[Federal Register Volume 70, Number 14 (Monday, January 24, 2005)]
[Proposed Rules]
[Pages 3318-3320]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-1221]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20111; Directorate Identifier 2004-NM-154-AD]
RIN 2120-AA64


Airworthiness Directives; Raytheon Model HS.125 Series 700A 
Airplanes, Model BAe.125 Series 800A Airplanes, and Model Hawker 800 
and Hawker 800XP Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Raytheon Model HS.125 series 700A airplanes, Model BAe.125 
series 800A airplanes, and Model Hawker 800 and Hawker 800XP airplanes. 
This proposed AD would require an inspection to determine the current 
rating of the circuit breakers of certain cockpit ventilation and 
avionics cooling system blowers; and for replacing the circuit breakers 
and modifying the blower wiring, as applicable. This proposed AD is 
prompted by a report indicating that a blower motor seized up and gave 
off smoke. Investigation revealed inadequate short circuit protection 
on the blower motor electrical circuit. We are proposing this AD to 
prevent smoke and fumes in the cockpit in the event that a blower motor 
seizes and overheats due to excessive current draw.

DATES: We must receive comments on this proposed AD by March 10, 2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to [fnl<>]http://dms.dot.gov and 
follow the instructions for sending your comments electronically.
     Government-wide Rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     By Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. 
and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Raytheon Aircraft Company, Department 62, P.O. Box 85, Wichita, Kansas 
67201-0085.
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or in person at the Docket Management Facility, 
U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, 
on the plaza level of the Nassif Building, Washington, DC. This docket 
number is FAA-2005-20111; the directorate identifier for this docket is 
2004-NM-154-AD.

FOR FURTHER INFORMATION CONTACT: Philip Petty, Aerospace Engineer, 
Electrical Systems Branch, ACE-119W, FAA, Wichita Aircraft 
Certification Office, 1801 Airport Road, room 100, Mid-Continent 
Airport, Wichita, Kansas 67209; telephone (316) 946-4139; fax (316) 
946-4107.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2005-20111; 
Directorate Identifier 2004-NM-154-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments submitted by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://

[[Page 3319]]

dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You can review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
can visit http://dms.dot.gov.

Examining the Docket

    You can examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the DMS receives them.

Discussion

    We have received a report indicating that a cockpit ventilation and 
avionics cooling system blower motor seized up and gave off smoke on a 
Raytheon Hawker Model 125-800 airplane. Investigation revealed 
inadequate short circuit protection on the blower motor electrical 
circuit. This condition, if not corrected, could result in smoke and 
fumes in the cockpit in the event that a blower motor seizes and 
overheats due to excessive current draw.

Relevant Service Information

    We have reviewed Raytheon Service Bulletin SB 24-3272, Revision 1, 
dated October 2000. The service bulletin describes procedures for 
inspecting to determine the current rating of the circuit breakers of 
certain cockpit ventilation and avionics cooling system blowers; and 
for replacing the circuit breakers and modifying the blower wiring, if 
applicable. Accomplishing the actions specified in the service 
information is intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other airplanes 
of this same type design. Therefore, we are proposing this AD, which 
would require accomplishing the actions specified in the service 
information described previously, except as discussed under 
``Difference Between the Proposed AD and the Service Information.''

Difference Between the Proposed AD and Service Information

    Although the service bulletin specifies that operators may contact 
the manufacturer for disposition of certain repair conditions, this 
proposed AD would require operators to repair those conditions 
according to a method approved by the FAA.

Costs of Compliance

    There are about 350 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 250 airplanes of 
U.S. registry. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD.

                                        Inspection and Modification Costs
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                                                                             Average
                           Action                              Work hours   labor rate   Parts cost    Cost per
                                                                             per hour                  airplane
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Inspection..................................................            1          $65     No parts          $65
Modification of cockpit blower circuit, if applicable.......            2           65          500          630
Modification of instrument panel blower circuit, if                    12           65          500        1,280
 applicable.................................................
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Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
subtitle VII, part A, subpart III, section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect 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.
    For the reasons discussed above, I certify that the 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. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD. See the ADDRESSES section for a location 
to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):


[[Page 3320]]


Raytheon Aircraft Company: Docket No. FAA-2005-20111; Directorate 
Identifier 2004-NM-154-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by March 10, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Raytheon Model HS.125 series 700A 
airplanes, Model BAe.125 series 800A airplanes, and Model Hawker 800 
and Hawker 800XP airplanes; equipped with Brailsford TBL-2.5 
blowers; as identified in Raytheon Service Bulletin SB 24-3272, 
Revision 1, dated October 2000; certificated in any category.

Unsafe Condition

    (d) This AD was prompted by a report indicating that a cockpit 
ventilation and avionics cooling system blower motor seized up and 
gave off smoke due to inadequate short circuit protection on the 
blower motor electrical circuit. We are issuing this AD to prevent 
smoke and fumes in the cockpit in the event that a blower motor 
seizes and overheats due to excessive current draw.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Inspection and Corrective Actions

    (f) Within 600 flight hours or six months after the effective 
date of this AD, whichever occurs first, inspect to determine the 
current rating of the circuit breakers of certain cockpit 
ventilation and avionics cooling system blowers; and replace the 
circuit breakers and modify the blower wiring, as applicable; by 
doing all the actions in accordance with the Accomplishment 
Instructions of Raytheon Service Bulletin SB 24-3272, Revision 1, 
dated October 2000.

Contacting the Manufacturer

    (g) Where the service bulletin suggests contacting the 
manufacturer for information if any difficulties are encountered 
while accomplishing the service bulletin, this AD would require you 
to contact the Manager, Wichita Aircraft Certification Office (ACO), 
FAA.

Alternative Methods of Compliance (AMOCs)

    (h) The Manager, Wichita ACO, has the authority to approve AMOCs 
for this AD, if requested in accordance with the procedures found in 
14 CFR 39.19.

    Issued in Renton, Washington, on January 12, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-1221 Filed 1-21-05; 8:45 am]
BILLING CODE 4910-13-P