Safety Recommendation A-16-002
Synopsis: On July 28, 2011, about 04:11 Korean standard time, Asiana Airlines Flight 991, a B747 400F airplane on a scheduled cargo flight from Incheon, Republic of Korea, to Shanghai, China, crashed into international waters about 130 km west of Jeju International Airport. The flight crew reported a cargo fire to Shanghai Area Control Center and attempted to divert to Jeju International Airport. The two pilots aboard the flight died. The wreckage of the airplane was distributed on the sea floor at an average depth of 85 meters (m), in an area 3 km by 4 km in a southwest-northeast direction. The ARAIB determined that the cause of this accident was a fire that developed on or near two pallets containing dangerous goods packages, including hybrid-electric vehicle lithium ion batteries and flammable liquids, but no physical evidence of the cause of the fire was found. The fire rapidly grew large and uncontained, which resulted in a loss of control and some portions of the fuselage separating from the aircraft in midair, thereby resulting in the crash. The ARAIB report cited as a contributing factor the flammable materials and lithium-ion batteries that were loaded together either in the same or adjacent pallets.
Recommendation: TO THE PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTATION: Establish maximum loading density requirements that restrict the quantities of Class 3 flammable hazardous materials or Class 9 lithium batteries stowed on a single pallet or ULD, or on a group of pallets or ULDs, within an aircraft such that cargo fires can be effectively managed by on-board fire suppression capabilities.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Alternate Action
Mode: Aviation
Location: Jeju Island, Korea, Republic Of
Is Reiterated: No
Is Hazmat: No
Accident #: DCA11RA087
Accident Reports:
Report #: None
Accident Date: 7/27/2011
Issue Date: 2/9/2016
Date Closed: 12/10/2020
Addressee(s) and Addressee Status: PHMSA (Closed - Acceptable Alternate Action)
Keyword(s): Hazmat

Safety Recommendation History
From: NTSB
Date: 12/10/2020
Response: We note that, on March 6, 2019, you published an interim final rule (IFR), “Hazardous Materials: Enhanced Safety Provisions for Lithium Batteries Transported by Aircraft,” which prohibits transporting lithium-ion cells and batteries as cargo on passenger aircraft; requires lithium ion cells and batteries to be shipped with not more than a 30-percent state of charge aboard cargo-only aircraft when not packed with or contained in equipment; and limits the use of alternative provisions for small lithium cell or battery shipments to one package per consignment. In addition, as we noted in our response to Safety Recommendation A-16-1, “Hazardous Materials: Harmonization with International Standards” established new requirements to segregate lithium cells and batteries from certain other hazardous materials when offered for transport or transported on aircraft. We understand that, due to various aircraft designs and markets, it would be difficult to establish the recommended specific maximum loading density requirements. The mitigations you mention are a more viable approach and represent an acceptable alternate solution to this problem. Accordingly, Safety Recommendation A-16-2 is classified CLOSED--ACCEPTABLE ALTERNATE ACTION.

