E6-9846. Airworthiness Directives; MD Helicopters, Inc., Model 600N Helicopters

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Proposed rule; withdrawal.

SUMMARY:

The FAA withdraws a notice of proposed rulemaking (NPRM) proposing a new Airworthiness Directive (AD) for MD Helicopters, Inc. (MDHI) Model 600N helicopters. The NPRM proposed adding six more inspection holes in the aft fuselage skin panels and inspecting the upper and lower tailboom attachment fittings, the upper longerons, and the angles and nutplates for cracks. Also, the NPRM proposed a terminating action of modifying the fuselage aft section to strengthen the tailboom attachments and longerons. Since issuing the NPRM, we have received a report of an in-flight separation of the tailboom in the inspection area. Based on that accident and due to the critical unsafe condition, we issued a final rule; request for comments that addressed the actions proposed in the NPRM. Accordingly, we withdraw the proposed AD.

ADDRESSES:

This information may be examined at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas.

FOR FURTHER INFORMATION CONTACT:

Jon Mowery, Aviation Safety Engineer, FAA, Los Angeles Aircraft Certification Office, Airframe Branch, 3960 Paramount Blvd., Lakewood, California 90712, telephone [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

Discussion

A proposal to amend 14 CFR part 39 by superseding AD 2001-24-51, Docket 2001-SW-57-AD, Amendment 39-12706 (67 FR 17934, April 12, 2002), for the MDHI Model 600N helicopters was published in the Federal Register on February 10, 2005 (70 FR 7063). In addition to retaining various requirements of AD 2001-24-51, the action proposed installing six more inspection holes in the aft fuselage skin panels and inspecting the upper and lower tailboom attachment fittings, the upper longerons, and the angles and nutplates for cracks. Also, the action proposed a terminating action of modifying the fuselage aft section to strengthen the tailboom attachments and longerons. That actions was prompted by analysis that shows that certain tailboom attachments and longerons may develop cracks. The proposed actions were intended to prevent failure of a tailboom attachment, loss of the tailboom, and subsequent loss of control of the helicopter.

Since issuing the NPRM, we have received an additional report of an in-flight separation of the tailboom in the inspection area. After reviewing the data, we issued a final rule; request for comments (AD 2006-08-12, 71 FR 24808, April 27, 2006) to correct a critical unsafe condition. That AD, 2006-08-12, requires the necessary actions proposed in the NPRM as well as other actions necessary to correct the unsafe condition.

FAA's Conclusion

Since we issued AD 2006-08-12, which includes the necessary actions that were previously proposed, we are withdrawing the NPRM.

Withdrawal of the NPRM does not preclude the FAA from issuing another notice in the future nor does it commit the agency to any course of action in the future.

Regulatory Impact

Since this action only withdraws an NPRM, it is neither a proposed nor a final rule and therefore is not covered under Executive Order 12866, the Regulatory Flexibility Act, or DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Withdrawal

Accordingly, we withdraw the NPRM, Docket No. 2004-SW-16-AD, published in the Federal Register on February 10, 2005, 70 FR 7063, FR Doc. 05-2608, filed February 9, 2005.

Issued in Fort Worth, Texas, on June 9, 2006.

Mark R. Schilling,

Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.