AD 96-12-26

On June 5, 1996, the FAA issued priority letter AD 96-12-26, applicable to BHTI-manufactured Model AH-1, HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P helicopters, which requires a visual inspection of each T/R blade for peeling, flaking, or bubbling paint that may indicate corrosion; an inspection for corrosion, if necessary; and, replacement of the T/R blade with an airworthy blade if corrosion is discovered. That action was prompted by an FAA determination, based on the manufacturer's data, that certain serial-numbered T/R blades were manufactured with internal leading edge doublers fabricated from clad aluminum instead of bare aluminum material. This condition, if not corrected, could result in debonding of the main spar leading edge doubler, which could lead to failure of a T/R blade and subsequent loss of control of the helicopter.

Since the unsafe condition described is likely to exist or develop on other BHTI-manufactured Model AH-1, HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P helicopters of the same type design, the FAA issued priority letter AD 96-12-26, to inspect for debonding of the main spar internal leading edge doubler, which could lead to failure of a T/R blade and subsequent loss of control of the helicopter. The AD requires, within 10 hours time-in-service (TIS) after the effective date of this AD, and thereafter at intervals of not more than 7 calendar days, a visual inspection of each T/R blade for peeling, flaking, or bubbling paint that may indicate corrosion, or corrosion along the bond lines viewed from the root and tip ends of the blade, and at the abrasion strip bond line on both sides of the blade from the root to the tip. If peeling, flaking, or bubbling paint is discovered, the paint in the affected area must be removed and the blade must be inspected for corrosion. If corrosion is discovered in the affected areas, the blade must be removedand replaced with an airworthy blade.

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 June 5, 1996 to all known U.S. owners and operators of BHTI-manufactured Model AH-1, HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P 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.

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 bysubmitting 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 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. 96-SW-11-AD." The postcard will be date stamped and returned to the commenter.

The regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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, 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 USC 106(g), 40113, 44701.

39.13 - [Amended] 2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: