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

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 94-NM-130-AD; Amendment 39-9020; AD 94-18-07]

Airworthiness Directives; McDonnell Douglas Model DC-10 and Model

MD-11 Series Airplanes and KC-10A (Military) Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment supersedes two existing airworthiness

directives (AD), applicable to all McDonnell Douglas Model DC-10 series

airplanes and KC-10A (military) airplanes and certain Model MD-11

series airplanes, that currently require inspections to determine the

serial numbers and to detect defects in the upper and lower lock links

on the nose landing gear (NLG), and rework or replacement of any

defective link with a serviceable link. This amendment requires

additional inspections and provides optional terminating action for

those inspections. This amendment is prompted by additional reports of

defects found on links that are required to be inspected by the

existing AD's. The actions specified in this AD are intended to prevent

collapse of the NLG.

DATES: Effective September 15, 1994.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of September 15, 1994.

Comments for inclusion in the Rules Docket must be received on or

before October 31, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

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

Attention: Rules Docket No. 94-NM-130-AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055-4056.

The service information referenced in this AD 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, 3229 East Spring Street, Long Beach,

California; or at the Office of the Federal Register, 800 North Capitol

Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: For Model DC-10 series airplanes and

Model KC-10A (military) airplanes: Maureen Moreland, Aerospace

Engineer, Airframe Branch, ANM-121L, FAA, Transport Airplane

Directorate, Los Angeles Aircraft Certification Office, 3229 East

Spring Street, Long Beach, California 90806-2425; telephone (310) 988-

5238; fax (310) 988-5210.

For Model MD-11 series airplanes: Wahib Mina, Aerospace Engineer,

Airframe Branch, ANM-121L, FAA, Transport Airplane Directorate, Los

Angeles Aircraft Certification Office, 3229 East Spring Street, Long

Beach, California 90806-2425; telephone (310) 988-5324; fax (310) 988-

5210.

SUPPLEMENTARY INFORMATION: In April 1994, the FAA issued AD 94-09-01,

amendment 39-8889 (59 FR 18722, April 20, 1994), applicable to

McDonnell Douglas Model MD-11 series airplanes, and AD 94-09-17,

amendment 39-8906 (59 FR 23144, May 5, 1994), applicable to McDonnell

Douglas Model DC-10 series airplanes and KC-10A (military) airplanes.

These AD's require inspections to determine the serial numbers and to

detect defects in the upper and lower lock links on the nose landing

gear (NLG), and rework or replacement of any defective link found. Both

actions were prompted by a report of cracking and subsequent failure of

an upper lock link on the center landing gear (CLG) on a McDonnell

Douglas Model MD-11 series airplane; the cracking and failure were

attributed to forging defects in the lock links.

The CLG lower lock links, NLG upper lock links, and NLG lower lock

links are similar in design to CLG upper lock links and are

manufactured by the same forging supplier; therefore, these lock links

may have the same forging defects. These lock links also may be

installed on Model DC-10 series airplanes and KC-10A (military)

airplanes. Consequently, AD 94-09-17 was issued to address the lock

links installed on Model DC-10 series airplanes and KC-10A (military)

airplanes.

Failure of the lock links on the CLG would result in collapse of

the CLG; collapse of the CLG does not present an unsafe condition.

Cracking and subsequent failure of the NLG lock links, if not

corrected, could result in collapse of the NLG, which could reduce

controllability of the airplane during takeoff or landing. The actions

required by AD 94-09-01 and AD 94-09-17 are intended to prevent

collapse of the NLG.

Since the issuance of those AD's, the FAA has received reports of

two additional defective lock links with three cracks that have been

attributed to forging defects. These defective lock links were found on

the NLG's on Model DC-10 and MD-11 series airplanes during

accomplishment of the inspections required by the existing AD's.

Subsequently, the FAA has determined that defects in the lock links may

exist as a result of improperly accomplished fluorescent penetrant

inspections of the entire lock link during manufacturing. After

manufacture of a lock link, its material is etched and a fluorescent

penetrant inspection is performed to detect forging defects. The

fluorescent penetrant inspections accomplished on the affected lock

links were performed without accomplishment of the etching process.

Forging defects in these lock links could result in eventual failure of

the lock link and subsequent collapse of the NLG.

The FAA has reviewed and approved McDonnell Douglas DC-10 Alert

Service Bulletin A32-238 and MD-11 Alert Service Bulletin A32-47, both

dated July 15, 1994, that describe procedures for visual inspections to

determine the serial numbers of the upper and lower lock links on the

NLG. The alert service bulletins also describe three phases of

inspections:

1. Phase I inspections involve an on-aircraft eddy current

inspection to detect defects in the upper and lower lock links on the

NLG. These inspections are designed to detect particular defects in

areas of the highest probability of forging flaws.

2. Phase II inspections entail expanded off-aircraft eddy current

inspections to detect defects of the upper and lower lock links on the

NLG. These inspections are more extensive than Phase I inspections and

are designed to detect defects in an expanded area where flaws could

exist.

