1996 Valujet incident

A shipper sending used Oxygen Generators UN3356 for Valujet caused the aircraft to crash. The FAA and NTSB after investigating found that neither the shipper nor carrier was properly trained. The box actually contained new Oxygen Generators UN3356 not used ones. They had been improperly packaged and secured and one of the generators discharged in-flight. The cargo compartment was not pressurized and a fire should not have been able to burn, due to the lack of oxygen.

Since the shipment contained Oxygen Generators the fire was self sustaining. Once one discharged the fire feed off the reaction and the temperature rose rapidly. As the fire increased the result was more Oxygen Generators discharging. At this point the fire was hot enough to melt the aircraft itself. All this took was approximately 10 minutes.

NTSB Report
The National Transportation Safety Board determines the probable cause(s) of this accident as follows: which resulted from a fire in the airplane's class D cargo compartment that was initiated by the actuation of one or more oxygen generators being improperly carried as cargo, were

  1. the failure of SabreTech to properly prepare, package, and identify unexpended chemical oxygen generators before presenting them to ValuJet for carriage;
  2. the failure of ValuJet to properly oversee its contract maintenance program to ensure compliance with maintenance, maintenance training, and hazardous materials requirements and practices; and
  3. the failure of the Federal Aviation Administration (FAA) to require smoke detection and fire suppression systems in class D cargo compartments.

Contributing to the accident was the failure of the FAA to adequately monitor ValuJet's heavy maintenance programs and responsibilities, including ValuJet's oversight of its contractors, and SabreTech's repair station certificate; the failure of the FAA to adequately respond to prior chemical oxygen generator fires with programs to address the potential hazards; and ValuJet's failure to ensure that both ValuJet and contract maintenance facility employees were aware of the carrier's 'no-carry' hazardous materials policy and had received appropriate hazardous materials training. (NTSB Report AAR-97/06)