[Federal Register Volume 68, Number 190 (Wednesday, October 1, 2003)]
[Proposed Rules]
[Pages 56598-56600]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-24842]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-287-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 767-400ER Series 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 all Boeing Model 767-400ER series 
airplanes. This proposal would require repetitive high frequency eddy 
current inspections of the aft lower lugs of the deflection control 
track of the outboard flap for cracks, and replacement of any cracked 
deflection control track with a new track assembly. This action is 
necessary to prevent fatigue cracking in the aft lower lug run-out 
region of the deflection control track. Fatigue cracking of the 
deflection control track, if not detected and corrected in a timely 
manner, could result in the loss of the secondary load path for the 
outboard flap, resulting in the loss of the outboard flap and 
consequent reduced controllability of the airplane in the event that 
the primary load path also fails. This action is intended to address 
the identified unsafe condition.

DATES: Comments must be received by Novemeber 17, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-287-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. 2002-NM-287-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 or 2000 or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Candice Gerretsen; Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6428; fax (425) 917-6590.

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:
    [sbull] 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 56599]]

    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] 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 2002-NM-287-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. 2002-NM-287-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received several reports of cracked deflection control 
tracks on the outboard end of the outboard flaps on Boeing Model 767-
300 series airplanes. These cracks all initiated in the aft lower lug 
run-out region. In one case, the crack initiated at inclusions that are 
typical of the slag products that are a result of the casting process. 
After a crack initiates, it is propagated by fatigue until the track 
fractures.
    The deflection control track on Model 767-400 ER series airplanes 
is identical to that on the affected Model 767-300 series airplanes. 
However, on the Model 767-300 series airplanes the deflection control 
track does not act as a load path, so the Model 767-300 series 
airplanes are not subject to mandatory action for this condition at 
this time. Fatigue analysis for the Model 767-400ER series airplanes 
showed that the cracking should not occur before 12,000 total flight 
cycles. Fatigue cracking of the deflection control track for Model 767-
400ER series airplanes, if not detected and corrected in a timely 
manner, could result in the loss of the secondary load path for the 
outboard flap resulting in the loss of the outboard flap and consequent 
reduced controllability of the airplane in the event that the primary 
load path also fails.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
767-27A0183, dated May 9, 2002, which describes procedures for 
repetitive high frequency eddy current inspections of the aft lower 
lugs of the deflection control track of the outboard flap for cracks, 
and replacement of any cracked deflection control track with a new 
track assembly.

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 bulletin described previously.

Interim Action

    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.

Changes to 14 CFR Part 39/Effect on the Proposed AD

    On July 10, 2002, the FAA issued a new version of 14 CFR part 39 
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness 
directives system. The regulation now includes material that relates to 
altered products, special flight permits, and alternative methods of 
compliance (AMOCs). Because we have now included this material in part 
39, only the office authorized to approve AMOCs is identified in each 
individual AD.

Change to Labor Rate Estimate

    We have reviewed the figures we have used over the past several 
years to calculate AD costs to operators. To account for various 
inflationary costs in the airline industry, we find it necessary to 
increase the labor rate used in these calculations from $60 per work 
hour to $65 per work hour. The cost impact information, below, reflects 
this increase in the specified hourly labor rate.

Cost Impact

    There are approximately 38 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 38 airplanes of U.S. registry 
would be affected by this proposed AD, that it would take approximately 
3 work hours per airplane to accomplish the proposed inspection, and 
that the average labor rate is $65 per work hour. Based on these 
figures, the cost impact of the proposed AD on U.S. operators is 
estimated to be $7,410, or $195 per airplane, per inspection cycle.
    The 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 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.

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.

[[Page 56600]]

Sec.  39.13  [Amended]

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

Boeing: Docket 2002-NM-287-AD.

    Applicability: All Model 767-400ER series airplanes, 
certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent fatigue cracking in the aft lower lug run-out region 
of the deflection control track, which could result in the loss of 
the secondary load path for the outboard flap, resulting in loss of 
the outboard flap and consequent reduced controllability of the 
airplane in the event that the primary load path also fails, 
accomplish the following:

Initial Inspection

    (a) Before the accumulation of 12,000 total flight cycles, or 
within 1,200 flight cycles after the effective date of this AD, 
whichever occurs later, perform a high frequency eddy current (HFEC) 
inspection for cracks in the aft lower lug of the deflection control 
track on the outboard flap, in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 767-27A0183, dated May 
9, 2002.

Repetitive Inspections

    (b) If no crack is detected during any HFEC inspection required 
in paragraph (a) of this AD, repeat the inspection at intervals not 
to exceed 1,200 flight cycles.

Corrective Action

    (c) If any crack is detected during any HFEC inspection required 
by paragraph (a) of this AD, before further flight, replace the 
deflection control track with a new track assembly, in accordance 
with the Accomplishment Instructions in Boeing Alert Service 
Bulletin 767-27A0183, dated May 9, 2002. Within 12,000 flight cycles 
following the replacement, perform the HFEC inspection specified in 
paragraph (a) of this AD, and repeat inspections as specified in 
paragraph (b) of this AD.

Alternative Methods of Compliance

    (d) In accordance with 14 CFR 39.19, the Manager, Seattle 
Aircraft Certification Office, FAA, is authorized to approve 
alternative methods of compliance for this AD.

    Issued in Renton, Washington, on September 25, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-24842 Filed 9-30-03; 8:45 am]
BILLING CODE 4910-13-P