E8-9566. Airworthiness Directives; Hawker Beechcraft Corporation Model 390 Airplanes

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

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: [phone].
• 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: [phone]; fax: [phone].

FOR FURTHER INFORMATION CONTACT:

Anthony Flores, Aerospace Engineer, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Wichita, Kansas 67209; telephone: [phone]; fax: [phone].

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:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
Hydraulic pressure output fitting assembly: 8 work-hours × $80 per hour = $640	$100	$740	$134,680
Hydraulic Pump Case Drain Check Valve: 16 work-hours × $80 per hour = $1,280	4,353	5,633	1,025,206

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 [phone]) 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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by adding the following new AD:

Hawker Beechcraft Corporation: Docket No. FAA-2008-0492; Directorate Identifier 2008-CE-023-AD.

Comments Due Date

(a) We must receive comments on this airworthiness directive (AD) action by June 30, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Model 390 airplanes, serial numbers RB-4 through RB-224, that are certificated in any category.

Unsafe Condition

(d) This 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 issuing this AD to prevent hydraulic fluid leaking 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.

Compliance

(e) To address this problem, you must do the following, unless already done:

Actions	Compliance	Procedures
(1) Remove current preformed packing (part number (P/N) MS28778-6), elbow fitting (P/N MS21908J6), and jam nut (P/N AN924-6J) from the left and right hydraulic pump pressure output port and install new preformed packing (P/N MS28778-6), union (P/N MS21902J6), and swivel fitting (P/N NAS1762J0606) in the left and right hydraulic pressure pump output port	Within the next 200 hours time-in-service (TIS) after the effective date of this AD or within the next 6 months after the effective date of this AD, whichever occurs first	Follow Hawker Beechcraft Mandatory Service Bulletin SB 29-3869, dated January 2008.
(2) Install hydraulic pump case drain check valve Kit No. 390-5803-0001	Within the next 200 hours TIS after the effective date of this AD or within the next 6 months after the effective date of this AD, whichever occurs first	Hawker Beechcraft Mandatory Service Bulletin SB 29-3851, dated January 2008.

Alternative Methods of Compliance (AMOCs)

(f) The Manager, Wichita Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Anthony Flores, Aerospace Engineer, Wichita ACO, 1801 Airport Road, Room 100, Wichita, Kansas 67209; telephone: [phone]; fax: [phone]. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

Related Information

(g) To get copies of the service information referenced in this AD, contact Hawker Beechcraft Corporation, 9709 East Central, Wichita, Kansas 67201; telephone: [phone]; fax: [phone]. To view the AD docket, go to U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, or on the Internet at http://www.regulations.gov.

Issued in Kansas City, Missouri, on April 24, 2008.

James E. Jackson,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.