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Proposed Rule

Airworthiness Directives; Lockheed Model 1329 Series Airplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

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Start Preamble

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Lockheed Model 1329 series airplanes. This proposed AD would require repetitive inspections to detect crack damage in the front spar cap assembly of the lower vertical stabilizer; reworking the spar cap doublers if no crack damage is found during any inspection; and repairing if any crack damage is found during any inspection. This proposed AD is prompted by reports of cracks in the front spar cap assembly of the lower vertical stabilizer at box beam station 24 on the aft side of the 25% chord line. We are proposing this AD to find and fix cracks in the front spar cap assembly of the lower vertical stabilizer, which could result in rapid crack propagation and failure of the front spar cap. Failure of the front spar cap could lead to loss of rudder control and consequent reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

DATES:

We must receive comments on this proposed AD by August 23, 2004.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD.

  • DOT Docket Web site: Go to­http://dms.dot.gov and follow the instructions for sending your comments electronically.
  • Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
  • Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, Washington, DC 20590.
  • By fax: (202) 493-2251.
  • Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

You can get the service information identified in this proposed AD from Lockheed Martin Aircraft & Logistics Center, 120 Orion Street, Greenville, South Carolina 29605.

You may examine the contents of this AD docket on the Internet at http://dms.dot.gov, or at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., room PL-401, on the plaza level of the Nassif Building, Washington, DC.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Carl Gray, Aerospace Engineer, Airframe Branch, ACE-117A, FAA, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30349; telephone (770) 703-6131; fax (770) 703-6097.

End Further Info End Preamble Start Supplemental Information

SUPPLEMENTARY INFORMATION:

Docket Management System (DMS)

The FAA has implemented new procedures for maintaining AD dockets electronically. As of May 17, 2004, new AD actions are posted on DMS and assigned a docket number. We track each action and assign a corresponding directorate identifier. The DMS AD docket number is in the form “Docket No. FAA-2004-99999.” The Transport Airplane Directorate identifier is in the form “Directorate Identifier 2004-NM-999-AD.” Each DMS AD docket also lists the directorate identifier (“Old Docket Number”) as a cross-reference for searching purposes.

Comments Invited

We invite you to submit any written relevant data, views, or arguments regarding this proposed AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2004-18557; Directorate Identifier 2004-NM-174-AD” in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments submitted by the closing date and may amend the proposed AD in light of those comments. Start Printed Page 40822

We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

We are reviewing the writing style we currently use in regulatory documents. We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications that affect you. You can get more information about plain language at http://www.faa.gov/​language and http://www.plainlanguage.gov.

Examining the Docket

You may examine the AD docket in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647-5227) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the DMS receives them.

Discussion

We have received reports of cracks in the front spar cap assembly of the lower vertical stabilizer at box beam station 24 on the aft side of the 25% chord line for certain Lockheed Model 1329 series airplanes. Investigation revealed that the cracks began at the upper aft fillet radius in the aft tang of the spar cap doublers, a location in the original design where several stress concentrations can accumulate to create a poor fatigue feature. Undetected cracks in the front spar cap assembly of the lower vertical stabilizer, if not found and repaired, could result in rapid crack propagation and failure of the front spar cap. Failure of the front spar cap could lead to loss of rudder control and consequent reduced controllability of the airplane.

Relevant Service Information

We have reviewed Lockheed Service Bulletin 329-302, dated July 9, 2003 (for Model 1329-23A, -23D, and -23E series airplanes); and Lockheed Service Bulletin 329II-55-4, dated July 9, 2003 (for Model 1329-25 series airplanes). These service bulletins describe procedures for the following actions:

1. Repetitive detailed inspections to detect crack damage in the front spar cap assembly of the lower vertical stabilizer.

2. Reworking the spar cap doublers by smoothing the radius to a finish to remove all burrs, sharp edges, and extraneous tool marks and by touching up the finish to prevent corrosion, if no crack damage is found during any inspection.

3. Repairing if any crack damage is found during any inspection.

The service bulletins also specify to report inspection findings to the manufacturer. We have determined that accomplishment of the actions specified in the service bulletins will adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. Therefore, we are proposing this AD, which would require repetitive inspections to detect crack damage in the front spar cap assembly of the lower vertical stabilizer; reworking the spar cap doublers if no crack damage is found during any inspection; and repairing if any crack damage is found during any inspection. The proposed AD would require you to use the service information described previously to perform these actions, except as discussed under “Differences Between the Proposed AD and the Service Bulletins.”

Differences Between the Proposed AD and the Service Bulletins

Operators should note that, although the Lockheed service bulletins specify to inspect within a certain grace period “or at the next annual inspection, whichever occurs first,” this proposed AD would require inspection within a grace period of 150 flight hours or 300 flight hours, depending on whether an airplane has accumulated more or less than 10,000 total flight hours.

Operators should note also that, although the Lockheed service bulletins specify that operators may contact the manufacturer for disposition of certain repair conditions, this proposed AD would require operators to repair those conditions in accordance with a method approved by the FAA.

