[Federal Register Volume 61, Number 179 (Friday, September 13, 1996)]
[Proposed Rules]
[Pages 48431-48433]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-23446]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-121-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 727-200 Series Airplanes; 
McDonnell Douglas MD-11 Airplanes; and British Aerospace Avro Model 
146-RJ Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain transport category 
airplanes equipped with certain Honeywell Standard Windshear Detection 
System (WSS). This proposal would require a revision to the FAA-
approved airplane flight manual to alert the flightcrew of the 
potential for significant delays in the WSS detecting windshear when 
the flaps of the airplane are in transition. The proposal also would 
require replacement of the currently-installed line replaceable unit 
(LRU) with a modified LRU having new software that eliminates delays in 
the WSS. This proposal is prompted by a report of an accident during 
which an airplane encountered severe windshear during a missed 
approach. The actions specified by the proposed AD are intended to 
prevent significant delays in the WSS detecting hazardous windshear, 
which could lead to the loss of flight path control.

DATES: Comments must be received by October 24, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-121-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00

[[Page 48432]]

p.m., Monday through Friday, except Federal holidays.
    Information related to this rulemaking action may be examined at 
the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the FAA, Los Angeles Aircraft Certification Office, 
3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT: J. Kirk Baker, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, California 
90712; telephone (310) 627-5345; fax (310) 627-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 96-NM-121-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules 
Docket No. 96-NM-121-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On January 18, 1996, the FAA issued AD 96-02-06, amendment 39-9494 
(61 FR 2095, January 25, 1996), applicable certain transport category 
airplanes equipped with certain Honeywell Standard Windshear Detection 
Systems (WSS). That AD requires a revision to the FAA-approved Airplane 
Flight Manual (AFM) to alert the flightcrew of the potential for 
significant delays in the WSS detecting windshear when the flaps of the 
airplane are in transition. That AD also requires replacement of the 
currently-installed line replaceable unit (LRU) with a modified LRU 
having new software that eliminates delays in the WSS. That action was 
prompted by a report of an accident during which an airplane 
encountered severe windshear during a missed approach. The actions 
required by that AD are intended to prevent significant delays in the 
WSS detecting hazardous windshear, which could lead to the loss of 
flight path control.
    Since the issuance of that AD, the FAA has determined that certain 
Boeing Model 727-200 series airplanes, McDonnell Douglas Model MD-11 
airplanes, and British Aerospace Model Avro 146-RJ series airplanes may 
be equipped with Honeywell WSS that have the same design feature that 
can delay detection of windshear when the airplane's flaps are in 
transition. In light of this, these airplane models are subject to the 
same unsafe condition addressed in AD 96-02-06.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require a revision to the FAA-approved AFM to alert 
the flightcrew of the potential for significant delays in the WSS 
detecting windshear when the flaps of the airplane are in transition. 
The proposed also would require replacement of the currently-installed 
LRU with a modified LRU having new software that eliminates delays in 
the WSS.

    Note: The FAA's normal policy is that when an AD requires a 
substantive change, such as a change (expansion) in its 
applicability, the ``old'' AD is superseded by removing it from the 
system and a new AD is added. In the case of this AD action, the FAA 
normally would have proposed superseding AD 96-02-06 to expand its 
applicability to include the additional affected airplanes. However, 
in reconsideration of the entire fleet size that would be affected 
by a supersedure action, and the consequent workload associated with 
revising maintenance record entries, the FAA has determined that a 
less burdensome approach is to issue a separate AD applicable only 
to these additional airplanes. This proposed AD would not supersede 
AD 96-02-06; airplanes listed in the applicability of AD 96-02-06 
are required to continue to comply with the requirements of that AD. 
This proposed AD is a separate AD action, and is applicable only to 
Boeing Model 727-200 series airplanes, McDonnell Douglas Model MD-11 
airplanes, and British Aerospace Model Avro 146-RJ series airplanes, 
equipped with the specified Honeywell WSS.

