62-11-03 GRAVINER: Amdt. 429 Part 507 Federal Register April 21, 1962. Applies to Aircraft Equipped With Automatic Fire Extinguisher Cartridge Mark 2, A-716, A-717, A-718, A-719 and Fenwal P/N 690202-3, A-716, A-717, A-718, A-719. (The Fenwal Installations Noted Are Graviner Systems. Some Mark 2 Cartridges Modified to Mark 3 Have "-3" Added to The Number on The Flat Plate, i.e., A-716-3, Etc. This AD Does Not Apply to Mark 3 Cartridges.)
Compliance required as indicated.
As a result of instances of the igniter wire in extinguisher cartridges becoming corroded in service, the following shall be accomplished:
(a) Within the next 275 hours' time in service or the next 60 days, whichever occurs first after effective date of this AD, unless already accomplished within the past 275 hours' time in service or the past 60 days conduct a continuity inspection of the cartridge circuits using a safety ohmmeter which restricts the current used to 13 milliamperes. A resistance reading of between 5 and 6 ohms indicates a serviceable fuse wire. A resistance reading not between 5 and 6 ohms indicates a defective fuse wire. Repetitive inspection of all cartridge circuits shall be accomplished within each succeeding 550 hours' time in service or 120 days, whichever occurs first after the last inspection.
(b) Replace defective Mark 2 cartridges with either serviceable Mark 2 cartridges or with Mark 3 cartridges which have an improved fuse wire. If Mark 2 cartridges are installed the repetitive inspection specified in (a) shall be continued. If Mark 3 cartridges are installed the repetitive inspections specified in (a) may be discontinued.
(c) Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, International Division, may adjust the repetitive inspection intervals specified in this AD to permit compliance of an established inspection period of the operator if the requestcontains substantiating data to justify the increase for such operator.
(Graviner Technical Notice No. 2 covers this subject.)
This supersedes AD 61-02-01.
This directive effective May 22, 1962.