Discussion
On June 7, 2013, at 78 FR 34282, the Federal Register published our notice of proposed rulemaking (NPRM), which proposed to amend 14 CFR part 39 by adding an AD that would apply to certain Bell Model 206L-3 and 206L-4 helicopters. The NPRM proposed to require installing a placard on the instrument panel below the dual tachometer and revising the Operating Limitations section of the Model 206L-3 and 206L-4 RFMs by inserting pages that limit steady-state operations between speeds of 71.8% and 91.5%. The proposed requirements were intended to prevent turbine failure, engine power loss, and subsequent loss of control of the helicopter.
The NPRM was prompted by TCCA AD No. CF-2005-28R1, dated June 14, 2007, to correct an unsafe condition for certain Model 206L-3 and 206L- 4 helicopters. TCCA, which is the aviation authority for Canada, advises of several failures of third stage turbine wheels used in Rolls-Royce 250-C30S and 250-C47B engines. According to TCCA, Rolls- Royce determined that detrimental vibrations can occur within a particular range of turbine speeds, and may be a contributing factor to these failures. Bell has revised the RFM and provided a corresponding decal to inform pilots to avoid steady-state operations between 71.8% and 91.5% turbine speeds. The TCCA AD requires amending the RFMs, advising pilots of the change, and installing a decal as described in Bell Alert Service Bulletin (ASB) No. 206L-05-134, dated June 8, 2005, or later revisions.
On October 3, 2014, at 79 FR 59695, the Federal Register published our supplemental notice of proposed rulemaking (SNPRM), which proposed to revise the applicability and change the procedures for updating the RFM. The SNPRM proposed adding Bell Model 206L-1 helicopters with Engine Upgrade Kit part number (P/N) 206-706-520 installed, to the applicability. Engine Upgrade Kit P/N 206-706-520 replaces the Rolls- Royce 250-C28B engine with a Rolls-Royce 250-C30P engine. The condition causing the failures of third stage turbine wheels used in Rolls-Royce 250-C30S and 250-C-47B engines could also exist in Rolls-Royce 250-C30P engines. The SNPRM
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also proposed removing Bell Model 206L-3 and 206L-4 helicopters having Rolls-Royce 250-C20R engines installed under STC No. SR00036SE from the applicability because that engine is not affected by the unsafe condition. The SNPRM also proposed changing the procedures for modifying the RFM Limitations Section from inserting revised RFM pages to inserting a copy of this AD into the RFM or by making pen and ink changes.
Comments
We gave the public the opportunity to comment on the SNPRM (79 FR 59695, October 3, 2014) but we received no comments.
FAA's Determination
These helicopters have been approved by the aviation authority of Canada and are approved for operation in the United States. Pursuant to our bilateral agreement with Canada, TCCA, its technical representative, has notified us of the unsafe condition described in the TCCA AD. We are issuing this AD because we evaluated all information provided by TCCA, reviewed the relevant information, considered the comment received, and determined the unsafe condition exists and is likely to exist or develop on other helicopters of these same type designs and that air safety and the public interest require adopting the AD requirements as proposed.
Differences Between This AD and the TCCA AD
The TCCA AD requires compliance within 10 calendar days; this AD requires compliance within 30 days. This AD is applicable to Model 206L-1 helicopters with Engine Upgrade Kit P/N 206-706-520 installed because the same unsafe condition exits on this model, and the TCCA AD is not.
Related Service Information
Bell issued ASB No. 206L-05-134, Revision A, dated April 9, 2007, which describes procedures for installing a placard on the instrument panel below the main rotor RPM (Nr)/power turbine RPM(N2) dual tachometer and for inserting the RFM changes into the flight manual. Revision A of the ASB was issued to exclude Bell Model 206L-3 and 206L- 4 helicopters with 250-C20R engines installed under STC No. SR00036SE from the requirements of the ASB.
Costs of Compliance
We estimate that this AD will affect 616 helicopters of U.S. Registry. We estimate that operators may incur the following costs in order to comply with this AD. Based on an average labor rate of $85 per work-hour, amending the RFM requires about 0.5 work-hour, for a cost per helicopter of about $43 and a cost to U.S. operators of $26,488. Installing the decal requires about 0.2 work-hour, and required parts cost $20, for a cost per helicopter of $37 and a cost to U.S. operators of $22,792. Based on these estimates, the total cost of this AD is $80 per helicopter and $49,280 for the fleet.
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 helicopters 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 to the extent that it justifies making a regulatory distinction; 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.
We prepared an economic evaluation of the estimated costs to comply with this AD and placed it in the AD docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.