AD 97-21-03

This amendment adopts a new airworthiness directive (AD), applicable to certain Raytheon Model BAe 125-800A series airplanes and Hawker 800 series airplanes, that requires a detailed visual inspection of the fuel feed hose assemblies of the auxiliary power unit (APU) to detect overheating, degradation, proper routing, and adequate clearance; and the correction of any discrepancies found. This amendment also requires modification of the fuel feed hose of the APU. This amendment is prompted by reports of heat damage to the fuel feed hose assembly of the APU due to contact between the hose assembly and hot surfaces. The actions specified by this AD are intended to prevent heat damage of the fuel feed hose, which could lead to a possible fire/smoke hazard when failure of the hose assembly occurs and consequent fuel mist or spray is emitted into the rear equipment bay.

Final rule.

97-21-03 RAYTHEON AIRCRAFT COMPANY (Formerly Raytheon Aircraft Corporation; Beech Aircraft Corporation; Raytheon Corporate Jets, Inc.; British Aerospace, PLC; DeHavilland; Hawker Siddeley): Amendment 39-10156. Docket 95-NM-142-AD.

Applicability: Model BAe 125-800A series airplanes (including military variants C-29A and U-125) and Hawker 800 series airplanes, constructor's numbers 8091 and subsequent; equipped with Turbomach auxiliary power unit (APU) (Modification 259404B); certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent heat damage to the fuel feed hose assemblies of the auxiliary power unit (APU), which could lead to a possible fire/smoke hazard if failure of the hose assembly occurs and fuel mist or spar is consequently emitted into the rear equipment bay, accomplish the following:

(a) Within 75 days after the effective date of this AD, perform a one-time detailed visual inspection to detect overheating or degradation of the hose assemblies; to verify proper routing of fuel feed hose assembly of the APU; and to verify if adequate clearance (0.5 inch) exists between the hose assembly (outlet from the fuel pump box of the APU) and the left-handmixer valve/main air valve assemblies and associated hot air ducting; in accordance with Hawker Service Bulletin SB. 49-45, dated May 15, 1995.

(1) If any overheating or degradation is detected, prior to further flight, replace the hose assembly with a new assembly and ensure that proper clearance and routing exists, in accordance with the service bulletin.

(2) If the clearance of the hose assembly is improperly routed, prior to further flight, re-route the assembly maintaining proper clearance, in accordance with the service bulletin.

(3) If the clearance of the hose assembly is inadequate and the hose assembly is properly routed, prior to further flight, adjust the hose assembly to achieve the 0.5-inch clearance, in accordance with the service bulletin.

(b) Prior to the accumulation of 200 flight hours after the effective date of this AD, modify the fuel feed hose of the APU, in accordance with Hawker Service Bulletin SB.49-47-25A825A, dated August 1, 1995.(c) Accomplishment of the modification of the fuel feed hose of the APU in accordance with Hawker Service Bulletin SB.49-47-25A825A, dated August 1, 1995, constitutes terminating action for the requirements of this AD.

(d) 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(e) Special flight permits may be issued in accordance with sections 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.

(f) The actions shall be done in accordance with Hawker Service Bulletin SB. 49-45, dated May 15, 1995, and Hawker Service Bulletin SB.49-47-25A825A, dated August 1, 1995. The incorporation by reference of that document was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Raytheon Aircraft Company, Manager Service Engineering, Hawker Customer Support Department, P.O. Box 85, Wichita, Kansas 67201-0085. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

NOTE 3: The subject of this AD is addressed in British airworthiness directive 005-05-95.

(g) This amendment becomes effective on November 19, 1997.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Raytheon Model BAe 125-800A series airplanes and Hawker 800 series airplanes was published as a supplemental notice of proposed rulemaking (NPRM) in the Federal Register on October 25, 1996 (61 FR 55233). That action proposed to require a detailed visual inspection of the fuel feed hose assemblies of the auxiliary power unit (APU) to detect overheating, degradation, proper routing, and adequate clearance; and the correction of any discrepancies found. That action also proposed to require modification of the fuel feed hose of the APU.

Consideration of Comments Received
Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

Explanation of Change Made to the Proposal
The FAA has revised the final rule to reflect the corporate name change of Beech Aircraft Corporation to Raytheon Aircraft Company.

Conclusion
After careful review of the available data, the FAA has determined that air safety and the public interest require the adoption of the rule with the change previously described. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact
The FAA estimates that 70 Raytheon Model BAe 125-800A series airplanes and Hawker 800 series airplanes of U.S. registry will be affected by this AD. It will take approximately 2 work hours per airplane to accomplish the required inspection at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the inspection required by this AD on U.S. operators is estimated to be $8,400, or $120 per airplane.

It will take approximately 4 work hours per airplane to accomplish the required modification, at an average labor rate of $60 per work hour. Required parts will cost approximately $218 per airplane. Based on these figures, the cost impact of the modification required by this AD on U.S. operators is estimated to be $32,060, or $458 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

Regulatory Impact
The regulations adopted herein will 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 final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under 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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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. 106(g), 40113, 44701.

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