Here’s what Lt. Col. Doug Soifer had to say: “On our very first TDY to Mildenhall,
Mike Smith (the pilot) and I were lucky enough to be there for Air Fete—the big annual
air show at Mildenhall.
We got to fly the first day and thought we did a good job.
During the 20 minute sortie we had a real hard kick during one pass when we went to
afterburner and pulled up tight.”
He continued: “We didn’t think much about it until we landed and were overwhelmed by
people as we stepped off the jet and asked us what we did.
We had no idea what they were talking about until someone brought over his camcorder and
showed us the tape.”
Then he began to describe the thirteen fireballs that came out of the aircraft’s exhaust.
“It looked beautiful, and people wanted to know if it could be done again,” he said.
“They used the picture of us with the flames coming out for the next year’s Air Fete
poster.
Mike and I became known as the ‘Fireball Twins.’
The maintenance people figured it was the TEB (triethylborane) shooting out of its container
and igniting the JP-7.
With that start, we had an exciting six weeks in England.”
The SR-71 burned JP-7 fuel, one-of-a-kind fuel that is three times as expensive as the
type used in airliners.
In order to meet the specs of the aircraft, fuel-maker Shell Oil invented a compound blend
of kerosene distillates—hundreds of hydrocarbons with all but 5 percent of the aromatics removed
in processing.
Low aromatics point to the fact that it is a “clean” mixture, with low levels of
impurities like sulfur, nitrogen, and oxygen.
This JP-7 fuel allows for “high thermal oxidative stability”—or it is considered
to be more predictable in extreme temperatures.
“To ignite the JP-7 for engine start, and to light the afterburner section, a liquid
chemical ignition system was used.
The liquid chemical, triethylborane, had the physical property of exploding when exposed
to air,” according to the Aviation Geek Club.
“During engine start, rising fuel pressure in the fuel control signaled the ignition
system that a metered amount of TEB could be injected into the engine combustion section,
after the pilot moved the throttle from cut-off to the idle position.
Preceded slightly by fuel, the TEB exploded and ignited the JP-7.”
