In recent years, the FAA has received reports of 14 incidents and/or accidents involving intentional or inadvertent operation of the propellers in the beta range during flight on airplanes equipped with turboprop engines. (For the purposes of this amendment, beta is defined as the range of propeller operation intended for use during taxi, ground idle, or reverse operations as controlled by the power lever settings aft of the flight idle stop.)
Five of the fourteen in-flight beta occurrences were classified as accidents. In each of these five cases, operation of the propellers in the beta range occurred during flight. Operation of the propellers in the beta range during flight, if not prevented, could result in loss of airplane controllability, or engine overspeed with consequent loss of engine power.
Communication between the FAA and the public during a meeting held on June 11-12, 1996, in Seattle, Washington, revealed a lack of consistency ofthe information on in-flight beta operation contained in the FAA-approved Airplane Flight Manual (AFM) for airplanes that are not certificated for in-flight operation with the power levers below the flight idle stop. (Airplanes that are certificated for this type of operation are not affected by the above-referenced conditions.)
FAA's Determinations
The FAA has examined the circumstances and reviewed all available information related to the incidents and accidents described previously. The FAA finds that the Limitations Section of the AFM s for certain airplanes must be revised 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. The FAA has determined that the affected airplanes include those that are equipped with turboprop engines and that are not certificated for in-flight operation with the power levers below the flightidle stop. Since British Aerospace Model HS 748 series airplanes meet these criteria, the FAA finds that the AFM for these airplanes must be revised to include the limitation and statement of consequences described previously.
U.S. Type Certification of the Airplane
This airplane model is manufactured in the United Kingdom and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. The FAA has reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, this AD is being issued to prevent loss of airplane controllability, or engineoverspeed and consequent loss of engine power caused by the power levers being positioned below the flight idle stop while the airplane is in flight.
This AD requires revising 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, and to provide a statement of the consequences of positioning the power levers below the flight idle stop while the airplane is in flight.
This is considered to be interim action until final action is identified, at which time the FAA may consider additional rulemaking.
Cost Impact
None of the British Aerospace Model HS 748 series airplanes affected by this action are on the U.S. Register. All airplanes included in the applicability of this rule currently are operated by non-U.S. operators under foreign registry; therefore, they are not directly affected by this AD action. However, the FAA considers that this rule is necessary to ensure that the unsafe condition is addressed in the event that any of these subject airplanes are imported and placed on the U.S. Register in the future.
Should an affected airplane be imported and placed on the U.S. Register in the future, it would require approximately 1 work hour to accomplish the required actions, at an average labor charge of $60 per work hour. Based on these figures, the cost impact of this AD would be $60 per airplane.
Determination of Rule's Effective Date
Since this AD action does not affect any airplane that is currently on the U.S. register, it has no adverse economic impact and imposes no additional burden on any person. Therefore, prior notice and public procedures hereon are unnecessary and the amendment may be made effective in less than 30 days after publication in the Federal Register.
Comments Invited
Although this action is in the form of a final rule and was not preceded by notice and opportunity for public 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 shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." 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 Number 97-NM-98-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.
For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is nota "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: