01-21231. Airworthiness Directives; Agusta S.p.A. Model A109C, A109E, and A109K2 Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes superseding an existing airworthiness directive (AD) for Agusta S.p.A. Model A109C, A109E, and A109K2 helicopters. That AD requires inspecting between the metal shells and honeycomb core by a tapping inspection of the upper and lower sides of the main rotor blade (blade) tip cap for bonding separation, by a visual inspection for swelling or deformation, and by a visual inspection of the welded bead along the leading edge for a crack. This action would contain the same requirements as the existing AD but would also require a tap inspection of the tip cap for bonding separation in the blade bond area and a dye penetrant inspection of the tip cap leading edge along the welded joint line of the upper and lower tip cap skin shells for a crack. This proposal is prompted by three occurrences in which the blade tip cap leading edge opened in flight due to cracks, resulting in excessive helicopter vibration. The actions specified by the proposed AD are intended to prevent failure of a blade tip cap, excessive vibration, and subsequent loss of control of the helicopter.

DATES:

Comments must be received on or before October 22, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2001-SW-15-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. You may also send comments electronically to the Rules Docket at the following address: [e-mail]. Comments may be inspected at the Office of the Regional Counsel between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT:

Richard Monschke, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, Fort Worth, Texas 76193-0110, telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed 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 above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this document may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their mailed comments submitted in response to this proposal must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket No. 2001-SW-15-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2001-SW-15-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

Discussion

On February 5, 1999, the FAA issued AD 98-19-04, Amendment 39-11039 (64 FR 7494, February 16, 1999), to require inspecting between the metal shells and honeycomb core for bonding separation by a tapping inspection of the upper and lower sides of the blade tip cap, by a visual inspection for swelling or deformation, and by a visual inspection of the welded bead along the leading edge of the blade tip cap for a crack. That action was prompted by two discoveries of cracks in the leading edge of blade tip caps. The cracks were discovered after pilots experienced increased vibration during flight. Subsequent investigation revealed that bonding separation of the honeycomb material in the blade led to deformation and cracking of the blade tip cap. The requirements of that AD are intended to prevent a blade tip cap failure, excessive vibration, and subsequent loss of control of the helicopter.

Since the issuance of that AD, Agusta S.p.A. has issued Alert Bollettino Tecnico (ABT) Nos. 109-106, 109K-22, and 109EP-1, all Revision B, and dated December 19, 2000, that specify inspecting the tip cap of blades, part number (P/N) 709-0103-01 (all dash numbers) up through serial number 1428, preceded by code AJ or EM, for debonds and cracks.

We have identified an unsafe condition that is likely to exist or develop on other Agusta S.p.A. Model A109C, A109E, and A109K2 helicopters of the same type design. The proposed AD would supersede AD 98-19-04 but would retain the same requirements and would also require a tap inspection of the tip cap for bonding separation in the blade bond area and a dye penetrant inspection of the tip cap leading edge along the welded joint line of the upper and lower tip cap skin shells for a crack. Installing tip cap, P/N 709-0103-29-109, on all affected blades would be terminating action for the requirements of this AD.

We estimate that 44 helicopters of U.S. registry would be affected by this proposed AD and that it would take approximately 6 work hours per helicopter for the initial and repetitive inspections of the fleet. The average labor rate is $60 per work hour. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $15,840. This estimate is based on the assumption that no blade will need to be replaced as a result of these inspections.

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that 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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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 removing Amendment 39-11039 (64 FR 7494, February 16, 1999), and by adding a new airworthiness directive (AD) to read as follows:

Agusta S.p.A. Docket No. 2001-SW-15-AD. Supersedes AD 98-19-04, Amendment 39-11039, Docket No. 98-SW-40-AD.

Applicability: Model A109C, A109E, and A109K2 helicopters, with main rotor blade (blade), part number (P/N) 709-0130-01-all dash numbers, having a serial number (S/N) up to and including S/N 1428 with a prefix of either “EM-” or “A5-”, installed, certificated in any category.

Note 1:

This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must use the authority provided in paragraph (f) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any helicopter from the applicability of this AD.

Compliance: Required within 10 hours time-in-service (TIS), unless accomplished previously, and thereafter at intervals not to exceed 25 hours TIS.

To prevent failure of a blade tip cap, excessive vibration, and subsequent loss of control of the helicopter, accomplish the following:

(a) Tap inspect the upper and lower sides of each tip cap for bonding separation between the metal shells and the honeycomb core using a steel hammer, P/N 109-3101-58-1, or a coin (quarter) in the area indicated as honeycomb core on Figure 1 of Alert Bollettino Tecnico Nos. 109-106, 109K-22, or 109EP-1, all Revision B, and dated December 19, 2000 (ABT), as applicable. Also, tap inspect for bonding separation in the tip cap to blade bond area (no bonding voids are permitted in this area).

(b) Visually inspect the upper and lower sides of each blade tip cap for swelling or deformation.

(c) Dye-penetrant inspect the tip cap leading edge along the welded joint line of the upper and lower tip cap skin shells for a crack in accordance with the Compliance Instructions, paragraph 3, of the applicable ABT.

(d) If any swelling, deformation, crack, or bonding separation that exceeds the prescribed limits in the applicable maintenance manual is found, replace the blade with an airworthy blade.

(e) Replacement blades affected by this AD must comply with the repetitive inspection requirements of this AD. Replacing an affected blade with a blade having an airworthy blade tip cap, P/N 709-0103-29-109, is terminating action for the requirements of this AD for that blade.

(f) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Regulations Group, Rotorcraft Directorate, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Regulations Group.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group.

(g) A special flight permit may be issued under 14 CFR 21.197 and 21.199 to operate the helicopter to a location where the requirements of this AD can be accomplished. No special flight permit will be issued for any flight with a known tip cap crack.

Note 3:

The subject of this AD is addressed in Ente Nazionale per l'Aviazionne Civile (Italy) AD's 2000-571, 2000-572, and 2000-573, all dated December 22, 2000.

Issued in Fort Worth, Texas, on August 14, 2001.

Eric Bries,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.