51-20-02 MARTIN: Applies to All Models 202 and 202A Airplanes, Except as Noted.
Compliance required as specified.
In order to comply with recommendations of the Martin 202 Modification Board, the following items must be accomplished. In all cases, modifications which are demonstrated to provide a level of safety equivalent to that provided by the modifications listed herein will be acceptable in lieu of the listed modifications.
1. Compliance required not later than January 1, 1952.
(a) Cover heater ignition interlock relay box tightly. (Applies to Model 202 airplanes only.)
(b) Cover autopilot servo control relay box tightly. (Applies to Model 202 airplanes only.)
(c) Cover AC distribution panel tightly or replace with enclosed relays.
(d) Enclose all uncovered relays in the DC distribution panel in a box or replace with enclosed relays.
(e) Cover heating and ventilating control box tightly.
2. Compliance required not later than November 15, 1951.
Either replace present dural crossfeed line with a continuous piece of fire-resistant hose where it passes through the fuselage and relocate the fittings to a location outboard of the fuselage, or provide adequately drained liquid and vapor-proof shroud for the fuel crossfeed line where it passes through the main electrical compartment in the fuselage.
(Glenn L. Martin Service Bulletin No. 173 covers one method of compliance with this item.) (Applies to Model 202 airplanes only.)
3. Compliance required not later than March 1, 1952.
Make electrical hydraulic pump explosion proof.
(Glenn L. Martin Service Bulletin No. 188, issued for the Model 202A, covers this same subject and may be used for both 202 and 202A airplanes.)
4. Compliance required not later than March 1, 1952.
Install separate circuit breakers for the pitot tube heater circuits.
(Glenn L. Martin Service Bulletin No. 118, issued for the Model 202A, covers this same subject and may be used for both 202 and 202A airplanes.)
5. Compliance required not later than March 1, 1952.
Replace all 75ST aileron hinge fittings with steel parts.
(Glenn L. Martin Maintenance Note No. 164 covers this same subject.) (Applies to Model 202 airplanes only.)