[Federal Register Volume 64, Number 227 (Friday, November 26, 1999)]
[Proposed Rules]
[Pages 66418-66419]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-30802]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-102-AD]
RIN 2120-AA64


Airworthiness Directives; Dornier Model 328-100 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Proposed rule; withdrawal.

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SUMMARY: This action withdraws a notice of proposed rulemaking (NPRM) 
that proposed a new airworthiness directive (AD), applicable to certain 
Dornier Model 328-100 series airplanes. That action would have required 
a revision to the FAA-approved Airplane Flight Manual (AFM) to prohibit 
in-flight operation of the auxiliary power unit (APU). That proposal 
also would have required inspection of the APU fire extinguisher 
discharge cartridge for corrosion, and replacement of the discharge 
cartridge with a new cartridge, if necessary; and modification of the 
fire extinguishing system tube assembly. Accomplishment of these 
actions would have terminated the AFM revision. Since the issuance of 
the NPRM, the manufacturer has advised the Federal Aviation 
Administration (FAA) that, on all of the affected Model 328-100 series 
airplanes, the APU fire extinguisher discharge cartridges have been 
inspected, all corroded discharge cartridges have been replaced with 
new cartridges, and modification of the fire extinguishing system tube 
assemblies

[[Page 66419]]

has been accomplished. Accordingly, the proposed rule is withdrawn.

FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager, 
International Branch, ANM-116, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone 
(425) 227-2196; fax (425) 227-1320.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to add a new airworthiness 
directive (AD), applicable to certain Dornier Model 328-100 series 
airplanes, was published in the Federal Register on June 28, 1999 (64 
FR 34590). The proposed rule would have required a revision to the FAA-
approved Airplane Flight Manual (AFM) to prohibit in-flight operation 
of the auxiliary power unit (APU); inspection of the APU fire 
extinguisher discharge cartridge for corrosion, and replacement of the 
discharge cartridge with a new cartridge, if necessary; and 
modification of the fire extinguishing system tube assembly. After 
accomplishment of the inspection, modification, and replacement (if 
necessary), the AFM revision would be removed. The proposed rule was 
prompted by issuance of mandatory continuing airworthiness information 
by a foreign civil airworthiness authority. The proposed actions were 
intended to correct deficiencies in the design of the fire 
extinguishing system that did not allow for adequate fluid drainage. 
This condition, if not corrected, could have resulted in operational 
failure of the APU fire extinguisher.

Actions That Occurred Since the NPRM Was Issued

    Since the issuance of that NPRM, the manufacturer has provided the 
FAA with confirmation that, on all of the affected Dornier Model 328-
100 series airplanes, the APU fire extinguisher discharge cartridges 
have been inspected, all corroded discharge cartridges have been 
replaced with new cartridges, and modification of all the fire 
extinguishing system tube assemblies has been accomplished.

FAA's Conclusions

    Upon further consideration, the FAA has determined that the 
proposed actions of the NPRM (Rules Docket 99-NM-102-AD) are 
unnecessary since the unsafe condition that those actions were intended 
to address no longer exists. Accordingly, the proposed rule is hereby 
withdrawn.
    Withdrawal of this notice of proposed rulemaking constitutes only 
such action, and does not preclude the agency from issuing another 
notice in the future, nor does it commit the agency to any course of 
action in the future.

Regulatory Impact

    Since this action only withdraws a notice of proposed rulemaking, 
it is neither a proposed rule nor a final rule and therefore is not 
covered under Executive Order 12866, the Regulatory Flexibility Act, or 
DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 
1979).

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Withdrawal

    Accordingly, the notice of proposed rulemaking, Docket 99-NM-102-
AD, published in the Federal Register on June 28, 1999 (64 FR 34590), 
is withdrawn.

    Issued in Renton, Washington, on November 19, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-30802 Filed 11-24-99; 8:45 am]
BILLING CODE 4910-13-P