Discussion
On May 28, 1999, the FAA issued priority letter AD 99-12-02, which applies to all Raytheon Beech Models 45 (YT-34), A45 (T-34A, B-45), and D45 (T-34B) airplanes. That AD resulted from a report of an in-flight separation of the right wing on a Raytheon Beech Model A45 (T-34A) airplane. The airplane was involved in mock aerial combat with another Beech Model A45 (T-34A) airplane.
The left wing remained attached to the airplane following separation of the right wing. As the airplane made ground contact, the left wing forward and rear spars and wing attach fittings sustained overload fractures.
Examination of the right wing revealed structural fatigue cracks at several of the fracture surfaces. Although it did not separate from the airplane, the left wing also showed structural fatigue cracks at several locations.
Priority letter AD 99-12-02 requires fabricating two placards using letters of at least 1/10-inch in height with each consisting of the following words, and installing these placards on the airplane instrument panels (one on the front panel and one on the rear panel) next to the airspeed indicators within the pilot s clear view:
"Never exceed speed, Vne-175 MPH (152 knots) IAS; Normal Acceleration (G) Limits - 0, and +2.5; ACROBATIC MANEUVERS PROHIBITED."
This AD also requires marking the airspeed indicators to specify the limitations referenced in the placards, and incorporating a copy of the AD into the Limitations Section of the Airplane Flight Manual (AFM).
The FAA's Determination and Explanation of the AD
Since an unsafe condition was identified that is likely to exist or develop in other Raytheon Beech Models 45 (YT-34), A45 (T-34A, B-45), and D45 (T-34B) airplanes of the same type design airplanes, the FAA:
1. determined that the Beech Models 45 (YT-34), A45 (T-34A, B-45), and D45 (T-34B) airplanes should not be operated without restrictions until the wing structure has been inspected in accordance with inspection procedures approved by the FAA, and the structure is found to be free of cracks;
2. determined that all of the above-referenced airplanes should be restricted to normal category operation and prohibited from acrobatic and utility category operations; the flight load factor should be limited to 0 to 2.5 G; and the maximum airspeed should be limited to 175 miles per hour (mph) (152 knots);
3. determined that immediate AD action should be taken to assure the operational safety of these airplanes; and
4. issued AD 99-12-02 as a priority letter on May 28, 1999.
Determination of the Effective Date of the AD
Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual letters issued on May 28, 1999, to all known U.S. operators of Raytheon Beech Models 45 (YT-34), A45 (T-34A, B-45), and D45 (T-34B) airplanes. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective as to all persons.
Differences Between This AD and The Service Information and Possible Follow-up Action
The actions required by this AD are different than those recommended in Raytheon Safety Communiqu No. 162, Rev. 1, dated June 1999, which specifies not operating the affected airplanes. Based on the service history of the wing structure of the Raytheon Beech Models 45 (YT-34), A45 (T-34A, B-45), and D45 (T-34B) airplanes and all available information related to the referenced accident, the FAA has determined that the restrictions imposed by this AD will continue to assure the operational safety of these airplanes until detailed inspection procedures are developed.
When inspection procedures are developed for the wing structure of the affected airplanes, the FAA will evaluate these procedures and will decide whether to initiate further rulemaking action. Further action may include alleviating the restrictions imposed by this AD.
Comments Invited
Although this action is in the form of a final rule that involves requirements affecting immediate flight safety and, thus, was not preceded by notice and opportunity to comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.
Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule
must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket No. 99-CE-22-AD." The postcard will be date stamped and returned to the commenter.
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.
The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, 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, 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 a new airworthiness directive (AD) to read as follows: