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Safety Recommendation Details

Safety Recommendation A-09-044
Details
Synopsis: On June 28, 2008, about 2215 Pacific daylight time, an ABX Air Boeing 767-200, N799AX, operating as flight 1611 from San Francisco International Airport (SFO), San Francisco, California, experienced a ground fire before engine startup. The captain and the first officer evacuated the airplane through the cockpit windows and were not injured, and the airplane was substantially damaged. The cargo flight was operating under the provisions of 14 Code of Federal Regulations (CFR) Part 121. At the time of the fire, the airplane was parked near a loading facility, all of the cargo to be transported on the flight had been loaded, and the doors had been shut.
Recommendation: TO THE FEDERAL AVIATION ADMINISTRATION: Prohibit the use of electrically conductive combustible oxygen hoses unless the conductivity of the hose is an intentional and approved parameter in the design.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Aviation
Location: San Francisco, CA, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA08MA076
Accident Reports: Ground Fire Aboard Cargo Airplane, ABX Air Flight 1611, Boeing 767-200, N799AX
Report #: AAR-09-04
Accident Date: 6/28/2008
Issue Date: 7/8/2009
Date Closed: 9/16/2015
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s): Hazmat

Safety Recommendation History
From: NTSB
To: FAA
Date: 9/16/2015
Response: We note that, on December 9, 2014, you issued final policy PS-ANM-25.1441-01, “Mitigating Fire Hazards in Gaseous Oxygen Systems.” This policy satisfies Safety Recommendations A-09-44, -48 and -50, which are classified CLOSED—ACCEPTABLE ACTION.

From: FAA
To: NTSB
Date: 7/30/2015
Response: -From Michael P. Huerta, Administrator: In our letter dated April 9, 2014, the Federal Aviation Administration (FAA) advised that we had determined that existing airworthiness standards related to these safety recommendations are adequate. As noted in our previous response to these recommendations, we drafted policy to clarify our guidance associated with the use of flexible oxygen hoses and address other potential oxygen system issues that could result in a fire. As a result, the FAA issued final policy PS-ANM-25.1441-0 1, Mitigating Fire Hazards in Gaseous Oxygen Systems, on December 9, 2014. The final policy statement is located at the following Web site: http://rgl.faa.gov/Regulatoryand_Guidance_Library/rgPolicy.nsf/0/A54651A8AABE42F486257DC4006DAD32?0penDocument. I believe the FAA has effectively addressed these safety recommendations and consider our actions complete.

From: NTSB
To: FAA
Date: 6/3/2014
Response: We note that, to address potential issues in new designs that could cause fires, you drafted a policy to clarify guidance on the use of flexible oxygen hoses and other potential oxygen system issues. We also note that the proposed policy was made available for public comment on August 28, 2013, and that you are currently reviewing comments for incorporation into the final policy. Pending issuance of the final policy, Safety Recommendations A-09-44, -48 and -50 remain classified OPEN—ACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 4/9/2014
Response: -From Michael P. Huerta, Administrator: In the Federal Aviation Administration's (FAA) letters dated January 15, 2013 and July 13, 2011, we listed airworthiness directives (ADs) that we have issued on this subject for transport category airplanes. Since that date, we proposed an AD to require replacement of crew oxygen system hoses on Boeing 777 series airplanes (reference docket F AA-2012-0104 published February 8, 20 12). We are working to address comments received and expect to issue the final AD by May 31, 2014. The FAA completed a review of oxygen system designs from transport airplane manufacturers and concluded that they do not present a safety concern. We identified a number of design approaches that mitigate a potential safety concern for new designs including: • Elimination of flexible hoses in continually pressurized systems; • Use of flexible hose designs that are inherently non-conductive; and • Installation of grounding/bonding straps at the hose ends if conductive hoses are installed. To address potential issues for new designs, we drafted policy intended to clarify guidance on the use of flexible oxygen hoses. This draft policy is also intended to address other potential oxygen system issues that could result in a fire. We recognize that policy and guidance will not mandate a change to airplanes currently in-service with previously approved designs, but based on our design review we determined that fleetwide rulemaking is unnecessary. Our proposed policy was made available for public comment on August 28, 2013, and we are reviewing comments for incorporation into a final policy.

