59-01-01 CONVAIR: Applies to All 240 and 340 Aircraft and to 440, Serial Nos. 312 Through 502.
Compliance required as follows: 440 aircraft not later than December 31, 1958; 340 and 240 aircraft not later than April 30, 1960.
Inflight fire experience and fire tests on the Convair engine nacelle have shown the need for further improvement in detecting fires originating in zones one and two. Additional continuous type detector coverage was provided in production 440 aircraft for the zone one bellmouth and zone two chimney areas. Because of false warnings the original system was rendered inoperative by Convair Service Air Gram No. 173, and an improvement program was initiated. This program has now been completed and a revised system developed with functional reliability proven by test under laboratory and service conditions.
To improve and reactivate the continuous type fire detector system installation on 440 aircraft and to provide equivalent coverage for 240 and 340aircraft, the following must be accomplished:
(1) On 440 aircraft, the existing continuous type fire detector system must be modified to incorporate improved detector elements and assemblies, including connectors, control box cannon plugs and mounting provisions. Upon accomplishment, the continuous type system must be made operative. On aircraft of Serial Nos. 503 and subsequent which incorporate these changes, the system must be maintained operative.
(Convair Service Bulletin No. 440-41 covers an acceptable method of accomplishing these changes.)
(2) On 240 and 340 aircraft, either modification (a) or modifications (b) and (c) must be accomplished:
(a) Install additional fire detector coverage consisting of a continuous type system installed in each augmenter bellmouth and each vent chimney, similar to that now installed on 440 aircraft. The airplane flight manual must be revised to include a description of the system operation and the required emergency procedures.
(Convair Service Bulletin No. 340-222 covers an acceptable method of accomplishment of this installation on 340 aircraft. Service bulletins applicable to 240 aircraft will be published at a later date, if there is a request for such information from operators desiring to accomplish this in preference to the modifications described in items (b) and (c) following.)
(b) Install at least three unit-type detectors at each augmenter tube bellmouth or on brackets mounted on the shroud or engine cowling and located in close proximity to the bellmouths, such as to be in the path of flames which would enter the bellmouth in the event of fire. Existing detectors at the upper cowl flaps and those mounted on the upper side shroud panels may be counted among the three units specified, provided they are installed in accordance with Convair Bulletins No. 240-419 and No. 240-419A or conform to original Model 340 production configuration. The third bellmouth detector location must conformwith figure 6 of Technical Development Center Report No. 250. Revised detector installations must be ground and flight tested in accordance with Thomas A. Edison Installation Manual, Publication No. 1058, dated July 15, 1950, to assure correct circuit adjustment.
(c) To minimize flame stratification and improve effectiveness of present fire detection, a reduction in airflow rate in zone two must be effected by modifications in accordance with Convair Service Bulletin 340-176 or equivalent for the 340 aircraft, and in accordance with Convair Service Bulletin 240-473 or equivalent for the 240 aircraft.
This supersedes AD 58-10-01.