2010-5857. Airworthiness Directives; The Boeing Company Model 757 Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

We are adopting a new airworthiness directive (AD) for certain Model 757 airplanes. This AD requires inspecting to verify the part number of the low-pressure flex-hoses of the flightcrew and supernumerary oxygen system installed under the oxygen mask stowage box at a flightcrew and supernumerary oxygen mask location, and replacing with a new non-conductive low-pressure flex-hose of the oxygen system if necessary. This AD results from reports of a low-pressure flex-hose of a flightcrew oxygen system that burned through due to inadvertent electrical current from a short circuit in an adjacent audio select panel. We are issuing this AD to prevent inadvertent electrical current, which can cause the low-pressure flex-hose of a flightcrew or supernumerary oxygen system to melt or burn, resulting in oxygen system leakage and smoke or fire.

DATES:

This AD is effective May 3, 2010.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in the AD as of May 3, 2010.

ADDRESSES:

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.

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 AD, the regulatory evaluation, any comments received, and other information. The address for the Docket Office (telephone [phone]) is the Document Management Facility, U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT:

Nicholas Wilson, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Model 757 airplanes. That NPRM was published in the Federal Register on September 29, 2009 (74 FR 49827). That NPRM proposed to require inspecting to verify the part number of the low-pressure flex-hoses of the flightcrew and supernumerary oxygen system installed under the oxygen mask stowage box at a flightcrew and supernumerary oxygen mask location, and replacing with a new non-conductive low-pressure flex-hose of the oxygen system if necessary.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the comments received from the six commenters.

Support for the NPRM

Boeing, Air Line Pilots Association, International (ALPA), and the National Transportation Safety Board (NTSB) support the NPRM.

Request To Withdraw NPRM

American Airlines states that the NPRM is unnecessary and should be retracted. The commenter states that, given the Boeing compliance recommendation of “earliest opportunity when manpower, material and facilities are available,” risk analysis for the unsafe condition was found to be below the extremely improbable threshold. The commenter states that the NPRM would affect 102 of its airplanes, all of which have been modified to preclude the unsafe condition. The commenter also states that, of the 485 airplanes affected by the NPRM, it has mitigated the risk on 25 percent of the U.S. fleet. The commenter states that the three other large U.S. operators have also incorporated Boeing Service Bulletin 757-35A0015, Revision 2, dated June 15, 2000. The commenter states that this combined effort has substantially addressed the U.S. fleet and reduced the risk probabilities even further. The commenter also states that it has put procedures in place to preclude reintroducing the unsafe condition. The commenter also states that, since Boeing Service Bulletin 757-35A0015, dated September 2, 1999, was issued 10 years ago, the FAA appears to agree that at least 13 years is an appropriate interval of time in which the affected airplanes could continue to operate without compromising safety. The commenter states that the compliance period appears arbitrary and is not based on accepted risk assessment practices.

We do not agree to withdraw the NPRM. Sufficient information exists to demonstrate that our risk analysis for the unsafe condition is adequate in determining the compliance times required in this AD. We acknowledge that American Airlines has been proactive in compliance with the requirements of this AD; however, not every operator has been quite as proactive. According to various bilateral airworthiness agreements with countries around the world, we are obligated to advise other civil airworthiness authorities of unsafe conditions identified in products manufactured in the United States. The issuance of ADs is the means by which we satisfy this obligation. Even if the current U.S.-registered fleet is in compliance with the requirements of the AD, the issuance of the rule is still necessary to ensure that any affected airplane imported and placed on the U.S. register in the future will be required to be in compliance as well. The manufacturer has advised us that not all of the affected airplanes worldwide have been modified. Issuance of this AD will ensure that the airplanes are modified before they are permitted to operate in the U.S. We have not changed the AD in this regard.

Request To Allow a One-time Ferry Flight

FedEx requests that a one-time ferry flight to a maintenance base be allowed for airplanes in a non-compliant configuration due to being in storage. FedEx states that a ferry flight would be required after the 36-month compliance date.

We partially agree with the request for a one-time ferry flight. We agree with allowing special flight permits for the purpose of flying the airplane to a repair facility to do the work required by this AD. However, we disagree with revising this AD to specifically state that special flight permits are approved for this purpose. Special flight permits are currently allowed under section 39.23 of the Federal Aviation Regulations (14 CFR 39.23). No change has been made to the AD in this regard.

