03-9861. Airworthiness Directives; Various Surplus Military Airplanes Manufactured by Consolidated, Consolidated Vultee, and Convair

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment adopts a new airworthiness directive (AD) that is applicable to various surplus military airplanes manufactured by Consolidated, Consolidated Vultee, and Convair. This action requires repetitive inspections to find fatigue cracks in the lower rear cap of the wing front spar, front spar web, and lower skin of the wings; repair or replacement of any cracked part with a new part; and follow-on inspections at new intervals. This action is necessary to find and fix fatigue cracking, which could result in structural failure of the wings and consequent loss of control of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Effective May 7, 2003.

Comments for inclusion in the Rules Docket must be received on or before June 23, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-23-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2003-NM-23-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

Information pertaining to this AD may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT:

John Cecil, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

On July 18, 2002, while dropping retardant on a fire near Lyons, Colorado, a United States Department of Agriculture (USDA) Forest Service Model P4Y-2 airplane was involved in an accident, resulting from the structural failure of the center wing. Investigation revealed fatigue cracking in the lower rear cap of the wing front spar, front spar web, and lower skin of the wings. The fatigue cracking has been attributed to the age, time-in-service, and flight cycles of the airplane. Such fatigue cracking, if not found and fixed in a timely manner, could result in structural failure of the wings and consequent loss of control of the airplane.

FAA's Determination

We have determined that high-cycle fatigue cracks in the area of the lower rear cap of the wing front spar, front spar web, and lower skin of the wings are likely to occur on various surplus military airplanes. Repetitive inspections of these areas are necessary to ensure that fatigue cracks will be found in a timely manner, and corrective action taken, to preclude crack growth to a size that would create an unacceptable risk of structural failure. While inspection methodologies exist that can be used to find cracks, we are currently unaware of any for the subject airplanes. Therefore, owners and operators must submit inspection procedures and repetitive inspection intervals to the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, for approval. The inspection procedures must be sufficiently reliable to determine the location, size, and orientation of cracks that are very small, so that the crack will not grow to a critical length at limit load before the next scheduled inspection.

If any crack is found during any inspection, operators must replace the cracked part with a new part; or repair and inspect at new intervals per a method approved by the FAA.

Explanation of the Requirements of the Rule

Since an unsafe condition has been identified that is likely to exist or develop on other surplus military airplanes of the same type design, this AD is being issued to find and fix fatigue cracking of the wings, which could result in structural failure of the wings and consequent loss of control of the airplane. This AD requires repetitive inspections to find cracks in the lower rear cap of the wing front spar, front spar web, and lower skin of the wings; and repair or replacement of any cracked part with a new part; and follow-on inspections at new intervals.

Determination of Rule's Effective Date

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

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 shall 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.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the AD is being requested.
• Include justification (e.g., reasons or data) for each request.

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 Number 2003-NM-23-AD.” The postcard will be date stamped and returned to the commenter.

Regulatory Impact

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
• 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 the following new airworthiness directive:

2003-08-13 Various surplus military airplanes manufactured by Consolidated, Consolidated Vultee, and Convair: Amendment 39-13126. Docket 2003-NM-23-AD.

Applicability: Including, but not limited to, all of the following surplus military airplanes, certificated in any category:

Consolidated Vultee Model PB4Y-1, P4Y-2, and LB-30 airplanes;

Consolidated and Convair Model B-24 airplanes; and

Consolidated Model C-109 and C-87 airplanes.

Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes 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 (c) 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 as indicated, unless accomplished previously.

To find and fix fatigue cracking in the lower rear cap of the wing front spar, front spar web, and lower skin of the wings, which could result in structural failure of the wings and consequent loss of control of the airplane, accomplish the following:

Initial & Repetitive Inspections

(a) Within 30 days after the effective date of this AD, do the actions specified in paragraphs (a)(1) and (a)(2) of this AD per a method approved by the Manager, Los Angeles Certification Office (ACO), FAA.

(1) Do an inspection (between 39 and 63 inches outboard of the airplane center line on both the left and right sides of the wings) to find cracks in the lower rear cap of the wing front spar, front spar web, and lower skin of the wings localized under the front spar lower cap. Special detailed inspection procedures must be sufficiently reliable to determine the location, size, and orientation of the cracks.

(2) Develop repetitive inspection intervals that prevent crack growth from exceeding the minimum residual strength required to support limit load on the affected structure. The repetitive inspection intervals must be approved by the Manager, Los Angeles ACO. Thereafter, do the inspection approved per paragraph (a)(1) of this AD at the intervals approved per this paragraph.

(b) If any crack is found during any inspection required by this AD, before further flight, do the action(s) specified in paragraphs (b)(1) and (b)(2) of this AD per a method approved by the Manager, Los Angeles ACO.

(1) Repair or replace the cracked part or structure.

(2) Repeat the inspection required by paragraph (a)(1) of this AD at reduced intervals approved by the Manager, Los Angeles ACO to find cracks before the growth is critical and exceeds the minimum residual strength required to support limit load on the affected structure.

Alternative Methods of Compliance

(c) 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, Los Angeles ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles ACO.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO.

Special Flight Permits

(d) Special flight permits may be issued in accordance with §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Effective Date

(e) This amendment becomes effective on May 7, 2003.

Issued in Renton, Washington, on April 16, 2003.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.