DEPARTMENT OF TRANSPORTATION
FEDERAL AVIATION ADMINISTRATION
14 CFR Part 39
[Docket No. FAA-2008-0492; Directorate Identifier 2008-CE-023-AD] RIN
2120-AA64
AIRWORTHINESS DIRECTIVES; Hawker Beechcraft Corporation Model 390 Air-
planes
AGENCY: Federal Aviation Administration (FAA), Department of Transportat-
ion (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: We propose to adopt a new airworthiness directive (AD) for
certain Hawker Beechcraft Corporation (HBC) Model 390 airplanes. This
proposed AD would require you to remove the current preformed packing,
elbow fitting, and jam nut from the left and right hydraulic pump pressure
output port and replace with new parts. This proposed AD would also
require you to install a hydraulic pump case drain check valve. This
proposed AD results from nine occurrences of hydraulic fluid leaking from
the engine hydraulic pump output fitting as a result of an improperly
installed elbow connecting the output port to the pulse dampener hose. We
are proposing this AD to prevent hydraulic fluid leaks from the left and
right hydraulic fluid pump and to prevent the flow of hydraulic fluid into
the engine compartment. The loss of hydraulic fluid can result in loss of
airplane hydraulic system pressure and the consequent loss of hydraulic
system functions including gear extension/retraction, spoiler functions,
and anti-skid braking system actuation. The inability of the hydraulic
installation to isolate flow of hydraulic fluid could result in a
hazardous amount of flammable fluid in the corresponding engine
compartment. These conditions, if not corrected, could result in loss of
system functions and/or fire in the engine compartment.
DATES: We must receive comments on this proposed AD by June 30, 2008.
ADDRESSES: Use one of the following addresses to comment on this proposed
AD:
Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the
instructions for submitting comments.
Fax: (202) 493-2251.
Mail: U.S. Department of Transportation, Docket Operations, M-30, West
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE.,
Washington, DC 20590.
Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30,
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE.,
Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday,
except Federal holidays.
For service information identified in this proposed AD, contact Hawker
Beechcraft Corporation, 9709 East Central, Wichita, Kansas 67201;
telephone: (316) 676-5034; fax: (316) 676-6614.
FOR FURTHER INFORMATION CONTACT: Anthony Flores, Aerospace Engineer, Wich-
ita Aircraft Certification Office, 1801 Airport Road, Room 100, Wichita,
Kansas 67209; telephone: (316) 946-4174; fax: (316) 946-4107.
SUPPLEMENTARY INFORMATION:
COMMENTS INVITED
We invite you to send any written relevant data, views, or arguments
regarding this proposed AD. Send your comments to an address listed under
the ADDRESSES section. Include the docket number, "FAA- 2008-0492;
Directorate Identifier 2008-CE-023-AD" at the beginning 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 received 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://
www.regulations.gov, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive concerning this proposed AD.
DISCUSSION
We have received information of nine occurrences of hydraulic fluid
leaking from the engine hydraulic pump output fitting on HBC Model 390
airplanes. During installation of the elbow fitting, the preformed packing
was installed on the fitting threads, which caused the fitting threads to
damage the preformed packing when the fitting was tightened. The loss of
hydraulic fluid can result in loss of airplane hydraulic system pressure
and the consequent loss of hydraulic system functions including gear
extension/retraction, spoiler functions, and anti-skid braking system
actuation.
The current hydraulic system installation lacks the means of shutting off
the flow of hydraulic fluid between the left and right engine hydraulic
pump case drain return lines. The installation of check valves would allow
flow from the hydraulic pump case drain to the reservoir and prevent flow
back through the hydraulic pump case drain lines. This installation would
reduce the volume of hydraulic fluid loss into the engine compartment in
the event of a leak in the left or right engine hydraulic system. The
inability of the hydraulic installation to isolate flow of hydraulic fluid
could result in a hazardous amount of flammable fluid in the corresponding
engine compartment.
These conditions, if not corrected, could result in loss of system
functions and/or fire in the engine compartment.
RELEVANT SERVICE INFORMATION
We have reviewed Hawker Beechcraft Mandatory Service Bulletin SB 29-3869,
dated January 2008; and Hawker Beechcraft Mandatory Service Bulletin SB
29-3851, dated January 2008.
The service information describes procedures for:
Removing the current preformed packing, elbow fitting, and jam nut from
the left and right hydraulic pump pressure output port and replacing with
new parts; and
Installing a hydraulic pump case drain check valve.
FAA'S DETERMINATION AND REQUIREMENTS OF THE PROPOSED AD
We are proposing this AD because we evaluated all information and
determined the unsafe condition described previously is likely to exist or
develop on other products of the same type design. This proposed AD would
require you to remove the current preformed packing, elbow fitting, and
jam nut from the left and right hydraulic pump pressure output port and
replace with new parts. This proposed AD would also require you to install
a hydraulic pump case drain check valve.
COSTS OF COMPLIANCE
We estimate that this proposed AD would affect 182 airplanes in the U.S.
registry.
We estimate the following costs to do the proposed modifications:
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TOTAL COST PER TOTAL COST ON
LABOR COST PARTS COST AIRPLANE U.S. OPERATORS
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Hydraulic pressure output
fitting assembly: 8 work-
hours x $80 per hour = $640. $100 $740 $134,680
Hydraulic Pump Case Drain
Check Valve: 16 work-hours
x $80 per hour = $1,280. 4,353 5,633 1,025,206
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HBC will provide warranty credit as specified in Hawker Beechcraft
Mandatory Service Bulletin SB 29-3869, dated January 2008; and Hawker
Beechcraft Mandatory Service Bulletin SB 29-3851, dated January 2008.
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 and placed it in the AD docket.
EXAMINING THE AD DOCKET
You may examine the AD docket that contains the proposed AD, the
regulatory evaluation, any comments received, and other information on the
Internet at http://www.regulations.gov; or in person at the Docket
Management Facility between 9 a.m. and 5 p.m., Monday through Friday,
except Federal holidays. The Docket Office (telephone (800) 647-5527) is
located at the street address stated in the ADDRESSES section. Comments
will be available in the AD docket shortly after receipt.
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 AD: