Docket No: LEAVE BLANK

Directorate ID:

AD PROPOSAL WORKSHEET

This AD Worksheet contains some questions that are applicable to proposed ADs that are related to ADs 

issued by foreign airworthiness authorities. Those questions are noted with a . For ADs concerning 

domestic (U.S.-manufactured) products, you are not required to answer those questions.

PROPOSED ACTION: [Place an X on the appropriate line.]

Emergency AD Is this action one of the following?

Final Rule; Request for Comments AD Supersedure (Docket No. )

X Notice of Proposed Rulemaking AD Revision (Docket No. )

Other Supplemental NPRM (Docket No. )

1. Applicability (Make/Model/Component/Part or Serial Number).

Click here to do a search for the correct make/model designation. 

All EC135 Models on TCDS, Specifically: EC135 P1, EC135 T1, EC135 P2, EC135 T2, EC135 P2+, EC135 T2+

2. Responsible Engineer:

Name/Branch (Office)/Title: Joseph R. Holton, Jr., ASW-112, Aviation Safety Engineer

Telephone: 817-222-4964

Fax: 817-222-5961

3. Directorate Project Officer:

Name/Title/Branch: Chinh Vuong, Aviation Safety Engineer, ASW-112

4. What is the unsafe condition AND its cause? (What is the end-level effect on the helicopter if the unsafe 

condition is not detected/corrected?)

The control of the tail rotor system is impaired by the binding of a bearing in the linear transducer linkage plate and

the abrasion of the under side of the helicopter floor by a screw in the linear transducer linkage rod.

5. What prompted this AD; i.e., an accident, incident, analysis, report?

EUROCOPTER DEUTSCHLAND GmbH (ECD) was informed of an incident in which an impaired controllability of the 

tail rotor was detected. Examinations have shown that the bearing of the linear transducer was subject to binding and 

the control range was limited.
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6. If this action relates to a non-U.S. product (foreign manufacturer), has the foreign airworthiness authority 

issued an AD concerning the same unsafe condition? If not, explain why we are issuing a unilateral AD. 

If yes, provide the following information and attach a copy of the foreign airworthiness authority’s AD:

Foreign Authority: EASA

AD Number: 2006-0318 R1

Date of issuance: 27 October 2006, Revision 1

7. What are the differences between the manufacturer's service information, other ADs (foreign or U.S.), and 

the requirements of this AD? State all the differences between our AD and other ADs or service 

information and the reasons for each difference, such as why we are requiring a different compliance 

time, or state that we do not require returning the part to the manufacturers for repair. 

This AD differs from the MCAI and/or service information as follows:

(1) EASA AD 2006-0318 R1, Revision 1, dated 27 October 2006, specifies that the initial inspection of the 

affected bearing take place no later than October 31, 2006 (Compliance Paragraph (1)). This AD requires 

that this inspection take place within 45 days from the effective date of this AD.

(2) EASA AD 2006-0318 R1, Revision 1, dated 27 October 2006, Compliance Paragraph (5), states that 

certain modifications will be made to parts held as spares. This AD will not include instructions to modify 

or inspect spare parts.

(3) EASA AD 2006-0318 R1, Revision 1, dated 27 October 2006, Compliance Paragraph (2) specifies that 

certain repairs be made according to ECD Alert Service Bulletin (ASB) EC135-67A-12, dated 2006-09-01, 

Revision 01. In describing these repairs the ASB in Paragraph 3.D says to “contact ECD customer support” 

if a certain damage area is exceeded. This AD will instead say to repair the component with an airworthy 

unit if the damage limit is exceeded.

8. What are your proposed corrective actions? Complete the following table.

SERVICE 

INFORMATION 

REFERENCED

(Attach a clean 

original.)

WHAT ACTION IS 

REQUIRED? 

(List specific 

action or ASB 

paragraph.)

WHAT IS THE 

INITIAL 

COMPLIANCE 

TIME FOR THE 

ACTION?

IF ACTION IS

REPEATED? 

At WHAT 

INTERVAL?

