AD 97-26-12

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 Piper Models PA-31T, PA-31T1, PA-31T2, PA-31T3, PA-42, PA-42-720, and PA-42-1000 airplanes was published in the Federal Register as a notice of proposed rulemaking (NPRM) on July 24, 1997 (62 FR 39793).

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 could 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 documented accidents 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 one comment received on the NPRM. No comments were received regarding the FAA's determination of the cost to the public.

Comment Disposition The commenter states that the applicability statement of the NPRM is unclear. The commenter explains that the NPRM references Models PA-42, PA-42-720, and PA-42-1000 airplanes. No reference is made to Model PA-42-720R airplanes. The commenter explains that since common practice is for the FAA to refer to groups of aircraft as a "series", a reasonable inference would be that the Model PA-42-720R airplanes should be included in the applicability of the NPRM. On the other hand, the Model PA-42-720R airplanes are covered by another type certificate than the models referenced in the NPRM so one could also infer that the Model PA-42-720R airplanes should not be included. The commenter asks for clarification on this issue and requests that the FAA not make such obvious differing inferences.

The FAA concurs that the NPRM references Models PA-42, PA-42-720, and PA-42-1000 airplanes, and that no reference is made to Model PA-42-720R airplanes. The FAA also concurs that referencing the term "series" in the Applicability section of an AD could cause confusion. The FAA is making a conscious effort to list all affected models in the Applicability section of all AD s, as was done in the NPRM. The term series in the Applicability section puts the burden of interpreting which airplanes are affected on the owners/operators. The term "series" is acceptable when referring to a large number of airplane models in the narrative of the preamble of the AD. In this NPRM, the FAA s intent was to not include the Model PA-42-720R airplanes. Allaffected models are listed in the Applicability section. No changes to the final rule have been made 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 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 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. Thecompliance 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 607 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 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, 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.

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