E8-24986. Airworthiness Directives; Eurocopter France Model EC 155B and EC155B1 Helicopters

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for Eurocopter France (Eurocopter) Model EC 155B and EC155B1 helicopters that would supersede an existing AD. The airworthiness authority of France has issued a mandatory continuing airworthiness information (MCAI) AD that requires a 50 percent reduction in the life of each affected main rotor blade (blade). The MCAI also requires, for each affected blade, initial and repetitive inspections for correct alignment of the tip cap, correct tenon filler wedge (wedge) position, a crack in the tenon, and erosion in a specified zone in the end of the leading edge. Also, the MCAI requires measuring the vertical clearance between each blade assembly and a straight edge at the blade-to-tip cap junction and replacing any blade that has a cracked tenon. This proposal contains those same requirements as described in the MCAI and requires replacing any blade with a measured vertical clearance exceeding a certain limit. A misalignment, crack, or erosion in a blade could lead to failure of the blade and subsequent loss of control of the helicopter.

DATES:

We must receive comments on this proposed AD by November 20, 2008.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

You may get the service information identified in this proposed AD from American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, TX 75053-4005, telephone [phone], fax [phone], or at http://www.eurocopter.com.

Examining the AD Docket: You may examine the AD docket on the Internet at http://www.regulations.gov,, or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the economic evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Jim Grigg, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Safety Management Group, Fort Worth, Texas 76193-0112, telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2008-0947; Directorate Identifier 2007-SW-46-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD based on those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

On June 1, 2004, we issued AD 2004-12-06, Amendment 39-13665 (69 FR 32857, June 14, 2004). That AD was issued based on MCAI AD F-2003-418 and required inspecting each blade for a crack in the blade tip cap mounting bracket (tenon), measuring the vertical clearance between each blade assembly and a straight edge at the blade-to-tip cap junction, and replacing the blade if a crack is found or if the measured distance is not within certain specifications.

The Direction Generale de L'Aviation Civile (DGAC), which is the aviation authority for France, has issued AD No. F-2004-106, dated July 7, 2004 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified French-certificated helicopters. The MCAI states: “Airworthiness Directive (AD) F-2003-418 was issued following the discovery of a crack in the main rotor blade tip cap attachment tenon. AD F-2003-418 required operators to make sure that there is no crack in the affected zone, and to monitor the blade in operation. Crack growth can lead to the loss of the blade tip cap and make it impossible to control the helicopter.”

The DGAC canceled AD F-2003-418 on July 7, 2004, by issuing AD F-2003-418R1 and AD F-2004-106 on the same day. AD F-2004-106 covers the requirements of AD F-2003-418; reduces the service life of each blade from 20,000 flying hours to 10,000 flying hours; renders certain checks and corrective actions mandatory, and refers to Eurocopter Alert Service Bulletin (ASB) No. 62A006, dated May 18, 2004, which superseded Alert Telex No. 05A004, dated November 3, 2003.

You may obtain further information by examining the MCAI and service information in the AD docket.

Since we issued AD 2004-12-06, after further investigations and tests and based on MCAI AD F-2004-106, we have determined that an additional inspection for correct position of the wedge of the tenon at the blade tip and erosion in a specific zone at the end of the leading edge of the blade and a reduction in service life for certain serial-numbered blades are necessary.

Relevant Service Information

Eurocopter has issued ASB No. 62A006, dated May 18, 2004. This ASB forms the basis for issuing MCAI AD F-2004-106 and supersedes Alert Telex No. 05A004, which was the basis for MCAI AD F-2003-418. The actions described in the MCAI are intended to correct the same unsafe condition as that identified in the service information.

FAA's Evaluation and Unsafe Condition Determination

This product has been approved by the aviation authority of France, and is approved for operation in the United States. Pursuant to our bilateral agreement with this State of Design, we have been notified of the unsafe condition described in the MCAI. We are proposing this AD because we evaluated all pertinent information provided by France and determined an unsafe condition exists and is likely to exist or develop on other products of these same type designs. We have determined an additional inspection for correct position of the wedge of the tenon at the blade tip and erosion in a specific zone at the end of the leading edge of the blade and a reduction in service life for certain serial-numbered blades are necessary.

Differences Between This AD and the MCAI

We have reviewed the MCAI and related service information and, in general, agree with their substance. The following are the differences between the AD and the MCAI:

• We refer to the actions proposed by this AD by using the word “inspect” rather than “check” to indicate that the actions are done by a mechanic rather than a pilot.
• The AD would not require you to contact the manufacturer as specified in the service information.
• We use the words “time-in-service” rather than “flight hours.”
• We do not use the compliance date of September 30, 2004 to remove affected blades because that date has passed.

These differences are highlighted in the “Differences Between This AD and the MCAI” section of this proposed AD.

Costs of Compliance

We estimate that this proposed AD would affect about 6 helicopters of U.S. registry. We also estimate that it would take about 1.5 work-hours to do the initial inspection and about 0.5 work hours to do the repetitive inspection. The average labor rate is $80 per work-hour. Required parts would cost about $97,000 per blade. Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $587,520 for the first year and $586,800 each subsequent year, assuming one blade per helicopter will need to be replaced each year and 20 repetitive inspections will be needed per helicopter each year.

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.

Regulatory Findings

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 above, 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); 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 proposed 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

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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. The FAA amends § 39.13 by removing Amendment 39-13665 (69 FR 32857, June 14, 2004) and adding the following new AD:

Eurocopter France: Docket No. FAA-2008-0947; Directorate Identifier 2007-SW-46-AD.

Comments Due Date

(a) We must receive comments by November 20, 2008.

Other Affected ADs

(b) This proposed AD would supersede AD 2004-12-06, Amendment 39-13665, Docket No. 2004-SW-05-AD.

Applicability

(c) This AD applies to Model EC 155B and B1 helicopters, with main rotor blade (blade), part number (P/N) 365A11-0080-00, installed, certificated in any category.

Reason

(d) Based upon further review, investigation, and fatigue tests, the Direction Generale de L'Aviation Civile (DGAC), France, has cancelled its AD F-2003-418, which formed the basis for our AD 2004-12-06, which was prompted by the discovery of cracks in a blade tip cap attachment tenon. In these further reviews prompted by the findings related to the tip cap area after a tip cap was removed because of abnormal tilt in the flapping direction, in addition to a crack in the tenon, some blades were found to have incorrect tenon filler wedge (wedge) positioning and erosion in the zone of the tenon leading edge. All these findings constitute unsafe conditions that could result in failure of the blade and subsequent loss of control of the helicopter.

Actions and Compliance

(e) Required as indicated, unless already done, do the following:

(1) Before further flight, reduce the blade service life from 20,000 to 10,000 hours time-in-service (TIS).

(2) For a blade with a Serial Number (S/N) 808 or less:

(i) Before the first flight of each day and on or before reaching each 10 hour TIS interval during the day, inspect for correct alignment of the blade tip cap junction in the flapping direction as shown in Figure 3 and by following the Accomplishment Instructions, paragraph 2.B.4., Eurocopter France Alert Service Bulletin 62A006, dated May 18, 2004 (ASB), except this AD does not require you to contact the manufacturer.

(A) During the initial alignment inspection, mark the position of the ruler and record the initial clearance value of “DO” by following the Accomplishment Instructions, paragraph 2.B.3.a)3. through 2.B.3.a)6. of the ASB. The initial clearance distance between the lower edge of the 24 inch (500mm) straight edge ruler and the upper surface of the blade assembly at the blade-to-tip cap junction is called “DO.”

(B) If the measured clearance as determined by paragraph 2.B.4. of the ASB is equal to or greater than “DO” + 2mm, replace the blade with an airworthy blade before further flight.

(ii) Within the next 3 months, remove and inspect each blade for the correct wedge position, a crack in the tenon, correct alignment of the blade tip cap, and erosion in the leading edge in Zone 1 by following the Accomplishment Instructions, paragraph 2.B, of the ASB except this AD does not require you to contact the manufacturer.

(A) If the wedge is incorrect (dissymmetrical position) as shown in Figure 2 of the ASB, using a 10x or higher magnifying glass and a light, inspect the imbedded portion of the tenon as shown in Figure 5 of the ASB for a crack by following the Accomplishment Instructions, paragraph 2.B.3., of the ASB.

(1) If a crack is found in the tenon, before further flight, replace the blade with an airworthy blade.

(2) If no crack is found in the tenon, inspect the end of the leading edge of the blade for erosion in Zone 1 as shown in Figure 7 of the ASB.

(B) If the wedge position is correct (symmetrical position) as shown in Figure 1 of the ASB, inspect the end of the leading edge of the blade for erosion in Zone 1 as shown in Figure 7 of the ASB.

(C) Thereafter, on or before 660 hours TIS and at intervals not to exceed 660 hours TIS, remove the blade and the blade tip cap, scrap the 35 attachment screws, and inspect the end of the leading edge of the blade for erosion in Zone 1 as shown in Figure 7 of the ASB.

(3) For a blade with a S/N of 809 or greater:

(i) For a blade that has less than 660 hours TIS, on or before 660 hours TIS and thereafter, at intervals not to exceed 660 hours TIS, remove the blade and the blade tip cap, scrap the 35 attachment screws, and inspect the end of the leading edge of the blade for erosion in Zone 1 as shown in Figure 7 of the ASB.

(ii) For a blade that has 660 or more hours TIS, on or before 100 hours TIS and thereafter, at intervals not to exceed 660 hours TIS, remove the blade and the blade tip cap, scrap the 35 attachment screws, and inspect the end of the leading edge of the blade for erosion in Zone 1 as shown in Figure 7 of the ASB.

(4) If any inspection of the end of the leading edge of a blade in Zone 1, as shown in Figure 7 of the ASB, results in:

(i) Erosion in Zone 1—clean and caulk the eroded zone by following the Accomplishments Instructions, paragraph 2.B.6., of the ASB, and reinstall the blade tip cap and caulk the gap in accordance with the Accomplishment Instructions, paragraph 2.B.7, of the ASB.

(ii) No Erosion in Zone 1—reinstall the blade tip cap and caulk the gap in accordance with the Accomplishment Instructions, paragraph 2.B.7., of the ASB.

Differences Between This AD and the MCAI

(f) We have identified the following differences:

(1) We refer to the actions required by this AD by using the word “inspect” rather than “check” to indicate that the actions are done by a mechanic rather than a pilot.

(2) We do not require you to contact the manufacturer as specified in the service information.

(3) We use the words “hours time-in-service” rather than “flight hours.”

(4) We did not use the compliance date of September 30, 2004 to remove affected blades because that date has passed.

Other Information

(g) Alternative Methods of Compliance (AMOCs): The Manager, Safety Management Group, FAA, ATTN: Jim Grigg, Aviation Safety Engineer, Fort Worth, Texas 76193-0112, telephone [phone], fax [phone], has the authority to approve AMOCs for this AD, if requested, using the procedures found in 14 CFR 39.19.

Related Information

(h) MCAI Airworthiness Directive AD No. F-2004-106, Revision A, dated July 7, 2004, contains related information.

Air Transport Association of America (ATA) Tracking Code

(i) ATA Code 6210: Rotor(s).

Issued in Fort Worth, Texas, on October 1, 2008.

Mark R. Schilling,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.