74-17-03 DEHAVILLAND: Amendment 39-1914. Applies to Model DHC-2 (Mk I) Beaver Airplane. Compliance required within the next 110 hours in service after the last inspection pursuant to this directive and thereafter at intervals not to exceed 110 hours in service from a preceding inspection.
To prevent carbon monoxide from entering the airplane cabin, accomplish the following:
(a) For airplanes using the intensifier tube cabin heater system, remove the tube and perform a visual inspection on both the intensifier tube and the exhaust pipe for any holes, cracks, flaking or weld separations.
(b) For airplanes using heater jackets, remove the jacket and perform the same inspection as in (a) above.
Replace or repair parts found to have any holes, cracks flaking or weld separations. Make welding repairs in accordance with Advisory Circular AC 43.13-1 or an FAA approved equivalent.
Upon submission of substantiation data through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, Eastern Region, may adjust the repetitive inspection intervals specified in this AD.
This Directive supersedes Airworthiness Directive 57-13-02.
This amendment is effective August 12, 1974.