E9-12112. Airworthiness Directives; Boeing Model 707 Airplanes, and Model 720 and 720B Series Airplanes

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) that applies to certain Boeing Model 707 airplanes, and Model 720 and 720B series airplanes. The existing AD currently requires repetitive detailed inspections to detect cracks and corrosion on any existing repairs and at certain body stations (STA) of the visible surfaces of the wing to body terminal fittings including the web, flanges, and ribs; and applicable related investigative and corrective actions. This proposed AD would retain the requirements of the existing AD and would require repetitive ultrasonic inspections to detect any stress corrosion cracks within the outboard flange of the left and right body terminal fittings at STA 820, and related investigative and corrective actions if necessary. This proposed AD would also provide for an optional terminating action for the repetitive inspections. This proposed AD also adds two airplanes to the applicability. This proposed AD results from reports of cracks found in the wing to body terminal fittings during routine inspections. We are proposing this AD to detect and correct cracks and corrosion in the body terminal fittings above and below the floor, which could cause loss of support for the wing and could adversely affect the structural integrity of the airplane.

DATES:

We must receive comments on this proposed AD by July 10, 2009.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone [phone], extension 1; fax [phone]; e-mail, [e-mail]; Internet, https://www.myboeingfleet.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221 or 425-227-1152.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Berhane Alazar, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2009-0476; Directorate Identifier 2008-NM-188-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

On August 6, 2008, we issued AD 2008-17-10, amendment 39-15648 (73 FR 50703, August 28, 2008), for certain Boeing Model 707 airplanes, and Model 720 and 720B series airplanes. That AD requires repetitive detailed inspections to detect cracks and corrosion on any existing repairs and at certain body stations (STA) of the visible surfaces of the wing to body terminal fittings including the web, flanges and ribs; and applicable related investigative and corrective actions. That AD resulted from reports of cracks found in the wing to body terminal fittings during routine inspections. We issued that AD to detect and correct cracks and corrosion in the body terminal fittings, which could cause loss of support for the wing and could adversely affect the structural integrity of the airplane.

Relevant Service Information

We have reviewed Boeing 707 Alert Service Bulletin A3524, Revision 1, dated September 18, 2008. (AD 2008-17-10 refers to Boeing 707 Special Attention Service Bulletin 3524, dated July 18, 2007, as the appropriate source of service information for accomplishing the required actions in that AD.) Revision 1 of this service bulletin adds procedures, for certain airplanes, to do repetitive ultrasonic inspections for stress corrosion cracks within the outboard flange of the left and right body terminal fittings at STA 820, and if necessary, related investigative and corrective actions. The related investigative action is an inspection to determine whether the modification or repair meets the specifications of Boeing 707/720 Service Bulletin 2912, Revision 1, dated March 13, 1970. The corrective action is contacting Boeing for repair instructions. Revision 1 of Boeing 707 Alert Service Bulletin A3524 also adds two airplanes to the effectivity.

Boeing 707 Alert Service Bulletin A3524, Revision 1, refers to Boeing 707/720 Service Bulletin 2912, Revision 1, dated March 13, 1970, as an additional source of service information for doing certain inspections and repairs.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to develop on other airplanes of the same type design. For this reason, we are proposing this AD, which would supersede AD 2008-17-10 and would retain the requirements of the existing AD. This proposed AD would also add, for certain airplanes, repetitive ultrasonic inspections to detect any stress corrosion cracks within the outboard flange of the left and right body terminal fittings at STA 820, and related investigative and corrective actions if necessary. This proposed AD would also add two airplanes to the applicability.

Costs of Compliance

There are about 128 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

Action	Work hours	Average labor rate per hour	Cost per airplane	Number of U.S.- registered airplanes	Fleet cost
Inspections (required by AD 2008-17-10)	20	$80	$1,600 per inspection cycle	11	$17,600 per inspection cycle.
Inspections (new proposed action)	20 to 30, depending on group	80	$1,600 to $2,400 per inspection cycle	Up to 13	Up to $31,200 per inspection cycle.

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
• Incorporation by reference
• 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 FAA amends § 39.13 by removing amendment 39-15648 (73 FR 50703, August 28, 2008) and adding the following new AD:

Boeing: Docket No. FAA-2009-0476; Directorate Identifier 2008-NM-188-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by July 10, 2009.

Affected ADs

(b) This AD supersedes AD 2008-17-10.

Applicability

(c) This AD applies to Model 707-100 long body, -200, -100B long body, and -100B short body series airplanes; Model 707-300, -300B, -300C, and -400 series airplanes; and Model 720 and 720B series airplanes; certificated in any category; as identified in Boeing 707 Alert Service Bulletin A3524, Revision 1, dated September 18, 2008.

Subject

(d) Air Transport Association (ATA) of America Code 57: Wings.

Unsafe Condition

(e) This AD results from new findings of cracks found in the wing to body terminal fittings during routine inspections. We are issuing this AD to detect and correct cracks and corrosion in the body terminal fittings above and below the floor, which could cause loss of support for the wing and could adversely affect the structural integrity of the airplane.

