Ethiopian B772 at Shanghai on Jul 22nd 2020, aircraft burned down on apron

Last Update: March 1, 2024 / 18:39:22 GMT/Zulu time

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Incident Facts

Date of incident
Jul 22, 2020

Classification
Accident

Airline
Ethiopian Airlines

Flight number
ET-3739

Departure
Shanghai Pudong, China

Destination
Addis Ababa, Ethiopia

Aircraft Registration
ET-ARH

Aircraft Type
Boeing 777-200

ICAO Type Designator
B772

An Ethiopian Airlines Boeing 777-200 freighter, registration ET-ARH performing flight ET-3739 from Shanghai Pudong (China) to Addis Ababa (Ethiopia), was preparing for departure at the apron, when at about 15:57L (07:57Z) smoke was observed from the aft crown of the aircraft, emergency services responded and extinguished the fire by about 17:01L (09:01Z). No injuries are being reported. The aircraft sustained substantial damage.

The aircraft had safely arrived as flight ET-3738 (dep Jul 21st) from Brussels (Belgium) to Shanghai Pudong (China) and had taxied to the apron at about 11:53L (03:53Z).

China's Civil Aviation Authority have opened an investigation.

Ethiopian Airlines confirmed the aircraft caught fire in Shanghai. It was scheduled to fly from Shanghai to Addis Ababa (Ethiopia) and further on to Sao Paulo,SP (Brazil) and San Diego,CA (USA).

On Aug 26th 2020 the NTSB reported they have assigned an accredited representative to assist the investigation by the Civil Aviation Administration of China (CAAC) according to ICAO Annex 13 representing the state of manufacture and design of the aircraft.

According to Media Reports in China the final report was obtained by some media, however, it was never published and is also not available from ICAO's report database. According to these media reports the cause the fire was not caused by batteries or electrical components of the aircraft.

Instead, the investigation concluded the most probable cause of the accident were Chlorine Dioxide Desinfection tablets, which in the high temperatures and humid environment spontaneously ignited.

The investigation reported the aircraft had been loaded with 69.3 tons of cargo from all over China, including four shipments containing Lithium Ion batteries, however, upon detailed inspection it was found that the batteries internally were intact although showing discolouration on the outside demonstrating that the batteries had been affected by heat/fire from the outside. At the position showing the most damage within the cargo bay a shipment containing the Chlorine Dioxide tablets had been loaded. These tablets were classified a slow nano release cleansing material (used to prevent build a disinfection shield to prevent epidemics), the tablets were thus rated "dangerous goods", the local Reseach Institute of Chemical Industry stated the material was primarily an oxidizer and secondarily corrosive.

Experiments confirmed the tablets were susceptible for spontaneous ignition at temperatures near 80 degrees C and damp conditions. At the time of the accident outside ambient temperatures had been 34 degrees C. Further experiments demonstrated that inside pallets in the cargo bay temperatures of 80 degrees C were reached in these conditions causing condensation inside the films of the tablets. These were sufficient conditions for spontaneous combustion to occur.

On Jun 5th 2023 The Aviation Herald was able to get hold of the final report in Chinese only (Editorial note: to serve the purpose of global prevention of the repeat of causes leading to an occurrence an additional timely release of all occurrence reports in the only world spanning aviation language English would be necessary, a Chinese only release does not achieve this purpose as set by ICAO annex 13 and just forces many aviators to waste much more time and effort each in trying to understand the circumstances leading to the occurrence. Aviators operating internationally are required to read/speak English besides their local language, investigators need to be able to read/write/speak English to communicate with their counterparts all around the globe).

The report concludes the probable cause of the accident was:

The investigation team concluded that in this accident, the fire started in the area of the aircraft's main cargo hold station STA1790-STA2129; the fire point was at the right side of the main cargo hold station STA1916-STA2048 (the main cargo hold PR position), and that the most probable cause of the fire was spontaneous combustion of chlorine dioxide disinfectant tablets loaded in the main cargo hold in the high temperature and humidity, which triggered the fire. (Editorial note: I forgot to include the conclusion on Jun 5th 2023, discovered the missing cause on Mar 1st 2024 and finally added it.)