDRESSES: Submit comments in triplicate to the FAA, Central Region, 
Office of the Assistant Chief Counsel, Attention: Rules Docket No. 95-
CE-53-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106. 
Comments may be inspected at this location between 8 a.m. and 4 p.m., 
Monday through Friday, holidays excepted.
    Service information that applies to the proposed AD may be obtained 
from Jetstream Aircraft Limited, Prestwick International Airport, 
Ayrshire, KA9 2RW, Scotland; telephone (44-292) 79888; facsimile (44-
292) 79703; or Jetstream Aircraft Inc., Librarian, P.O. Box 16029, 
Dulles International Airport, Washington, D.C. 20041-6029; telephone 
(703) 406-1161; facsimile (703) 406-1469. This information also may be 
examined at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. Tom Rodriguez, Program Manager, 
Brussels Aircraft Certification Division, FAA, Europe, Africa, and 
Middle East Office, c/o American Embassy, B-1000 Brussels, Belgium; 
telephone (32 2) 508.2715; facsimile (32 2) 230.6899; or Mr. S.M. 
Nagarajan, Project Officer, Small Airplane Directorate, Aircraft 
Certification Service, FAA, 1201 Walnut, suite 900, Kansas City, 
Missouri 64106; telephone (816) 426-6932; facsimile (816) 426-2169.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications should identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report that summarizes each FAA-public contact concerned 
with the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket No. 95-CE-53-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Central Region, Office of the Assistant Chief Counsel, 
Attention: Rules Docket No. 95-CE-53-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Discussion

    The FAA has determined that reliance on critical repetitive 
inspections on aging commuter-class airplanes carries an unnecessary 
safety risk when a design change exists that could eliminate or, in 
certain instances, reduce the number of those critical inspections. In 
determining what inspections are critical, the FAA considers (1) the 
safety consequences if the known problem is not detected during the 
inspection; (2) the probability of the problem not being detected 
during the inspection; (3) whether the inspection area is difficult to 
access; and (4) the possibility of damage to an adjacent structure as a 
result of the problem.
    These factors have led the FAA to establish an aging commuter-class 
aircraft policy that requires incorporating a known design change when 
it could replace a critical repetitive inspection. With this policy in 
mind, the FAA conducted a review of existing AD's that apply to JAL 
HP137 Mk1, Jetstream series 200, and Jetstream Models 3101 airplanes. 
Assisting the FAA in this review were (1) Jetstream Aircraft Limited 
(JAL); (2) the Regional Airlines Association (RAA); (3) the Civil 
Aviation Authority

[[Page 12772]]

(CAA) for the United Kingdom; and (4) several operators of the affected 
airplanes.
    From this review, the FAA identified AD 82-20-04 R1, Amendment 39-
4586, as one to which the FAA's aging aircraft policy applies, and 
which should be superseded with a new AD that would require a 
modification that would eliminate the need for short-interval and 
critical repetitive inspections. AD 82-20-04 R1 currently requires 
repetitively inspecting the main landing gear (MLG) hinge fitting, 
support angles, and attachment bolts on British Aerospace (currently 
known as JAL) HP137 Mk1 and Jetstream series 200 airplanes, and 
repairing or replacing any part that is cracked beyond certain limits.

Relevant Service Information

    The following service information is relevant to this subject:

--British Aerospace Jetstream Mandatory Service Bulletin (MSB) No. 7/5, 
which includes procedures for inspecting the left main landing gear 
hinge attachment nuts to the auxiliary and aft spars for signs of 
relevant movement between the nuts and hinge fitting on HP137 Mk1 and 
Jetstream series 200 airplanes. This MSB incorporates the following 
effective pages:

------------------------------------------------------------------------
             Pages                Revision level            Date        
------------------------------------------------------------------------
2 and 4.......................  Original Issue...  March 31, 1982.      
1 and 3.......................  Revision 1.......  May 23, 1988.        
------------------------------------------------------------------------

--British Aerospace MSB No. 7/8, which includes procedures for 
inspecting the MLG hinge fitting for cracks, and repairing cracked 
hinge fittings on HP137 Mk1 and Jetstream series 200 airplanes. This 
MSB incorporates the following effective pages:

------------------------------------------------------------------------
             Pages                Revision level            Date        
------------------------------------------------------------------------
2, 5, 6, 7, and 8.............  Revision 2.......  January 6, 1983.     
1, 3, and 4...................  Revision 3.......  May 23, 1988.        
------------------------------------------------------------------------

--Jetstream Alert Service Bulletin (ASB) 32-A-JA 850127, which includes 
procedures for inspecting the MLG hinge fitting and support angle for 
cracks on Jetstream Model 3101 airplanes. This ASB incorporates the 
following effective pages:

------------------------------------------------------------------------
             Pages                Revision level            Date        
------------------------------------------------------------------------
5 through 14..................  Original Issue...  April 17, 1985.      
1 through 4...................  Revision 2.......  November 11, 1994.   
------------------------------------------------------------------------

--Jetstream Service Bulletin (SB) 57-JM 5218, which includes procedures 
for installing improved design MLG fittings, part number (P/N) 
1379133B1 and 1379133B2 (Modification 5218) on HP137 Mk1, Jetstream 
series 200, and certain Jetstream Model 3101 airplanes. This SB 
incorporates the following effective pages:

------------------------------------------------------------------------
             Pages                Revision level            Date        
------------------------------------------------------------------------
3, 5, 6, 7, 8, 9, 11, 12, 17,   Revision 1.......  September 29, 1987.  
 18, 19, 21, 22, 23, 24, 27,                                            
 28, 29, 30, and 31.                                                    
25 and 26.....................  Revision 2.......  August 24, 1988.     
10 and 20.....................  Revision 3.......  January 29, 1990.    
1, 2, 4, 13, 14, 15, and 16...  Revision 4.......  October 31, 1990.    
------------------------------------------------------------------------

The FAA's Determination

    Based on its aging commuter-class aircraft policy and after 
reviewing all available information, including the referenced service 
information, the FAA has determined that AD action should be taken to 
(1) require the incorporation of Modification 5218 on the affected 
airplanes, as terminating action for the repetitive short-interval 
inspections required by AD 82-20-04 R1; and (2) prevent structural 
failure of the MLG caused by fatigue cracking, which could result in 
loss of control of the airplane during landing operations.

Explanation of the Provisions of the Proposed AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other JAL HP137 Mk1, Jetstream series 200, and 
Jetstream Model 3101 airplanes of the same type design, the FAA is 
proposing to supersede AD 82-20-04 R1 with a new AD. The proposed AD 
would (1) retain the requirement of repetitively inspecting the MLG 
hinge fitting, support angles, and attachment bolts, and repairing or 
replacing any part that is cracked; (2) incorporate the Jetstream Model 
3101 airplanes into the Applicability of the AD; and (3) require the 
installation of improved design MLG fittings, part number (P/N) 
1379133B1 and 1379133B2 (Modification 5218), as terminating action for 
the repetitive inspections. Accomplishment of the proposed actions 
would be in accordance with the service bulletins referenced 
previously.

Differences Between the Proposed AD, CAA for the United Kingdom AD, and 
Existing AD 82-20-04 R1

    AD 82-20-04 R1 allows continued flight if cracks are found in the 
MLG hinge fitting support angles that propagate no further than the 
tooling holes. The applicable service bulletin specifies replacement of 
the support angles only if cracks are found exceeding this limit, as 
does CAA AD 015-05-85. The proposed AD, if adopted, would not allow 
continued flight if any crack is found. FAA policy is to disallow 
airplane operation when known cracks exist in primary structure, unless 
the ability to sustain ultimate load with these cracks is proven. The 
main landing gear is considered primary structure, and the FAA has not 
received any analysis to prove that ultimate load can be sustained with 
cracks in this area.

Cost Impact

    The FAA estimates that 71 airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 271 
workhours (inspections: 61 workhours; installation: 210 workhours) per 
airplane to accomplish the proposed actions, and that the average labor 
rate is approximately $60 an hour. Parts to accomplish the proposed AD 
are provided by the manufacturer at no cost to the owners/operators of 
the affected airplanes. Based on these figures, the total cost impact 
of the proposed AD on U.S. operators is estimated to be $1,154,460 or 
$16,260 per airplane. This figure only takes into account the cost of 
the initial inspections and inspection-terminating modification and 
does not take into account the cost of repetitive inspections. The FAA 
has no way of determining the number of repetitive inspections each 
HP137 Mk1, Jetstream series 200, and Jetstream Model 3101 airplane 
owner/operator would incur.
    This figure is also based on the presumption that no affected 
airplane operator has accomplished the proposed installation. This 
action would eliminate the repetitive inspections required by AD 82-20-
04 R1. The FAA has no way of determining the operation levels of each 
individual owner/operator of the affected airplanes, and subsequently 
cannot determine the repetitive inspection costs that would be 
eliminated by the proposed action. The

[[Page 12773]]

FAA estimates these costs to be substantial over the long term.
    In addition, JAL has informed the FAA that parts have been 
distributed to owners/operators that would equip approximately 39 of 
the affected airplanes. Presuming that each set of parts has been 
installed on an affected airplane, the cost impact of the proposed 
modification upon the public would be reduced $634,140 from $1,154,460 
to $520,320.

Regulatory Flexibility Determination and Analysis

    The Regulatory Flexibility Act of 1980 (RFA) was enacted by 
Congress to ensure that small entities are not unnecessarily or 
disproportionally burdened by government regulations. The RFA requires 
government agencies to determine whether rules would have a 
``significant economic impact on a substantial number of small 
entities,'' and, in cases where they would, conduct a Regulatory 
Flexibility Analysis in which alternatives to the rule are considered. 
FAA Order 2100.14A, Regulatory Flexibility Criteria and Guidance, 
outlines FAA procedures and criteria for complying with the RFA. Small 
entities are defined as small businesses and small not-for-profit 
organizations that are independently owned and operated or airports 
operated by small governmental jurisdictions. A ``substantial number'' 
is defined as a number that is not less than 11 and that is more than 
one-third of the small entities subject to a proposed rule, or any 
number of small entities judged to be substantial by the rulemaking 
official. A ``significant economic impact'' is defined by an annualized 
net compliance cost, adjusted for inflation, which is greater than a 
threshold cost level for defined entity types.
    FAA Order 2100.14A, Regulatory Flexibility Criteria and Guidance, 
defines a small entity as ``a small business or small not-for-profit 
organization which is independently-owned and operated and has no more 
than a specified number of employees or aircraft.'' For operators of 
aircraft for hire (those entities that are affected by 14 CFR parts 
121, 127, and 135), the size threshold specified in FAA Order 2100.14A 
is nine aircraft.
    There are only nine different operators of JAL HP137 Mk1, Jetstream 
series 200, and Jetstream Model 3101 airplanes. Of these nine, only 
four operate less than nine airplanes. Because four is a number that is 
less than 11 and the rulemaking official has not determined this number 
to be substantial, the proposed AD would not significantly affect a 
number of small entities.
    A copy of the full Cost Analysis and Regulatory Flexibility 
Determination for the proposed action may be examined at the FAA, 
Central Region, Office of the Assistant Chief Counsel, Attention: Rules 
Docket No. 95-CE-53-AD, Room 1558, 601 E. 12th Street, Kansas City, 
Missouri.

Regulatory Impact

    The regulations proposed herein would not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) Is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 
will not have a significant economic impact, positive or negative, on a 
substantial number of small entities under the criteria of the 
Regulatory Flexibility Act. A copy of the draft regulatory evaluation 
prepared for this action has been placed in the Rules Docket. A copy of 
it may be obtained by contacting the Rules Docket at the location 
provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Airworthiness Directive 
(AD) 82-20-04 R1, Amendment 39-4468, and adding a new AD to read as 
follows:

Jetstream Aircraft Limited: Docket No. 95-CE-53-AD. Supersedes 82-
20-04 R1, Amendment 39-4468.

    Applicability: The following model and serial number airplanes, 
certificated in any category, that do not have improved design MLG 
fittings, part number (P/N) 1379133B1 and 1379133B2 (Modification 
5218), installed in accordance with Jetstream Service Bulletin (SB) 
57-JM 5218:

------------------------------------------------------------------------
                Model                             Serial Nos.           
------------------------------------------------------------------------
HP137 Mk1...........................  All serial numbers.               
Jetstream Series 200................  All serial numbers.               
Jetstream 3101......................  601 through 695.                  
------------------------------------------------------------------------

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (f) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated after the effective date of 
this AD, unless already accomplished.
    To prevent structural failure of the MLG caused by fatigue 
cracking, which could result in loss of control of the airplane 
during landing operations, accomplish the following:

    Note 2: The compliance times of this AD are presented in 
landings. If the total number of airplane landings is not kept or is 
unknown, hours time-in-service (TIS) may be used by multiplying the 
total number of airplane hours TIS by 0.75.

    (a) For the HP137 Mk1 and Jetstream series 200 airplanes, within 
the next 50 landings after the effective date of this AD or within 
200 landings after the last inspection required by AD 82-20-04 R1 
(superseded by this AD), whichever occurs first, and thereafter at 
intervals not to exceed 200 landings, accomplish the following in 
accordance with British Aerospace Mandatory Service Bulletin (MSB) 
No. 7/5, which incorporates the following pages:

------------------------------------------------------------------------
             Pages                Revision level            Date        
------------------------------------------------------------------------
2 and 4.......................  Original Issue...  March 31, 1982.      
1 and 3.......................  Revision 1.......  May 23, 1988.        
------------------------------------------------------------------------

    (1) Inspect the MLG hinge attachment nuts to auxiliary and aft 
spars on both the left and right MLG for signs of fuel leakage or 
signs of relative movement between the nuts and hinge fitting.

