This amendment adopts a new AD for MD Helicopters, Inc. Model MD900 helicopters. This action requires installing a fail-safe device; and, thereafter, before the first flight of each day, checking for bent clips, taut lanyards, or piston rod movement. If any of these conditions are found, this AD requires replacing the control rod assembly with airworthy parts before further flight. This amendment is prompted by an accident report of
fatigue failure of the piston rod in the spring capsule of the control rod assembly. This condition, if not corrected, could result in failure of the piston rod and subsequent loss of control of the helicopter.
The FAA has reviewed MD Helicopters, Inc. Service Bulletin SB900- 094, dated March 17, 2004 (SB), which describes procedures for installing a fail-safe device to prevent separation of the piston rod from the spring capsule if a fracture occurs. The SB also describes a daily pilot check of the piston rod and fail-safedevice after installing it.
This unsafe condition is likely to exist or develop on other helicopters of the same type design. Therefore, this AD is being issued to prevent fatigue failure of the piston rod and subsequent loss of control of the helicopter. This AD requires:
Installing a fail-safe device on or before September 17, 2004, or based on specified hours time-in-service (TIS) of the control rod assembly, whichever occurs first.
Before the first flight of each day, after installing a fail-safe device, unzipping the ceiling panel in the baggage compartment and checking for bent clips on the outer bell-crank assembly, taut lanyards connected to clips, and movement of the piston rod. An owner/operator (pilot), holding at least a private pilot certificate, may perform these checks. Pilots may perform these checks because they require no tools and can be done equally well by a pilot or a mechanic. However, the pilot must enter compliance with these requirements into the helicopter maintenance records by following 14 CFR 43.11 and 91.417(a)(2)(v).
If the bellcrank assembly has taut lanyards, bent clips, or the piston rod moves in any direction, replacing the control rod assembly with an airworthy control rod assembly before further flight.
Mechanics perform the actions following the SB described previously. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the controllability or structural integrity of the helicopter. Therefore, installing a fail-safe device is required before further flight for those helicopters that have a control rod assembly with 790 or more hours TIS, and this AD must be issued immediately.
Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30days.
The FAA estimates that this AD will affect 29 helicopters and take about 0.5 work hour to install a fail-safe device at an average labor rate of $65 per work hour. The daily check requires only a minimal amount of time and, therefore, the costs are negligible. Required parts will cost about $322 per helicopter. Based on these figures, we estimate the total cost impact of the AD on U.S. operators to be $10,280.50.
Comments Invited
Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption ADDRESSES. All communications received on or before the closing date forcomments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.
Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their mailed comments submitted in response to this rule must submit a self- addressed, stamped postcard on which the following statement is made: "Comments to Docket No. 2004-SW-10-AD." The postcard will be date stamped and returned to the commenter.
The regulations adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.
The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, 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 a new airworthiness directive to read as follows: