AD 2000-18-51

Effective November 30, 2000, to all persons except those persons to whom it was made immediately effective by Emergency AD 2000-18-51, issued on August 31, 2000, which contained the requirements of this amendment.

Comments for inclusion in the Rules Docket must be received on or before January 16, 2001.

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2000-SW-35-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. You may also send comments electronically to the Rules Docket at the following address: 9-asw-adcomments@faa.gov.

Marc Belhumeur, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office, Fort Worth, Texas 76193-0170, telephone (817) 222-5177, fax (817) 222-5783.

The FAA issued AD 86-06-08R1 on May 12, 1987 (52 FR 24135, June 29, 1987), which amended AD 86-06-08 (51 FR 11300, April 2, 1986). Those AD's required an initial and repetitive fluorescent dye penetrant inspection of each grip. On August 31, 2000, the FAA issued Emergency AD 2000-18-51, for BHTI Model 47B, 47B-3, 47D, 47D-1, 47G, 47G-2, 47G2A, 47G-2A-1, 47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5, 47G-5A, 47H-1, 47J, 47J-2, 47J-2A, and 47K helicopters. That emergency AD supersedes AD 86-06-08 and AD 86-06-08R1 and requires recurring liquid penetrant or eddy current inspections of the grip threads for a crack. If a crack is detected, the AD requires, before further flight, replacing the cracked grip with an airworthy grip. The AD also establishes a retirement life of 1,200 hours TIS for each grip. That action was prompted by the results of an investigation of an August 1998 accident in which a grip failed on a BHTI Model 47G-2 helicopter due to a fatigue crack. An analysis of Australian field service data revealed fatigue cracks in the majority of the grips inspected. Since issuance of Emergency AD 2000-18-51, other cracked grips with less than 1200 hours TIS have been discovered. This condition, if not corrected, could result in failure of a grip, loss of a main rotor blade, and subsequent loss of control of the helicopter.

Since the unsafe condition described is likely to exist or develop on other BHTI Model 47B, 47B-3, 47D, 47D-1, 47G, 47G-2, 47G2A, 47G-2A-1, 47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5, 47G-5A, 47H-1, 47J, 47J-2, 47J-2A, and 47K helicopters of the same type designs, the FAA issued Emergency AD 2000-18-51 to prevent failure of a grip, loss of a main rotor blade, and subsequent loss of control of the helicopter. The AD requires the following for grips, part number (P/N) 47-120-135-2, 47-120-135-3, 47-120-135-5, 47-120-252-1, 47-120-252-7, and 47-120-252-11, and for grips manufactured under Parts Manufacturer Approval, P/N 74-120-252-11 and 74-120-135-5:

• Within 100 hours TIS since initial installation on any helicopter or within 10 hours TIS for grips with 100 or more hours TIS, conduct a liquid penetrant or eddy current inspection of the grip threads for a crack.

• Thereafter, conduct the liquid penetrant or eddy current inspection of the grip threads at intervals not to exceed 200 hours TIS.

• If a crack is detected, before further flight, replace the cracked grip with an airworthy grip.

• Establish a retirement life of 1200 hours time-in-service (TIS) for each grip.

The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the structural integrity and controllability of the helicopter. Therefore, the above actions are required at the specified time intervals, and this AD must be issued immediately.

Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual letters issued on 2000-18-51 to all known U.S. owners and operators of BHTI Model 47B, 47B-3, 47D, 47D-1, 47G, 47G-2, 47G2A, 47G-2A-1, 47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-3B-2A, 47G-4, 47G-4A, 47G-5, 47G-5A, 47H-1, 47J, 47J-2, 47J-2A, and 47K helicopters. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective to all persons.

The FAA estimates that 1000 helicopters of U.S. registry will be affected by this AD, that it will take approximately 10 work hours per helicopter to accomplish either inspection, and that the average labor rate is $60 per work hour. Required parts, if a grip needs to be replaced, will cost approximately $4,000 per grip (there are two grips on each helicopter). Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $8,600,000, assuming one inspection per helicopter and replacement of both grips on each helicopter.

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, both before and after the closing date for comments, 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. 2000-SW-35-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.

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:

1. The authority citation for part 39 continues to read as follows:

2. Section 39.13 is amended by removing Amendment 39-5260 (51 FR 11300, April 2, 1986) and Amendment 39-5626 (52 FR 24135, June 29, 1987) and by adding a new airworthiness directive to read as follows: