[Federal Register Volume 64, Number 197 (Wednesday, October 13, 1999)]
[Proposed Rules]
[Pages 55440-55441]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-26714]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-131-AD]
RIN 2120-AA64
Airworthiness Directives; Saab Model SAAB SF-340 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Proposed rule; withdrawal.
-----------------------------------------------------------------------
SUMMARY: This action withdraws a notice of proposed rulemaking (NPRM)
that proposed a new airworthiness directive (AD), applicable to Saab
Model SAAB SF-340 series airplanes. That action would have required
replacement of the existing pneumatic de-icing boot pressure indicator
switch with a newly designed switch. Since the issuance of the NPRM,
the Federal Aviation Administration (FAA) has received new data that
demonstrates that the unsafe condition cannot occur. Accordingly, the
proposed rule is withdrawn.
FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager,
International Branch, ANM-116, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
227-2110; fax (425) 227-1149.
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 Saab Model SAAB SF-340 series airplanes,
was published in the Federal Register as a Notice of Proposed
Rulemaking (NPRM) on July 22, 1999 (64 FR 39450). The proposed rule
would have required replacement of the existing pneumatic de-icing boot
pressure indicator switch with a newly designed switch. That action was
prompted by an occurrence on a similar airplane model in which the
pneumatic de-icing boot indication light may have provided the
flightcrew with misleading information as to the proper functioning
[[Page 55441]]
of the de-icing boots. The proposed actions were intended to prevent
ice accumulation on the airplane leading edges, which could reduce
controllability of the airplane.
Actions That Occurred Since the NPRM Was Issued
Since the issuance of that NPRM, the manufacturer has provided the
Federal Aviation Administration (FAA) with test and analytical data
that substantiate that Saab Model SAAB SF-340 series airplanes feature
a pneumatic boot de-icing system that assures the proper pneumatic
threshold has been reached for effective pneumatic de-ice boot
operation prior to illuminating the indication light. The FAA concludes
that the de-icing boot design on Saab Model SAAB SF-340 series
airplanes includes sufficient robust features to preclude the unsafe
condition addressed in the NPRM.
FAA's Conclusions
Upon further consideration, the FAA has determined that the
proposed actions of the NPRM (Docket 99-NM-131-AD) are unnecessary
because the identified unsafe condition does not exist on Saab Model
SAAB SF-340 series airplanes. 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 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-131-
AD, published in the Federal Register on July 22 (64 FR 39450), is
withdrawn.
Issued in Renton, Washington, on October 6, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-26714 Filed 10-12-99; 8:45 am]
BILLING CODE 4910-13-P
