[Federal Register Volume 66, Number 94 (Tuesday, May 15, 2001)]
[Notices]
[Pages 26905-26906]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-12104]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration


Proposed Revisions to Advisory Circular--Flight Test Guide for 
Certification of Transport Category Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed advisory circular revision and request for 
comments.

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SUMMARY: The Federal Aviation Administration requests comments 
regarding a proposed revision to Advisory Circular (AC) 25-7A, ``Flight 
Test Guide for Certification of Transport Category Airplanes.'' The 
proposed revision provides revised guidance concerning proposed 
rulemaking published elsewhere in this issue of the Federal Register 
concerning the airspeed indicating system. This notice provides 
interested persons an opportunity to comment on the proposed revision 
to the AC concurrently with the proposed rulemaking.

DATES: Comments must be received on or before July 16, 2001.

ADDRESSES: Send all comments on the proposed AC revision to the Federal 
Aviation Administration, Attention: Don Stimson, Airplane & Flight Crew 
Interface Branch, ANM-111, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Ave SW., Renton, WA 98055-4056. 
Comments may be examined at the above address between 7:30 a.m. and 4 
p.m. weekdays, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Patricia Siegrist, Program Management 
Branch, ANM-114, at the above address, telephone (425) 227-2126, or 
facsimile (425) 227-1320.

SUPPLEMENTARY INFORMATION:

Comments Invited

    You are invited to comment on the proposed revision to the AC by 
submitting written data, views, or

[[Page 26906]]

arguments. You must identify the title of the AC and submit comments in 
duplicate to the address specified above. The Transport Airplane 
Directorate will consider all comments received on or before the 
closing date for comments before issuing a revision to the AC.

Discussion

    By a notice of proposed rulemaking published in this same issue of 
the Federal Register, the Federal Aviation Administration (FAA) 
proposes to amend the airworthiness standards for transport category 
airplanes concerning the airspeed indicating system. The proposed 
amendment would update the current standards by adding airspeed 
indication requirements for speeds greater than and less than the speed 
range for which airspeed indication accuracy requirements currently 
apply, would add a requirement that airspeed indications not cause the 
pilot undue difficulty between the initiation of rotation and the 
achievement of a steady climbing condition during takeoff, and would 
also add a requirement to limit the effects of airspeed lag. The 
proposed amendment would harmonize these standards with those being 
proposed for the European Joint Aviation Requirements (JAR-25).
    To address the additional rulemaking requirements proposed for part 
25, the FAA also proposes to revise Advisory Circular (AC) 25-7A to 
describe acceptable means of showing compliance with the proposed rule. 
This revision only addresses guidance material associated with the 
airspeed indicating system, and should not be confused with other 
proposed revisions of AC 25-7A for which the FAA is currently seeking 
comment. Issuance of a revised AC is contingent on adoption of the 
proposed revisions to part 25.

Proposed Revisions to AC 25-7A

    1. Replace existing paragraph 177a(1)(v) with new paragraphs 
a(1)(v) and (vi) to read as follows:
    (v) An acceptable means of compliance when demonstrating a 
perceptible speed change between 1.3 VS to stall warning 
speed is for the rate of change of IAS with CAS to be not less than 
0.75.
    (vi) An acceptable means of compliance when demonstrating a 
perceptible speed change between VMO to VMO+\2/3\ 
(VDF-VMO) is for the rate of change of IAS with 
CAS to be not less than 0.50.
    2. Redesignate existing paragraph 177a(1)(v), Airspeed Lag, as 
paragraph 177a(1)(vii).

    Issued in Renton, Washington, on May 2, 2001.
Lirio L. Nelson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-12104 Filed 5-14-01; 8:45 am]
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