01-8727. Airworthiness Directives; Dornier Model 328-300 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Proposed rule; withdrawal.

SUMMARY:

This action withdraws a notice of proposed rulemaking (NPRM) that proposed a new airworthiness directive (AD), applicable to certain Dornier Model 328-300 series airplanes. That action would have required replacement of the hydraulic line tube assemblies with improved tube assemblies and flexible hose assemblies. Since the issuance of the NPRM, the Federal Aviation Administration (FAA) has received information from Fairchild Dornier indicating that the replacement has already been carried out on all of the affected airplanes. Accordingly, the proposed rule is withdrawn.

FOR FURTHER INFORMATION CONTACT:

Dan Rodina, Aerospace Engineer, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

A proposal to amend part 39 of the Federal Aviation Regulations to add a new airworthiness directive (AD), applicable to certain Dornier Model 328-300 series airplanes, was published in the Federal Register on June 15, 2000 (65 FR 37500). The proposed rule would have required replacement of the hydraulic line tube assemblies with improved tube assemblies and flexible hose assemblies. That action was prompted by information from the Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, indicating that pressure spikes and vibration during manual activation of the hydraulic changeover valve may cause cracking of the hydraulic lines that pressurize the braking systems of these airplanes. The pressure spikes create a high bending stress near the sleeve at the changeover valve. The proposed actions were intended to prevent cracking of the hydraulic lines, which could result in loss of hydraulic pressure for certain braking systems on the airplane.

Actions Since Issuance of Notice of Proposed Rulemaking (NPRM)

Since the issuance of that NPRM, the FAA has received a comment from Fairchild Dornier indicating that the replacement of the hydraulic line tube assemblies had been accomplished in all airplanes world-wide, which are affected by the rule. Therefore, Fairchild Dornier requested the FAA to withdraw the NPRM.

FAA's Conclusions

The FAA concurs that, if all of the requirements of the NPRM have already been accomplished on all affected airplanes world-wide, the NPRM may be withdrawn.

Withdrawal of this NPRM constitutes only such action, and does not preclude the agency 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 a notice of proposed rulemaking, it is neither a proposed nor a final rule and therefore, is not covered under Executive Order 13132, 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, the notice of proposed rulemaking, Docket 2000-NM-07-AD, published in the Federal Register on June 15, 2000 (65 FR 37500), is withdrawn.

Issued in Renton, Washington, on April 3, 2001.

Donald L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.