Scenarios
There was comprehensive testing of all the various chemistries and sizes in a series of simulated cargo fire scenarios using shipping cartons placed in a test Boeing 727 airframe – either through overheating or through directly heating the battery up to 190 degrees Celsius.
Test showed that smoke caused by the fire quickly engulfed the flight deck within eight or nine minutes of detection. In one test, after that test had finished with halon levels nearing zero and oxygen levels increasing, a single battery in thermal runway led to a flash fire, causing an explosion that ripped through the test airframe and blew the flight deck door off its hinges. Tests in the hold of a freighter aircraft showed that smoke started to pour into the flight deck within five minutes and became so severe that it soon became fully obscured by smoke.
ICAO flight operations chiefs already believe that on the basis of accepted safety review processes, the transport of lithium metal batteries on passenger aircraft poses an unacceptable risk because – even though the chances of one occurring are remote, the severity of an onboard fire would be catastrophic. They insist that because so little data exists on the size of global shipments of lithium batteries worldwide, the worst case scenario has to be assumed.
The working group will also have to decide next week whether to treat all aircraft – passenger and cargo – in the same way. While freighters do not have to carry any fire suppression mechanism under current rules, the aircraft manufacturing industry points out that modern aircraft are certified only to carry general cargo – and not the ‘unique hazards’ of carry dangerous goods such as lithium batteries.
Following the February testing, next week’s meeting will be asked to consider restrictions up to and including an outright ban on lithium metal battery cargo to be implemented as soon as possible. There may be the possibility of compromise position which would involve restrictions chiefly on carrying certain types of battery, restricting their quantity and improving packaging. Under existing rules, there are no limits to the number of packages containing dangerous goods that can be transported on any single aircraft.