Page:CAB Accident Report, United Air Lines Flight 823.pdf/31

FEDERAL AVIATION AGENCY
WASHINGTON, D. C. 20553

 

December 15, 1964

 

In repy
refer to: FS-431

 

Mr. B. R. Allen
Director, Bureau of Safety
Civil Aeronautics Board
Washington, D. C. 20428

 

Dear Mr. Allen:

This is in reply to your letter of November 17, 1964, regarding discrepancies in the Pyrene fire extinguisher system on the United Air Lines Vickers Viscount aircraft.

Our studies concerning the Viscount CO₂ system of which you were advised in our letter of October 19, 1962, have not been completed. For your information, Vickers Armstrong has notified all Viscount operators with cockpit CO₂ systems to manually discharge the extinguishing agent into the lower cargo bin

Pending completion of our investigation, as an interim precautionary measure, we are instructing our field personnel to request all Viscount operators with this same system to take the following action:

1. Re-emphasize to their pilots the need to don smoke masks before discharging the lower cargo bin CO₂ cylinder.

1. Instruct their pilots to manually discharge CO₂ for the lower cargo compartment

1. Notify their pilots that it is possible for CO₂ to leak into the cockpit area.

We certainly appreciate your recommendations.

Sincerely yours,

/s/ C. W. Walker

for
George S. Moore
Director
Flight Standards Service