Operators should also note that, although the Accomplishment Instructions of the referenced Lockheed service bulletins specify that operators may report all inspection findings to the manufacturer, this proposed AD would require operators to report all inspection findings to the FAA. Because the cause of the cracking is not known, these required inspection reports will help determine the extent of the cracking in the affected fleet. Based on the results of these reports, we may determine that further corrective action is warranted.

Costs of Compliance

This proposed AD would affect about 85 airplanes of U.S. registry and 98 airplanes worldwide. The proposed actions would take about 1 work hour per airplane, at an average labor rate of $65 per work hour. No parts are required. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $5,525, or $65 per airplane.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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.

For the reasons discussed above, I certify that the proposed regulation:

1. Is not a “significant regulatory action” under Executive Order 12866;

2. Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

3. Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

Start Part Start Printed Page 40823

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Start Authority

Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

Lockheed: Docket No. FAA-2004-18557; Directorate Identifier 2004-NM-174-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this AD action by August 23, 2004.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Lockheed Model 1329-23A, -23D, and -23E series airplanes, serial numbers 5001 through 5162 inclusive, and Lockheed Model 1329-25 series airplanes, serial numbers 5201 through 5240 inclusive; certificated in any category.

Unsafe Condition

(d) This AD was prompted by reports of cracks in the front spar cap assembly of the lower vertical stabilizer at box beam station 24 on the aft side of the 25% chord line. We are issuing this AD to find and fix cracks in the front spar cap assembly of the lower vertical stabilizer, which could result in rapid crack propagation and failure of the front spar cap, leading to loss of rudder control and consequent reduced controllability of the airplane.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Service Bulletin References

(f) The term “service bulletin,” as used in this AD, means the Accomplishment Instructions of the following service bulletins, as applicable:

(1) For Model 1329-23A, -23D, and -23E series airplanes: Lockheed Service Bulletin 329-302, dated July 9, 2003; and

(2) For Model 1329-25 series airplanes: Lockheed Service Bulletin 329II-55-4, dated July 9, 2003.

Initial and Repetitive Inspections

(g) Do a detailed inspection to detect any crack damage in the left and right radius detail of the spar cap doublers, at the applicable time specified in paragraph (g)(1) or (g)(2) of this AD, in accordance with the service bulletin.

Note 1:

For the purposes of this AD, a detailed inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”

(1) For airplanes that have accumulated 10,000 or more total flight hours as of the effective date of this AD: Inspect within 150 flight hours after the effective date of this AD. Repeat the detailed inspection thereafter at intervals not to exceed 150 flight hours.

(2) For airplanes that have accumulated fewer than 10,000 total flight hours as of the effective date of this AD: Inspect within 300 flight hours after the effective date of this AD. Repeat the detailed inspection thereafter at intervals not to exceed 300 flight hours. At the time the airplane has accumulated 10,000 or more flight hours since the most recent inspection, repeat the detailed inspection thereafter at intervals not to exceed 150 flight hours.

No Damage Detected

(h) If no crack damage is found during any inspection required by paragraph (g) of this AD, before further flight, rework the spar cap doublers by performing the actions in paragraphs (h)(1) and (h)(2) of this AD, in accordance with the service bulletin.

(1) Remove all burrs, sharp edges, and extraneous tool marks by smoothing the radius to an RMS 125 finish.

(2) Touch up finish to prevent corrosion.

Damage Detected: Corrective Action

(i) If any crack damage is found during any inspection required by paragraph (g) of this AD, and the service bulletin specifies to contact Lockheed Martin Technical Support Center for repair instructions: Before further flight, repair in accordance with a method approved by the Manager, Atlanta Aircraft Certification Office (ACO), FAA. For a repair method to be approved by the Manager, Atlanta ACO, as required by this paragraph, the Manager's approval letter must specifically refer to this AD.

Parts Installation

(j) As of the effective date of this AD, no person shall install a spar cap doubler, part number (P/N) JE15-2 L/R or P/N JE15-15 L/R, on any airplane unless it has been reworked as required by paragraph (h) of this AD.

Reporting Requirement

(k) Submit a report of the findings (both positive and negative) of any inspection required by paragraph (g)(1) or (g)(2) of this AD to the Manager, Atlanta ACO, FAA, Small Airplane Directorate, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30349; fax (770) 703-6097; at the applicable time specified in paragraph (k)(1) or (k)(2) of this AD. (The report must include the inspection results, a description of any discrepancy found (e.g., crack length and location), the airplane serial number, and the number of landings and flight hours on the airplane.) Information collection requirements contained in this AD have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056.

(1) For airplanes on which any inspection required by paragraph (g) of this AD is accomplished after the effective date of this AD: Submit the report within 30 days after performing those inspections.

(2) For airplanes on which any inspection required by paragraph (g) of this AD has been accomplished before the effective date of this AD: Submit the report within 30 days after the effective date of this AD.

Previously Accomplished Initial Inspections

(l) Initial inspections accomplished within 12 months prior to the effective date of this AD in accordance with the service bulletin are considered acceptable for compliance with the applicable actions specified in paragraph (g) of this AD.

Alternative Methods of Compliance (AMOCs)

(m) The Manager, Atlanta ACO, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

Start Signature

Issued in Renton, Washington, on June 29, 2004.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 04-15381 Filed 7-6-04; 8:45 am]

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