Daily Rules, Proposed Rules, and Notices of the Federal Government
For service information identified in this proposed AD, contact MD Helicopters Inc., Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615, Mesa, AZ 85215-9734, telephone 1-800-388-3378, fax 480-346-6813, or at
We invite you to participate in this rulemaking by submitting written comments, data, or views. We also invite comments relating to the economic, environmental, energy, or federalism impacts that might result from adopting the proposals in this document. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. To ensure the docket does not contain duplicate comments, commenters should send only one copy of written comments, or if comments are filed electronically, commenters should submit only one time.
We will file in the docket all comments that we receive, as well as a report summarizing each substantive public contact with FAA personnel concerning this proposed rulemaking. Before acting on this proposal, we will consider all comments we receive on or before the closing date for comments. We will consider comments filed after the comment period has closed if it is possible to do so without incurring expense or delay. We may change this proposal in light of the comments we receive.
We are proposing to adopt a new AD for the specified MDHI helicopters with certain serial-numbered tailboom assemblies installed. Customers returned two tailboom assemblies to the manufacturer that contained an improperly installed frame ring at station 209.78. The frame rings were installed with too short a distance between an aft longeron rivet and the outboard edge of the frame ring. This is known as a short-edge margin condition.
We are proposing this AD because we evaluated all known relevant information and determined that an unsafe condition exists and is likely to exist or develop on other helicopters of these same type designs.
MDHI has issued one Service Bulletin (SB), dated July 20, 2010, with 3 different numbers: SB No. SB369D-207 for the Model 369D helicopters, SB No. SB369E-102 for the Model 369E helicopters, and SB No. SB369F-087 for the Model 369F and FF helicopters. The MDHI SB describes procedures for measuring the distance from the aft face of the station 209.78 canted frame ring to the center of the No. 1 and No. 2 aft rivet locations on each of the four longerons spaced 90° apart around the frame ring. If a short-edge margin condition exists, the SB specifies modifying the tailboom by installing a repair doubler at each affected location.
This proposed AD would require measuring the distance from the aft face of the station 209.78 frame ring to the center of rivet No. 1 and rivet No. 2 at the four locations where the frame ring attaches to the tailboom longeron. If either the No. 1 or No. 2 aft rivet at a frame-ring-to-tailboom longeron location is more than 0.50 inches (12.7 millimeters) from the aft face of the
We estimate that this proposed AD would affect 109 helicopters of U.S. registry. We estimate that operators may incur the following costs in order to comply with this AD. $340 for 4 work hours to access and measure for a short-edge margin condition at $85 per hour for a total of $37,060 for the fleet.
The on-condition costs for installing the doubler are not included in our cost estimate because we have no way of determining the number of aircraft that might need a doubler, which would require about 8 work hours at $85 per hour for a total of $699 additional labor for each helicopter and $19 for required parts.
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.
We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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, I certify this proposed 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);
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 proposed AD and placed it in the AD docket.
Air transportation, Aircraft, Aviation safety, Incorporation by Reference, Safety.
Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:
1. The authority citation for part 39 continues to read as follows:
49 U.S.C. 106(g), 40113, 44701.
2. The FAA amends § 39.13 by adding the following new Airworthiness Directive (AD):
This AD applies to Model 369D, E, F, and FF helicopters with tailboom assembly, part number (P/N) 369D23500-505, -507, -511, or -513 with a serial number prefix of “7604” and -0001 through -0003, -0006 through -0047, -0049 through -0082, or -0084 through -0113, installed, certificated in any category.
This AD defines the unsafe condition as too short an edge distance from an aft longeron rivet to the edge of a tailboom frame ring, which could result in failure of the tailboom and subsequent loss of control of the helicopter.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
(1) Within 6 months or 100 hours time-in-service, whichever occurs first, measure the distance from the aft face of the station 209.78 frame ring to the center of rivet No. 1 and rivet No. 2 at the four locations where the frame ring attaches to the tailboom longeron as depicted in Figure 2 of MD Helicopters Service Bulletin (SB) No. SB369D-207, SB369E-102, and SB369F-087, dated July 20, 2010. SB369D-207 applies to the Model 369D helicopters; SB369E-102 applies to the Model 369E helicopters; and SB369F-087 applies to Model 369F and FF helicopters.
The one MD Helicopters SB, dated July 20, 2010, contains three different numbers: SB369D-207; SB369E-102; and SB369F-087.
(2) If either the No. 1 or No. 2 aft rivet at a frame-ring-to-tailboom-longeron location is more than 0.50 inches (12.7 millimeters) from the aft face of the station 209.78 frame ring, before further flight, modify that location by fabricating and installing a doubler over the location as depicted in Figures 3 and 4 and by following the Accomplishment Instructions, paragraph 2.C., of the SB for your model helicopter.
(1) The Manager, Los Angeles Aircraft Certification Office, FAA, may approve AMOCs for this AD. Send your proposal to John Cecil, Aerospace Engineer, FAA, Los Angeles Aircraft Certification Office, Airframe Branch, 3960 Paramount Blvd., Lakewood, California 90712-4137, telephone (562) 627-5228, fax (562) 627-5210, email
(2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, we suggest that you notify your principal inspector, or lacking a principal inspector, the manager of the local flight standards district office or certificate holding district office before operating any aircraft complying with this AD through an AMOC.
Joint Aircraft System Component (JASC) Code 5302: Rotorcraft Tailboom.