47-31-03 NAVION: (Was mandatory Note 12 of AD-782-3.) Applies to Serial Numbers NAV-4-2 Through NAV-4-1010 Which Incorporate Koehler Model 2250 Fuel Strainers.
To be accomplished not later than November 1, 1947.
To preclude the possibility of loss of fuel pressure due to air leakage into the fuel system through the CCA-1550-1/8 drain cock on the Koehler Model 2250 fuel strainer, remove this draincock and install Whittaker Model 7600-1/8 drain cock.
(NAA Field Service Bulletin No. 32 dated May 1, 1947, covers this rework.)