[Federal Register Volume 61, Number 188 (Thursday, September 26, 1996)]
[Notices]
[Pages 50531-50532]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-24643]


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DEPARTMENT OF TRANSPORTATION

Aircraft Flight Recorder and Cockpit Voice Recorder

AGENCY: Federal Aviation Administration, DOT.

ACTION: Cancellation of Technical Standard Order (TSO's) C123 and C124; 
request for comments.

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SUMMARY: This is a cancellation of TSO-C123, Cockpit Voice Recorder 
System, and TSO-C124, Flight Data Recorder Systems. TSO-C123 prescribes 
the minimum performance standard that cockpit voice recorder were 
required to be identified with marking ``TSO-C123,'' dated 5/3/91. TSO-
C124 prescribes the minimum performance standards that flight data 
recorder systems were required to be identified with marking ``TSO-
C124,'' dated 2/21/92. This cancellation will ensure that future 
cockpit voice recorder systems, and flight data recorders are produced 
under TSO-C123a, Cockpit Voice Recorder System, and TSO-C124a, Flight 
Data Recorder Systems.

EFFECTIVE DATE: August 2, 1998. Comments for inclusion in the TSO's 
Docket Files must be received on or before November 25, 1996.

ADDRESSES: Submit comments to the Federal Aviation Administration 
(FAA), Technical Programs and Continued Airworthiness Branch (AIR-120), 
Attention: File No. TSO-C123 and TSO-C124, 800 Independence Avenue, 
SW., Washington, DC 20591

FOR FURTHER INFORMATION CONTACT: Ms. Bobbie J. Smith, Technical Program 
and Continued Airworthiness Branch, AIR-120, Aircraft Engineering 
Division, Aircraft Certification Service, Federal Aviation 
Administration, 800 Independence Avenue, SW., Washington, DC 20591, 
Telephone (202) 267-9546, and FAX Number 202-267-5340.

SUPPLEMENTARY INFORMATION: 

Background

    This notice cancels TSO-C123, Cockpit Voice Recorder System, and 
TSO-C124, Flight Data Recorder Systems. TSO-C123 prescribes the minimum 
performance standard that cockpit voice recorder were required to be 
identified with marking ``TSO-C123,'' dated 5/3/91. TSO-C124 prescribes 
the minimum performance standards that flight data recorder systems 
were required to be identified with marking ``TSO-C124,'' dated 2/21/
92. This cancellation will ensure that future cockpit voice recorder 
systems, and flight data recorders are produced under TSO-C123a, 
Cockpit Voice Recorder System, dated 8/2/96, and TSO-C124a, Flight Data 
Recorder Systems, dated 8/1/96.
    The National Transportation Safety Board reported that seven flight 
recorder media destroyed by postimpact fire in six accidents prompted 
concern about the adequacy of the performance standards for flight 
recorders. Minimum performance standards for impact and fire protection 
are outlined in four Technical Standard Orders (TSO's): TSO-C84 and 
TSO-C123 address CVR's and TSO-C51a and TSO-C124 address FDR's. TSO-C84 
and TSO-C51a were canceled May 18, 1996.
    The FAA Technical Center released a report on its study of flight 
recorder fire test requirements. The study determined that the high 
intensity, 30-minute fire test specified in the European Organization 
for Civil Aviation Equipment (EUROCAE), ED-56A, ``Minimum Operational 
Requirements for Cockpit Voice Recorder System,'' and European 
Organization for Civil Aviation Electronics (EUROCAE), ED-55, ``Minimum 
Operation Specification for Flight Data Recorder Systems,'' (and TSO-
C124) is not as severe as a 30-minute jet fuel pool fire the test is 
intended to replicate,. The Technical Center found that doubling the 
exposure time from 30 to 60 minutes on the fire test produced a total 
heat that is equivalent to the heat experienced in a 30-minute 
postimpact jet fuel pool fire. The study also determined that flight 
recorders meeting the 10-hour low-intensity fire test conditions 
described in ED-56A would survive postimpact smoldering fires involving 
natural materials.
    The Safety Board recommended that the FAA should revise TSO-C123 
and TSO-C124 to reflect the findings of the FAA fire test study by (a) 
incorporating the long-term, low-intensity fire test requirements 
described in ED-56A, and (b) incorporating the high-intensity fire test 
requirements described in ED-55 and ED-56A, with the exception of 
extending the duration of the high-intensity fire test from 30 minutes, 
as specified in the EUROCAE documents, to 60 minutes. to improve the 
fire requirements for flight recorder certification and to upgrade the 
standards in the TSO's, the Board recommended that the FAA cancel the

[[Page 50532]]

original TSO-C123 and TSO-C124 within 2 years after issuing the revised 
versions.
    Based on the findings of the NTSB and the FAA Technical Center 
study, TSO-C123 and TSO-C124 are canceled August 2, 1998. TSO-C123a, 
Cockpit Voice Recorder Systems, and TSO-C124a, Flight Data Recorder 
Systems were issued 8/2/96, and 8/1/96, respectively. TSO-C123a and 
TSO-C124a, incorporate the long-term, low-intensity fire test 
requirements, with the exception of extending the duration of the high-
intensity fire test from 30 minutes, as specified in the EUROCAE 
documents, to 60 minutes.

The Cancellation Procedure

    The FAA anticipates that this cancellation will not result in 
adverse or negative comments, and therefore is issuing it without prior 
opportunity to comment. The revised TSO-C123a and TSO-C124a have been 
issued and the majority of manufacturers are producing units under the 
new standards. Unless a written adverse or negative comment, or a 
written notice of intent to submit an adverse or negative comment is 
received within the comment period, the regulation will become 
effective on the date specified above. After the close of the comment 
period, the FAA will published a document in the Federal Register 
indicating that no adverse or negative comments were received and 
confirming that date on which the cancellation become effective. If the 
FAA does receive, within the comment period, an adverse or negative 
comment, or written notice of intent to submit such a comment, a 
document withdrawing the cancellation will be published in the Federal 
Register.

Comments Invited

    Although this action is in the form of a final cancellation and not 
preceded by a notice, comments are invited. Interested persons are 
invited to comment on this cancellation by submitting such written 
data, views, or arguments as they may desire. Communications should 
identify the TSO Docket File number and be submitted to the address 
specified under the caption ADDRESSES. All communications received on 
or before the closing date for comments will be considered. Factual 
information that supports the commenter's ideas and suggestions is 
extremely helpful in evaluating the effectiveness of this action and 
determining whether additional action would be needed.

    Issued in Washington, DC., on September 18, 1996.
Abbas A. Rizvi,
Acting Manager, Aircraft Engineering Division, Aircraft Certification 
Service.
[FR Doc. 96-24643 Filed 9-25-96; 8:45 am]
BILLING CODE 4910-13-M