Date: 7/10/2020
Response: -From Howard R. Elliott, Administrator: PHMSA is addressing A-16-02 through multiple actions, which serve to adequately address the issues identified by NTSB. On March 6, 2019, PHMSA published interim final rule (IFR) “Hazardous Materials: Enhanced Safety Provisions for Lithium Batteries Transported by Aircraft (FAA Reauthorization Act of 2018)” (HM-224I; 84 FR 8006). The IFR harmonizes with international provisions adopted by the International Civil Aviation Organization (ICAO) Technical Instructions on the Transport of Dangerous Goods effective as of April 1, 2016, and addresses risks imposed by the transport of packaged lithium cells and batteries as cargo by aircraft independent of battery chemistry, cargo compartment characteristics, and loading configurations. Specifically, the IFR prohibits the transport of lithium ion cells and batteries as cargo on passenger carrying aircraft when not packed with or contained in equipment. This prohibition eliminates the risk of transporting packaged lithium ion cells and batteries in the cargo compartment of passenger carrying aircraft, including the risk of lithium cells and batteries transported with flammable materials. The IFR also establishes a state-of-charge (SOC) limit of 30 percent for packaged lithium ion cells and batteries for transport on cargo-only aircraft. The 30 percent SOC limit applied to cells and batteries is based on testing performed by the FAA William J. Hughes Technical Center and supported by multiple independent studies. These studies demonstrate that, independent of the initiating factor, lowering the state of charge reduces or eliminates the ability of a cell to experience thermal runaway, thereby greatly reducing or eliminating the potential for fire propagation. This reduction in risk at the battery package level is well supported by data and research as documented in the IFR. Addressing the risk at the package level provides a risk control in transport that reduces the likelihood of significant propagation due to thermal runaway that could otherwise impact adjoining cargo, including flammable liquids. The third provision in the IFR limits the number of packages of small batteries per consignment or overpack to one. This provision builds upon previous measures to reduce the number of cells and batteries in a package. This action reduces the risk of fire from shipping large quantities of excepted batteries that were previously being consolidated in overpacks, pallets, by relying instead on single-unit load devices and single aircraft cargo compartments. When combined with the requirements for segregation and packing restrictions for lithium batteries and flammable liquids adopted under the HM-215O final rule, as discussed in association with actions to address SR A-16-01, the rulemaking actions collectively provide for an alternative action that adequately addresses the intent of this SR. Nonetheless, we continue to work collaboratively with the FAA to identify further potential safety actions. Various multi-disciplinary groups are actively researching lithium battery safety to develop an adaptable framework to ensure that as technology advances, safety mitigation measures also advance across the entire stakeholder community. The efforts for continuous improvements of lithium battery safety are highlighted as follows. PHMSA and FAA are active members, providing specialized input, to the United Nations (UN) Sub-Committee of Experts on the Transport of Dangerous Goods (SCOE TDG). This sub-committee provides recommendations on the transport of dangerous goods to global governing authorities and international organizations in the form of the Recommendations on the Transport of Dangerous Goods, “Model Regulations.” On December 5, 2016, the UN SCOE TDG established an Informal Working Group (IWG) of the Sub-Committee for the “development of a comprehensive risk-based system to classify lithium batteries and cells for transport.” The IWG is ensuring that the risk-based system includes classification criteria and supporting test methods to facilitate the development of transport provisions. At a minimum, the IWG is focused on developing test methods specific to: 1) the sensitivity of propagation of thermal runaway in cells and batteries; and 2) the flammability and quantity of gases produced from cells and batteries in thermal runaway. The IWG continues to work on updating the classification criteria for lithium batteries. The ICAO Air Navigation Commission (ANC) established a Cargo Safety Sub-Group (CSSG) of the Flight Operations Panel (FLTOPSP) in June 2016. The CSSG was tasked to address the transport of dangerous goods, including lithium batteries by air cargo. The group developed recommendations and guidance to operators to conduct effective risk assessments. The CSSG also developed a new Chapter to be placed in Annex 6, Part I – Operation of Aircraft, titled Cargo Compartment Safety. This new chapter requires States to ensure that operators establish policies and procedures for the transport of items in cargo compartments through a safety risk assessment. It requires that operators ensure that the flight manual or other operational document contain the elements of the fire protection system and a summary of the demonstrated cargo compartment fire protection certification standards for the aircraft. It also requires an operator to establish policies and procedures that ensure, to a reasonable certainty, that in the event of a fire from items transported in the cargo compartment, such a fire can be detected and suppressed. Additionally, the CSSG created a guidance document, Guidance for Safe Operations Involving Aeroplane Cargo Compartments (Doc 10102), for States and operators to utilize in conducting the safety risk assessments on items carried in cargo compartments. Both the new Chapter in Annex 6 and Doc 10102 have an applicability date of November 2020. The FAA Offices of Aircraft Certification Service (AIR), Flight Standards Service (AFX), and Dangerous Goods Safety (AXH) participated in the ICAO CSSG. Finally, the FAA requires all 14 CFR Part 121 operators (air carriers) to meet the 14 CFR Part 5—Safety Management Systems (SMS) regulations. These regulations also apply to 14 CFR Part 135 operators with a voluntary SMS program. Pursuant to SMS, operators are required to apply safety risk management, which includes hazard identification, safety risk assessment and safety risk controls for cargo operations. The collective actions discussed address the intent of SR A-16-02. In closing, PHMSA and the FAA are committed to continuously helping to improve the safety of our Nation’s air transportation system. If I can be of further assistance, please do not hesitate to call me or have your staff contact Dirk Der Kinderen, NTSB Program Manager for the Office of Hazardous Materials Safety.

From: NTSB
Date: 9/21/2017
Response: On December 15, 2016, we held a teleconference with your staff and with staff from the Federal Aviation Administration (FAA) to discuss this recommendation. The FAA staff felt that, because this recommendation addresses an aircraft’s on-board fire suppression capabilities, it was the more appropriate organization to respond to Safety Recommendation A-16-2. We note from your current letter that the FAA will take primary responsibility for this recommendation and is initiating action to address it. We further note that you will update us regarding the FAA’s progress. Pending development of maximum loading density requirements that take into consideration an aircraft’s on-board fire suppression capabilities, Safety Recommendation A-16-2 remains classified OPEN--ACCEPTABLE RESPONSE.

