AD 2000-25-52

Effective February 6, 2001.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of February 6, 2001.

Comments for inclusion in the Rules Docket must be received on or before March 23, 2001.

Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 2000-SW-63-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.

The service information referenced in this AD may be obtained from Helicopter Technology Company, LLC, 12923 South Spring St., Los Angeles, CA 90061, telephone (310) 523-2750, fax (310) 523-2745. This information may be examined at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

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

On November 21, 2000, the FAA issued Emergency AD 2000-24-51 that applies to MDHI Model 369A, H, HE, HM, HS, D, E, FF, and 500N helicopters and requires, before further flight, performing a tap inspection on both the upper and lower surfaces of each blade. If any voids are detected that exceed specified inspection requirements, this AD requires replacing the unairworthy blade with an airworthy blade before further flight. That action was prompted by a blade failure due to fatigue cracking that originated at corrosion pits on the spar bonded surfaces, resulting in an accident that destroyed a Hughes Model 369D helicopter. That condition, if not corrected, could result in failure of a blade and subsequent loss of control of the helicopter.

Since the issuance of that AD, the FAA discovered an error in the applicability section. The part numbers are not listed correctly with the appropriate serial numbers and, as a result, the FAA received requests from operators to clarify which blade part numbers are affected since the emergency AD deviates from the applicable service bulletin. The intent of Emergency AD 2000-24-51 was not to deviate from the part numbers and serial numbers listed in the service bulletin. To assure affected blades are correctly identified, the FAA issued superseding Emergency AD 2000-25-52 to correct the applicability. The requirements for accomplishing the intent of the emergency AD remain the same.

The FAA has reviewed Helicopter Technology Company, LLC, Mandatory Service Bulletin No. 2100-2R2, dated November 14, 2000 (SB), which describes procedures for performing a one-time inspection of each blade for skin-to-spar bonding voids before further flight.

Since the unsafe condition described is likely to exist or develop on other MDHI Model 369A, H, HE, HM, HS, D, E, FF, and 500N helicopters of the same type designs, the FAA issued Emergency AD 2000-25-52 to detect a void in the bonding that could result in a crack due to corrosion pits on the blade spar bonded surfaces, failure of a blade, and subsequent loss of control of the helicopter. The AD requires, before further flight, performing a tap inspection on both the upper and lower surfaces of each blade. If any voids are detected that exceed specified inspection requirements, this AD requires replacing the unairworthy blade with an airworthy blade before further flight. The actions must be accomplished in accordance with the SB described previously. 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 actions listed previously are required before further flight, 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 December 5, 2000, to all known U.S. owners and operators of MDHI Model 369A, H, HE, HM, HS, D, E, FF, and 500N 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 300 helicopters of U.S. registry will be affected by this AD, that it will take approximately 3 work hours per helicopter to accomplish each inspection and 5 work hours per helicopter to replace 1 blade, and that the average labor rate is $60 per work hour. Required parts will cost approximately $10,000 per blade. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $3,630,000, assuming $12,100 per helicopter for 10 inspections ($1,800) and one blade replacement ($10,300).

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. 2000-SW-63-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 adding a new airworthiness directive to read as follows: