2017-16775. Airworthiness Directives; The Boeing Company Airplanes

AGENCY:

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

ACTION:

Proposed rule; withdrawal.

SUMMARY:

The FAA withdraws a notice of proposed rulemaking (NPRM) that published on May 10, 2016. Since the NPRM was issued, we have determined that the identified unsafe condition is adequately addressed by existing actions. Accordingly, the NPRM is withdrawn.

DATES:

As of August 11, 2017, the proposed rule, which was published in the Federal Register on May 10, 2016 (81 FR 28770), is withdrawn.

ADDRESSES:

You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2016-6417; 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 action, the NPRM (81 FR 28770, May 10, 2016) (“the NPRM”), the regulatory evaluation, any comments received, and other information. The address for the Docket Office (telephone [phone]) is the Docket 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:

Serj Harutunian, Aerospace Engineer, Propulsion Section, FAA, Los Angeles Aircraft Certification Office (ACO) Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: [phone]; fax: [phone]; email: [e-mail].

SUPPLEMENTARY INFORMATION:

Discussion

We proposed to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) with an NPRM for a new AD for all The Boeing Company Model DC-10-10 and DC-10-10F airplanes, Model DC-10-15 airplanes, Model DC-10-30 and DC-10-30F (KC-10A and KDC-10) airplanes, Model DC-10-40 and DC-10-40F airplanes, Model MD-10-10F and MD-10-30F airplanes, and Model MD-11 and MD-11F airplanes. The NPRM published in the Federal Register on May 10, 2016 (81 FR 28770). The proposed AD would have required replacement of the fuel pump housing electrical connector or replacement of the fuel pump housing; repetitive inspections for proper operation of the fuel pump, and corrective actions if necessary; and revising the maintenance or inspection program to incorporate new airworthiness limitations. The proposed AD also would have required, for certain airplanes, a general visual inspection of the protective cap and replacement if necessary. The NPRM was prompted by results from fuel system reviews conducted by the manufacturer and multiple reports of fuel pump housing electrical connector failures related to ingress of airplane fluids. The proposed actions were intended to prevent failure of the fuel pump housing electrical connector, which could result in a potential ignition source in a fuel tank and consequent fire or explosion.

Actions Since the NPRM Was Issued

Since we issued the NPRM, we have determined that the identified unsafe condition is adequately addressed by existing actions.

Comments

We gave the public the opportunity to participate in considering the NPRM. The following presents the comments received on the proposal and the FAA's response to each comment. Multiple commenters (Boeing, FedEx, United Parcel Service (UPS), and Lufthansa Cargo) requested certain changes to the NPRM that are considered moot in light of this withdrawal.

Requests To Withdraw the NPRM

UPS stated that the unsafe condition identified in the NPRM is addressed by Boeing Service Bulletin MD11-28-145, dated July 15, 2014 (installation of sealed terminal lugs on the existing GEN 1 fuel pump connector), in combination with repetitive inspections, which accomplishes the same intent as having installed the GEN 4 fuel pump connector. UPS stated that AD 2016-04-16, Amendment 39-18410 (81 FR 12806, dated March 11, 2016) (“AD 2016-04-16”), also addresses issues with the fuel system. UPS concluded that sealing of the current GEN 1 fuel pump connector via Boeing Service Bulletin MD11-28-145, dated July 15, 2014, in conjunction with the installation of the fault current detectors installed via Boeing Alert Service Bulletin MD11-28A133, dated June 5, 2014 (referenced as an appropriate source of service information in AD 2016-04-16), including a repetitive 24-month inspection of the connectors as required by paragraph (j) of AD 2016-04-16, addresses the unsafe condition described by the NPRM. UPS stated that, furthermore, the installation of the “uncommanded on” system via Boeing Service Bulletin MD11-28-137, dated June 24, 2014 (referenced as an appropriate source of service information in AD 2016-04-16), provides an additional level of safety in all pump positions where the tanks normally empty and can potentially support a combustible environment. UPS stated that the other pump positions on the airplane remain submerged in fuel, thus not providing a combustible environment.

FedEx stated that according to the fire pyramid or fire triangle, three elements—oxygen, fuel (jet fuel), and heat (ignition)—are needed in order to have fire or explosion. FedEx noted that all of the main fuel pumps on MD11/DC10 airplanes are covered by fuel during all flight phases. FedEx stated that these pumps do not meet the aforementioned condition where fuel vapors are present surrounding the pump. FedEx remarked that only pumps in fuel tanks that become empty during flights, i.e., auxiliary tanks and tail tanks, should be affected by the proposed AD. Based on this logic, FedEx concluded that the proposed AD should mandate the replacement of only the connector assemblies in any fuel tank that might normally be empty during flight. FedEx noted that AD 2016-04-16 has already addressed this safety concern and required the installation of fault current detectors in all fuel pumps. FedEx also noted that AD 2002-13-10, Amendment 39-12798 (67 FR 45053, dated July 8, 2002), requires repetitive inspections until a new connector assembly is certified.

We infer that FedEx and UPS are requesting we withdraw the NRPM because those commenters stated that the identified unsafe condition is already addressed.

We agree to withdraw the NPRM because the identified unsafe condition is adequately addressed by existing actions. When we issued the NPRM, we had determined that the NPRM was necessary to comply with the regulation titled “Transport Airplane Fuel Tank System Design Review, Flammability Reduction and Maintenance and Inspection Requirements” (66 FR 23086, May 7, 2001). In addition to new airworthiness standards for transport airplanes and new maintenance requirements, this rule included Special Federal Aviation Regulation No. 88 (“SFAR 88,” Amendment 21-78, and subsequent Amendments 21-82 and 21-83).

Subsequently, we have determined the fuel pump connector redesign/improvement issue is adequately addressed by the actions required by AD 2016-04-16. The risk of the unsafe condition developing during the remaining life of the airplanes identified in the applicability of the proposed AD (e.g., the TriJet fleet) has been greatly reduced by the installation of additional ignition prevention design features such as fault current detectors, automatic pump shutoff, and uncommanded dry running detection systems, which are mandated by AD 2016-04-16. The risk of a fuel tank explosion in a Trijet airplane with low flammability exposure time fuel tanks is not foreseeable.

We are considering further rulemaking to revise AD 2016-04-16 to include an optional replacement, i.e., installing the new connectors introduced in Boeing Service Bulletin DC10-28-264, dated May 15, 2015, and Boeing Service Bulletin MD11-28-146, dated May 15, 2015, as specified in the NPRM. Accomplishing this option would end the 24-month repetitive inspections required by paragraph (j) of AD 2016-04-16 for that airplane.

FAA's Conclusions

Upon further consideration, we have determined that the NPRM is not necessary to address the identified safety concern. Accordingly, the NPRM is withdrawn.

Withdrawal of the NPRM does not preclude the FAA from issuing another related action or commit the FAA to any course of action in the future.

Regulatory Impact

Since this action only withdraws an NPRM, it is neither a proposed nor a final rule and therefore is not covered under Executive Order 12866, the Regulatory Flexibility Act, or DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979).

Authority for This Rulemaking

This withdrawal of an NPRM is issued in accordance with authority delegated by the Executive Director, Aircraft Certification Service, as authorized by FAA Order 8000.51C. In accordance with that order, issuance of ADs is normally a function of the Compliance and Airworthiness Division, but during this transition period, the Executive Director has delegated the authority to issue ADs applicable to transport category airplanes to the Director of the System Oversight Division.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

The Withdrawal

Accordingly, we withdraw the NPRM, Docket No. FAA-2016-6417, Product Identifier 2015-NM-134-AD, which was published in the Federal Register on May 10, 2016 (81 FR 28770).

Issued in Renton, Washington, on August 2, 2017.

Jeffrey E. Duven,

Director, System Oversight Division, Aircraft Certification Service.