AD 94-05-09

This amendment adopts a new airworthiness directive (AD), applicable to certain Beech Model 400A airplanes, that requires an inspection to detect fatigue-related cracking in certain cabin seat frames; measurement to determine gap size between the bearing shafts and certain seat frames; and repair, if necessary. This amendment is prompted by in-service inspection reports of fatigue-related cracking radiating outward from the bushings welded into the cabin seat frames. The actions specified by this AD are intended to prevent separation of the cabin seat frames from their bases during an emergency landing.

Final rule.

94-05-09 BEECH AIRCRAFT CORPORATION: Amendment 39-8847. Docket 93-NM-145-AD.

Applicability: Model 400A airplanes; serial numbers RK-1 through RK-40 inclusive, and RK-45; equipped with Tosington Cabin Seat Frames having serial numbers prior to 5606, on which Modification Kit Number 303-307 has not been installed; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent separation of the cabin seat frames from their bases during an emergency landing, accomplish the following:

(a) Within 200 hours time-in-service after the effective date of this AD, perform a visual inspection to detect fatigue-related cracking extending radially outward from the bushings welded into the cabin seat frames, in accordance with Tosington Enterprises, Inc., Service Bulletin 001, dated July 1993. If any cracking is found, prior to further flight, repair by welding in accordance with the service bulletin.

(b) Within 200 hours time-in-service after the effective date of this AD, measure the gap size between the bearing shaft and the lower aft and/or forward seat frames in accordance with Tosington Enterprises, Inc., Service Bulletin 001, dated July 1993.

(1) If the gap size is 0.32 inch or greater, prior to further flight, repair by reinforcing the cabin seat frame in accordance with the service bulletin.

(2) If the gap size is less than 0.32 inch, no further action is required.

(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: 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 Federal Aviation Regulations (FAR) 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(e) The inspection, repairs, and measurement shall be done in accordance with Tosington Enterprises, Inc., Service Bulletin 001, dated July 1993. 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 Tosington Enterprises, Inc., 2261 Madera Road, Simi Valley, California 93065. 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 (ACO), 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 April 7, 1994.

A proposal to amend part 39 of the Federal Aviation Regulations to include an airworthiness directive (AD) that is applicable to certain Beech Model 400A airplanes was published in the Federal Register on November 8, 1993 (58 FR 59223). That action proposed to require a one-time visual inspection to detect fatigue-related cracking in certain cabin seat frames; measurement to determine gap size between the bearing shafts and certain seat frames; and repair, if necessary.

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the single comment received.

The commenter supports the proposed rule.

After careful review of the available data, including the comment noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

There are approximately 41 Beech Model 400A airplanes of the affected design inthe worldwide fleet. The FAA estimates that 29 airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required actions, and that the average labor rate is $55 per work hour. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $1,595, or $55 per airplane.

The total cost impact figure discussed above is 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.

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 14 CFR part 39 of the Federal Aviation Regulations as follows:

PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.

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