Request That Visual Inspections for the Part Number Not Be Required if Previously Done

Northwest Airlines requests that visual inspections for part numbers of the low-pressure oxygen flex hose not be required if the airline has previously complied with Boeing Service Bulletin 757-35A0015, Revision 2, dated June 15, 2000. The commenter provided no further justification for this request.

We agree that the visual inspection of the hose is not necessary if the operator has previously accomplished the actions specified in Boeing Service Bulletin 757-35A0015, Revision 2, dated June 15, 2000. Paragraph (f) of this AD states that the required actions must be done within the specified compliance times, “* * * unless the actions have already been done.” This AD does not require that the actions be redone if they were done before the effective date of the AD. No change to the AD is necessary in this regard.

Request To Reduce Proposed Compliance Time

ALPA requests a shorter compliance time. ALPA states that the 36-month inspection and replacement interval is too long due to a high degree of risk imposed on passengers and crew.

We do not agree. In developing an appropriate compliance time, we considered the safety implications, parts availability, and normal maintenance schedules for timely accomplishment of inspecting the low-pressure flex-hoses of the flightcrew and supernumerary oxygen system. Further, we arrived at the proposed compliance time with operator and manufacturer concurrence. In consideration of all of these factors, we determined that the compliance time, as proposed, represents an appropriate interval in which the inspection and replacement can be accomplished in a timely manner within the fleet, while still maintaining an adequate level of safety. Operators are always permitted to accomplish the requirements of an AD at a time earlier than the specified compliance time; therefore, an operator may choose to replace the oxygen hose before 36 months after the effective date of this AD in order to accomplish the requirements of this AD. If additional data are presented that would justify a shorter compliance time, we might consider further rulemaking on this issue. We have not changed the AD in this regard.

Request To Revise Applicability To Include Manufacturers of Other Airplanes With Similar Low-Pressure Oxygen Hoses

Although the NTSB fully supports the NPRM, the NTSB states that because the risk of fire from electrically conductive hoses is not restricted to Boeing models, the FAA should widen the inspection and replacement of oxygen hoses beyond the airplanes cited in the NPRM. The NTSB notes that the NPRM and the future rules mentioned in the NPRM would apply only to Boeing airplanes. The NTSB states that suppliers provide other airplane manufacturers with low-pressure oxygen hoses that are nearly identical to those that the NPRM seeks to identify and replace.

From these statements, we infer the NTSB is requesting that we revise the NPRM to add other airplane models to the applicability of the NPRM. We agree that suspect low-pressure oxygen hoses or similar hoses might be installed on airplane models produced by manufacturers other than Boeing. Determining whether an unsafe condition exists on these other airplanes is outside the scope of this AD. We will continue to evaluate the safety implications of these oxygen hoses as they apply to other manufacturers and initiate additional rulemaking to address the unsafe condition on those airplanes if necessary. We have not changed the AD in this regard.

Request To Remove Requirement for Recording Part Numbers

Northwest Airlines requests that we remove the proposed requirement to record the part number of the flex hose that is intended for replacement. Northwest Airlines states that once an oxygen hose has been identified as affected by the visual inspection confirming the part number, the affected hose will be replaced. Northwest Airlines states that there is no further instruction on where to record this information or what to do with it. Northwest Airlines states that requiring the recording of the part number of the affected oxygen hose does not provide any benefit or enhance safety.

We agree that recording the part number of the affected hose does not serve any safety interest. Recording the part number of the affected hose identified for replacement as specified in Boeing Service Bulletin 757-35A0015, Revision 2, dated June 15, 2000, is not necessary for compliance with this AD. We have revised paragraph (g)(1) of this AD to clarify that recording the part number of the affected oxygen hose is not necessary.

Explanation of Changes Made to This AD

We have revised this AD to identify the legal name of the manufacturer as published in the most recent type certificate data sheet for the affected airplane models.

Conclusion

We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We also determined that these changes will not increase the economic burden on any operator or increase the scope of the AD.

