[Federal Register Volume 59, Number 143 (Wednesday, July 27, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-18196]


[[Page Unknown]]

[Federal Register: July 27, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-74-AD]

 

Airworthiness Directives; Raytheon Corporate Jets Model BH/HS 
125-600A and -700A 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 all Raytheon Corporate Jets Model 
BH/HS 125-600A and -700A series airplanes. This proposal would require 
installation of two new circuit breakers in the 6 volt output circuits 
of the flight deck lighting transformers on electrical Panel `RY,' 
below the right pilot's seat. This proposal is prompted by a report of 
smoke in the flight deck due to a lighting transformer 6 volt output 
circuit short circuiting to ground. The actions specified by the 
proposed AD are intended to prevent smoke or fire in the flight deck 
due to inadequate circuit protection for 6 volt circuits of the flight 
deck lighting transformer.

DATES: Comments must be received by September 19, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-74-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.
    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: Bud 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-74-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-74-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 all Raytheon Corporate Jets Model BH/HS 
125-600A and -700A series airplanes. The CAA advises that an incident 
occurred on a Model HS 125-700B series airplane when a 6 volt output 
circuit from the flight deck lighting transformer on Panel 'RY' 
overheated and short-circuited to ground. This resulted in a release of 
acrid smoke in the flight deck. Investigation revealed that the 6 volt 
output circuit was not protected by a fuse or circuit breaker. This 
condition, if not corrected, could result in smoke and fire in the 
flight deck during flight.
    Since Model BH/HS 125-600A and 125-700A series airplanes are 
similar in type design to Model BH/HS 125-700B series airplanes, the 
FAA has determined that the addressed unsafe condition is likely to 
exist or develop on Model BH/HS 125-600A and 125-700A series airplanes.
    Raytheon Corporate Jets has issued Service Bulletin SB.24-310-
3544A&B, dated February 14, 1994, which describes procedures for 
installing circuit breakers in the 6 volt output circuits of two flight 
deck lighting transformers. The purpose of the circuit breakers is to 
provide circuit protection for the 6-volt output wires and to prevent 
overheating and short circuiting. 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 Sec. 21.29 of the Federal Aviation Regulations (14 CFR 
21.29) 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 installation of two 
new circuit breakers in the 6 volt output circuits of the flight deck 
lighting transformers on electrical Panel 'RY.' The actions would be 
required to be accomplished in accordance with the service bulletin 
described previously.
    The FAA estimates that 202 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 10 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 $500 per airplane. Based on these figures, the total cost 
impact of the proposed AD on U.S. operators is estimated to be 
$212,100, or $1,050 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 
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. 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 (Formerly British Aerospace PLC, Hawker 
Siddley): Docket 94-NM-74-AD.

    Applicability: All Model BH/HS 125-600A and -700A series 
airplanes, certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent smoke or fire in the flight deck due to short 
circuiting of the flight deck lighting transformers 6V output 
circuits, accomplish the following:
    (a) Within six months after the effective date of this AD, 
install circuit breakers in two 6 volt output circuits of the flight 
deck lighting transformers in accordance with Raytheon Corporate 
Jets Service Bulletin SB.24-310-3544A&B, dated February 14, 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 
Secs.  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 July 20, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-18196 Filed 7-26-94; 8:45am]
BILLING CODE 4910-13-U