Fuel Flammability
The NTSB's theory is that some unknown spark ignited the Jet A fuel vapors inside Flight 800's center fuel tank. This theory depends on 2 things: a) sufficient fuel vapors at the proper fuel/air mixture; and b) a sufficient spark to ignite the fuel vapors. Neither condition has been found to have been present in subsequent tests. In Boeing's recent filing with the NTSB they have stated that they have not found any source of spark in Flight 800. The NTSB would have you believe that Jet A fuel vapors are a virtual bomb waiting to go off, yet every day hundreds of 747's are sitting on hot runways in places like Saudi Arabia, India, etc. with empty center tanks and none have ever exploded. Every day aircraft with empty fuel tanks are hit by lightning, a spark thousands of times greater than necessary to ignite this vapor, yet these aircraft do not explode. Why, because the fuel vapor is not explosive. See lightning strike an aircraft. Still image.Jet A Fuel Demo - Cmdr. Donaldson demonstrates properties of Jet A fuel (this 4 minute film is in RealPlayer format and is 937kb. -3-21-00 This demo was originally produced for a talk Cmdr Donaldson gave in 1998 and was designed for a live presentation and therefore has no introduction. Cmdr Donaldson obtained a quantity of Jet A fuel from Kennedy airport and conducted several tests showing the properties of the fuel. In this test he inserts a lighted match into an open container of Jet A fuel and the fuel puts out the match because it needs to be heated to 127 degrees to ignite. However, when misted into the atmosphere, the fuel will burn quickly and even explode because it has the proper fuel/air mixture. This mixture does not exist in a 747 tank that has not been violently shaken by some outside force. Click here to download RealPlayer. Download File.
Jet A Fuel Experiment - RealPlayer Format 8 min. (2.0 mb) -3-25-00 In this experiment Cmdr. Donaldson uses a crab steamer to heat Jet A fuel beyond the fuel's boiling point. The experiment shows that the vapor does not become explosive until 185 degrees and even then it is not enough for a violent explosion. This closed container test uses a 5 gallon container placed on top of a propane burner. The container has a temperature probe inserted in the bottom of the tank to measure the internal fuel temperature. The ignition source uses a light bulb element to create an extreme spark. Click here to download RealPlayer. Download file.
The experiment starts with the fuel heated to 140 degrees which is the highest temperature that the NTSB estimated that the fuel could have reached at 14,000 ft. While the fuel is theoretically flammable at 127 degrees at sea level, you will see that there is no combustion until the fuel reaches 185 degrees. Then there is only a slow burn, approximately 3 seconds, in which the vapor is consumed and the fire goes out. The final test is with Jet A fuel and Propane, similar to the Cal Tech tank explosion video. You can see that the introduction of Propane adds significantly to the volatility and is not even remotely representative of the Jet A Fuel's true combustibility.
This experiment was originally filmed for a segment of the Discovery Channel which never aired. It has since been recreated using a home video camera. While the quality is not very good, I believe the point is well demonstrated.
EPA
- Fuel Tank Ignition Prevention Measures - 4-3-97 
