Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
NM-07-14
January 3, 2007
This is information only. Recommendations
aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin advises you, owners
and operators of Boeing Model 757-200 and 757-300 airplanes, to
accomplish the following:
Perform a one time
inspection of the 757 airplane to verify that they are equipped with
the correct M10444 APU/Cargo Fire Control Panel (APU/CFCP) part number
(P/N), as defined in the Illustrated Parts Catalogue (IPC) 26-22-03-01.
Thereafter, when performing
any maintenance on the APU/CFCP, insure that operators follow the
reinstallation/replacement procedures of the Airplane Maintenance
Manual (AMM) 26-22-03 and perform the tests specified in the AMM
thoroughly and completely, to insure that the correct APU/CFCP is
installed and functions properly when installed.
Background
We received reports of two different configurations of APU/CFCP
P/N’s. Each P/N is designated for a specific 757 airplane. They are not
interchangeable. However, because these parts are identical in form and
fit, there are no design features to prevent the inadvertent
installation of a P/N on an airplane that is not wired for it or
provide an automatic indication when the incorrect panel is installed.
During a routine inspection, one operator found the incorrect APU/CFCP
P/N installed in their 757 airplane. Installing the incorrect APU/CFCP
P/N on an airplane could result in improper operation, as shown in the
various scenarios detailed in the Boeing Service Letter 575-SL-26-028,
dated 19 July 2006.
Recommendations
We strongly recommend that you accomplish the actions suggested by
and detailed in the Boeing Service Letter (SL) 757-SL-26-028. This SL
points out consequences, in case of a cargo compartment fire, if you
install the incorrect M10444 APU/CFCP. The SL provides instructions for
inspection of the APU/CFCP and the performance of all the required
panel replacement tests, referenced in the Boeing AMM 26-22-03, to
insure proper installation and function of the APU/CFCP.