Airworthiness Directives; McDonnell Douglas Model MD-11 Series Airplanes and Model DC-10-30, DC-10-40, and KC-10A (Military) Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 95-NM-39-AD]

Airworthiness Directives; McDonnell Douglas Model MD-11 Series

Airplanes and Model DC-10-30, DC-10-40, and KC-10A (Military) Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness

directive (AD) that is applicable to certain McDonnell Douglas Model

MD-11 series airplanes and Model DC-10-30, DC-10-40, and KC-10A

(military) airplanes. For Model MD-11 series airplanes, this proposal

would require an inspection to determine the serial number of the

forward trunnion bolts on the main landing gear (MLG), and rework or

replacement of the bolts, if necessary. For Model DC-10-30, DC-

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10-40, and KC-10A (military) airplanes, this proposal would require an

inspection for evidence of missing chrome and for corrosion on the

chrome surfaces, or verification that the forward trunnion bolts have

been chrome plated in a specific manner; and rework or replacement of

the bolts, if necessary. This proposal is prompted by reports of chrome

flaking on the bearing surface of the trunnion bolts due to improper

cleaning of the base material prior to chrome plating. The actions

specified by the proposed AD are intended to prevent premature failure

of the trunnion bolts and subsequent collapse of the MLG as a result of

severe corrosion on the bearing surface and in the mechanical fuse due

to chrome flaking.

DATES: Comments must be received by October 17, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-103,

Attention: Rules Docket No. 95-NM-39-AD, 1601 Lind Avenue, SW., Renton,

Washington 98055-4056. Comments may be inspected at this location

between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal

holidays.

The service information referenced in the proposed rule may be

obtained from McDonnell Douglas Corporation, P.O. Box 1771, Long Beach,

California 90801-1771, Attention: Business Unit Manager, Technical

Administrative Support, Dept. L51, M.C. 2-98. This information may be

examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue,

SW., Renton, Washington; or at the FAA, Transport Airplane Directorate,

Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard,

Lakewood, California.

FOR FURTHER INFORMATION CONTACT: Maureen Moreland, Aerospace Engineer,

Airframe Branch, ANM-120L, FAA, Transport Airplane Directorate, Los

Angeles Aircraft Certification Office, 3960 Paramount Boulevard,

Lakewood, California 90712; telephone (310) 627-5238; fax (310) 627-

5210.

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 shall 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 summarizing 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 Number 95-NM-39-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, Transport Airplane Directorate, ANM-103, Attention: Rules

Docket No. 95-NM-39-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion

The FAA has received reports of chrome flaking on the bearing

surface of the forward trunnion bolts installed on the main landing

gear (MLG) of McDonnell Douglas Model MD-11 series airplanes and Model

DC-10-30 and -40 airplanes. Such chrome flaking has resulted in severe

corrosion on the bearing surface and in the mechanical fuse. This

condition has been attributed to improper cleaning of the base material

prior to chrome plating. This condition, if not corrected, could result

in premature failure of the trunnion bolts and subsequent collapse of

the MLG.

The FAA has reviewed and approved McDonnell Douglas MD-11 Service

Bulletin 32-45, Revision 1, dated May 1, 1995, which describes

procedures for a visual inspection of Model MD-11 series airplanes to

determine the serial number of the forward trunnion bolts, part number

ARG7558-503 or ARG7558-505, on the right and left MLG's. The service

bulletin also provides procedures for rework or replacement of the

bolts with serviceable parts, if necessary. Accomplishment of the

rework or replacement will minimize the possibility of chrome flaking

on the forward trunnion bolts.

The FAA also has reviewed and approved McDonnell Douglas Service

Bulletin DC10-32-239, Revision 1, dated June 6, 1995, which describes

procedures for a visual inspection of Model DC-10-30, DC-10-40, and KC-

10A (military) airplanes for evidence of missing chrome and for

corrosion on the chrome surfaces of the trunnion bolts, or verification

that the forward trunnion bolts have been chrome plated in a specific

manner. The service bulletin also provides procedures for certain

rework or replacement of the bolts with serviceable parts, if

necessary.

Since an unsafe condition has been identified that is likely to

exist or develop on other products of this same type design, this

proposal would require the following:

For Model MD-11 series airplanes, this proposal would require an

inspection to determine the serial number of the forward trunnion

bolts, and rework or replacement of the bolts with serviceable parts,

if necessary. The actions would be required to be accomplished in

accordance with the MD-11 service bulletin described previously.

