E6-7007. Airworthiness Directives; Boeing Model 757-200, -200PF, and -200CB Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 757-200, -200PF, and -200CB series airplanes. This proposed AD would require doing initial and repetitive detailed or high frequency eddy current inspections for cracks around the rivets at the upper fastener row of the skin lap splice of the fuselage, and repairing any crack found. This proposed AD results from a report indicating that certain modified rivets were incorrectly installed in some areas of the skin lap splices during production because they were drilled with a countersink that was too deep. We are proposing this AD to detect and correct premature fatigue cracking at certain skin lap splice locations of the fuselage, and consequent rapid decompression of the airplane.

DATES:

We must receive comments on this proposed AD by June 23, 2006.

ADDRESSES:

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

• DOT Docket Web site: Go to http://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.
• Fax: [phone].
• 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.

Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for the service information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT:

Dennis Stremick, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number “FAA-2006-24697; Directorate Identifier 2006-NM-045-AD” at the beginning 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 received by the closing date and may amend the proposed AD in light of those comments.

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.

Examining the Docket

You may examine the AD docket on the Internet at http://dms.dot.gov, or 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 [phone]) 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 Docket Management System receives them.

Discussion

We have received a report indicating that certain modified rivets were incorrectly installed in some areas of the skin lap splices of the fuselage during production because they were drilled with a countersink that was too deep. The deep countersink makes a knife edge condition in the skin panel. The knife edge condition can lead to cracks in the skin lap splices of the fuselage. This premature fatigue cracking could result in rapid decompression of the airplane.

Relevant Service Information

We have reviewed Boeing Special Attention Service Bulletin 757-53-0090, dated June 2, 2005. The service bulletin describes the following procedures, depending on the airplane configuration:

• Doing initial and repetitive detailed or high frequency eddy current (HFEC) inspections for cracks of the skin lap splice of the fuselage;
• Contacting Boeing for repair of cracking; and
• Sending inspection results to Boeing.

The service bulletin recommends compliance times at the following intervals:

Service Bulletin Recommended Compliance Times

Action	Recommended compliance times
Initial detailed or HFEC inspection	Before the accumulation of 37,500 total flight cycles or 3,000 flight cycles after issuance of the service bulletin, whichever is later.
Repetitive detailed inspections	Intervals not to exceed 1,200 flight cycles.
Repetitive HFEC inspections	Intervals not to exceed 12,000 flight cycles.

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. For this reason, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously, except as discussed under “Differences Between the Proposed AD and Service Bulletin.”

Differences Between the Proposed AD and Service Bulletin

The service bulletin specifies that you may contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require you to repair those conditions in one of the following ways:

• Using a method that we approve; or
• Using data that meet the certification basis of the airplane, and that have been approved by an Authorized Representative for the Boeing Delegation Option Authorization Organization whom we have authorized to make those findings.

The Accomplishment Instructions of the service bulletin specify reporting inspection findings to the manufacturer. This proposed AD would not require that action. We do not need this information from operators.

These differences have been coordinated with the manufacturer.

Costs of Compliance

There are about 294 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 160 airplanes of U.S. registry. The following tables provide the estimated costs for U.S. operators to comply with either the detailed or HFEC inspections in this proposed AD.

Estimated Costs for Detailed Inspection, per Inspection Cycle

Airplane group	Work hours	Average hourly labor rate	Cost per airplane
Group 1	7	$80	$560
Group 2	6	80	480
Group 3	12	80	960
Group 4	10	80	800

Estimated Costs for HFEC Inspection, per Inspection Cycle

Airplane group	Work hours	Average hourly labor rate	Cost per airplane
Group 1	12	$80	$960
Group 2	11	80	880
Group 3	20	80	1,600
Group 4	15	80	1,200

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

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 and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2006-24697; Directorate Identifier 2006-NM-045-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by June 23, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 757-200, -200PF, and -200CB series airplanes, certificated in any category; as identified in Boeing Special Attention Service Bulletin 757-53-0090, dated June 2, 2005.

Unsafe Condition

(d) This AD results from a report indicating that certain modified rivets were incorrectly installed in some areas of the skin lap splices during production because they were drilled with a countersink that was too deep. We are issuing this AD to detect and correct premature fatigue cracking at certain skin lap splice locations of the fuselage and consequent rapid decompression 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.

Initial and Repetitive Inspections

(f) Do initial and repetitive detailed or high frequency eddy current inspections for cracking around the rivets at the upper fastener row of the skin lap splice of the fuselage by doing all the actions in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 757-53-0090, dated June 2, 2005, except as provided by paragraphs (g) and (h) of this AD. Do the inspections at the applicable times specified in Paragraph 1.E., “Compliance,” of the service bulletin; except where the service bulletin specifies a compliance time after the original release date of the service bulletin, this AD requires compliance after the effective date of this AD.

Repair

(g) If any crack is found during any inspection required by this AD: Before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (i) of this AD.

No Reporting Required

(h) Although Boeing Special Attention Service Bulletin 757-53-0090, dated June 2, 2005, recommends that inspection results be reported to the manufacturer, this AD does not include that requirement.

Alternative Methods of Compliance (AMOCs)

(i)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office.

(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane.

Issued in Renton, Washington, on April 28, 2006.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.