Having learned how to remove and replace the engine AFES relays cover, you
will now proceed to learn how to remove and replace the Optical Fire Sensing
Optical Fire Sensing Apparatus - Removal and Installation.
Turn crew T/A panel MAINTenance switch to the vertical
position before removing an OFSA detector.
Note the position of the OFSA before removal.
Installed position of the OFSA is critical.
the OFSA in the correct position.
Removal for all four of the OFSA sensing apparatuses is the same.
Using Figure 27 and the following procedures, proceed
installation process as it applies to the crew AFES OFSA.
o Disconnect the electrical cable (Item 1) from the OFSA (Item 2).
o Now remove two screws (Item 3), two nuts (Item 4), two lockwashers
(Item 5), and four flat washers (Item 6). Be sure to replace the
o You can now remove the OFSA apparatus (Item 2) from the bracket.
The installation process for the OFSA is the reverse procedure of the
Before installation of the OFSA, ensure the lenses have
been cleaned as outlined in TM 9-2350-267-10.
Be sure you have used new
lockwashers for the installation process. When you install the electrical
cable (Item 1), turn