For Model DC-10-30, DC-10-40, and KC-10A (military) airplanes, this

proposal would require an inspection for evidence of missing chrome and

for corrosion on the chrome surfaces, or verification that the forward

trunnion bolts have been chrome plated in a specific manner; and rework

or replacement of the bolts with serviceable parts, if necessary. A

portion of the rework would be required to be accomplished in

accordance with the Component Maintenance Manual or a method approved

by the FAA. Other corrective actions would be required to be

accomplished in accordance with the DC-10 service bulletin described

previously.

As a result of recent communications with the Air Transport

Association (ATA) of America, the FAA has learned that, in general,

some operators may misunderstand the legal effect of AD's on airplanes

that are identified in the applicability provision of the AD, but that

have been altered or repaired in the area addressed by the AD. The FAA

points out that all airplanes identified in the applicability provision

of an AD are legally subject to the AD. If an airplane has been altered

or repaired in the affected area in such a way as to affect compliance

with the AD, the owner or operator is required to obtain FAA approval

for an alternative method of compliance with the AD, in accordance with

the paragraph of each AD that provides for such approvals. A note has

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been included in this notice to clarify this long-standing requirement.

There are approximately 414 Model MD-11 series airplanes and Model

DC-10-30, DC-10-40, and KC-10A (military) airplanes of the affected

design in the worldwide fleet. The FAA estimates that 196 airplanes of

U.S. registry would be affected by this proposed AD, that it would take

approximately 1 work hour per airplane to accomplish the proposed

actions, and that the average labor rate is $60 per work hour. Based on

these figures, the total cost impact of the proposed AD on U.S.

operators is estimated to be $11,760, or $60 per airplane.

The total cost impact figure discussed above is based on

assumptions that no operator has yet accomplished any of the proposed

requirements of this AD action, and that no operator would accomplish

those actions in the future if this AD were not adopted.

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 proposed

regulation (1) is not a ``significant regulatory action'' under

Executive Order 12866; (2) is not a ``significant rule'' under the 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 is contained 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), 40101, 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

McDonnell Douglas: Docket 95-NM-39-AD.

Applicability: Model MD-11 series airplanes, as listed in

McDonnell Douglas MD-11 Service Bulletin 32-45, Revision 1, dated

May 1, 1995; and Model DC-10-30, DC-10-40, and KC-10A (military)

airplanes, as listed in McDonnell Douglas DC-10 Service Bulletin

DC10-32-239, Revision 1, dated June 6, 1995; certificated in any

category.

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 use the authority

provided in paragraph (e) of this AD to request approval from the

FAA. This approval may address either no action, if the current

configuration eliminates the unsafe condition; or different actions

necessary to address the unsafe condition described in this AD. Such

a request should include an assessment of the effect of the changed

configuration on the unsafe condition addressed by this AD. In no

case does the presence of any modification, alteration, or repair

remove any airplane from the applicability of this AD.

Compliance: Required as indicated, unless accomplished

previously.

To prevent premature failure of the trunnion bolts and

subsequent collapse of the main landing gear (MLG), accomplish the

following:

(a) For Model MD-11 series airplanes: Within 18 months after the

effective date of this AD, perform a visual inspection to determine

the serial number of the forward trunnion bolts, part number

ARG7558-503 or ARG7558-505, on the right and left MLG's, in

accordance with McDonnell Douglas MD-11 Service Bulletin 32-45,

Revision 1, dated May 1, 1995.

(1) If the serial number of the trunnion bolt is STR0217,

STR0232, STR0237 through STR0242 inclusive, or STR0244 through

STR0284 inclusive; or if the trunnion bolt has been chrome plated in

accordance with the Component Maintenance Manual (CMM), Chapter 20-

10-02, Revision 31, dated September 1, 1991, since original

manufacture: No further action is required by this AD.

(2) For trunnion bolts other than those identified in paragraph

(a)(1) of this AD: Prior to further flight, remove the chrome

plating on the trunnion bolt, replace the plating, and reinstall the

reworked trunnion bolt; or replace the trunnion bolt with a

serviceable part; in accordance with McDonnell Douglas MD-11 Service

Bulletin 32-45, Revision 1, dated May 1, 1995.

(b) For Model MD-11 series airplanes: As of the effective date

of this AD, no person shall install a trunnion bolt having part

number ARG7558-503 or ARG7558-505 on the right or left MLG of any

airplane unless the bolt meets the condition specified in either

paragraph (b)(1), (b)(2), or (b)(3) of this AD.

(1) The trunnion bolt bears the serial number STR0217, STR0232,

STR0237 through STR0242 inclusive, or STR0244 through STR0284

inclusive; or

(2) The trunnion bolt has been chrome plated in accordance with

the CMM, Chapter 20-10-02, Revision 31, dated September 1, 1991,

since original manufacture; or

(3) The trunnion bolt has been reworked in accordance with

McDonnell Douglas MD-11 Service Bulletin 32-45, Revision 1, dated

May 1, 1995.

