[Federal Register Volume 67, Number 164 (Friday, August 23, 2002)]
[Proposed Rules]
[Pages 54593-54595]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-21508]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-358-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-10-10, DC-
10-10F, DC-10-15, DC-10-30, DC-10-30F, DC-10-30F (KC10A and KDC-10), 
MD-10-10F, and MD-10-30F Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain McDonnell Douglas Model 
DC-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F, DC-10-30F (KC10A 
and KDC-10), MD-10-10F, and MD-10-30F airplanes. This proposal would 
require inspections of the linear variable differential transducers 
(LVDTs) of the autopilot for discrepancies, and follow-on actions, if 
necessary. This action is necessary to prevent failure of the LVDTs, 
which could result in an automatic pitch trim malfunction or an 
autopilot disconnect, and consequent reduced controllability of the 
airplane. This action is intended to address the identified unsafe 
condition.

DATES: Comments must be received by October 7, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-358-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2001-NM-358-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Aircraft Group, Long Beach Division, 
3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data 
and Service Management, Dept. C1-L5A (D800-0024). This information may 
be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT: Technical Information: Ron Atmur, 
Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles 
Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, 
California 90712-4137; telephone (562) 627-5224; fax (562) 627-5210.
    Other Information: Sandi Carli, Airworthiness Directive Technical 
Editor/Writer; telephone (425) 687-4243, fax (425) 687-4248. Questions 
or comments may also be sent via the Internet using the following 
address: [email protected]. Questions or comments sent via the 
Internet as attached electronic files must be formatted in Microsoft 
Word 97 for Windows or ASCII text.

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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.

[[Page 54594]]

     For each issue, state what specific change to the proposed 
AD is being requested.
     Include justification (e.g., reasons or data) for each 
request.
    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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2001-NM-358-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-114, Attention: Rules 
Docket No. 2001-NM-358-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has been informed by the manufacturer that certain 
McDonnell Douglas Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-
30F, DC-10-30F (KC10A and KDC-10), MD-10-10F, and MD-10-30F airplanes 
having linear variable differential transducers (LVDT) were delivered 
with an undersize nylok element on the threaded extension end. If such 
undersizing is not corrected, the LVDT plunger jamnut could become 
loose causing an automatic pitch trim malfunction, an elevator stand-
off resulting in automatic pitch trim operation in one direction only, 
or an autopilot disconnect.
    Also, we received one report of a pitch trim incident in flight 
that resulted in an uncommanded nose-down pitch of the airplane. 
Investigation revealed that the cause of that incident was loose shear 
rivets in the drive assembly of the automatic pitch trim LVDT. The 
loose shear rivets allowed the automatic pitch trim LVDT to shift 
enough to command the horizontal stabilizer to put the airplane in a 
nose-down direction. Further investigation revealed additional 
airplanes with loose rivets, and one airplane with an additional 
problem with the attachment to the automatic pitch trim LVDT. Binding 
between the plunger and body of the LVDT due to loose rivets can cause 
failure of the LVDT shear rivets. Such conditions, if not corrected, 
could result in an automatic pitch trim malfunction and consequent 
reduced controllability of the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
DC10-22A126, dated October 31, 2001, which describes procedures for a 
visual inspection of the shear rivets of the LVDTs of the drive 
assembly of the automatic pitch trim for discrepancies (sheared and/or 
loose rivets), and these six follow-on conditions:
     Condition 1: If no sheared or loose rivets are found, no 
further action is needed.
     Condition 2: If any sheared and/or loose rivets are found, 
repair the drive assembly and repeat visual inspection of the LVDT for 
further discrepancies (misalignment, corrosion, bent plunger, 
restricted movement, or hangar binding). If no discrepancy is found, no 
further action is needed.
     Condition 3: If a discrepancy is found after doing 
Condition 2, do the corrective actions specified in Conditions 4 
through 6, as applicable.
     Condition 4: If the LVDT is misaligned, realign.
     Condition 5: If any corrosion, a bent plunger, or 
restricted movement of the LVDT is found, replace the existing LVDT 
with a new LVDT.
     Condition 6: If hangar binding of the LVDT is found, 
replace the LVDT hangar assembly with a new assembly.
    We also have reviewed and approved Boeing Alert Service Bulletin 
DC10-22A127, dated December 17, 2001, which describes procedures for a 
visual inspection of the LVDTs for affected serial numbers (with an 
undersize nylok element) and these two options for follow-on actions:
     Option 1: Replace any affected LVDT with a new LVDT; then 
do the automatic pitch trim adjustment/test.
     Option 2: Install a heat shrinkable sleeve over the LVDT 
jamnut; then do repetitive inspections for loose LVDT jamnuts until the 
LVDT is replaced.
    Accomplishment of the actions specified in the service bulletins is 
intended to adequately address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require accomplishment of the actions specified in 
the service bulletins described previously, except as discussed below.

Difference Between This Proposed AD and the Service Information

    The service bulletins described previously refer to a ``visual'' 
inspection. For the purposes of this AD, we have determined that the 
procedures in the service bulletins constitute a ``detailed 
inspection.'' Note 2 of this proposed AD defines such an inspection.

Explanation of AD Applicability

    We have specified model designations in the applicability of this 
proposed AD as published in the most recent type certificate data sheet 
for the affected models. These model designations differ in the 
referenced service bulletins.

Cost Impact

    There are approximately 394 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 252 airplanes of U.S. registry 
would be affected by this proposed AD.
    It would take approximately 1 work hour per airplane to accomplish 
the inspection specified in Boeing Alert Service Bulletin DC10-22A126, 
at an average labor rate of $60 per work hour. Based on these figures, 
the cost impact of this proposed inspection on U.S. operators is 
estimated to be $15,120, or $60 per airplane.
    It would take approximately 1 work hour per airplane to accomplish 
the inspection specified in Boeing Alert Service Bulletin DC10-22A127, 
at an average labor rate of $60 per work hour. Based on these figures, 
the cost impact of this proposed inspection on U.S. operators is 
estimated to be $15,120, or $60 per airplane.
    The cost impact figures discussed above are 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 proposed AD were not adopted. The cost impact 
figures discussed in AD rulemaking actions represent only the time 
necessary to perform the specific actions actually required by the AD. 
These figures typically do not include incidental costs, such as the 
time required to gain access and close up, planning time, or time 
necessitated by other administrative actions.
    Should an operator be required to perform the follow-on actions 
specified in Boeing Alert Service Bulletin DC10-

[[Page 54595]]

22A126, the cost estimates are as follows:
     Condition 2--Repair/inspect: 1 work hour per airplane at 
$60 per work hour.
     Condition 4--Realign: 1 work hour per airplane at $60 per 
work hour.
     Condition 5--Replace LVDT: 1 work hour per airplane at $60 
per work hour; estimated parts cost of $900.
     Condition 5--Replace hangar: 1 work hour per airplane at 
$60 per work hour; estimated parts cost of $100.
    Should an operator be required to perform the follow-on actions 
specified in Boeing Alert Service Bulletin DC10-22A127, the cost 
estimates are as follows:
     Option 1--Replace LVDT and do adjustment/test: 2 work 
hours per airplane at $60 per work hour; estimated parts cost of $900.
     Option 2--Install a heat shrinkable sleeve and inspect: 2 
work hours per airplane at $60 per work hour.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

McDonnell Douglas: Docket 2001-NM-358-AD.

    Applicability: Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30, 
DC-10-30F, DC-10-30F (KC10A and KDC-10), MD-10-10F, and MD-10-30F 
airplanes; as listed in Boeing Alert Service Bulletin DC10-22A126, 
dated October 31, 2001; and Boeing Alert Service Bulletin DC10-
22A127, dated December 17, 2001; 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 request approval for an 
alternative method of compliance in accordance with paragraph (c) 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, unless accomplished 
previously.
    To prevent failure of the linear variable differential 
transducers (LVDTs) of the autopilot, which could result in an 
automatic pitch trim malfunction or an autopilot disconnect, and 
consequent reduced controllability of the airplane, accomplish the 
following:

Detailed Inspections/Follow-On Actions

    (a) Within 90 days after the effective date of this AD: Do the 
detailed inspections of the LVDTs of the autopilot for discrepancies 
as required by paragraphs (a)(1) and (a)(2) of this AD.

    Note 2: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''

    (1) Inspect the LVDTs for affected serial numbers (with 
undersize nylok elements) per Figure 1 of Boeing Alert Service 
Bulletin DC10-22A127, dated December 17, 2001. If any affected 
serial number is found, before further flight, do either Option 1 
(including replacing the LVDT with a new LVDT and doing an automatic 
pitch trim adjustment/test), or Option 2 (including installing a 
heat-shrinkable sleeve over the LVDT jamnut and doing repetitive 
inspections for any loose jamnut every 500 flight hours until the 
LVDT is replaced with a new LVDT), of Condition 1 of the service 
bulletin, per the service bulletin. If any discrepancy is found, 
before further flight, replace the LVDT with a new LVDT. If no 
discrepancy is found, install a shield assembly per Condition 2 of 
the service bulletin.
    (2) Inspect the shear rivets of the LVDTs of the drive assembly 
of the automatic pitch trim for discrepancies (shearing and/or 
looseness), per Boeing Alert Service Bulletin DC10-22A126, dated 
October 31, 2001. If any discrepancy is found, before further 
flight, do Conditions 2 through 6 (including repairing the driver 
assembly and inspecting the LVDT within 9 months after doing the 
repair; doing an automatic pitch trim adjustment/test; aligning the 
LVDT; replacing the existing LVDT with a new LVDT; and replacing the 
hangar assembly with a new assembly), as applicable, of the service 
bulletin, per the service bulletin. If no discrepancy is found, no 
further action is required by this paragraph.

Spares

    (b) As of the effective date of this AD, no one may install an 
LVDT with a serial number listed in the ``Affected Serial Numbers'' 
table in Figure 1 of Boeing Alert Service Bulletin DC10-22A127, 
dated December 17, 2001, on any airplane.

Alternative Methods of Compliance

    (c) 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, Manager, Los Angeles Aircraft 
Certification Office (ACO), FAA. 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

Special Flight Permit

    (d) 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 19, 2002.
Vi L. Lipski,
Manager, , Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-21508 Filed 8-22-02; 8:45 am]
BILLING CODE 4910-13-P