# Aviation Accident Report: United Air Lines Flight 823/Attachment 1

FEDERAL AVIATION AGENCY Washington, D. C. 20553
January 2, 1964
In Reply Refer To: FS-110
Mr. Leon H. Tanguay Director, Bureau of Safety Civil Aeronautics Board Washington, D. C. 20428
Dear Mr. Tanguay:
This is to acknowledge your letter of December 17, 1963, reference B-1-96 regarding impact damage to the Lockheed 109-C flight data recorder installed in the PAWA 707, N709PA aircraft which crashed near Elkton, Maryland, on December 8, 1963.
Your recommendations are being studied and we will advise you further on this matter.
Sincerely yours,
/s/ W. Lloyd Lane
| For | George S. Moore |
| For | Director |
| For | Flight Standards Service |
FEDERAL AVIATION AGENCY Washington, D. C. 20553
February 27, 1964
In Reply Refer To: FS-110
Mr. Leon H. Tanguay Director, Bureau of Safety Civil Aeronautics Board Washington, D. C. 20428
Dear Mr. Tanguay:
This refers to your letter of December 17, 1963, reference B-1-96, regarding impact damage to the Lockheed 109-C flight data recorder installed in the Pan American World Airways B-707, N709PA, aircraft which crashed near Elkton, Maryland, on December 8, 1963, and our letter of acknowledgment dated January 2, 1964.
With respect to the Lockheed 109-C recorder, we are exploring what action can be taken to improve the crash resistance properties of this recorder. Consideration is being given to modifications for strengthening the record holder and the latches. If such modifications can be reasonably accomplished, we will study the possibility of a retrofit program by the airlines.
In addition, a project has been established to revise Technical Standard Order C51 to improve the performance standards related to crash resistance of recorders. We anticipate a notice of proposed rule making on this project by October 1, 1964.
The Agency also has two other related programs under way which can be expected to provide further useful information. One of these is an evaluation of tail-mounted recorders. The results will serve as a basis in considering future revisions to the installation requirements. The other program involves the development of an improved flight data recorder. It includes consideration of the greatly increased crash survivability capabilities which you recommend in this and previous correspondence.
We hope that this explains adequately the Federal Aviation Agency activities in the area of flight data recorders.
Sincerely yours,
/s/ Edward C. Hodson
For George S. Moore Director Flight Standards Service
CIVIL AERONAUTICS BOARD BUREAU OF SAFETY
July 17, 1964
Mr. George S. Moore Director Flight Standards Service Federal Aviation Agency Washington, D. C. 20553
Dear Mr. Moore,
This refers to your letter of February 27, 1964, which states the action being taken by the Federal Aviation Agency on the Board's letter dated December 17, 1963, relative to specific recommendations for improving the accuracy and the survivability of flight recorders.
As you know, the Lockheed 109C flight recorder installed in the United Air Lines Viscount 734, N7405, which crashed near Newport, Tennessee, on July 9, 1964, was very severely damaged by the ground impact and the ensuing fire. The mechanical damage was total demolishment of the case and the internal mechanism, and the ensuing fire consumed the accident portion of the flight record as well as fusing the tape on the spools.
In view of the interest being generated following the Newport accident, we would appreciate being advised as soon as possible as to the current status of the FAA actions outlined in your above letter.
Sincerely yours,
/s/ Leon H. Tanguay
Leon H. Tanguay Director, Bureau of Safety
FEDERAL AVIATION AGENCY Washington, D. C. 20553
August 7, 1964
Mr. Leon H. Tanguay Director, Bureau of Safety Civil Aeronautics Board Washington, D. C. 20428
Dear Mr. Tanguay:
This is in reply to your letter of July 17, 1964, reference B-80-96, concerning Federal Aviation Agency action on flight recorder improvements. The following outlines the current status of Agency action:
* An airworthiness directive is being processed as a Notice of Proposed Rule Making. This AD is directed at improving crash survivability on Lockheed Aircraft Service Company Flight Recorders, Models 109C and 109D, as follows:
** On Model 109C, serial number up to and including S/N 882, and Model 109D, serial numbers up to and including S/N 135, replace the tape cassette with a Lockheed Aircraft Service Company stainless steel cassette, P/N 4024570-1.
** On Model 109C, up to and including S/N 889, saw off near the case the two latch clamps which are to the left of the pitot pressure line connector when facing the pitot pressure connector. File the remaining edges of the clamp to conform to the contour of the recorder case and install Lockheed Aircraft Service Company clamping ring, P/N 4024582-1.
* AD action is being considered which will require improvements in the cassettes of the United Data Control and Fairchild flight recorders.