IS THIS ACTION 

TERMINATING 

ACTION? IF SO, 

FOR WHAT?

Yes – See ECD ASB 

EC135-67A-012, dated 

2006-10-18, Revision 01. 

See the O:\AD and 

Docket Information\2010-

SW-07-AD folder for the 

ASB.

Initial inspection 45 

days after effective 

date of AD. 

Replacement of 

bearing, repair of 

floor, one-time 

modification of rod.

45 days. Inspection of 

bearing at 800 

inspection cycle 

time (i.e. 

coincides with a 

800 periodical 

inspection in the 

ECD MSM)

No. Inspections 

continue at 800 hour 

intervals and parts are 

replaced/repaired as 

described in the ASB.
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9. If this AD is considered interim action, is the manufacturer developing terminating action? What is the 

source of your information? Provide any details such as description of the terminating action, 

manufacturer’s projected release date, etc.

This is not an interim action. The AD and ASB have not been revised in over 3 years. There is no terminating action. 

There is an initial inspection and then a periodical 800 hour inspection that coincides with the ECD MSM.

10. If there is a reporting requirement in this AD, what office should receive the response? (Normally, this 

will be the same as the office submitting this AD Worksheet.) Provide name and contact information 

(address, telephone, fax) of the FAA employee responsible for receiving the reports.

There is no reporting requirement, but questions are to be directed to:

Name/Branch (Office)/Title: Joseph R. Holton, Jr., ASW-112, Aviation Safety Engineer

Telephone: 817-222-4964

Fax: 817-222-5961

11. If this action is related to an NTSB safety recommendation, attach a copy of that recommendation and 

the FAA response.

No NTSB safety recommendation is related to this AD.

12. If replacement parts are required, are they available for all aircraft? Indicate your source for obtaining 

this information (name, organization, phone number).

Replacement kits and bearings are available from American Eurocopter located in Grand Prairie, Texas. I contacted 

Mr. Dave Vogel (phone 972-641-3573) at American Eurocopter on March 12, 2010 to gather this information.

15. Number of helicopters/products that will be affected? (Use numerical figures.)

Click here to do a search on the number of aircraft.

All EC135 Models = 214

16. For the economic analysis, answer the following questions. Be as specific as possible.

a. How many hours will it take to perform each action? List each required action separately (for example, 

give total hours for an inspection, then total hours for a modification, etc). Also state how long it will take 

to make changes to limitation sections, etc.

The worst case is approximately 13 hours for the modification of the LVDT rod and floor and the replacement of the 

bearing. If the bearing does not require replacement, the modification of the LVDT rod and floor will take 

approximately 10 hours. Follow on 800 hour periodic inspections will take approximately 10 hours.

b. What is the total cost for each replacement part required for this AD? 

The cost of the bearing is approximately $35 (USD). The cost of the replacement kit (minus the bearing) is $15 

(USD). Total cost, if replacing the bearing is required, is then approximately $50 (USD).
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c. Has the manufacturer given any warranty considerations? If yes, where is that information stated? Will 

the warranty cover costs for parts, labor, or both? Provide detailed, total costs, required in Questions 16a 

and 16b, even if the manufacturer is offering some type of warranty.

There are no warranty considerations.

d. What is the cost of terminating action, if any? Include the number of hours to accomplish the AD 

requirements; cost of parts; etc.).

The initial inspection and the follow-on 800 hour periodic inspections will take approximately 10 hours. Worst case 

labor costs are approximately 13 hours if the LVDT rod and floor require modifications are needed and the bearing 

must be replaced. The worst case labor costs are then: 13 hours x $85/hour = $1,105.00. The worst case parts cost 

(i.e. if modification of the LVDT rod and floor is required and replacement of the bearing is indicated) is $50.

After the initial inspection, follow-on inspections will take place at regularly scheduled 800 flight hour intervals as 

called out in the ECD MSM. These 800 hour inspections would likely not take place more than once per year.