(c) For Model DC-10-30, DC-10-40, and KC-10A (military)

airplanes: Within 18 months after the effective date of this AD,

accomplish either paragraph (c)(1) or (c)(2) of this AD, as

applicable, in accordance with McDonnell Douglas DC-10 Service

Bulletin DC10-32-239, Revision 1, dated June 6, 1995.

(1) For airplanes on which the forward trunnion bolts, part

number (P/N) ARG7558-501, installed on the left and right MLG's,

have accumulated 6,000 or more total flight hours or 2,000 or more

total flight cycles as of the date of the inspection: Remove the

bolts and perform a visual inspection for evidence of missing chrome

and for corrosion on the chrome surfaces, in accordance with the

service bulletin.

(i) If no evidence of missing chrome and no corrosion on the

chrome surfaces are found, no further action is required by this AD.

(ii) If any evidence of missing chrome or any corrosion on the

chrome surfaces is found, prior to further flight, accomplish either

paragraph (c)(1)(ii)(A) or (c)(1)(ii)(B) of this AD.

(A) Remove the chrome plating on the trunnion bolt in accordance

with the service bulletin; replace the plating in accordance with

the CMM, Chapter 20-10-02, Revision 31, dated September 1, 1991, or

in accordance with a method approved by a McDonnell Douglas

Designated Engineering Representative (DER) who has been given a

special delegation by the Manager, Los Angeles Aircraft

Certification Office (ACO), FAA, Transport Airplane Directorate, to

make such a finding; and reinstall the reworked bolt in accordance

with the service bulletin. Or

(B) Replace the trunnion bolt with a serviceable part in

accordance with the service bulletin.

(2) For airplanes other than those identified in paragraph

(c)(1) of this AD: Verify whether the forward trunnion bolts, part

number (P/N) ARG7558-501, installed on the left and right MLG's,

have been chrome plated since original manufacture, in accordance

with the CMM, Chapter 20-10-02, Revision 31, dated September 1,

1991, or

[[Page 43420]]

in accordance with a method approved by a McDonnell Douglas DER who has

been given a special delegation by the Manager, Los Angeles ACO, to

make such a finding.

(i) If the bolts have been chrome plated since original

manufacture, in accordance with the CMM, Chapter 20-10-02, Revision

31, dated September 1, 1991, or in accordance with a method approved

by a McDonnell Douglas DER who has been given a special delegation

by the Manager, Los Angeles ACO, to make such a finding: No further

action is required by this AD.

(ii) If any bolt has not been chrome plated since original

manufacture, in accordance with the CMM, Chapter 20-10-02, Revision

31, dated September 1, 1991, or in accordance with a method approved

by a McDonnell Douglas DER who has been given a special delegation

by the Manager, Los Angeles ACO, to make such a finding: Prior to

further flight, accomplish the requirements of either paragraph

(c)(1)(ii)(A) or (c)(1)(ii)(B) of this AD in accordance with the

service bulletin.

(d) For Model DC-10-30, DC-10-40, and KC-10A (military)

airplanes: As of the effective date of this AD, no person shall

install a trunnion bolt, having part number ARG7558-501, on the

right or left MLG of any airplane unless the bolt meets the

condition specified in either paragraph (d)(1), (d)(2), (d)(3), or

(d)(4) of this AD.

(1) The trunnion bolt has been chrome plated in accordance with

the CMM, Chapter 20-10-02, Revision 31, dated September 1, 1991,

since original manufacture; or

(2) The trunnion bolt has been chrome plated in accordance with

a method approved by a McDonnell Douglas DER who has been given a

special delegation by the Manager, Los Angeles ACO, to make such

findings; or

(3) The bolt has been reworked in accordance with McDonnell

Douglas DC-10 Service Bulletin DC10-32-239, Revision 1, dated June

6, 1995; or

(4) The bolt has accumulated 6,000 or more total flight hours or

2,000 or more total flight cycles and has been visually inspected

for evidence of missing chrome and for corrosion on the chrome

surfaces, in accordance with McDonnell Douglas DC-10 Service

Bulletin DC10-32-239, Revision 1, dated June 6, 1995, and no

evidence of missing chrome or corrosion on the chrome surfaces was

found.

(e) An alternative method of compliance or adjustment of the

compliance time that provides an acceptable level of safety may be

used if approved by the Manager, Los Angeles ACO. Operators shall

submit their requests through an appropriate FAA Principal

Maintenance Inspector, who may add comments and then send it to the

Manager, Los Angeles ACO.

Note 2: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Los Angeles ACO.

(f) 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.

Issued in Renton, Washington, on August 15, 1995.

S.R. Miller,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 95-20631 Filed 8-18-95; 8:45 am]

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