[[Page 12774]]

    (2) If any signs of fuel leakage or relative movement between 
the nuts and hinge fitting are found, prior to further flight, 
resecure the MLG hinge fitting to auxiliary spar in accordance with 
actions 3.8 through 3.15 of British Aerospace MSB No. 7/5.
    (b) Upon accumulating 4,000 landings or within the next 50 
landings after the effective date of this AD, whichever occurs 
later, and thereafter at intervals not to exceed 400 landings, 
inspect the MLG hinge support angles for cracks in accordance with 
the following, as applicable:
    (1) For the HP137 Mk1 and Jetstream series 200 airplanes: 
British Aerospace MSB 7/8, which incorporates the following 
effective pages:

------------------------------------------------------------------------
             Pages                Revision level            Date        
------------------------------------------------------------------------
2, 5, 6, 7, and 8.............  Revision 2.......  January 6, 1983.     
1, 3, and 4...................  Revision 3.......  May 23, 1988.        
------------------------------------------------------------------------

    (2) For the Jetstream Model 3101 airplanes: Jetstream Alert 
Service Bulletin (ASB) 32-A-JA 850127, which incorporates the 
following effective pages:

------------------------------------------------------------------------
             Pages                Revision level            Date        
------------------------------------------------------------------------
5 through 14..................  Original Issue...  April 17, 1985.      
1 through 4...................  Revision 2.......  November 11, 1994.   
------------------------------------------------------------------------

    (c) Install improved design MLG fittings, part number (P/N) 
1379133B1 and 1379133B2 (Modification 5218). Perform this 
installation at the compliance time (presented in paragraphs (c)(1) 
and (c)(2) of this AD) which occurs first. Accomplish this 
installation in accordance with Jetstream Service Bulletin (SB) 57-
JM 5218, which incorporates the following effective pages:

------------------------------------------------------------------------
             Pages                Revision level            Date        
------------------------------------------------------------------------
3, 5, 6, 7, 8, 9, 11, 12, 17,   Revision 1.......  September 29, 1987.  
 18, 19, 21, 22, 23, 24, 27,                                            
 28, 29, 30, and 31.                                                    
25 and 26.....................  Revision 2.......  August 24, 1988.     
10 and 20.....................  Revision 3.......  January 29, 1990.    
1, 2, 4, 13, 14, 15, and 16...  Revision 4.......  October 31, 1990.    
------------------------------------------------------------------------

    (1) Prior to further flight after finding any crack during an 
inspection required by paragraph (b) of this AD; or
    (2) Upon accumulating 20,000 landings or within the next 50 
landings after the effective date of this AD (whichever occurs 
later).
    (d) Incorporating Modification 5218 as required by paragraph (c) 
of this AD terminates the repetitive inspection requirement of this 
AD (paragraphs (a) and (b) of this AD).
    (e) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.
    (f) An alternative method of compliance or adjustment of the 
initial or repetitive compliance times that provides an equivalent 
level of safety may be approved by the Manager, Brussels Aircraft 
Certification Division, Europe, Africa, Middle East office, FAA, c/o 
American Embassy, 1000 Brussels, Belgium. The request should be 
forwarded through an appropriate FAA Maintenance Inspector, who may 
add comments and then send it to the Manager, Brussels Aircraft 
Certification Division. Alternative methods of compliance approved 
in accordance with AD 82-20-04 R1 (superseded by this action) are 
not considered approved as alternative methods of compliance with 
this AD.
    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Brussels Aircraft Certification Division.
    (g) All persons affected by this directive may obtain copies of 
the document referred to herein upon request to Jetstream Aircraft 
Limited, Manager Product Support, Prestwick Airport, Ayrshire, KA9 
2RW Scotland; or Jetstream Aircraft Inc., Librarian, P.O. Box 16029, 
Dulles International Airport, Washington, DC; or may examine this 
document at the FAA, Central Region, Office of the Assistant Chief 
Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.
    (h) This amendment supersedes AD 82-20-04 R1, Amendment 39-4468.

    Issued in Kansas City, Missouri, on March 10, 1997.
Michael Gallagher,
Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 97-6716 Filed 3-17-97; 8:45 am]
BILLING CODE 4910-13-U