From: NTSB
To: FAA
Date: 12/9/2013
Response: The National Transportation Safety Board (NTSB) has reviewed the Federal Aviation Administration’s (FAA) notice of proposed rulemaking (NPRM), titled “Airworthiness Directives; The Boeing Company Airplanes,” which was published at 78 Federal Register 63130 on October 23, 2013. The NPRM proposes to adopt a new airworthiness directive (AD) for certain Boeing Company Model 777F series airplanes. This proposed AD would require replacing the low pressure oxygen hoses with nonconductive low-pressure oxygen hoses in the stowage box and supernumerary ceiling area. The FAA is proposing this AD to prevent electrical current from passing through an internal, anticollapse spring of the low-pressure oxygen hose, which can cause the low-pressure oxygen hose to melt or burn and lead to an oxygen-fed fire on the flight deck. This proposed AD was prompted by a report of a fire on a Boeing 777 that originated near the first officer’s seat and caused extensive damage to the flight deck. On July 29, 2011, a Boeing B777 200, Egyptian registration SU-GBP, operated by EgyptAir, experienced a fire in the right lower portion of the cockpit area, adjacent to the electronic flight bag and an electrical power panel. The airplane was pushing back from a gate at Cairo Airport at the time the crew detected the fire; the 12 crewmembers and 307 passengers deplaned with no injuries. The right side of the cockpit was damaged by fire. This accident investigation was conducted by the Egyptian Central Directorate for Aircraft Accidents Investigation, Ministry of Civil Aviation. As the state of manufacture, the NTSB designated a US accredited representative to assist in the investigation. In addition, the NTSB investigated a similar accident involving oxygen hoses on a Boeing 767. On June 28, 2008, about 2215 Pacific daylight time, a Boeing 767-200, N799AX, operating as ABX Air flight 1611 from San Francisco International Airport, San Francisco, California, experienced a ground fire before engine startup. A contributing factor in this accident was the FAA’s failure to require the installation of nonconductive oxygen hoses after the safety issue concerning conductive hoses was initially identified by Boeing. On July 8, 2009, the NTSB issued Safety Recommendations A-09-43 and -44, asking the FAA to require operators to replace electrically conductive combustible oxygen hoses with electrically nonconductive hoses so that the internal hose spring cannot be energized and to prohibit the use of electrically conductive combustible oxygen hoses unless the conductivity of the hose is an intentional and approved parameter in the design. In response to these recommendations, the FAA issued ADs regarding the replacement and discontinued use of electrically conductive oxygen hoses on Boeing 737, 747, 757, 767, and 777 Model airplanes. While the FAA previously issued an AD regarding this issue on Boeing 777F Model airplanes, the old AD did not cover hoses installed at the supernumerary crew positions, while this proposed AD, based on Boeing Alert Service Bulletin 777-35A0029, does cover those hoses installed at the supernumerary crew positions. The NTSB concurs with the proposed AD, which would replace the low-pressure oxygen hoses in the stowage box and supernumerary ceiling area with new nonconductive low pressure oxygen hoses in Boeing 777F Model airplanes. The NTSB appreciates the opportunity to comment on this NPRM.

From: NTSB
To: FAA
Date: 3/26/2013
Response: We are encouraged that the FAA has issued the airworthiness directives (ADs) and completed the evaluations of several other manufacturers’ oxygen system designs, and that your agency has concluded that the designs evaluated to date pose no safety concerns. Pending the completion of your reviews and the issuance of appropriate ADs, Safety Recommendations A-09-43 and -44 remain classified OPEN—ACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 1/15/2013
Response: -From Michael P. Huerta, Administrator: In our previous letter to the Board, the Federal Aviation Administration (FAA) listed various airworthiness directives (ADs) that were issued on this subject for Boeing products. Since that date, we also have issued AD 2012- 13-05, effective August 16, 2012, that requires replacement of crew oxygen system hoses on Boeing 777 series airplanes. Additionally, we completed an evaluation of several manufacturers' oxygen system designs and concluded the reviewed designs are not a safety concern. As we continue to coordinate with additional airplane manufacturers to evaluate the use of flexible oxygen hoses on in-service airplanes, we will use the AD process if we find any safety concerns. I will keep the Board informed of the FAA's progress on Safety Recommendations A-09-43 and -44 and provide an update by December 2013.

From: NTSB
To: FAA
Date: 10/17/2011
Response: The NTSB disagrees with the FAA that its actions have satisfied these safety recommendations. We note that the FAA issued airworthiness directives (AD) related to replacement and discontinued use of electrically conductive oxygen hoses on Boeing products. Because the design of such hoses originated with a military specification that could be used by any hose manufacturer to develop and then distribute similar hoses to numerous airplane manufacturers, the problem with conductive hoses is not restricted to Boeing products. We believe that electrically conductive oxygen hoses in any airplane installation (not only Boeing products) constitute a safety hazard. As a result of these concerns, in our July 9, 2010, letter concerning these recommendations, we requested information about the FAA’s efforts to address oxygen hoses with an electrically conductive design, used by airplane manufacturers other than Boeing, which may be identified by different part numbers. In its current letter, the FAA replied that it does not agree that every potentially electrically conductive oxygen hose is a safety concern that requires replacement, because oxygen hoses that are normally unpressurized do not present the same risk of fire. The FAA is currently working with manufacturers to further understand the various installations and to evaluate the use of flexible oxygen hoses. If additional safety concerns are identified, the FAA plans to issue ADs to address those concerns. Accordingly, pending the completion of these reviews and the issuance of appropriate ADs, Safety Recommendations A-09-43 and -44 remain classified OPEN—ACCEPTABLE RESPONSE.

From: FAA
To: NTSB
Date: 7/13/2011
Response: CC# 201100278: - From J. Randolph Babbitt, Administrator: The airworthiness directives (AD) related to replacement and discontinued use electrically conductive oxygen hoses on Boeing products have been published. The ADs are follows: • 757 series -AD 2010-06-17, effective May 3, 2010 (enclosure 1); • 767 series -AD 2010-16-04, effective September 9,2010 (enclosure 2); • 747 series -AD 2010-16-05, effective September 9,2010 (enclosure 3); and • 737 series -AD 2010-16-06, effective September 9, 2010 (enclosure 4). The Federal Aviation Administration (FAA) does not concur that every potentially electrically conductive oxygen hose is a safety concern that requires replacement. Oxygen hoses that are normally unpressurized do not present the same risk of fire. The FAA believes that the potential concern is installation specific and we are working with manufacturers to further understand the various installations and evaluate the use of flexible oxygen hoses. If additional safety concerns a e identified, the AD process will be used to address the concerns. Section 25.1441 and existing advisory material contain appropriate standards to address this hazard. We will take appropriate steps to remind FAA personnel and designees to pay particular attention to the potential risk, applicable regulations, and FAA expectations to design and maintain hazard free oxygen systems at Aircraft Certification Office standardization meetings and designee conferences. I believe that the FAA has effectively addressed these safety recommendations, and I consider our actions complete.

From: NTSB
To: FAA
Date: 7/9/2010
Response: The NTSB is pleased that the FAA has assembled an interdisciplinary team of technical specialists to address these safety issues and looks forward to reviewing the FAA's findings related to Safety Recommendations A-09-44 and A-09-46 through -53 and, more importantly, its plan for addressing the safety deficiencies identified in these recommendations. Pending the NTSB's review of this information, Safety Recommendations A-09-44 and A-09-46 through -53 are classified OPEN – ACCEPTABLE RESPONSE.

From: NTSB
To: FAA
Date: 12/4/2009
Response: Notation 8116C: The National Transportation Safety Board (NTSB) has reviewed the Federal Aviation Administration’s (FAA) notice of proposed rulemaking (NPRM) titled, “Airworthiness Directives; Boeing Model 757 Airplanes,” which was published in 74 Federal Register 49827 on September 29, 2009. This NPRM proposes an airworthiness directive (AD) requiring the inspection of certain Boeing 757 airplanes to verify the part number of the flight crew and supernumerary oxygen system low pressure flex-hoses installed under the oxygen mask stowage boxes to ensure that the hoses are of a nonconductive design. The AD would require replacement of the older electrically conductive hoses. This NPRM also notes that the FAA plans to issue similar rules applicable to Boeing 737, 747, and 767 airplanes. The proposed AD results from an August 1997 incident, in which a hole was created in a low pressure flex hose in the flight crew oxygen system due to an electrical short circuit in an adjacent audio select panel. Following the incident, Boeing released Service Bulletins 757-35A-0015, Revision 2 and 757-35-A0016, Revision 1, both dated June 15, 2000, addressing the replacement of electrically conductive hoses. This proposed rule is partially consistent with three NTSB safety recommendations that resulted from the investigation of a June 28, 2008, preflight ground fire, which destroyed an ABX Air Boeing 767-200, N799AX, at San Francisco International Airport, San Francisco, California. The NTSB determined that the probable cause of that fire was the design of the supplemental oxygen system hoses and the lack of positive separation between electrical wiring and electrically conductive oxygen system components, as well as the FAA’s failure to require the installation of nonconductive oxygen hoses after Boeing initially identified the safety issue concerning conductive hoses. The NTSB issued the following safety recommendations to the FAA: Require operators to replace electrically conductive combustible oxygen hoses with electrically nonconductive hoses so that the internal hose spring cannot be energized. (A-09-43) Prohibit the use of electrically conductive combustible oxygen hoses unless the conductivity of the hose is an intentional and approved parameter in the design. (A 09 44) Require airplane manufacturers and operators to ensure that oxygen system tubing in proximity to electrical wiring is made of, sleeved with, or coated with nonconductive material or that the tubing is otherwise physically isolated from potential electrical sources. (A 09 47) These recommendations are currently classified “Open—Await Response.” The FAA’s initial response, dated September 23, 2009, is currently under review by the NTSB. The NTSB fully supports NPRM FAA-2009-0795 and welcomes future rules that would address similar installations in other Boeing models. However, the NTSB notes that this proposed rule and the future rules mentioned in the NPRM would apply only to Boeing airplanes and that the NTSB’s recommendations above are not restricted to those airplanes. Suppliers provide other airplane manufacturers with low-pressure oxygen hoses that are nearly identical to those that this proposed AD seeks to identify and replace. Because the risk of fire from electrically conductive hoses is not restricted to Boeing models, the NTSB urges the FAA to widen the inspection and replacement of oxygen hoses beyond the airplanes cited in this proposed rule. Thank you for the opportunity to comment on this NPRM.

From: FAA
To: NTSB
Date: 9/23/2009
Response: Letter Mail Controlled 10/5/2009 12:30:33 PM MC# 2090617 - From J. Randolph Babbitt, Administrator: To comprehensively address Safety Recommendations A-09-44, and A-09-46 through -53, the FAA has assembled a team of specialists from various technical disciplines to review the recommendations and assess the underlying safety issues. Following this review we will develop a plan to address each recommendation.