[Federal Register Volume 63, Number 59 (Friday, March 27, 1998)]
[Proposed Rules]
[Pages 14850-14851]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-8094]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-272-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-100, -200, -300, -SP, 
and -SR Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM); reopening of comment 
period.

-----------------------------------------------------------------------

SUMMARY: This document announces a reopening of the comment period for 
the above-referenced NPRM, applicable to

[[Page 14851]]

all Boeing Model 747-100, -200, -300, -SP, and -SR series airplanes. 
That NPRM invites comments concerning the proposed requirement for 
installation of components for the suppression of electrical transients 
and/or the installation of shielding and separation of the electrical 
wiring of the fuel quantity indication system (FQIS). This reopening of 
the comment period is necessary to afford all interested persons an 
opportunity to present their views on the proposed requirements of that 
NPRM.

DATES: Comments must be received by May 26, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 97-NM-272-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays.
    Information concerning this NPRM may be obtained from or examined 
at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., 
Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Chris Hartonas, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane 
Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, 
SW., Renton, Washington 98055-4056; telephone (425) 227-2864; fax (425) 
227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to all Boeing Model 747-100, -200, 
and -300 series airplanes was published in the Federal Register on 
December 1, 1997 (62 FR 63624). That action proposed to require 
installation of components for the suppression of electrical transients 
and/or the installation of shielding and separation of the electrical 
wiring of the fuel quantity indication system (FQIS). That action 
invites comments on regulatory, economic, environmental, and energy 
aspects of the proposal.
    That action was prompted by testing results, which revealed that 
excessive energy levels in the electrical wiring and probes of the fuel 
system could be induced by electrical transients. The actions specified 
by the proposed AD are intended to prevent electrical transients 
induced by electromagnetic interference (EMI) or electrical short 
circuit conditions from causing arcing of the FQIS electrical wiring or 
probes in the fuel tank, which could result in a source of ignition in 
the fuel tank.
    Since the issuance of that proposal, several commenters have raised 
issues regarding the ability to implement corrective action in a timely 
manner, particularly because the manufacturer has yet to issue a 
service bulletin. Based on these and other comments, the FAA has 
determined that further discussion and input may be beneficial prior to 
the adoption of a final rule. As a result, the FAA has decided to 
reopen the comment period for 60 days to receive additional comments.
    In addition, the applicability of the proposed rule addresses ``All 
Model 747-100, -200, and -300 series airplanes.'' However, the FAA's 
intent was that the proposal also apply to Model 747-SP and -SR series 
airplanes. Those airplanes are generally considered to be either Model 
747-100 or -200 series airplanes. Therefore, the applicability of the 
proposed rule is clarified as follows:
    ``All Model 747-100, -200, -300, -SP, and -SR series airplanes; 
certificated in any category.''
    The comment period for Rules Docket No. 97-NM-272-AD closes May 26, 
1998.
    Because only the applicability statement and no other portion of 
the proposal or other regulatory information has been changed, the 
entire proposal is not being republished.

    Issued in Renton, Washington, on March 23, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-8094 Filed 3-26-98; 8:45 am]
BILLING CODE 4910-13-P