AD 97-21-05

This amendment adopts a new airworthiness directive (AD), applicable to certain Raytheon Model DH.125-400A; BH.125-400A and -600A; HS.125-600A and -700A; BAe 125-800A series airplanes; and Hawker 800 and Hawker 800 XP series airplanes (including military variants C29A, U125, U125A). This amendment requires a one-time inspection to determine if certain high pressure oxygen hose assemblies are installed, and, if installed, replacement of those hose assemblies with new, improved hose assemblies. This amendment is prompted by a report that certain high pressure oxygen hose assemblies are susceptible to leakage due to those hose assemblies not meeting design specifications during manufacturing. The actions specified by this AD are intended to prevent leaks in high pressure oxygen hose assemblies, which, if not detected and corrected, could result in insufficient oxygen available to the passengers or crew if the cabin pressure altitude should rise to a level requiring emergencyoxygen.

Final rule.

97-21-05 RAYTHEON AIRCRAFT COMPANY (Formerly Beech, Raytheon Corporate Jets, British Aerospace, Hawker Siddeley, et al.): Amendment 39-10158. Docket 96-NM-274-AD.

Applicability: All Model DH.125-400A, BH.125-400A and -600A, HS.125-600A and -700A, and BAe 125-800A series airplanes; and Model Hawker 800 and Hawker 800 XP series airplanes (including Military Variants C29A, U125, and U125A airplanes); having serial numbers 1 through 258294 inclusive; on which Modification 252036 has been installed with a high pressure oxygen hose assembly having part number WKA 34609; 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 requestapproval for an alternative method of compliance in accordance with paragraph (c) 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.

NOTE 2: Raytheon (Beech) Model DH.125-400B, BH.125-400B and -600B, HS. 125-600B and -700B, and BAe 125-800B series airplanes are similar in design to the airplanes that are subject to the requirements of this AD, and therefore, also may be subject to the unsafe condition addressed by this AD. However, as of the effective date of this AD, those models are not type certificated for operation in the United States. Airworthiness authorities of countries in which those models are approved for operation should consider adopting corrective action, applicable to these models, that is similar to the corrective action required by this AD.

Compliance: Required as indicated, unless accomplished previously.

To prevent leaks in high pressure oxygen hose assemblies, which could result in insufficient oxygen quantity available to the passengers or crew if the cabin pressure altitude should rise to a level requiring emergency oxygen, accomplish the following:

(a) Within 90 days after the effective date of this AD, perform a one-time inspection to determine whether any high pressure oxygen hose assembly having a discrepant part number WKA 34609 is installed, in accordance with Raytheon Service Bulletin SB.35-46, dated September 30, 1996. If no discrepant part number is detected, no further action is required by this AD. If any hose assembly having discrepant part number WKA 34609 is installed, prior to further flight, replace the hose assembly with a hose assembly having part number 58179-101, in accordance with the service bulletin.

(b) As of the effective date of this AD, no person shall install ahigh pressure oxygen hose having part number WKA 34609 on any airplane.

(c) 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, Wichita Aircraft Certification Office (ACO), FAA, Small 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, Wichita ACO.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Wichita ACO.

(d) 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.

(e) The actions shall be done in accordance with Raytheon Service Bulletin SB.35-46, dated September 30, 1996. This incorporation by reference 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 FAA, Small Airplane Directorate, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid- Continent Airport, Wichita, Kansas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(f) This amendment becomes effective on November 24, 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 DH.125-400A; BH.125-400A and -600A; HS.125-600A and -700A; BAe 125-800A series airplanes; and Hawker 800 and Hawker 800 XP series airplanes (including military variants C29A, U125, U125A), was published in the Federal Register on July 24, 1997 (62 FR 39787). That action proposed to require a one-time inspection to determine if certain high pressure oxygen hose assemblies are installed, and, if installed, replacement of those hose assemblies with new, improved hose assemblies.

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.

Conclusion
The FAA has determined that air safety and the public interest require the adoption ofthe rule as proposed.

Cost Impact
The FAA estimates that 404 Raytheon Model DH.125-400A; BH.125-400A and -600A; HS.125-600A and -700A; BAe 125-800A; and Hawker 800 and Hawker 800 XP series airplanes (including military variants) of U.S. registry will be affected by this AD.

It will take approximately 1 work hour per airplane to accomplish the required actions, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the initial inspection required by this AD on U.S. operators is estimated to be $24,240, or $60 per airplane.

Should an operator be required to accomplish the replacement, it would take approximately 1 work hour per airplane to accomplish it, at an average labor rate of $60 per work hour. Required parts would be supplied by the manufacturer at no cost to the operators. Based on these figures, the cost impact of the replacement on U.S. operators is estimated to be $60 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: