This amendment adopts a new AD for the Eurocopter Model EC 155 B and B1 helicopters. This action requires:
For blades with 100 or less hours time-in-service (TIS), prior to reaching 110 hours TIS, inspecting the tenon for a crack, and replacing the blade if a crack is found in the tenon;
For blades with more than 100 hours TIS, within the next 10 hours TIS, inspecting the tenon for a crack, and replacing the blade if a crack is found in the tenon;
After accomplishing the initial inspection for a crack as described above, before further flight, establishing the baseline clearance ("DO") between a straight edge and the upper surface of the blade assembly at the blade-to-tip cap junction; and
Thereafter, before the first flight of each day and on or before reaching each 10 hours TIS interval during the day, measuring the clearance between the straight edge and the upper surface of the blade assembly of the blade-to-tip cap junction. If the measured distance is equal to or greater than "DO" + 2mm, replacing the blade is required.
This amendment is prompted by a report of a crack that was discovered on a tenon. This condition, if not detected, could result in loss of the blade tip cap, which could lead to severe vibration and loss of control of the helicopter.
The Direction Generale De L'Aviation Civile (DGAC), the airworthiness authority for France, notified the FAA that an unsafe condition may exist on Eurocopter EC 155 B and B1 helicopters. The DGAC advises of the discovery of a crack in a blade tenon, the growth of which could lead to the loss of the tip cap and make the helicopter impossible to control.
Eurocopter has issued Alert Telex No. 05A004, dated November 3, 2003, which specifies checks on each blade to ensure that there is no crack in the tenon to which the blade tip is attached. The DGAC classified this alert telex as mandatory and issued AD No. F-2003-418, dated December 24, 2003, adopting theactions contained in the manufacturer's alert telex to ensure the continued airworthiness of these helicopters in France.
These helicopter models are manufactured in France and are type certificated for operation in the United States under the provisions of 14 CFR 21.29 and the applicable bilateral agreement. Pursuant to the applicable bilateral agreement, the DGAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DGAC, reviewed all available information, and determined that AD action is necessary for products of these type designs that are certificated for operation in the United States.
This unsafe condition is likely to exist or develop on other helicopters of the same type design registered in the United States. Therefore, this AD is being issued to detect a crack in a tenon, which could result in loss of the tip cap, causing severe vibration and loss of control of the helicopter. This AD requires, for Eurocopter Model EC155 B and B1 helicopters:
For blades with 100 or less hours TIS, prior to reaching 110 hours TIS, an initial inspection of each tenon for a crack;
For blades with more than 100 hours TIS, within the next 10 hours TIS, an initial inspection of the tenon for a crack;
Replacing any blade if a crack is found in the tenon; and
After accomplishing the initial inspection for a crack as described above, before further flight, measuring the clearance between the lower edge of the straight edge to the upper surface of the blade assembly at the blade-to-tip cap junction ("DO") to establish the baseline clearance and then, before the first flight of each day (not to exceed 10 hours TIS), measuring the clearance between the lower edge of the straight edge and the upper surface of the blade assembly at the blade-to-tip cap junction for each blade, and if the distance is equal to or greater than "DO" + 2mm, replacing the blade with an airworthy blade.
The actions must be donein accordance with the alert telex described previously. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the controllability and structural integrity of the helicopter. Therefore, inspecting each blade for a crack in the tenon within the short compliance time is required, 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 30 days.
The FAA estimates that this AD will affect 6 helicopters. The initial inspection will take approximately 1.5 work hours, and the repetitive inspections will take 0.5 work hours to accomplish. It will take approximately 1 work hour to replace all 5 blades. The average labor rate is $65 per work hour. Required parts will cost approximately$97,000 per blade. Based on these figures, the total estimated cost impact of the AD on U.S. operators is $586,563, assuming one blade per helicopter will need to be replaced each year and that 20 repetitive inspections will be needed per helicopter each year.
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 for comments 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-05-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: