Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
CE-10-39
July 23, 2010
This is information only. Recommendations
aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin (SAIB) advises you
of an airworthiness concern regarding possible interference between the
front seat lap belt and the rear rudder pedals on American Champion
Aircraft Corporation (ACAC) Models 7ECA, 7GCAA, 7GCBC, 7KCAB, 8KCAB,
& 8GCBC.
At this time, this airworthiness concern is not considered an unsafe
condition that would warrant an airworthiness directive action under
Title 14 of the Code of Federal Regulations (14 CFR part 39).
Background
This SAIB resulted from an incident where an American Champion model
8KCAB (Decathlon) departed the runway upon landing. It was determined
that upon application of full left rudder by the front seat pilot, the
rearward moving aft right rudder pedal had caught on the right side of
the front dual lap belt aerobatic harness; interfering with the
rearward movement of the pedal and possibly applying right braking.
Upon examination of a video of the installation it was discovered that
the dual lap belt aerobatic harness was improperly installed in the
airplane, which contributed to the interference.
Examination of several other Decathlon airplanes with Hooker dual lap
belt aerobatic harnesses revealed that that the clearance between the
aft rudder pedals and the front seat aerobatic harness is typically
less than 1 inch. Although American Champion airplanes have been safely
operating with aerobatic harnesses for at least 15 years in the field,
American Champion has been proactive in avoiding any potential
interference problem through the issuance of Service Letter number 433.
The service letter specifies two items. First it introduces a flight
manual supplement that provides for a Pre-Start and a Pre-Flight check
of the front seat lap belt for proper tension and clearance with the
aft seat rudder pedals. Second the service letter provides instructions
for an easy change applicable to American Champion dual lap belt
installations (Hooker Competition harnesses) only. The change moves the
front seat upper secondary lap belt anchor fitting from the outside of
the outer lug to the inside of the outer lug. This provides for
additional clearance between the upper (secondary) lap belt and the aft
rudder pedals (see Figure 4 of the service letter)
The change described above may also apply to dual Hooker
lap/seat/safety belt installations done via Supplemental Type
Certificate number SA312CH on eligible airplanes. In this case, dual
lap/seat/safety belt installations may not be limited to only the
Hooker Competition harness, but any Hooker dual lap belt installation
that uses dual floor mounting tabs or lugs as the attach points for the
dual lap/seat/safety belts. In some older airplanes manufactured by a
previous type certificate holder, there may not be dual floor mount
tabs or lugs. In these cases, the secondary lap belt was connected to a
cross tube under the floor. Since the outer tab or lug does not exist
in these installations, the American Champion change is not applicable.
This airworthiness action has been taken after consideration of the
responses from ACAC as well as airplane owners/ operators through
relevant associations and type clubs, using the procedures found in the
Small Airplane Directorate Airworthiness Directives Manual Supplement
(Airworthiness Concern Process Guide).
Recommendations
We recommend that all that ACAC model airplanes identified in the
introduction above equipped with Hooker lap/seat/safety belt have
American Champion Service Bulletin number 433 incorporated. For
airplanes equipped with dual lap/seat/safety belt Hooker harnesses that
use airplane equipped floor mounted attach lugs/tabs for each of the
two harnesses, the upper or secondary lap belt should be moved from the
outside of the outer attach lug/tab to the inside of the outer attach
lug/tab per figure 4 of the service bulletin.
For Further Information Contact
Wesley Rouse, Aerospace Engineer, FAA Chicago Aircraft
Certification, 2300 E. Devon, Des Plaines, IL 60018; phone: (847)
294-8113; email: wess.rouse@faa.gov.
For Related Service Information Contact
To obtain a copy of American Champion service letter number 433,
contact American Champion Aircraft Corporation, P.O. Box 37, 32032
Washington Ave. – Hwy. D, Rochester, WI 53167; or visit their website
at www.amerchampionaircraft.com, select “Technical” and scroll down to
service letter number 433.