E8-29257. Airworthiness Directives; Boeing Model 707 Airplanes and Model 720 and 720B Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.

SUMMARY:

We are revising an earlier proposed airworthiness directive (AD) for all Boeing Model 707 airplanes and Model 720 and 720B series airplanes. The original NPRM would have required performing an operational test of the engine fuel suction feed of the fuel system, and other related testing if necessary. The original NPRM resulted from a report of in-service occurrences of loss of fuel system suction feed capability, followed by total loss of pressure of the fuel feed system. This action revises the original NPRM by reducing the compliance time for low-utilization airplanes, and including corrective actions that were inadvertently omitted from certain sections. The corrective actions are replacing the o-rings if any leakage is found in the couplings, and replacing the fuel line if any leakage is found in the fuel line. We are proposing this supplemental NPRM to detect and correct failure of the engine fuel suction feed capability of the fuel system, which could result in multi-engine flameout, inability to restart the engines, and consequent forced landing of the airplane.

DATES:

We must receive comments on this supplemental NPRM by January 5, 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:

Sue Lucier, Aerospace Engineer, Propulsion Branch, ANM-140S, 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-2008-0645; Directorate Identifier 2007-NM-358-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

We issued a notice of proposed rulemaking (NPRM) (the “original NPRM”) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to all Boeing Model 707 airplanes and Model 720 and 720B series airplanes. That original NPRM was published in the Federal Register on June 20, 2008 (73 FR 35092). That original NPRM proposed to require performing an operational test of the engine fuel suction feed of the fuel system, and other related testing if necessary.

Actions Since Original NPRM was Issued

Since we issued the original NPRM, we have learned that corrective actions were inadvertently omitted from the Summary section and paragraph (f) of the original NPRM. The corrective actions were identified in the relevant service information section of the original NPRM and include replacing the o-rings if any leakage is found in the couplings, and replacing the fuel line if any leakage is found in the fuel line.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the comments received from a single commenter.

Request To Change Repetitive Test Interval for Low-Utilization Airplanes

Boeing asks that we add a maximum time interval of 3 years to the current 6,000-flight-hour repetitive test interval specified in paragraph (f) of the original NPRM. Boeing states that low-utilization airplanes may not meet the 6,000-flight-hour threshold for several years.

We agree to change the repetitive test interval. The data provided by the manufacturer justify a change to the repetitive test interval currently specified in the original NPRM to acknowledge that elapsed calendar time, as well as operational time, can affect suction feed capability. We have determined that changing the intervals in terms of calendar and operational time, as recommended by the manufacturer, will ensure an adequate level of safety for the affected fleet. We have changed the compliance time for the repetitive operational tests specified in paragraph (f) of this supplemental NPRM as requested.

Request To Clarify Reason for the Unsafe Condition

Boeing asks that we clarify the description of in-service occurrences of loss of fuel system suction feed capability specified in the original NPRM, which states that the proposed AD results from reports of two in-service engine flameout events operating on suction feed with undetected air leak failures. Boeing notes that there are no known reports of any engine flameout-related events in the Model 707 airplane fleet. Boeing recognizes that undetected air leaks could exist, and the maintenance procedure is a proactive measure to ensure engine flameout will not occur due to air leaks while on suction feed operation. Boeing is unclear as to the incidents in question and only through further investigation discovered that the engine suction feed incidents did not occur within the Model 707 airplane fleet. Boeing asks that we clarify the Summary, Discussion, and Unsafe Condition sections, and “FAA's Determination and Requirements of this Proposed AD.”

We agree that the Summary and Discussion sections and “FAA's Determination and Requirements of this Proposed AD” could be clarified in the supplemental NPRM as Boeing requests. The inaccurate language which was contained in the original NPRM is not restated in the supplemental NPRM. Therefore, no change to the supplemental NPRM is necessary in this regard.

Request To Clarify the Requirement for Additional Testing

Boeing asks that we clarify the requirement for additional testing of the engine fuel feed manifold specified in the Summary section. Boeing states that this requirement would be better described as performing corrective action in case the engine suction feed operational test is not successful. Boeing asks that we change the second sentence in the Summary section as follows: “This proposed AD would require performing an operational test of the engine fuel suction feed of the fuel system. If necessary, corrective actions may be required, before further flight.”

We agree with the request to clarify the requirement for additional testing of the engine fuel feed manifold. As specified under “Actions Since Original NPRM was Issued,” we have added the corrective action language that was not included in the original NPRM to this supplemental NPRM.

Request To Allow Later Revisions of the Referenced Service Bulletin

Boeing asks that we revise the original NPRM to allow further revisions to the Boeing Alert Service Bulletin A3527, dated November 7, 2007 (referenced in the original NPRM as the source of service information for accomplishing the specified actions). Boeing states that the service bulletin may be revised over time which would require frequent requests for alternative methods of compliance (AMOC).

We do not agree with the request. This supplemental NPRM must be consistent with FAA policy and Office of the Federal Register regulations, which do not allow references to the use of “later revisions” of the applicable service information in ADs. Therefore, no change to the supplemental NPRM is necessary in this regard.

FAA's Determination and Proposed Requirements of the Supplemental NPRM

We are proposing this supplemental NPRM because we evaluated all pertinent information and determined an unsafe condition exists and is likely to exist or develop on other products of the same type design. Certain changes described above expand the scope of the original NPRM. As a result, we have determined that it is necessary to reopen the comment period to provide additional opportunity for the public to comment on this supplemental NPRM.

Costs of Compliance

We estimate that this proposed AD would affect 21 airplanes of U.S. registry. We also estimate that it would take 1 work-hour per product, per test, to comply with this proposed AD. The average labor rate is $80 per work-hour. Based on these figures, we estimate the cost of this proposed AD to the U.S. operators to be $1,680, or $80 per product, per test.

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 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 this 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.

You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.

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 adding the following new AD:

Boeing: Docket No. FAA-2008-0645; Directorate Identifier 2007-NM-358-AD.

Comments Due Date

(a) We must receive comments by January 5, 2009.

Affected ADs

(b) None.

Applicability

(c) This AD applies to all Boeing Model 707-100 long body, -200, -100B long body, and -100B short body series airplanes; and Model 707-300, -300B, -300C, and -400 series airplanes; and Model 720 and 720B series airplanes; certificated in any category.

Unsafe Condition

(d) This AD results from a report of in-service occurrences of loss of fuel system suction feed capability, followed by total loss of pressure of the fuel feed system. We are issuing this AD to detect and correct failure of the engine fuel suction feed of the fuel system, which could result in multi-engine flameout, inability to restart the engines, and consequent forced landing of the airplane.

Compliance

(e) Comply with this AD within the compliance times specified, unless already done.

Operational Test/Other Specified and Corrective Actions

(f) Within 18 months after the effective date of this AD: Perform an operational test of the engine fuel suction feed of the fuel system, and perform all other related testing and corrective actions, as applicable, before further flight, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin A3527, dated November 7, 2007. Repeat the operational test thereafter at intervals not to exceed 6,000 flight hours or 36 months, whichever occurs first.

Alternative Methods of Compliance (AMOCs)

(g)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, ATTN: Sue Lucier, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle ACO, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone], has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

(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 appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

Issued in Renton, Washington, on November 28, 2008.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.