Unlike hydrogen gasoline will ignite over a relatively narrow
 range of mixtures. 10:1 to about 18:1. The tank environment is
 always too rich to ignite the mixture.

 Paul Lamar

 Brings to mind the TWA 747 loss a number of years ago where government
 investigators concluded shorting wires in empty tank ignited jet fuel
 vapors
 causing explosion. I was skeptical from the start. Seems to me all 747
 aircraft that vintage would have been grounded immediately for inspection.


 Al K

 My wife Robin worked for TWA in those days as a mechanic. All 747's were
 inspected
 for loose or bare wires. Robin, due to her small size, spent many hours
 crawling
 around in fuel tanks. A nasty job. Nothing was found. It was common
 practice to take
 off with empty center tank if you did not need it. This reduced the
 stress on
 the wing spar. That meant thousands of successful
 747 take offs were made with empty center tanks. They also did their
 damnedest to
 ignite the mostly empty center tank on an old 747 with out success.

 IMHO it was shot down in error by the Navy and covered up by the Clinton
 administration.
 Think of the political fall out if they admitted shooting it down in error.

 Heck cars would be blowing up all over the place. Fuel flows through
 the pump past the armature and past the brushes.

 What they do with a fuel air bomb is first blow up the tank to distribute
 the fuel in the air to roughly the proper mixture and then ignite the
 mixture
 with a flare. Then you get the really big bang. Forget the movies of
 cars and
 gasoline tank trucks blowing up.

 A can of gas will put out a match but don't ask me to demonstrate :)
 Do it with a robot.

Paul Lamar


    NOT a Match, but a cigarette, Virg
    

I've seen it done without igniting the fumes (cigarette).
Harold Lunt