On December 22, 2006, the FAA issued Emergency AD 2006-26-51 for the specified model helicopters, which requires, before further flight, marking the position of the tail rotor control lever dynamic weights (weights), removing the split pins and the weights, and by referring to Figure 1 of the manufacturer's service bulletin, visually inspecting the area around the split pin bore for score marks, notches, scratches, or other damage that exceeds the maintenance manual limitations or a crack and replacing any unairworthy tail rotor control lever before further flight. The AD also requires, within 10 hours TIS, and thereafter at intervals not to exceed 25 hours TIS, repeating the visual inspection of the tail rotor control lever and replacing any unairworthy tail rotor control lever with an airworthy tail rotor control lever before further flight. Also required is reassembling the tail rotor control lever by following the appropriate maintenance instruction. Thataction was prompted by an in- flight incident in which a dynamic weight broke off the tail rotor control lever subsequently leading to considerable vibrations. A visual inspection revealed that the threaded portion of the control lever containing the dynamic weight had broken off. This condition, if not corrected, could result in separation of the weights in flight, severe vibration, and subsequent loss of control of the helicopter.
The Luftfahrt-Bundesamt (LBA) has issued an Emergency AD in accordance with Article 10.1 of European Union Regulation 1592/2002. The LBA, the airworthiness authority for the Federal Republic of Germany, notified the FAA that an unsafe condition may exist on these helicopter models. The LBA advises of an in-flight incident in which a dynamic weight broke off the tail rotor control lever resulting in considerable vibrations. The LBA advises that this can lead to reduced controllability of the helicopter.
The FAA has reviewed Eurocopter Alert Service Bulletin No. MBB BK 117 C-2-64A-002, dated December 21, 2006 (ASB), which describes procedures for initial and recurrent visual inspections of the tail rotor control lever. The ASB specifies inspecting the area around the split pin bore for damage, and if score marks, notching, scratching, a crack, or something similar are detected to contact ECD customer support. In addition, the manufacturer states in that ASB that it is effective for Model MBB BK117 C-2 helicopters, Serial Number (S/N) 9075 and higher, and those helicopters from S/N 9004 up to and including S/N 9074 on which Alert Service Bulletin MBB BK 117 C-2-67-006, dated July 25, 2006, (SB MBB BK 117-C-2-67-006) has been accomplished. The referenced SB MBB BK 117-C-2-67-006, states that it offers improvements with regard to a reduction of the operational pedal control forces. These improvements involved two modifications (1) Installing modified pedal control levers, and (2) installing an optimized tail rotor control lever assembly "consisting of modified weights and modified control lever pre-assys.'' Installing the optimized tail rotor control lever assembly involved replacing the 2 control levers, Part Number (P/ N) B642M1009102, with 2 control levers, P/N B642M1009103, and replacing the 4 weights, P/N B642M1011201 with 4 weights, P/N B642M1011202. The LBA classified this ASB as mandatory and issued LBA AD D-2006-428, effective December 22, 2006, to ensure the continued airworthiness of these helicopters in Germany.
This helicopter model is manufactured in the Federal Republic of Germany and is type certificated for operation in the United States under the provisions of 14 CFR 21.29 and the applicable bilateral agreement. The FAA has examined the findings of the LBA, 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.
Since the unsafe condition described is likely to exist or develop on other ECD Model MBB-BK 117 C-2 helicopters of the same type design, the FAA issued Emergency AD 2006-26-51 to prevent separation of the weights in flight, severe vibration, and subsequent loss of control of the helicopter. The AD requires the following:
Before further flight, marking the position of the weights, removing the split pins, removing the weights, and visually inspecting the tail rotor control lever in the area around the split pin bore for score marks, notching, scratching, or a crack.
If you find score marks, notching, or scratches, that exceed the maintenance manual limits, or find a crack, replacing the tail rotor control lever with an airworthy tail rotor control lever before further flight.
If you do not find score marks, notching, scratches, or a crack, within 10 hours TIS, and thereafter at intervals not to exceed 25 hours TIS, repeating the visual inspection of the tail rotor control lever.
After any repetitive inspection, if you find score marks, notching, or scratches, that exceed the maintenance manual limits or find a crack, replacing the tail rotor control lever with an airworthy tail rotor control lever before further flight.
Reassembling the tail rotor control lever by following the appropriate maintenance instruction.
The actions must be accomplished in accordance with the specified portions of the ASB described previously. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the structural integrity and controllability of the helicopter. Therefore, the actions previously described are required at the specified short time intervals, and this AD must be issued immediately.
Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual letters issued on December 22, 2006 to all known U.S. owners and operators of ECD Model MBB-BK 117 C-2 helicopters. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to 14 CFR 39.13 to make it effective to all persons.
The FAA estimates that this AD will affect 26 helicopters on the U.S. registry. The before-flight inspection, the 10-hour TIS inspection, and each of the repetitive 25-hour TIS inspections (assuming 24 repetitive inspections per year per helicopter) including marking the position of the weights, removing the split pins, removing the weights, and visually inspecting the tail rotor control lever and reassemblying an airworthy tail rotor control lever will take about 1 work hour per inspection per helicopter. Replacing 1 tail rotor control lever and 1 weight will take about 3 work hours. The average labor rate is $80 per work hour. Required parts, if necessary, will cost about $4,166 for each tail rotor control lever (2 per helicopter); $496 for each weight (4 per helicopter); and $.21 for each cotter pin (4 per helicopter). Based on these figures, we estimate the total cost impact of the AD on U.S. operators for the first year will be $181,532 ($6,982 per helicopter, assuming 1 tail rotor control lever and 1 weight are replaced on each helicopter in the fleet during the first year).
Comments Invited
This AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any written data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include "Docket No. FAA-2006-26721; Directorate Identifier 2006-SW-28-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD. We will consider all comments received by the closing date and may amend the AD in light of those comments.
We will post all comments we receive, without change, to http://dms.dot.gov , including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. Using the search function of our docket Web site, you can find and read the comments to any of our dockets, including the name of the individual who sent the comment. You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov .
Regulatory Findings
We have determined that 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 thatthe regulation:
1. Is not a "significant regulatory action'' under Executive Order 12866;
2. Is not a "significant rule'' under the 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.
We prepared an economic evaluation of the estimated costs to comply with this AD. See the DMS to examine the economic evaluation.
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.
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.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: