01-1586. Airworthiness Directives; MD Helicopters, Inc. Model 369A, H, HE, HM, HS, D, E, FF, and 500N Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This document publishes in the Federal Register an amendment adopting Emergency Airworthiness Directive (AD) 2000-25-52 which was sent previously to all known U.S. owners and operators of MD Helicopters, Inc. (MDHI) Model 369A, H, HE, HM, HS, D, E, FF, and 500N helicopters. This amendment supersedes an existing emergency AD that requires, before further flight, performing a tap inspection on both the upper and lower surfaces of each main rotor blade (blade). If any voids are detected that exceed specified inspection requirements, the emergency AD also requires replacing the unairworthy blade with an airworthy blade before further flight. This amendment requires the same actions as the emergency AD and corrects the applicability to include the appropriate serial numbers. This amendment is prompted by the discovery of an error in the emergency AD. The actions specified by this AD are intended to prevent failure of a blade and subsequent loss of control of the helicopter.

DATES:

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.

ADDRESSES:

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: [e-mail].

The service information referenced in this AD may be obtained from Helicopter Technology Company, LLC, 12923 South Spring St., Los Angeles, CA 90061, telephone [phone], fax [phone]. 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.

FOR FURTHER INFORMATION CONTACT:

Marc Belhumeur, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office, Fort Worth, Texas 76193-0170, telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

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).

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. 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.

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:

2000-25-52 MD Helicopters, Inc.: Amendment 39-12083. Docket No. 2000-SW-63-AD. Supersedes Emergency AD 2000-24-51, Docket No. 2000-SW-62-AD.

Applicability: Model 369A, H, HE, HM, HS, D, E, FF, and 500N helicopters, with main rotor blade (blade), part number (P/N) 500P2100-BSC (serial number (S/N) with a prefix of “K” and 101 through 562); P/N 500P2100-101 or P/N 500P2100-301 (S/N with a prefix of “A” and 001 through 999 or S/N with a prefix of “B” and 001 through 529); or blade, P/N 500P2300-501 (S/N with a prefix of “T” and 101 through 107), manufactured by Helicopter Technology Company, LLC, 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 otherwise 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 request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required before further flight, unless accomplished previously.

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, accomplish the following:

(a) Perform a tap inspection on both the upper and lower surfaces of each blade in accordance with the “INSPECTION” paragraph of Helicopter Technology Company, LLC, Mandatory Service Bulletin Notice No. 2100-2R2, dated November 14, 2000 (SB). If any voids on a blade are detected that exceed specified inspection requirements of the SB, replace the unairworthy blade with an airworthy blade before further flight.

(b) 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, Rotorcraft Certification Office, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Rotorcraft Certification Office.

Note 2:

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

(c) Special flight permits may be issued in accordance with 14 CFR 21.197 and 21.199 to operate the helicopter to a location where the requirements of this AD can be accomplished.

(d) The tap inspections shall be accomplished in accordance with the “INSPECTION” paragraph of Helicopter Technology Company, LLC, Mandatory Service Bulletin Notice No. 2100-2R2, dated November 14, 2000. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Helicopter Technology Company, LLC, 12923 South Spring St., Los Angeles, CA 90061, telephone [phone], fax [phone]. Copies may be inspected 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.

(e) This amendment becomes effective on February 6, 2001, to all persons except those persons to whom it was made immediately effective by Emergency AD 2000-25-52, issued December 5, 2000, which contained the requirements of this amendment.

Issued in Fort Worth, Texas, on January 10, 2001.

Henry A. Armstrong,

Manager, Rotorcraft Directorate, Aircraft Certification Service.