A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to all Fairchild Model F-27 series airplanes was published in the Federal Register on April 24, 1997 (62 FR 19948). That action proposed to require revising the Limitations Section of the Airplane Flight Manual (AFM) to prohibit positioning the power levers below the flight idle stop while the airplane is in flight, and to provide a statement of the consequences of positioning the power levers below the flight idle stop while the airplane is in flight.
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.
Conditional Support for the Proposal
One commenter supports the intent of the proposed rule, but remarks that, if an inherent design problem exists on the affected airplanes to allow flightcrews to select the power levers below the flight idle stop while in flight, the FAA should consider the addition of a mechanical means to preclude such selection. The FAA acknowledges the commenter s concern, and may consider additional rulemaking to address that concern in the future on certain airplanes. However, until such final action is identified, the FAA considers it appropriate to proceed with issuance of this AD. No change to the AD is required.
Request to Withdraw the Proposal
One commenter, an operator, requests that the proposed rule be withdrawn for the following reasons. One, the commenter points out that the Fairchild Model F-27 series airplane has been type certificated for more than 35 years and has flown millions of flight hours without a single report of an intentional or inadvertent ground fine pitch (GFP) selection in flight. Two, the commenter s research of the flight manuals revealed that there is no normal or abnormal operational condition that would result in GFPselection being made in flight. Therefore, the commenter considers the unsafe condition to be a "perceived" problem. Three, the commenter states that, because the Model F-27 series airplane is equipped with a Rolls-Royce Dart engine that requires a positive torque pressure on approach, the power lever must be positioned beyond flight idle with the propeller in a corresponding position above the flight fine lock to maintain a positive torque pressure. Therefore, the commenter concludes that the system design is adequate and that an unsafe condition does not exist. Four, the commenter considers that the proposed rule would cause a "great economic burden" to the owners and operators. Five, the commenter states that the FAA did not specify that the "perceived" unsafe condition does affect airplanes built in accordance with the requirements of part 4B of the Civil Air Regulations (CAR).
The FAA does not concur with the commenter s request to withdraw the proposed rule. As explained in the proposed rule, the accident/incident history of several airplanes involving intentional or inadvertent operation of the propellers in the beta range indicates that an unsafe condition does exist on airplanes equipped with turboprop engines. The FAA considers that revision of the AFM, as required in the final rule, will ensure that pilots are reminded that positioning of power levers below the flight idle stop while the airplane is in flight is prohibited. The FAA further considers this to be a minimum action to ensure that pilots do not carry certain flight habits from an airplane design that mitigates the effects of beta inflight over to a design that does not.
However, the FAA notes that the commenter addresses GFP rather than operations below the flight idle stop, although the operations manual refers to both. To clarify the usage of those terms, the FAA has added the phrase "(i.e., including ground fine pitch)" as a parenthetical definition of "below the flight idlestop" in paragraph (a) of the final rule.
In addition, since operators may simply insert a copy of the AD into the AFM in order to comply with the requirements of this rule, the FAA cannot consider that action to be a "great economic burden."
Finally, the FAA did not specify that the AD was also applicable to airplanes that had been type certificated in accordance with the requirements of part 4b of the CAR since, by definition, the applicability of this AD specifically states that the AD applies to all airplanes.
Conclusion
After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the change previously described. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.
Interim Action
This is considered interim action until final action is identified, at which time the FAA mayconsider further rulemaking.
Cost Impact
There are approximately 70 Fairchild Model F-27 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 7 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 $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $420, or $60 per airplane.
The 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.
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 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, 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 the following new airworthiness directive: