[Federal Register Volume 59, Number 118 (Tuesday, June 21, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-14678]


[[Page Unknown]]

[Federal Register: June 21, 1994]


DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

 

Emergency Locator Transmitters; Notice

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of technical standard order authorization withdrawal.

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SUMMARY: This notice withdraws each Technical Standard Order (TSO) C91 
authorization to the extent that it allows the authorization holder to 
identify or mark emergency locator transmitters (ELT's) with ``TSO-
C91),'' and sets a date for the termination of ELT's manufactured under 
TSO-C91. This withdrawal will ensure that future ELT's are produced 
under TSO-C91a, issued previously which requires a higher minimum 
operational performance standard for ELT's.

EFFECTIVE DATES: For automatic ELT's December 19, 1994. For survival 
ELT's: June 21, 1996.

FOR FURTHER INFORMATION CONTACT:
Mr. Phil Akers, Technical Analysis Branch, AIR-120, Aircraft 
Engineering Division, Aircraft Certification Service, Federal Aviation 
Administration, 800 Independence Avenue SW., Washington, DC. 20591, 
Telephone (202) 267-9571.

SUPPLEMENTARY INFORMATION: 

Background

    In April 1990, the FAA proposed that all future installations of 
Emergency Locator Transmitters (ELT's) use equipment approved under 
Technical Standard Order (TSO) C91a (55 FR 12316, April 2, 1990). The 
FAA also proposed the termination of the manufacture of TSO-C91 ELT's 
by withdrawing the TSO-C91 manufacturing authorizations. These actions 
were based on the known unsatisfactory performance of ELT's approved 
under TSO-C91.
    In April 1985, the FAA issued TSO-C91a, which provides an improved 
minimum operational performance standard (MOPS) for 121.5/243.0 MHz 
ELT's. In December 1992, the FAA issued TSO-C126, which provides a MOPS 
for 406 MHz ELT's. ELT's approved under either of these TSO's may be 
used to comply with the Federal Aviation Regulations for ELT's.
    Accordingly, this notice withdraws TSO-C91 to the extent that it 
authorizes the holder to mark ELT's with the designation ``TSO-C91.'' 
For automatic ELT's manufactured under TSO-C91, this cancellation is 
effective December 19, 1994. For survival ELT's manufactured under TSO-
C91, this withdrawal is effective June 21, 1996.

    Issued in Washington, DC on June 10, 1994.
Richard A. Kirsch,
Acting Manager, Aircraft Engineering Division, Aircraft Certification 
Service.
[FR Doc. 94-14678 Filed 6-20-94; 8:45 am]
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