[Federal Register Volume 66, Number 137 (Tuesday, July 17, 2001)]
[Proposed Rules]
[Pages 37197-37198]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-17759]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-27-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 727-100 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 
Boeing Model 727-100 series airplanes.

[[Page 37198]]

That action would have required repetitive inspections to detect 
corrosion of the lower surface of the wing center section and the 
surrounding area, and follow-on actions. Since the issuance of the 
NPRM, the Federal Aviation Administration (FAA) has received new 
information that indicates that the unsafe condition does not exist on 
the airplanes identified in the proposed rule. Accordingly, the NPRM is 
withdrawn.

FOR FURTHER INFORMATION CONTACT: Stan Wood, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, 1601 
Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-
2772; fax (425) 227-1181.

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 Boeing Model 727-100 series 
airplanes, was published in the Federal Register as a Notice of 
Proposed Rulemaking (NPRM) on April 5, 2000 (65 FR 17827). The NPRM 
would have required repetitive inspections to detect corrosion of the 
lower surface of the wing center section and the surrounding area, and 
follow-on actions. The NPRM was prompted by a report from the 
manufacturer indicating that the affected airplanes were subject to 
corrosion progression through the lower surface of the wing center 
section into the center wing fuel tank, and subsequent fuel leakage 
into the ram air duct. The proposed actions were intended to detect and 
correct such conditions, which, if combined with a leak in the primary 
or secondary heat exchanger, could result in the release of fuel vapors 
into the cabin and consequent adverse effects on flight crew and 
passengers.

Actions Since the NPRM Was Issued

    Since the issuance of the NPRM, the FAA has received new 
information concerning the configuration of Model 727-100 series 
airplanes, which are identified in the applicability of the NPRM. The 
NPRM was based on configuration similarities between those airplanes 
and Model 727-200 series airplanes, which are identified in the 
applicability of AD 85-24-02, amendment 39-5170 (50 FR 47356, November 
18, 1985). That AD addresses a corrosion problem in the area of the 
lower surface of the wing center section, which forms the upper wall of 
the ram air plenum chambers. As a result of the corrosion problem, fuel 
leaked into the plenum chambers and fuel vapors were circulated into 
the airplane air conditioning system and cockpit. The FAA has verified 
that the configuration of the subject area on Model 727-100 series 
airplanes is not the same as that on Model 727-200 series airplanes. 
Therefore, the three Model 727-100 series airplanes affected by the 
NPRM are not susceptible to the unsafe condition.

FAA's Conclusions

    Upon further consideration, the FAA has determined that the 
identified unsafe condition does not exist on the airplanes identified 
in the NPRM. 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 2000-NM-27-
AD, published in the Federal Register on April 5, 2000 (65 FR 17827), 
is withdrawn.

    Issued in Renton, Washington, on July 10, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-17759 Filed 7-16-01; 8:45 am]
BILLING CODE 4910-13-U