The estimated yearly cost per helicopter would then be: $1,105.00 (labor) + $50 (parts) = $1,155.00

Fleet cost would then be: $1,155.00 x 214 helicopters = $247,170.00

This estimate is worst case as it assumes all 214 helicopters will require all modifications and repairs and it does not 

take into account that there will already be 800 hour periodic maintenance taking place in the area concurrently, i.e. 

the area will be opened up and being looked for other regularly occurring maintenance.

e. Does this AD require a one-time inspection or repetitive inspections? If repetitive, how many inspections 

do you anticipate per year? (If the inspections are based on hours TIS, assume 200 hours per year for 

Part 91 operators and 600 hours per year for commercial operators (133, 135, 137). State how many 

inspections you assume they will need to conduct per year, and provide any information that supports 

your assumption

This AD calls for a one-time inspection and then 800 hour follow-on inspections that coincide with regularly 

scheduled maintenance in the ECD MSM.

f. What rationale or assumptions were used for determining the cost impact? For example, if you’re 

proposing a modification to a possible unairworthy part, how many aircraft are you assuming will need 

the modification? How did you determine the number of aircraft that will require the modification—what 

information or data did you use to make the assumption?

Action Time to 

Accomplis

h (Hours)

Labor 

Rate

Parts 

Cost

Cost per 

Aircraft

Affected 

fleet size

Fleet Cost 

Inspect bearing for binding and 

rough running but only modify rod 

and floor.

10 $85.00 $15.00 

(kit 

only)

$865.00 214*

(assume 

100% of 

fleet)

$185,110.00

Inspect bearing for binding or 

rough running. Modify the rod and 

floor if needed and replace bearing.

13 $85.00 $50.00 

(kit and 

bearing)

$1,155.00 214*

(assume 

100% of 

fleet)

$247,170.00

Follow-on 800 hour inspection, 

assuming no modifications or 

replacements (worst case once per 

year)

10 $85.00 0 $850.00 214*

(assume 

100% of 

fleet)

$181,900.00

(conservative –

can be combined

with 800 insp.)
5

17. Should a special flight permit be permitted?

 Permitted

___X__ Permitted with limitations (List the limitations.) One time flight permit permitted with only essential 

flight crew on board.

_____ Prohibited

18. If this is an Emergency AD, in general, how is the product utilized?

This is not an Emergency AD.

External Loads (Logging) Firefighting Other

Offshore Support Agriculture

Air Ambulance Airtaxi

19. Do you have reason to believe that this action would be considered "sensitive?” If yes, explain below.

Maybe, the owner/operator was very wealthy and connected politically to the Republican Party.

20. Indicate Yes or No to the following questions:

No Are other Directorates involved in any similar actions?

No Does this action affect the Presidential fleet? (i.e. not S-61)

Not likely Does this action affect the FAA fleet? (unless rented or leased)

No Have the proposed procedures been verified (i.e., by MIDO, AEG, FSDO)?

Not likely Does this AD affect intrastate aviation in Alaska?

No If so, are regulatory distinctions appropriate to accommodate the extent to which 

Alaska is not served by transportation modes other than aviation?

21. Check each category that describes the cause of the unsafe condition addressed by this AD:

X Design Problem X Maintenance

Unapproved Parts/Gas Other

X Quality Control Problem

22. If this is a QC problem, notify the MIDO. Indicate your point-of-contact, their phone number, and date 

of conversation, or include a copy of any email message regarding this action. List the enforcement status 

and EIR Number, if applicable.

I have coordinated this with Fort Worth AEG personnel. The ASB essentially make a design change to correct the 

issue.

23. JASC Code. State the Joint Aviation Safety Component code number and subject. 

 For example: “JASC Code: 7100: Powerplant System.”

JASC Code = 6720 Tail Rotor Control System
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Signature Section

Signature indicates concurrence with proposed action.

 J.R. Holton, Jr. March 15, 2010

Responsible Engineer Date

ACO Manager (not applicable if based on Date

foreign, or MCAI AD)

 Chinh Vuong March 15, 2010

Project Officer (EC135) Date

 March 15, 2010

AEG Representative (EC135) Date