Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
CE-11-47 R1
January 30, 2012
This is information only. Recommendations
aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin (SAIB) alerts
operators, pilots, and aircraft manufacturers of possible inner tube
failures made from butyl rubber by Goodyear Aviation Tires, (Goodyear).
At this time, the failure of the inner tubes is not an unsafe condition
that would warrant airworthiness directive (AD) action under Title 14
of the Code of Federal Aviation Regulations (14 CFR) part 39.
The SAIB has been revised to incorporate updated information from
Goodyear and highlight inner tube failures are not limited to only cold
weather operations.
Background
There have been several reports of Goodyear inner tubes failures during
cold weather operations. The failures were reported following short
flights or following ground operations. Goodyear is aware of these
failures and has made several attempts to improve the cold weather
performance of its inner tubes. In November 2008, Goodyear incorporated
a change to its compound for their butyl rubber inner tubes. Since
then, the reliability of the inner tubes had increased, but cold
weather failures were still reported. Therefore, Goodyear has started
to test another improvement to their butyl rubber inner tubes made from
an updated compound. Following successful field testing, Goodyear will
make the improved inner tubes available.
Goodyear inner tube failures are not limited to only cold weather
operations, additional failures have been reported. Goodyear is aware
of the issues from the field and began an improvement program to
investigate and improve the inner tubes. A flex crack was occasionally
observed on the natural fold from the extrusion process during
manufacturing. The compound was modified to reduce the impact of
extrusion, optimize splicing pressure and improve flex which should
improve crack resistance. Additionally cold temperature properties of
the tube were improved to further enhance performance for cold
temperature operations. Inner tubes were produced with the improved
compound and field tested with positive results. As of August 15, 2011
the production has been changed over to the modified compound for
5.00-5 inner tubes.
Recommendations
The FAA recommends you provide special attention during pre-flight to airplane tires with Goodyear butyl rubber inner tubes by:
Checking to ensure that all tires are properly inflated and are holding pressure;
Being prepared to compensate for a flat tire during landing as this might pull the airplane to the affected side; and
Providing extra awareness during cross wind landing conditions on narrow and on short runways.
Owners of airplanes with Butyl Rubber inner tubes, made by Goodyear, should contact Goodyear for further information.
For Further Information Contact
Anthony Flores, Aerospace Engineer, 2300 East Devon Ave, Des Plaines,
IL 60018; fax; (847) 294-7834; e-mail: anthony.flores@faa.gov.