[Federal Register Volume 59, Number 82 (Friday, April 29, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-10231]


[[Page Unknown]]

[Federal Register: April 29, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-35-AD]

 

Airworthiness Directives; Raytheon Corporate Jets Model BAe 125-
1000A 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 Raytheon Corporate Jets 
Model BAe 125-1000A series airplanes. This proposal would require 
modification of the control circuit wiring for the engine thrust 
reversers and of the wiring for annunciation of rudder bias status. 
This proposal is prompted by a report that a single dormant electrical 
fault in the control circuit of the thrust reversers could cause a 
thrust reverser to deploy if the pilot selects reverse thrust during 
the approach phase of flight; and by reports that if an asymmetric 
thrust reverser condition occurs, the correct rudder bias may not be 
annunciated before the flight crew applies high reverse thrust. The 
actions specified by the proposed AD are intended to prevent adversely 
affected controllability of the airplane.

DATES: Comments must be received by June 22, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-35-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9 a.m. and 3 p.m., Monday through Friday, except Federal 
holidays.
    The service information referenced in the proposed rule may be 
obtained from Raytheon Corporate Jets Inc., 3 Bishops Square, St. 
Albans Road West, Hatfield, Hertfordshire, AL109NE, United Kingdom. 
This information may be examined at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: William Schroeder, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone (206) 
227-2148; fax (206) 227-1320.

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 94-NM-35-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. 94-NM-35-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom, recently notified the FAA that an 
unsafe condition may exist on certain Raytheon Corporate Jets Model BAe 
125-1000A series airplanes. The CAA advises that a single dormant 
electrical fault in the control circuit of the thrust reversers could 
cause a thrust reverser to deploy if the pilot selects reverse thrust 
during the approach phase of flight. The CAA also advises that, 
currently, a 4-second time delay occurs in the rudder bias annunciation 
system. This annunciation system provides a warning to the flight crew 
that an asymmetric thrust reverser condition may exist. If an 
asymmetric thrust reverser condition occurs, and the flight crew does 
not receive sufficient warning from the annunciation system, the flight 
crew may apply high reverse thrust.
    These conditions, if not corrected, could adversely affect the 
controllability of the airplane.
    Raytheon Corporate Jets has issued Service Bulletin SB.78-9-3662B, 
dated January 7, 1994, that describes procedures for modification of 
the control circuit wiring of the left and right engine thrust 
reversers and of the wiring for annunciation of rudder bias status. The 
modification involves grounding the normally closed contacts of the 
deploy microswitch to remove possible dormant shorts, wiring new 
independently signalled contacts in series with the power supply to the 
deploy valve solenoid, separating the wiring for the rudder bias not 
inhibited annunciation (warning) from the wiring for the uncommanded 
hydraulic pressure warning to bypass the 4-second time delay, and other 
miscellaneous wiring changes to the thrust reverser wiring system. 
Accomplishment of the modification will improve the integrity of the 
electrical control circuits of the thrust reversers by eliminating the 
possibility of single dormant failures in the thrust reverser system. 
Accomplishment of the modification will also correct the status 
annunciation of the rudder bias by ensuring that, when an asymmetric 
thrust reverser condition occurs, the status of the rudder bias system 
is annunciated to the flight crew before the power settings for high 
reverse thrust are applied. The CAA classified this service bulletin as 
mandatory in order to assure the continued airworthiness of these 
airplanes in the United Kingdom.
    This airplane model is manufactured in the United Kingdom and is 
type certificated for operation in the United States under the 
provisions of Section 21.29 of the Federal Aviation Regulations and the 
applicable bilateral airworthiness agreement. Pursuant to this 
bilateral airworthiness agreement, the CAA has kept the FAA informed of 
the situation described above. The FAA has examined the findings of the 
CAA, reviewed all available information, and determined that AD action 
is necessary for products of this type design that are certificated for 
operation in the United States.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design registered 
in the United States, the proposed AD would require modification of the 
control circuit wiring for the engine thrust reversers and of the 
wiring for annunciation of rudder bias status. The actions would be 
required to be accomplished in accordance with the service bulletin 
described previously.
    The FAA estimates that 19 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 60 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $55 per work hour. Required parts would cost 
approximately $1,000 per airplane. Based on these figures, the total 
cost impact of the proposed AD on U.S. operators is estimated to be 
$81,700, or $4,300 per airplane.
    The total cost impact figure discussed above is 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.
    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. 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 14 
CFR part 39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

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

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13   [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Raytheon Corporate Jets, Inc.: Docket 94-NM-35-AD.

    Applicability: Model BAe 125-1000A series airplanes; serial 
numbers 258151, 258159, and 259003 through 259044 inclusive; 
certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent in-flight deployment of a thrust reverser, which 
could adversely affect the controllability of the airplane, 
accomplish the following:
    (a) Within 8 months after the effective date of this AD, modify 
the control circuit wiring for the left and right engine thrust 
reversers and rudder bias status annunciation, in accordance with 
Raytheon Corporate Jets Service Bulletin SB.78-9-3662B, dated 
January 7, 1994.
    (b) 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, Standardization Branch, ANM-113, 
FAA, Transport Airplane Directorate. Operators shall submit their 
requests through an appropriate FAA Principal Maintenance Inspector, 
who may add comments and then send it to the Manager, 
Standardization Branch, ANM-113.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (c) Special flight permits may be issued in accordance with 
Federal Aviation Regulations (FAR) 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 April 22, 1994.
S.R. Miller,
 Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-10231 Filed 4-28-94; 8:45 am]
BILLING CODE 4910-13-U