Explanation of Change to Costs of Compliance

Since issuance of the NPRM, we have increased the labor rate used in the Costs of Compliance from $80 per work-hour to $85 per work-hour. The Costs of Compliance information, below, reflects this increase in the specified hourly labor rate.

Costs of Compliance

We estimate that this AD would affect 485 airplanes of U.S. registry. We also estimate that it would take 1 work-hour per product to comply with this AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this proposed AD to the U.S. operators to be $41,225, or $85 per product.

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

This AD will not have federalism implications under Executive Order 13132. This AD 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.

For the reasons discussed above, I certify that this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Is not a “significant rule” under 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

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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:

2010-06-17 The Boeing Company: Amendment 39-16242. Docket No. FAA-2009-0795; Directorate Identifier 2009-NM-083-AD.

Effective Date

(a) This airworthiness directive (AD) is effective May 3, 2010.

Affected ADs

(b) None.

Applicability

(c) This AD applies to The Boeing Company Model 757-200, -200CB, -200PF, and -300 series airplanes, certificated in any category; as identified in the service bulletins listed in Table 1 of this AD.

Table 1—Applicability

Boeing Service Bulletin	Revision	Dated	Applicable model/series
757-35A0015	2	June 15, 2000	757-200, 757-200CB, 757-200PF.
757-35A0016	1	June 15, 2000	757-300.

Subject

(d) Air Transport Association (ATA) of America Code 35: Oxygen.

Unsafe Condition

(e) This AD results from reports of a low-pressure flex-hose of a flightcrew oxygen system that burned through due to inadvertent electrical current from a short circuit in an adjacent audio select panel. We are issuing this AD to prevent inadvertent electrical current which can cause the low-pressure flex-hoses used in the flightcrew and supernumerary oxygen system to melt or burn, resulting in oxygen system leakage and smoke or fire.

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.

Inspection

(g) Within 36 months after the effective date of this AD, inspect to determine whether any low-pressure flex-hose of the flightcrew and supernumerary oxygen systems installed under the oxygen mask stowage location has a part number identified in Table 2 of this AD. A review of airplane maintenance records is acceptable in lieu of this inspection if the part number of the low-pressure flex-hoses of the flightcrew and supernumerary oxygen system can be conclusively determined from that review.

(1) For any low-pressure flex-hose having a part number identified in Table 2 of this AD, before further flight, replace the hose with a new or serviceable part, in accordance with the Accomplishment Instructions of the applicable service bulletin identified in Table 1 of this AD. Recording the part number of the hose being replaced is not required by this AD.

(2) For any low-pressure flex-hose not having a part number identified in Table 2 of this AD, no further action is required by this paragraph.

Parts Installation

(h) As of the effective date of this AD, no person may install a flightcrew or supernumerary oxygen hose with a part number identified in Table 2 of this AD on any airplane.

Table 2—Applicable Part Numbers

Boeing specification part No.—	Equivalent Boeing supplier part numbers—
	Sierra Engineering	Spencer Fluid	Puritan Bennett	Hydraflow	AVOX (formerly Sierra Engineering)
60B50059-70	835-01-70	9513-20S5-18.0	ZH784-20	38001-70	9513-835-01-70
60B50059-81	835-01-81	9513-20S5-24.0	ZH784-81	38001-81	9513-835-01-81

Actions Accomplished According to Previous Issue of Service Bulletin

(i) Actions accomplished before the effective date of this AD in accordance with Boeing Alert Service Bulletin 757-35A0015, dated September 2, 1999, or Revision 1, dated November 11, 1999; or Boeing Alert Service Bulletin 757-35A0016, dated November 11, 1999; are considered acceptable for compliance with the corresponding actions specified in this AD.

Alternative Methods of Compliance (AMOCs)

(j)(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: Nicholas Wilson, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle ACO, 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.

Material Incorporated by Reference

(k) You must use Boeing Service Bulletin 757-35A0015, Revision 2, dated June 15, 2000; or Boeing Service Bulletin 757-35A0016, Revision 1, dated June 15, 2000; as applicable; to do the actions required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) 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.

(3) You may review copies of the 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.

(4) You may also review copies of the service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html.

Issued in Renton, Washington, on March 9, 2010.

Jeffrey E. Duven,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.