Cost Impact

    There are approximately 200 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 100 airplanes of U.S. registry 
would be affected by this proposed AD.
    It would take approximately 1 work hour per airplane to accomplish 
the proposed AFM revision, at an average labor rate of $60 per work 
hour. Based on these figures, the cost impact of the AFM revision 
proposed by this AD on U.S. operators is estimated to be $6,000, or $60 
per airplane.
    It would take approximately 10 work hour per airplane to accomplish 
the proposed replacement, at an average labor rate of $60 per work 
hour. Required parts would be supplied by Honeywell at no cost to the 
operators. Based on these figures, the cost impact of the proposed AD 
on U.S. operators is estimated to be $60,000, or $600 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the proposed requirements 
of this AD action, and that no operator would accomplish those actions 
in the future if this AD were not adopted.

Regulatory Impact

    The regulations proposed herein would not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, will not have a significant economic impact, 
positive or negative, on a substantial number of small entities under 
the criteria of the Regulatory Flexibility Act. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket.

[[Page 48433]]

A copy of it may be obtained by contacting the Rules Docket at the 
location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:
Boeing; McDonnell Douglas; and British Aerospace Regional Aircraft 
Limited, AVRO International Aerospace Division (Formerly British 
Aerospace, PLC; British Aerospace Commercial Aircraft Limited): 
Docket 96-NM-121-AD.

    Applicability: The following models and series of airplanes, 
certificated in any category, equipped with Honeywell Standard 
Windshear Detection Systems (WSS) having the part numbers indicated 
below:

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  Manufacturer and model of airplane         Type of computer                       Part numbers                
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Boeing 727-200 series.................  Expandable Windshear       4053818-904, -905, or -906.                  
                                         (Honeywell STC).                                                       
McDonnell Douglas MD-11 series........  Flight Control Computer    4059001-906.                                 
                                         (OEM TC).                                                              
British Aerospace Avro 146-RJ70A, -     Flight Control Computer    4068300-903.                                 
 RJ85A, and -RJ100A series.              (OEM TC).                                                              
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    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (d) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent significant delays in the Honeywell Standard 
Windshear Detection Systems (WSS) detecting hazardous windshear, 
which could lead to the loss of flight path control, accomplish the 
following:
    (a) Within 14 days after the effective date of this AD, revise 
the Limitations Section of the FAA-approved Airplane Flight Manual 
(AFM) to include the following statement. This may be accomplished 
by inserting a copy of this AD in the AFM.
    During sustained banks of greater than 15 degrees or during flap 
configuration changes, the Honeywell Windshear Detection and 
Recovery Guidance System (WSS) is desensitized and alerts resulting 
from encountering windshear conditions will be delayed.
    (b) Within 30 months after the effective date of this AD, 
replace the currently-installed line replaceable unit (LRU) with a 
modified LRU having new software that eliminates delays in the WSS 
detecting windshear when the flaps of the airplane are in 
transition, in accordance with a method approved by the Manager, Los 
Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane 
Directorate. Accomplishment of this replacement constitutes 
terminating action for the requirements of paragraph (a) of this AD; 
after the replacement has been accomplished, the AFM limitation 
required by paragraph (a) of this AD may be revised to read as 
follows:
    During sustained banks of greater than 15 degrees, the Honeywell 
Windshear Detection and Recovery Guidance System (WSS) is 
desensitized and alerts resulting from encountering windshear 
conditions will be delayed.
    (c) As of 12 months after the effective date of this AD, no 
person shall install on any airplane an LRU that has not been 
modified in accordance with paragraph (b) of this AD. However, an 
unmodified LRU may be installed on the airplane for up to 12 months 
after the effective date of this AD, provided that, during that 
time, the AFM limitation required by paragraph (a) of this AD 
remains in effect.
    (d) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Los Angeles ACO. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Los Angeles ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (e) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

    Issued in Renton, Washington, on September 6, 1996.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-23446 Filed 9-12-96; 8:45 am]
BILLING CODE 4910-13-U