The bulletin
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SPECIAL
AIRWORTHINESS
INFORMATION
BULLETIN
AIRCRAFT CERTIFICATION SERVICE 800 INDEPENDENCE AVENUE, S.W.
WASHINGTON, DC 20591
U.S. Department of Transportation Federal Aviation Administration
No. ACE-98-32 June 2, 1998
Published by: FAA, AFS-610, P.O. Box 26460, Oklahoma City, OK 73125 This is issued for informational purposes only and any recommendation for corrective action is not mandatory.
Introduction The purpose of this Special Airworthiness Informa tion Bulletin (SAIB) is to inform registered owners/operators of American Champion Airc raft Corporation (ACA C) model 8GCBC “Scout” airplanes of an Alternate Method of Complian ce (AMOC) that provides an alternate to the inspection hole/cover installation provisions of Federal Aviation Administration (FAA) Airworthiness Directive (AD) 98-05-04.
Background AD 98-05-04 was issued based on reports of w ood spar damage including cracks, compression cracks, longitudinal cracks through the bolt holes or nail holes; or loose or missing nails, which, if not corrected, could eventually result in in-flight failure of the wing with consequent loss of the airplane. AD 98-05-04 requires:
1. Installation of top and bottom surface inspection holes and covers per ACAC Service Letter (SL) 417 dtd., August 17, 1997; or ACAC SL 417, Rev. A, dtd., October 2, 1997; or ACAC SL 417, Rev. B, dtd., February 10, 1998. ACAC SL 417 and SL 417 Rev. A, required installation of top and bottom surface inspection hol es and covers. ACAC SL 417, Rev. B, allowed optional fabric patches in place of inspection cover installation.
2. ACAC SL 406, dtd., March 28, 1994, required di rect access to the entire wing spar, including the top of the spar, per ACAC SL 417.
3. As a result of comments received from th e field, the FAA has approved ACAC SL 406, Rev. A, dtd., May 6, 1998, as an AMOC for AD 98-05-04, paragraphs (a)(1), (a)(2), (a)(4), and (f), only. ACAC SL 406, Rev. A, provides an altern ate initial inspection method by utilizing a high intensity flexible light, (for example a “Bend-A- Light”) and a small inspection mirror, at the wing spar top doubler plate edges, where compression cracks typically occur.
Recommendation
1. The FAA recommends that initial compressi on crack inspections be performed per ACAC SL 406, Rev. A and ACAC SL 417, Rev. C. Please see attachments. If the initial inspection indicates a possible compression crack or othe r spar damage, recommend additional inspection holes be installed, as required, to obtain direct vi sual access to the spar t op or bottom surface, per ACAC SL 406, Figure 1.
2.a. The AMOC initial inspection provisions are not recommended for inspectors who do not have experience with wood compression failures.
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2.b. The AMOC initial inspection provisions ar e not recommended for incorporation on aircraft with wing damage history since the last spar inspection.
3. The FAA requests that any spar damage including airplane model, spar total hours, type of service and any previous wing damage history, be reported to the FAA via the service difficulty reporting system. Service difficulty reports ma y be reported on FAA Form 8010-4, Malfunction or Defect Report, or electronically by contacting the FAA Aviation Data Systems Branch, AFS-620, Attention: John Jackson at (405) 954-6486, or by E-Mail at <john_e_jackson@mmacmail.jccbi.gov.
For Further Information Contact:
FAA, Chicago Aircraft Certifica tion Office, Attention: Mr. William Rohder, or Mr. Nick Miller, 2300 East Devon Avenue, Des Plaines, IL 60018, telephone (847) 294-7697 or -7837, fax
(847) 294-7834, or FAA, Small Airplane Director ate, Attention: Mr. Roger Chudy, 1201 Walnut, Suite 900, Kansas City, MO 64106, telephone (816) 426-5688, fax (816) 426-2169.