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 to all Mitsubishi Heavy Industry (Mitsubishi) MU-2B series airplanes was published in the Federal Register as a notice of proposed rulemaking (NPRM) on July 2, 1997 (62 FR 35696).
The NPRM proposed to require amending the Limitations Section of the AFM to prohibit the positioning of the power levers below the flight idle stop while the airplane is in flight, including a statement of consequences if the limitation is not followed. This AFM amendment shall consist of the following language:
"Positioning of power levers below the flight idle stop while the airplane is in flight is prohibited. Such positioning may lead to loss of airplane control or may result in an overspeed condition and consequent loss of engine power."
The NPRM was the result of numerous incidents and five documentedaccidents involving airplanes equipped with turboprop engines where the propeller beta was improperly utilized during flight.
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the two comments received from the manufacturer, Mitsubishi Heavy Industries, Inc.
Comment Issue No. 1: Change the "Explanation of the Provisions of the Proposed AD" section of the NPRM
Mitsubishi explains that the statement "Since an unsafe condition has been identified that could exist or develop on other Mitsubishi MU-2B airplanes of the same type design," is misleading in that it leads the reader to believe that there is a design flaw with the MU-2B series airplanes. Mitsubishi includes proposed language to replace this phrase.
The FAA concurs that this statement could be misleading. This language is not repeated in the final rule so therefore no change is needed at this time. The FAA will keep Mitsubishi's comments in mind while drafting future AD's. No changes have been made to the final rule as a result of this comment.
Comment Issue No. 2: The Model MU-2B-26A Excluded from the NPRM
Mitsubishi states that the Model MU-2B-26A airplanes are excluded from the NPRM, and asks if this was an oversight on the FAA's part. Mitsubishi feels that these airplanes should be included in the AD.
Mitsubishi is correct in assuming that excluding the Model MU-2B-26A airplanes from the NPRM was an oversight. To add these airplanes in this rulemaking action would require the FAA to reopen the comment period and delay final rule action for all of the MU-2B series airplanes. The FAA will address the Model MU-2B-26A airplanes in a future rulemaking action. No changes have been made to the final rule as a result of this comment.
The FAA's Determination
After careful review of all available information related to the subject presented above, the FAA has determined that air safetyand 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 the compliance time of this AD should be specified in calendar time instead of hours time-in-service. While the condition addressed by this AD is unsafe while the airplane is in flight, the condition is not a result of repetitive airplane operation; the potential of the unsafe condition occurring is the same on the first flight as it is for subsequent flights. The compliance time of "30 days after the effective date of this AD" will not inadvertently ground airplanes and would assure that all owners/operators of the affected airplanes accomplish this AD in a reasonable time period.
Cost Impact
The FAA estimates that 437 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 1 workhour per airplane to incorporate the required AFM amendment, and that the average labor rate is approximately $60 an hour. Since an owner/operator who holds at least a private pilot's certificate can accomplish this AD, as authorized by sections 43.7 and 43.9 of the Federal Aviation Regulations (14 CFR 43.7 and 43.9), the only cost impact upon the public is the time it will take the affected airplane owner/operators to amend the AFM.
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 thereasons 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, 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 authoritycitation for part 39 continues to read as follows:
Authority: 49 USC 106(g), 40113, 44701.
39.13 [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive (AD) to read as follows: