[Federal Register Volume 63, Number 1 (Friday, January 2, 1998)]
[Notices]
[Page 137]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-34159]
Federal Register / Vol. 63, No. 1 / Friday, January 2, 1998 /
Notices
[[Page 137]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
Proposed Advisory Circular (AC) 120-XX, Repair Assessment of
Pressurized Fuselages
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed advisory circular.
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SUMMARY: This notice invites pubic comment on a proposed Advisory
Circular (AC) which provides guidance as to acceptable means of
accomplishing the requirements of a proposed rule on the subject of
repair assessment of pressurized fuselages published elsewhere in the
issue of the Federal Register
DATES: Comments must be received on or before April 2, 1998.
ADDRESSES: Send all comments on the proposed AC to: Dorenda Baker,
Manager, Aging Aircraft Program, ANM-109, FAA Transport Airplane
Directorate, Aircraft Certification Service, 1601 Lind Ave SW., Renton,
WA 98055-4056. Comments may be examined at the above address between
7:30 a.m. and 4:00 p.m. weekdays, except Federal holidays.
FOR FURTHER INFORMATION CONTACT:
Pat Siegrist, Regulations Branch, ANM-114, FAA Transport Airplane
Directorate, Aircraft Certification Service, 1601 Lind Avenue SW.,
Renton, WA 98055-4056; telephone (425) 227-2126.
SUPPLEMENTARY INFORMATION:
Comments Invited
A copy of the subject AC may be obtained by contacting the person
named above under FOR FURTHER INFORMATION CONTACT. Interested persons
are invited to comment on the proposed AC by submitting such written
data, views, or arguments as they may desire. Commenters must identify
the title of the AC and submit comments in duplicate to the address
specified above. All comments received on or before the closing date
for comments will be considered by the Transport Airplane Directorate
before issuing the final AC.
Discussion
Advisory Circular (AC) 120-xx, Repair Assessment of Pressurized
Fuselages, has been written to provide guidance on how to incorporate
FAA-approved repair assessment guidelines into an operator's FAA-
approved maintenance or inspection program as proposed in [insert
notice number], published elsewhere in this issue of the Federal
Register. The draft AC provides proposed guidance as to acceptable
means of accomplishing the requirements of the rule. The following is a
summary of the contents of the AC:
1. Repair Assessment Process. Assessment of existing repairs
installed on the fuselage pressure boundary of affected airplanes will
establish a damage-tolerance based structural inspection program and
replacement times, where needed. Utilizing the repair assessment
guidelines developed by the manufacturers of the affected airplanes,
two principle techniques have been identified that can be used to
accomplish the repair assessment.
2. Implementation. The proposed rule would require the repair
assessment guidelines to be approved by the Aircraft Certification
Office having cognizance over the type certificate for the affected
airplane. The means by which the repair assessment guidelines would be
incorporated into the FAA-approved maintenance or inspection program
would be subject to the approval of the certificate holder's principle
maintenance inspector (PMI) or other cognizant airworthiness inspector.
3. Recommended schedule for accomplishing the repair assessment.
The repair assessment activity should be completed in accordance with
the schedule in the FAA Approved Repair Assessment Guidelines for each
of the affected airplanes. Any necessary corrective actions to be taken
as a result of the evaluation would be incorporated into the FAA-
approved maintenance or inspection program.
4. New Repairs. The operator would have to assess new repairs using
the assessment guidelines, unless the new repairs are accomplished
according to structural repair manuals, or any other equivalent method
that incorporates damage tolerance methods of design and evaluation.
The aircraft manufacturers of the affected models are updating their
structural repair manuals to address damage tolerance methodology. FAA
Advisory Circular 25.1529-1, ``Instructions for Continued Airworthiness
of Structural Repairs on transport Airplanes,'' provides guidance for
installing new damage tolerance based repairs.
5. Sale and Transfer of Airplanes. Before an airplane is added to
an operator's operations specifications, a program for accomplishment
of the repair assessment should be established.
6. Repairs to Structural Modification Certified by a Supplemental
Type Certificate (STC). The operator would need to establish a repair
assessment program for structure modified by an STC.
Issued in Washington, D.C. on December 22, 1997.
Thomas E. McSweeny,
Director, Aircraft Certification Service.
[FR Doc. 97-34159 Filed 12-31-97; 8:45 am]
BILLING CODE 4910-13-M
