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 Dornier Model 328-100 series airplanes was published in the Federal Register on December 9, 1997 (62 FR 64784). That action proposed to require revising the Limitations Section of the Airplane Flight Manual (AFM) to modify the limitation that prohibits the positioning of the power levers below the flight idle stop while the airplane is in flight, and to add a statement of the consequences of positioning the power levers below the flight idle stop while the airplane is in flight.
Comments Received
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 existson 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 for 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.
Proposed Rule Unnecessary: AFM Already Revised
One commenter, an operator, states that the proposal is an inappropriate method of addressing the perceived unsafe condition. The commenter points out that, because the manufacturer has issued a revision to the AFM that contains the exact wording as the proposed rule, the proposed rule is redundant and a waste of taxpayers money.
The FAA does not concur with the commenter's suggestion that the proposed rule is redundant. Since the issuance of the proposal, the manufacturer has issued Dornier 328-100 Airplane Flight Manual Temporary Revision (TR) 02-099, dated November 18, 1996. The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, approved this TR. The FAA acknowledges that the TR contains the exact wording as that specified in paragraph (a) of this final rule. In light of this, the FAA has revised this final rule to include insertion of this TR as an additional method of compliance with the requirements of paragraph (a) of this AD.
As explained in the preamble of the proposed rule, the FAA has received reports of 14 incidents and/or accidents involving intentional or inadvertent operation of the propellers in the ground beta range during flight on airplanes equipped with turboprop engines. Such operation of the propellers in the beta range during flight, if not prevented, could result in an unsafe condition (loss of airplane controllability, or engine overspeed with consequentloss of engine power). The FAA has determined that this unsafe condition could exist or eventually develop on the affected airplanes, and that revising the Limitations Section of the AFM must be mandated to ensure that safety is not degraded. The appropriate vehicle for mandating such action to correct an unsafe condition is the airworthiness directive.
Withdraw Proposed Rule: Pilot Training Needed
This same commenter states that the unsafe condition addressed by the proposal is not a problem with the airplane itself, but rather with lack of education for the pilots regarding the operation of turboprop engines. The FAA infers that the commenter requests that the FAA withdraw the proposed rule.
The FAA does not concur with the commenter s request. The requirements of this final rule will reinforce the education and training of pilots of turboprop airplanes by ensuring that the pilots are aware that the AFM prohibits operating the power levers below the flight idle gate in flight and advises of the consequence of such actions. The FAA finds that the actions required by this final rule will ensure that the pilots are aware of a potential in-flight unsafe condition.
Withdraw Proposed Rule: Issuance of AD May Adversely Affect Airplane Sales
One commenter suggests that the issuance of the AD may create the illusion that a unique and dangerous unsafe condition exists on the airplane. The commenter further suggests that the issuance of the AD could cause an adverse effect on current or future lease and sales of the airplane. The FAA infers that the commenter requests that the proposed rule be withdrawn.
The FAA does not concur. As stated in the preamble of the proposal, the identified unsafe condition has been found to exist on airplanes equipped with turboprop engines, not just the airplanes addressed in this particular AD. The FAA is currently in the process of addressing the identified unsafe condition on other airplanes equipped with turbopropengines. While it is understandable that a manufacturer would like to minimize any adverse implications regarding the safety of its products, the purpose of an AD is to correct an identified unsafe condition in aircraft, regardless of where it is or what it is caused by. The FAA has determined that, because of the identified unsafe condition addressed by this AD, the continued operational safety of the airplanes necessitates issuance of the final rule.
Revise the Cost Estimate
One commenter asserts that the cost estimate provided in the proposal gives an erroneous figure because the cost of an AFM change is not a fixed cost. The commenter further states that, since there is no terminating action for the requirements of the proposed AD, a record must be made and continuously maintained. Further, the commenter notes that additional work and expenses are incurred if a request for an alternative method of compliance is submitted to the FAA.
The FAA does not concur that the cost estimate should be revised. In this case, the FAA considers that once the AFM has been revised in accordance with the final rule, no further action is required. Furthermore, the FAA considers any "additional expense" incurred by an operator or the FAA (as a result of requests for approval of an alternative method of compliance) to be negligible when compared to the necessity to ensure the operational safety of the airplane.
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.
Cost Impact
The FAA estimates that 60 Dornier Model 328-100 series airplane 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 $3,600, 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, Incorporation by reference, 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: