Page:CAB Accident Report, United Air Lines Flight 823.pdf/23

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Mr. George S. Moore Director Flight Standards Service Federal Aviation Agency Washington, D. C. 20553

Dear Mr. Moore:

This is in reference to your letter of August 7, 1964, regarding the status of the actions concerning flight recorder improvements.

Item No. 2 in the above mentioned letter refers to the Airworthiness Directive action being considered which will require improvements in the cassettes of the United Data Control and the Fairchild flight recorders. We have been apprised of the proposed modifications to flight data recorders manufactured by United Data Control for their Model F-542. These modifications include additional recording medium protection plates against tearing and crushing, and a magazine handle latch to preclude inadvertent unlocking of the magazine. The modification improvements are covered by UDC Dwg. SK-260, revision A, dated June 19, 1964. We understand that similar modifications have not been proposed for the Fairchild Model 5424 flight recorder.

We recommend, therefore, that the AD include reference to all of the above described modifications as an acceptable means of compliance for the Fairchild Model 5424 recorder as well as the UDC Model F-542, inasmuch as the designs are comparable.

The last sentence in Item No. 4 of your letter reads, in part: "... the recorder shall be located as far aft as practicable and shall not be located aft where aft-mounted engines are likely to crush the recorder during impact." The following rewording is suggested as more appropriate: "... the shall be located as far aft as practicable  shall not be  where aft-mounted engines are likely to crush the  during  impact." The above underlining is merely to point out the changes.

We would appreciate being advised as soon as possible relative to the action contemplated on the issuance of the AD.

Sincerely yours,

/s/ Leon H. Tanguay