AD 96-24-07

This amendment adopts a new airworthiness directive (AD) that applies to certain HOAC Austria Model DV-20 Katana airplanes. This action requires replacing the muffler with one of improved design, installing a heat shield around the exhaust system endpipe, and adjusting the airplane weight and balance. This AD results from reports of cracks in the welding joint that connects the exhaust system endpipe to the muffler on three of the affected airplanes. The actions specified by this AD are intended to prevent separation of the exhaust system endpipe from the muffler because of cracks in the welding that connects these parts, which could result in heat damage to the electrical system and engine controls.

Final rule.

96-24-07 HOAC AUSTRIA: Amendment 39-9832; Docket No. 95-CE-62-AD.

Applicability: Model DV-20 Katana airplanes, serial numbers 20005 through 20078, certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been 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 within the next three calendar months after theeffective date of this AD, unless already accomplished.

To prevent separation of the exhaust system endpipe from the muffler because of cracks in the welding that connects these parts, which could result in heat damage to the electrical system and engine controls, accomplish the following:

(a) For any Model DV-20 Katana airplane incorporating a serial number in the range of 20005 through 20078, replace the muffler with one that incorporates a type "f" endpipe. The letter "F" is stamped on the endpipe of these type "f" parts. Accomplish this action in accordance with HOAC Austria Maintenance Manual, Doc No. 4.02.02.

(b) For any Model DV-20 Katana airplane incorporating a serial number in the range of 20005 through 20058, accomplish the following:

(1) Install a heat shield in accordance with Drawing No. DV2-7800R01-00, as referenced in HOAC Austria Service Bulletin (SB) No. 20-7/2, dated September 8, 1994.

(2) Adjust the mass (weight) and center of gravity (CG) in accordance with the instructions in HOAC Austria SB No. 20-7/2, dated September 8, 1994.

(c) 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.

(d) An alternative method of compliance or adjustment of the compliance time that provides an equivalent level of safety may be approved by the Manager, Brussels Aircraft Certification Division, FAA, Europe, Africa, and Middle East Office, c/o American Embassy, B-1000 Brussels, Belgium. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Brussels Aircraft Certification Division.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Brussels Aircraft Certification Division.(e) The installation required by this AD shall be done in accordance with HOAC Drawing No. DV2-7800R01-00, as referenced in HOAC Austria Service Bulletin No. 20-7/2, dated September 8, 1994. The adjustment required by this AD shall be done in accordance with HOAC Austria Service Bulletin No. 20-7/2, dated September 8, 1994. 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 to HOAC Austria Ges.m.b.H., N.A. Otto-Strabe 5, A-2700, Wiener Neustadt. Copies may be inspected at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(f) This amendment becomes effective on January 17, 1997.

Events Leading to the Issuance of This AD

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply certain HOAC Austria Model DV-20 Katana airplanes was published in the Federal Register on August 22, 1996 (61 FR 43317). The action proposed to require replacing the muffler with one of improved design, installing a heat shield around the exhaust system endpipe, and adjusting the airplane weight and balance. Accomplishment of the proposed muffler replacement as specified in the notice of proposed rulemaking (NPRM) would be in accordance with the applicable maintenance manual; accomplishment of the proposed heat shield installation as specified in the NPRM would be in accordance with Drawing No. DV2-7800R01-00, as referenced in HOAC Austria Service Bulletin (SB) No. 20-7/2, dated September 8, 1994; and accomplishment of the weight and balance adjustment as specified in the NPRM would be in accordance with HOAC Austria SB No. 20-7/2, dated September 8, 1994.

The NPRM resulted from reports of cracks in the welding joint that connects the exhaust system endpipe to the muffler on three of the affected airplanes.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposed rule or the FAA's determination of the cost to the public.

The FAA's Determination
After careful review of all available information related to the subject presented above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. The FAA has determined that these minor corrections will not change the meaning of the AD and will not add any additional burden upon the public than was already proposed.

Compliance Time of This AD
The FAA has determined that an interval of three calendar months is an appropriate compliance time toaddress the identified unsafe condition in a timely manner. This compliance time was deemed appropriate after considering the safety implications, the average utilization rate of the affected fleet, and the availability of the replacement parts.

Cost Impact
The FAA estimates that 5 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 1 workhour per airplane to accomplish the required action, and that the average labor rate is approximately $60 an hour. HOAC Austria will provide parts at no cost to the affected airplane owners/operators. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $300 or $60 per airplane. The FAA is unaware of any affected airplane that already has the required muffler replacement and heat shield installation.

Regulatory Impact
The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government andthe 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 copy of the final evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting 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 USC 106(g), 40113, 44701.

Section 39.13 - [AMENDED]
2. Section 39.13 is amended by adding a new airworthiness directive (AD) to read as follows: