AD 2004-07-11
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing | 767-400ER | Airworthiness Directives; Boeing Model 767-400ER Series Airplanes |
Unsafe Condition
Fatigue cracking in the aft lower lug run-out region of the deflection control track of the outboard flap.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect the aft lower lugs of the deflection control track of the outboard flap using repetitive high frequency eddy current inspections for cracks. Replace any cracked deflection control track with a new track assembly.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Before further flight
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
All Boeing Model 767-400ER series airplanes.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
This amendment adopts a new airworthiness directive (AD), applicable to all Boeing Model 767-400ER series airplanes, that requires 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.
Document Text
Show stored source text (verify against official source)
[Federal Register Volume 69, Number 66 (Tuesday, April 6, 2004)]
[Rules and Regulations]
[Pages 17911-17913]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 04-7351]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2002-NM-287-AD; Amendment 39-13555; AD 2004-07-11]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 767-400ER Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to all Boeing Model 767-400ER series airplanes, that
requires 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: Effective May 11, 2004.
The incorporation by reference of a certain publication listed in
the regulations is approved by the Director of the Federal Register as
of May 11, 2004.
ADDRESSES: The service information referenced in this AD may be
obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle,
Washington 98124-2207. This information may be examined at the Federal
Aviation Administration (FAA), Transport Airplane Directorate, Rules
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of
the Federal Register, 800 North Capitol Street, NW., suite 700,
Washington, DC.
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: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to all Boeing Model 767-400ER series
airplanes was published in the Federal Register on October 1, 2003 (68
FR 56598). That action proposed to 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.
Comments
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Request To Change Compliance Time
One commenter requests that the proposed repairs be deferred until
the next major base visit. The commenter states that the compliance
time of ``before the accumulation of 12,000 total flight cycles'' in
the proposed AD would cause maintenance program issues. The commenter
states that the inspections and repairs will create an undue burden to
the airline operators due to parts availability and the costs
affiliated with immediate repair of a cracked deflection control track.
The FAA does not agree with the commenter's request to change the
compliance time. In developing an appropriate compliance time for this
action, we considered the safety implications, parts availability, and
normal maintenance schedules for the timely accomplishment of the
inspections and repairs. We have determined, based on fatigue analysis
by
[[Page 17912]]
the manufacturer, that a compliance time of ``before the accumulation
of 12,000 total flight cycles'' will ensure an acceptable level of
safety. We also provided a grace period of 1,200 flight cycles, in
order to allow the operators to align the inspections with regular
maintenance checks. Last, due to safety implications and the
consequences associated with continued service without proper repair,
repairs must be made before further flight.
Model 767-400ER Not Subject to Proposed AD
The commenter states that all of the cracked deflection control
tracks were reported on Model 767-300 series airplanes and no reports
have been made for Model 767-400ER series airplanes. The commenter also
states that the utilization for the Model 767-300 series airplanes and
Model 767-400ER series airplanes are often completely different.
We infer from the commenter's statement, that the Model 767-400ER
deflection control tracks should not be subject to the proposed AD.
While we do agree that the airplanes operate differently and cracking
has only been found on Model 767-300 series airplanes, we do not agree
with the commenter that Model 767-400ER deflection control tracks
should not be subject to this AD. Based on fatigue analysis and similar
construction, we find sufficient data exists to establish the
probability of the deflection control track cracking on the Model 767-
400ER series airplanes. Since the deflection control track acts as a
secondary load path on Model 767-400ER series airplanes and not on
Model 767-300 series airplanes, this AD is limited to Model 767-400ER
series airplanes only.
Conclusion
After careful review of the available data, including the comments
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule as proposed.
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
will be affected by this AD, that it will take approximately 3 work
hours per airplane to accomplish the required inspection, and that the
average labor rate is $65 per work hour. Based on these figures, the
cost impact of the 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 requirements of this AD
action, and that no operator would accomplish those actions in the
future if this 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 adopted herein will 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 final rule does not have federalism
implications under Executive Order 13132.
For the reasons discussed above, I certify that this action (1) is
not a ``significant regulatory action'' under Executive Order 12866;
(2) is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action
and it is contained in the Rules Docket. A copy of it 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
0
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
0
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]
0
2. Section 39.13 is amended by adding the following new airworthiness
directive:
2004-07-11 Boeing: Amendment 39-13555. 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.
Incorporation by Reference
(e) The actions shall be done in accordance with Boeing Alert
Service Bulletin 767-27A0183, dated May 9, 2002. 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 Boeing Commercial Airplanes, P.O. Box 3707, Seattle,
Washington 98124-2207. Copies may be inspected at the FAA, Transport
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or
at the Office of the Federal Register, 800 North Capitol Street,
NW., suite 700, Washington, DC.
Effective Date
(f) This amendment becomes effective on May 11, 2004.
[[Page 17913]]
Issued in Renton, Washington, on March 22, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 04-7351 Filed 4-5-04; 8:45 am]
BILLING CODE 4910-13-P
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.