* Technical Standard Order C-51, Aircraft Flight Recorders, is being revised to incorporate increased crash strength standards. Regulatory documentation leading to issuance of ​Notice of Proposed Rule Making is nearing completion. We anticipate issuance of the NPRM on this subject before October 1, 1964.
* The NPRM on the installation of the flight recorder is being finalized and is expected to be released on or about October 1, 1964. The proposed rule will require the flight recorder to be located and mounted in the airplane in such a manner that the probability of the rupture of the container as a result of crash impact will be minimized. We further state that in compliance with this requirement 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.
* In regard to our program to investigate improved recorders (24 parameters), we have received proposals from five manufacturers. We will evaluate the proposals and select those recorders considered best suitable for the program. This action is expected to be completed by November 1, 1964.
Sincerely yours,
/s/ George S. Moore
George S. Moore Director Flight Standards Service
CIVIL AERONAUTICS BOARD Washington, D. C. 20428
In Reply Refer To: B-80-96
August 21, 1964
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 record holder shall be located as far aft as practicable but shall not be located in a position where aft-mounted engines are likely to crush the record during crash 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
Leon H. Tanguay Director, Bureau of Safety
FEDERAL AVIATION AGENCY Washington, D. C. 20553
In Reply Refer to: FS-102
August 28, 1964
Mr. Leon H. Tanguay Director, Bureau of Safety Civil Aeronautics Board Washington, D. C. 20428
Dear Mr. Tanguay:
This is to acknowledge your letter of August 21, 1964, reference B-80-96, regarding the status of the actions concerning flight recorder improvements.
Your recommendations that the Airworthiness Directive include reference to all 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, is being considered and we will advise you further on this matter.
Sincerely yours,
/s/ James F. Randolph
For George S. Moore Director Flight Standards Service
FEDERAL AVIATION AGENCY Washington, D. C. 20553
January 11, 1965
In Reply Refer To: FS-120
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 August 21, 1964, and, in addition, confirmation of telephone information forwarded to your office regarding the latest developments on the airworthiness directives for the Lockheed Air Service, Fairchild Flight Data, and United Data Control Recorders.
The following outlines the current status of Agency actions:
* Lockheed Aircraft Service Company Flight Recorders, Models 109C and 109D. An airworthiness directive was published in the Federal Register on July 29, 1964, as a Notice of Proposed Rule Making. An airworthiness directive has been published on December 28, 1964.
* Fairchild Camera and Instrument Corporation Flight Recorder Model F-5424. The airworthiness directive was published in the Federal Register on November 20, 1964, as a Notice of Proposed Rule Making.
* United Data Control Flight Recorder Model 542. The airworthiness directive was published as a Notice of Proposed Rule Making in the Federal Register on December 5, 1964.
In reference to your comments on the proposed rule for installation of flight recorders, we will consider your recommendations in our proposed rule making action now in preparation.
Sincerely yours,
/s/ George S. Moore
George S. Moore Director Flight Standards Service
FAA AIRWORTHINESS DIRECTIVE
Compliance required within eight months after the effective date of this AD, unless already accomplished.
To improve the crash survivability of the flight record, modify the Lockheed Aircraft Service Company flight recorder Models 109C and 109D as follows:
(a) On Model 109C serial numbers up to and including Serial Number 882 and Model 109D up to and including Serial Number 135, replace the tape cassette with a Lockheed Aircraft Service Company stainless steel cassette P/N 4024570-1.
This directive effective January 27, 1965.
Revise AD 65-1-3, Models 109C and 109D flight recorders, by deleting paragraph (b).
This amendment effective September 11, 1965.
Revise AD 65-1-3, Models 109C and 109D flight recorders, by:
1. Changing the compliance statement to read.
Compliance required as indicated, unless already accomplished.
2. Changing paragraph (a) to read:
(a) Within eight months after the effective date of Amendment 39-17 (29 F. R. 18477), on Model 109C, serial numbers up to and including Serial Number 882 and Model 109D up to and including Serial Number 135, replace the tape cassette with a Lockheed Aircraft Service Company stainless steel cassette P/N 4024570-1.
​3. Adding the following new paragraph (b) and the following parenthetical reference statement to read:
(b) Within eight months after March 24, 1966, on Model 109C, up to and including Serial Number 889, saw off near the case the two latch clamps which are to the left of the pitot pressure line connector when facing the pitot pressure line connector. File the remaining edges of the clamp to conform to the contour of the recorder case, and install Lockheed Aircraft Service Company clamping ring, P/N 4024582-803, or an equivalent approved by the Chief, Aircraft Engineering Division, FAA Western Region.
(Lockheed Aircraft Service Company Bulletin No. 31-12 dated April 1, 1965, covers this subject.)
This amendment effective March 24, 1966.