Compliance

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

Restatement of Requirements of AD 2008-17-10

Inspections and Corrective Actions

(g) For airplanes identified in Boeing 707 Special Attention Service Bulletin 3524, dated July 18, 2007: Within 24 months after October 2, 2008 (the effective date of AD 2008-17-10), do detailed inspections and applicable related investigative and corrective actions, by accomplishing all the actions specified in the Accomplishment Instructions of Boeing 707 Special Attention Service Bulletin 3524, dated July 18, 2007; or Boeing 707 Alert Service Bulletin A3524, Revision 1, dated September 18, 2008; except as provided by paragraph (h) of this AD. After the effective date of this AD, use only Boeing 707 Alert Service Bulletin A3524, Revision 1, dated September 18, 2008. Repeat the detailed inspections thereafter at intervals not to exceed 24 months. Do all applicable related investigative and corrective actions before further flight.

(h) If any crack or corrosion is found during any inspection required by paragraph (g) of this AD, and Boeing 707 Special Attention Service Bulletin 3524, dated July 18, 2007; or Boeing 707 Alert Service Bulletin A3524, Revision 1, dated September 18, 2008; specifies to contact Boeing for appropriate action: Before further flight, repair the terminal fittings using a method approved in accordance with the procedures specified in paragraph (o) of this AD.

No Information Submission

(i) Although Boeing 707 Special Attention Service Bulletin 3524, dated July 18, 2007; and Boeing 707 Alert Service Bulletin A3524, Revision 1, dated September 18, 2008; specify to submit information to the manufacturer, this AD does not include that requirement.

New Requirements of This AD

Inspections

(j) For Group 1 and Group 2 airplanes identified in Boeing 707 Alert Service Bulletin A3524, Revision 1, dated September 18, 2008, on which a modification or repair was done in accordance with Boeing 707/720 Service Bulletin 2912, Revision 1, dated March 13, 1970: At the later of the times specified in paragraphs (j)(1) and (j)(2) of this AD, do an ultrasonic inspection to detect any stress corrosion cracks within the outboard flange of the left and right body terminal fittings at body station (STA) 820, and all applicable related investigative and corrective actions, by accomplishing all the actions specified in the Accomplishment Instructions of Boeing 707 Alert Service Bulletin A3524, Revision 1, dated September 18, 2008, except as provided by paragraph (m) of this AD. Repeat the ultrasonic inspection thereafter at intervals not to exceed 24 months or 2,000 flight cycles, whichever occurs first. Do all applicable related investigative and corrective actions before further flight.

(1) Within 24 months or 2,000 flight cycles after the effective date of this AD, whichever occurs first.

(2) Within 24 months or 2,000 flight cycles after doing the repair or modification, whichever occurs first.

(k) For Group 3 and 4 airplanes identified in Boeing 707 Alert Service Bulletin A3524, Revision 1, dated September 18, 2008: Within 2,000 flight cycles or 24 months after the effective date of this AD, whichever occurs first, do an ultrasonic inspection to detect any stress corrosion cracks within the outboard flange of the left and right body terminal fittings at STA 820, and all applicable corrective actions, by accomplishing all the actions specified in the Accomplishment Instructions of Boeing 707 Alert Service Bulletin A3524, Revision 1, dated September 18, 2008, except as provided by paragraph (m) of this AD. Repeat the ultrasonic inspection thereafter at intervals not to exceed 24 months or 2,000 flight cycles, whichever occurs first. Do all applicable corrective actions before further flight.

(l) For Group 4 airplanes identified in Boeing 707 Alert Service Bulletin A3524, Revision 1, dated September 18, 2008: Within 24 months after the effective date of this AD, do detailed inspections for corrosion and cracking of the body terminal fittings at STA 820, and all applicable related investigative and corrective actions, by accomplishing all the actions specified in the Accomplishment Instructions of Boeing 707 Alert Service Bulletin A3524, Revision 1, dated September 18, 2008, except as provided by paragraph (m) of this AD. Repeat the detailed inspections thereafter at intervals not to exceed 24 months. Do all applicable related investigative and corrective actions before further flight.

Exception to Certain Procedures

(m) If any crack or corrosion is found during any inspection required by paragraph (j), (k), or (l) of this AD, and Boeing 707 Alert Service Bulletin A3524, Revision 1, dated September 18, 2008, specifies to contact Boeing for appropriate action: Before further flight, repair the terminal fittings using a method approved in accordance with the procedures specified in paragraph (o) of this AD.

Note 1:

Boeing 707 Alert Service Bulletin A3524, Revision 1, dated September 18, 2008, refers to Boeing 707/720 Service Bulletin 2912, Revision 1, dated March 13, 1970, as an additional source of service information for doing certain inspections and repairs.

Optional Terminating Action

(n) Replacing a body terminal fitting with a fitting made from 7075-T73 material, using a method approved in accordance with the procedures specified in paragraph (o) of this AD, terminates the repetitive inspections required by this AD for that fitting only.

Alternative Methods of Compliance (AMOCs)

(o)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Berhane Alazar, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone]; or, e-mail information to [e-mail].

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

(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, and the approval must specifically refer to this AD.

Issued in Renton, Washington, on May 15, 2009.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.