Discussion
Recent analysis by the FAA on the Viking Air Limited Model DHC-3 (Otter) airplanes equipped with a Honeywell TPE331-10 or -12JR turboprop engine installed per Supplemental Type Certificate (STC) SA09866SC revealed that airspeed limitations for the affected airplanes are not adjusted for the installation of a turboprop engine as stated in the regulations. 14 CFR 23.1505 paragraph (c) applies to turbine engine airplanes and includes the following: "* * * a maximum operating limit speed (VMO/MMO-airspeed or Mach number, whichever is critical at a particular altitude) must be established as a speed that may not be deliberately exceeded in any regime of flight (climb, cruise, or descent) unless a higher speed is authorized for flight test or pilot training operations. VMO/MMO must be established so that it is not greater than the design cruising speed VC/MC and so that it is sufficiently below VD/MD and the maximum speed shown under 23.251 tomake it highly improbable that the latter speeds will be inadvertently exceeded in operations. The speed margin between VMO/MMO and VD/MD or the maximum speed shown under 23.251 may not be less than the speed margin established between VC/MC and VD/MD under 23.335(b), or the speed margin found necessary in the flight test conducted under 23.253.''
The FAA has discovered that the affected airplanes, as currently certificated, have airspeed indicators with color band markings that do not comply with 14 CFR 23.1505(c). This could result in reduced safety margins that may result in an unsafe condition.
Based on further analysis with application of the regulations, the FAA has determined that an airspeed limitation of 134 miles per hour (mph) for airplanes with floats and 144 mph for basic land airplanes would address the concern for the unsafe condition.
This condition, if not corrected, could result in loss of airplane structural integrity due to the affected airplanes being able to operate at speeds that exceed the speeds established in the Federal aviation regulations for safe operation.
FAA's Determination
We are issuing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.
AD Requirements
This AD requires incorporating revised airspeed limitations and marking the airspeed indicator accordingly. There is also a requirement for the installation of a temporary placard until the airspeed indicator can be modified but not to exceed a certain period of time.
FAA's Justification and Determination of the Effective Date
An unsafe condition exists that requires the immediate adoption of this AD. The FAA has found that the risk to the flying public justifies waiving notice and comment prior to adoption of this rule because it could result in loss of airplane structural integrity due to the affected airplanes being able to operate at speeds that exceed the speeds established in the Federal aviation regulations for safe operation. Therefore, we find that notice and opportunity for prior public comment are impracticable and that good cause exists for making this amendment effective in less than 30 days.
Comments Invited
This AD is a final rule that involves requirements affecting flight safety and was not preceded by notice and an opportunity for public comment. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include the docket number FAA-2011-0543 and Directorate Identifier 2011-CE-018-AD at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments.
We will post all commentswe receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD.
Costs of Compliance
We estimate that this AD affects 25 airplanes of U.S. registry
We estimate the following costs to comply with this AD:
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Estimated Costs ----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Airplane Flight Manual Limitation, 10 work-hours x $85 per $90 $940 $23,500
Placard, and Airspeed Indicator hour = $850.
Modification. ----------------------------------------------------------------------------------------------------------------
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. "Subtitle VII: Aviation Programs'' describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701: "General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.
Regulatory Findings
This AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect 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.
For the reasons discussed above, I certify that this AD:
(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),
(3) Will not affect intrastate aviation in Alaska, and
(4) 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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.