AD/CESSNA 150/42 - Battery/Battery Contactor Cable Routing (Cth)

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES

Cessna 150, F150, 152 & F152 Series Aeroplanes

AD/CESSNA 150/42 Battery/Battery Contactor Cable Routing 11/88 DM

Applicability: Aircraft model 150D, 150E, 150F, 150G, 150H, 150J, 150K, 150L, 150M, A150K, A150L, A150M, F150G, F150H, F150J, F150K, F150L, F150M, FA150K, FA150L, FRA150L and FRA150M all serial numbers, which have undergone any modifications to relocate the battery from the firewall to the aft fuselage, and

Model 150, 150A, 150B, 150C all serial numbers, which have undergone any modifications in which the battery has been moved from its location just aft of the baggage compartment aft bulkhead to any other aft position.

Requirement: To prevent failure of the up elevator cable, perform the following:

(a) Tie the "battery to battery contactor" cable to the lock pin which attaches the battery box cover to the battery box using either MIL-C-5649 cord, MS17821 or MS3367 tiedown strap to achieve a minimum of one inch clearance between the battery cable and the elevator up cable.

(b) Visually inspect the battery cable and elevator cable for damage. Prior to next flight, repair any such damage found.

Compliance: Within 25 hours time in service after 20 August 1988.

Background: A recent fatal accident [FAA AD 88-15-06 Amendment 39-5977 refers] involving a Cessna 150D occurred after modification to relocate the battery box from the firewall to the aft fuselage. The up elevator control cable was found to have chafed against the battery to battery contactor cable such that the insulation on the latter cable was destroyed resulting in an electrical short circuit of the battery cable. This produced sufficient electrical resistance and subsequent heat to cause the up elevator cable to fail.