3. Phase III inspections include an off-aircraft fluorescent

penetrant inspection to detect defects in the upper and lower lock

links on the NLG. These inspections include etching of the link

material prior to accomplishing a fluorescent penetrant inspection.

Accomplishment of Phase III inspections will ensure that all forging

defects are detected.

For NLG's on which a defective lock link is found, the alert

service bulletins describe procedures for rework of the defective lock

link, or replacement of the defective lock link with a serviceable lock

link. Accomplishment of the fluorescent penetrant inspection and rework

of any defective lock link found during that inspection, or replacement

of any defective lock link found during that inspection, eliminates the

need for the eddy current inspections specified in the alert service

bulletins.

Since an unsafe condition has been identified that is likely to

exist or develop on other airplanes of this same type design, this AD

supersedes AD 94-09-01 and AD 94-09-17 to require inspections to

determine the serial numbers and to detect defects in the upper and

lower lock links on the NLG, and rework of any defective lock link, or

replacement of any defective lock link with a serviceable lock link.

This AD also provides an optional terminating action for the required

inspections. The actions are required to be accomplished in accordance

with the alert service bulletins described previously.

This AD also requires that operators report inspection findings to

the FAA in the event any defect is found during any inspection.

The FAA is considering further rulemaking to require accomplishment

of the optional terminating action specified in this AD. However, the

proposed compliance time is sufficiently long so that notice and time

for public comment would not be impracticable.

Since a situation exists that requires the immediate adoption of

this regulation, it is found that notice and opportunity for prior

public comment hereon are impracticable, and that good cause exists for

making this amendment effective in less than 30 days.

Comments Invited

Although this action is in the form of a final rule that involves

requirements affecting flight safety and, thus, was not preceded by

notice and an opportunity for public comment, comments are invited on

this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All

communications received on or before the closing date for comments will

be considered, and this rule may be amended in light of the comments

received. Factual information that supports the commenter's ideas and

suggestions is extremely helpful in evaluating the effectiveness of the

AD action and determining whether additional rulemaking action would be

needed.

Comments are specifically invited on the overall regulatory,

economic, environmental, and energy aspects of the rule that might

suggest a need to modify the 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

AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments

submitted in response to this rule must submit a self-addressed,

stamped postcard on which the following statement is made: ``Comments

to Docket Number 94-NM-130-AD.'' The postcard will be date stamped and

returned to the commenter.

The regulations adopted herein will 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 final

rule does not have sufficient federalism implications to warrant the

preparation of a Federalism Assessment.

The FAA has determined that this regulation is an emergency

regulation that must be issued immediately to correct an unsafe

condition in aircraft, and that it is not a ``significant regulatory

action'' under Executive Order 12866. It has been determined further

that this action involves an emergency regulation under DOT Regulatory

Policies and Procedures (44 FR 11034, February 26, 1979). If it is

determined that this emergency regulation otherwise would be

significant under DOT Regulatory Policies and Procedures, a final

regulatory evaluation will be prepared and placed in the Rules Docket.

A copy of it, if filed, may be obtained from the Rules Docket at the

location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by

reference, Safety.

Adoption of the Amendment -

Accordingly, pursuant to the authority delegated to me by the

Administrator, the Federal Aviation Administration amends 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 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended] -

2. Section 39.13 is amended by removing amendments 39-8889 (59 FR

18722, April 20, 1994) and 39-8906 (59 FR 23144, May 5, 1994), and by

adding a new airworthiness directive (AD), amendment 39-9020, to read

as follows:

94-18-07 McDonnell Douglas: Amendment 39-9020. Docket 94-NM-130-AD.

Supersedes AD 94-09-01, Amendment 39-8889; and AD 94-09-17,

Amendment 39-8906.

-Applicability: All Model DC-10 series airplanes and Model KC-

10A (military) airplanes; and Model MD-11 series airplanes, as

listed in McDonnell Douglas MD-11 Alert Service Bulletin A32-47,

dated July 15, 1994; certificated in any category. -

Compliance: Required as indicated, unless accomplished

previously.

-Note 1: Visual inspections of the lock links, as required by

paragraph (a) of this AD, and eddy current inspections of the lock

links, as required by paragraph (b)(1) of this AD, that have been

accomplished prior to the effective date of this AD in accordance

with McDonnell Douglas DC-10 Alert Service Bulletin A32-237, dated

April 11, 1994; or McDonnell Douglas MD-11 Alert Service Bulletin

A32-44, dated March 22, 1994, or Revision 1, dated June 16, 1994; as

applicable; are considered acceptable for compliance with the

applicable action specified in this amendment.

-To prevent collapse of the nose landing gear (NLG), accomplish

the following: -

(a) Within 30 days after the effective date of this AD, perform

a visual inspection to determine the serial number of the upper lock

links, part number ACG7396-1, and the lower lock links, part number

ACG7237-1, on the NLG, in accordance with McDonnell Douglas DC-10

Alert Service Bulletin A32-238, dated July 15, 1994; or McDonnell

Douglas MD-11 Alert Service Bulletin A32-47, dated July 15, 1994; as

applicable. -

(b) If the serial number of the lock link coincides with any of

the suspect serial numbers listed in McDonnell Douglas DC-10 Alert

Service Bulletin A32-238, dated July 15, 1994; or McDonnell Douglas

MD-11 Alert Service Bulletin A32-47, dated July 15, 1994; as

applicable; accomplish paragraphs (b)(1) and (b)(2) of this AD in

accordance with the alert service bulletin. -

(1) Prior to further flight, perform an eddy current inspection

to detect defects in the lock link in accordance with Phase I

(``Eddy Current Inspection--On Aircraft'') of the Accomplishment

Instructions of the applicable alert service bulletin. -

(2) Perform an expanded eddy current inspection to detect

defects in the lock link, in accordance with Phase II (``Expanded

Eddy Current Inspection--Off Aircraft'') of the Accomplishment

Instructions of the applicable alert service bulletin at the time

specified in paragraph (b)(2)(i) or (b)(2)(ii) of this AD, as

applicable. -

(i) For Model DC-10 series airplanes and Model KC-10A airplanes:

Inspect prior to the accumulation of 450 landings after the

effective date of this AD, and thereafter at intervals not to exceed

450 landings. -

(ii) For Model MD-11 series airplanes: Inspect prior to the

accumulation of 330 landings after the effective date of this AD,

and thereafter at intervals not to exceed 330 landings. -

(c) If any defect is found during any inspection required by

paragraph (b) of this AD, prior to further flight, accomplish either

paragraph (c)(1) or (c)(2) of this AD in accordance with McDonnell

Douglas DC-10 Alert Service Bulletin A32-238, dated July 15, 1994;

or McDonnell Douglas MD-11 Alert Service Bulletin A32-47, dated July

15, 1994; as applicable. -

(1) Rework the lock link; or -

(2) Replace the defective lock link with a serviceable lock link

that has been inspected in accordance with paragraphs (a) and (b) of

this AD and, if the lock link was found to contain any defect, that

has been reworked in accordance with paragraph (c)(1) of this AD. -

(d) Accomplishment of a fluorescent penetrant inspection to

detect defects of the lock links, in accordance with Phase III

(``Fluorescent Penetrant Inspection--Off Aircraft'') of the

Accomplishment Instructions of McDonnell Douglas DC-10 Alert Service

Bulletin A32-238, dated July 15, 1994; or McDonnell Douglas MD-11

Alert Service Bulletin A32-47, dated July 15, 1994; as applicable;

constitutes terminating action for the inspections required by

paragraph (b) of this AD. -

(e) If any defect is found during an inspection performed in

accordance with paragraph (d) of this AD, prior to further flight,

accomplish either paragraph (e)(1) or (e)(2) of this AD in

accordance with McDonnell Douglas DC-10 Alert Service Bulletin A32-

238, dated July 15, 1994; or McDonnell Douglas MD-11 Alert Service

Bulletin A32-47, dated July 15, 1994; as applicable. -

(1) Rework the lock link; or -

(2) Replace the defective lock link with a serviceable lock link

that has been inspected in accordance with paragraphs (a) and (b) of

this AD and, if the lock link was found to contain any defect, that

has been reworked in accordance with paragraph (e)(1) of this AD. -

(f) As of the effective date of this AD, no person shall install

an upper lock link, part number ACG7396-1, or a lower lock link,

part number ACG7237-1, on the NLG of any airplane unless that lock

link has been inspected in accordance with paragraphs (a) and (b) of

this AD and reworked, as necessary, in accordance with paragraph

(c)(1) or (e)(1) of this AD. -

(g) Within 30 days after any defect is found during any

inspection required by this AD, submit a report of inspection

findings to the Manager, Los Angeles Aircraft Certification Office

(ACO), 3229 East Spring Street, Long Beach, California 90806-2425;

fax (310) 988-5210. The report must include a description of the

defect found, the part number of the defective lock link, the serial

number of the defective lock link, the number of landings on the

defective lock link, and the serial number of the airplane.

Information collection requirements contained in this regulation

have been approved by the Office of Management and Budget (OMB)

under the provisions of the Paperwork Reduction Act of 1980 (44

U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-

0056. -

(h) 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, FAA, Transport

Airplane Directorate. 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.

-(i) Special flight permits may be issued in accordance with

Secs. 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. -

(j) The actions shall be done in accordance with McDonnell

Douglas DC-10 Alert Service Bulletin A32-238, dated July 15, 1994;

and McDonnell Douglas MD-11 Alert Service Bulletin A32-47, dated

July 15, 1994. This incorporation by reference was approved by the

Director of the Federal Register in accordance with 5 U.S.C. 552(a)

and 1 CFR part 51. Copies 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. Copies may be inspected at the FAA, Transport

Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or

at the FAA, Transport Airplane Directorate, Los Angeles Aircraft

Certification Office, 3229 East Spring Street, Long Beach,

California; or at the Office of the Federal Register, 800 North

Capitol Street, NW., suite 700, Washington, DC. -

(k) This amendment becomes effective on September 15, 1994.

Issued in Renton, Washington, on August 25, 1994.

N.B. Martenson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-21482 Filed 8-30-94; 8:45 am]

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