Jet fuel question

From:         stedder@tulsix.utulsa.edu (Stephen Tedder)
Organization: UTexas Mail-to-News Gateway
Date:         13 Jun 94 19:31:48 
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1. Yes, the octane number of jet fuel is much lower than that of gasoline.
Octane number is not particularly meaningful in the operation of turbine
engines, however. 
2. Does jet fuel have to meet environmental standards? Not my department.
I am not aware of any emissions requirements on aircraft themselves.
I can tell you that jet engine test cells, like all stationary sources
of pollution, require environmental permits. Jet aircraft are much
more efficient than automobiles and therefore burn much less fuel,
per passenger-mile. 
3. Is there lead in jet fuel? No. Lead compounds were added to gasoline
to reduce the knocking tendency of the fuel. Jet engines have no
tendency to knock and do not require any anti-knock additives.
4. Emissions related to automobiles? Well, think it over. There are only
a few thousand airliners operating in the US. My company, American Airlines,
has one of the biggest fleets at 656 in May, and there are only three
or so others that come close. Military aircraft fly only a small fraction
of the hours that airliners do. But there are millions of cars, in fact,
millions are sold every year! And aircraft are much more efficient than
cars. So order-of-magnitude, anyway, a good guess would be that cars
contribute a much bigger burden of pollutants than airplanes.

As a point of interest, Jet-A, the typical airliner fuel, is similar
to kerosene or diesel fuel. It is much less volatile than gasoline.
Interestingly, a GE CF6-6 engine can, in an emergency, be operated
on gasoline. (Don't try this at home, we're trained professionals!)
But don't ever try to run a gasoline engine on jet fuel!!
-- 
Steve Tedder stedder@tulsix.utulsa.edu
	     918 292-3301