Date: 7/14/2017
Response: -From Howard W. McMillan, Acting Deputy Administrator: I would like to extend a note of appreciation to your staff for their cooperation in discussions with PHMSA and FAA in determining the preferred path forward regarding Safety Recommendation A-16-002. FAA will take primary responsibility for this recommendation and is commencing work immediately. PHMSA will update NTSB on FAA's progress accordingly.

From: NTSB
Date: 8/18/2016
Response: We note that you concur with the intent of this recommendation and that you have been working with the Federal Aviation Administration to determine the specific actions you will take to satisfy it. Pending completion of the recommended action, Safety Recommendation A-16-2 is classified OPEN--ACCEPTABLE RESPONSE.

Date: 6/6/2016
Response: -From Marie Therese Dominguez, Administrator: PHMSA concurs with the intent of both safety recommendations to enhance the safe transportation of lithium batteries by air and shares your concerns regarding the potential for lithium batteries to initiate and contribute to the severity of a fire in the cargo compartments of aircraft in the presence of flammable liquids. The safe transport of lithium batteries by air has been an ongoing concern for PHMSA, the Federal Aviation Administration (FAA), and the U.S. Department of Transportation. PHMSA participates in a number of international forums, including the International Civil Aviation Organization (ICAO) Dangerous Goods Panel (DGP), as part of the ongoing process of harmonizing the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) with international standards and regulations and is committed to ensuring the ICAO Technical Instructions for the Safe Transport of Dangerous Goods by Air and the HMR provide a level of safety such that lithium batteries can be carried without putting an aircraft or its occupants at risk. As you stated in your letter, the ICAO DGP met in Montreal, Quebec, Canada in October 2015 to consider the development of further measures to mitigate the risks associated with the transport of lithium batteries when carried as cargo. With respect to Safety Recommendation A-16-001, temporary measures to mitigate the hazards of lithium battery transport by cargo aircraft were proposed (pending a comprehensive solution that would mitigate these hazards) to the DGP. These measures included, among others, the segregation of lithium batteries from other dangerous goods (e.g., flammable liquids). Given the complex nature of the safety problem that underlies Recommendation A-16-001, segregation or the other identified measures may or may not provide the ultimate solution to the problem. The DGP may also consider measures that are in addition to or in lieu of segregation, such as those that recognize that different operators have different mitigating tools available to them based on the size of their operation and the types of cargo compartments and fire suppressions systems available on their aircraft. Such measures would also need to provide enough flexibility to allow for the use of fire containment covers, fire resistant containers and unit load devices that could contain or suppress a lithium battery fire. PHMSA, in cooperation with the FAA, will continue to work within the ICAO DGP to address this issue during the current 2016-2017 biennium. Decisions taken by the DGP would be considered for adoption within the HMR in the earliest possible rulemaking once this work is complete. With respect to Safety Recommendation A-16-002, PHMSA has been engaged with FAA in determining the best course of action to address this recommendation. Discussions and collaboration are ongoing and we plan to provide you with a more detailed plan of action on this recommendation in a follow-up response to this letter. We note that recent measures approved by the ICAO Governing Council may provide for an alternative approach that would address the NTSB 's concerns of stowage of lithium batteries with flammable liquids. Based on recommendations from the ICAO Air Navigation Commission, as well as the Dangerous Goods, Flight Operations, and Airworthiness panels, the ICAO Governing Council approved three new measures to enhance lithium battery safety, effective April1, 2016. These measures include: (1) prohibiting the transport of lithium ion batteries as cargo aboard passenger aircraft; (2) requiring lithium ion batteries to be transported at not more than a 30 percent state of charge; and (3) limiting current provisions for small lithium batteries to no more than one package per consignment. PHMSA supports ICAO's measures and intends to incorporate these amendments into the HMR in an interim final rule anticipated for publication in September 2016. The timeline for this rulemaking may be reviewed at: In addition, the ICAO Dangerous Goods and Flight Operations panels recommended that operators conduct a safety risk assessment on the transport of dangerous goods and lithium batteries. The safety risk assessment process should include the implementation of necessary mitigation measures in order to ensure the safe transport of dangerous goods including lithium batteries as cargo on aircraft. In summary, PHMSA is engaged in a number of important actions to further ensure the safety of lithium batteries on aircraft. PHMSA will continue to coordinate with FAA through the international standards organizations in consultation with industry and research institutions to assess incident data focusing on root causes and ongoing research to gauge any necessary changes to lithium battery transport requirements. Finally, PHMSA will follow-up with the NTSB with greater detail on all of its initiatives affecting lithium battery safety with respect to Safety Recommendations A-16-001 and A-16-002 when we have collectively determined a planned course of action to further address the recommendations.