The bulletin
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FAA Aviation Safety
SPECIAL AIRWORTHINESS
INFORMATION BULLETIN SAIB: CE-12-43 SUBJ: Wings; Small aircraft with wooden wings and solid wood spars Date: August 15, 2012 This is information only. Recommendations aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin is being issued to inform the public about an airworthiness issue on small aircraft with wooden wings and solid wood spars that while not uncommon, continues to occur.
At this time, this airworthiness concern is not considered an unsafe condition that would warrant an airworthiness directive (AD) action under title 14 of the code of Federal Regulations (14 CFR part
39).
Background
Various vintage airplanes were designed with solid wood spars. Recently, a foreign authority notified the Federal Aviation Administration (FAA) that, during an airworthiness inspection of a vintage biplane imported from the United States, it was determined that at least one lower wing spar had cracks at the spar attach fitting. This particular type was originally approved in the 1940s, and the age of the particular spar was not able to be determined, but was deemed to have some age due to its visual appearance. Additional investigation brought to light that the airplane had probably been ground looped in the past and the damage, while not directly linked to this occurrence, was consistent with such an event without being either previously detected or repaired.
Recommendations
The FAA realizes that such events occur (and have occurred) frequently and that most, if not all, airplanes subject to such an event are inspected immediately. However, the discovery of this previously undetected damage leads the FAA to remind owners and operators of the importance of conducting appropriate inspections and repairs in the event of a ground loop and of the importance of inspections during routine maintenance. FAA Advisory Circular AC 43.13-1B Change: 1: Acceptable Methods, Techniques, and Practices – Aircraft Inspection and Repair, provides further information and procedures for such inspections.
For Further Information Contact
Karl Schletzbaum, Aerospace Engineer, Small airplane Directorate, ACE-112, Room 300, 901 Locust Street, Kansas City, MO 64106; phone: (816) 329-4146; fax: (816) 329-4090; e-mail:
karl.schletzbaum@faa.gov