AD 58-08-03

58-08-03 DOUGLAS AND LOCKHEED: Applies to All Douglas DC3, Lockheed 18, and PV-1 Aircraft Having Bromochloromethane (CB) Fire Extinguisher Systems. (NOTE: Not Applicable to Systems Which Provide Leakproof Enclosures for the Fire Extinguishing Agent Containers.)

Compliance required by October 1, 1958.

Due to the toxicity hazard for crew and passengers existing in these airplanes having Bromochloromethane (CB) fire extinguishing system installed, particularly when the fire extinguishing agent containers are installed in the fuselage, one of the following must be accomplished.

1. The Bromochloromethane (CB) fire extinguisher agent must be replaced with a quantity of Freon 13B1 (Bromo-tri or CF3Br, equal to 0.8 times the installed weight of Bromochloromethane (CB) and a suitable breathing oxygen supply must be provided for the crew as specified in CAR 4b.651.

2. The Bromochloromethane (CB) fire extinguisher agent must be replaced with a quantity of carbon dioxide (CO2)equal to 1.25 times the installed quantity of Bromochloromethane (CB) and a suitable breathing oxygen supply must be provided for the crew as specified in CAR 4b.651.

3. The installed Bromochloromethane (CB) system must be shown to comply with the requirements of CAR 4b.371(b) and 4b.484(b)(2).

NOTE: This may be accomplished by enclosing the containers with a similar or equivalent system to that shown on AiResearch Drawings C-4900-77B sheets 1 to 3 inclusive.