Given that water that flashes to steam can really expand, was a water,
water-glycol or water-alcohol mix ever considered for an afterburner?
Heat up the nozzles in the jet exhaust pipe, and then inject water/
glycol as needed? Instead of fuel, good old water gets used. Steam
trail should be huge, but otherwise it may be doable, though the
pressures generated would be pretty huge.
You note the issue of pressures to contain the steam, but there's also
the question of sustaining the temperature in the tailpipe. Injecting
water into jet exhaust would have a significant cooling effect and
that would degrade your steam generation pretty quickly.
Water injection was employed to increase the mass of effluent. We had
afterburner water injection on the J-75 engine of the F-105. A 38
gallon tank of water was mounted above the A/B section and after
burner ignition on take-off roll, the water would provide an extra
2000 pounds of thrust, which is less than 10% of total engine thrust.
The water tank was not stressed for manueving flight and any water not
expended on takeoff was jettisoned.
The KC-135 had water injection to the basic engine.
Fighter Pilot (USAF-Ret)
And of course the inevitable happened one day at Holloman AFB, when
someone filled a Thud's water tank with JP-4. Story goes that when
the pilot selected AB on takeoff, the tail of the jet exploded.
That has to be a wives tail. Unless they backed a fuel truck up
to the plane and everyone was completely stupid that day, I don't
see how that could happen.
That's the way I read it as well. All modern jets use single point
refueling in which a high pressure nozzle is attached to a terminal
point and then all tanks are filled simultaneously. There is no hose
stuck into a wing with a gas cap.
The water tank was clearly placarded as well as being a reservoir for
demineralized water only. You didn't simply drag the garden hose over.
Water was not routinely used for peacetime operations either. It was
strictly a combat load option. A refueling, gas & go at Holloman
wouldn't have serviced water under most situations.
Since the normal operation of AB is dumping hundreds of pounds per
minute of JP4 into the tail pipe, it really wouldn' make any
difference if you dumped an extra couple of gallons in from the water
I'm betting this is one of those "I bet it must have happened..."
On the KC-135A it was standard as well as the early B-52. A fully
loaded A model 135 took every inch of the runway with water
The caption is:58-0043 (cn 17788) Of the 133rd ARS/New Hamspshire
ANG, based at Pease AFB. Seen on hold at runway 29 while a dirty
'A' model KC-135 gets aloft covering the airfield in smoke. Last
noted in storage at 309th AMARG.
The Buff was downright impressive when it had the J-57 engines.
You would think it was dumping a lot of fuel smoke when it was
really the water injection making all that smoke.
Both AC used Water Injection pretty much all the time for takeoff
to get it's 13,000 lb thrust per engine.
I can see how someone used to the 'progressive' afterburners
of later jets might think that (any) F-105 had exploded, if
they heard it, rather than saw it.
F-105 AB starts with an explosion, every time - and is near
Maybe it was gasoline? Or one could inject it under circumstances that
were unusual where it was confined.
Or, the flame followed the fuel up into the tank, something unlikely
Anyway, due to the mixup on the similar trailers, JP-4 was loaded
instead of water.
Result: Boom on takeoff.
Safety aspect was of course to make sure the tanks for water and the
tanks for JP-4 were easily distinguishable, not painted the same
> Anyway, due to the mixup on the similar trailers, JP-4 was loaded
> instead of water.
> Result: Boom on takeoff.
> Safety aspect was of course to make sure the tanks for water and the
> tanks for JP-4 were easily distinguishable, not painted the same
I have nothing to add except a side view. I strongly doubt that both
water and JP-4 hoses had the same fittings/valves/etc. There's a good
design practice (born in the USA AFAIK) that any junction should be made
such that wrong mating would be impossible. My side view looks like
OK, you've introduced the safety bulletin aspect which indicated that
the incident happened. While the tank possibly could have been
serviced with the surplus fuel bowser which would be an over-the-wing
style nozzle, how do we get an explosion when you dump some JP-4 (a
relatively small amount) into an A/B can which already contains a
hydrant like flow of JP-4 from the A/B fuel control?
Typical operations did not use water injection. It was strictly for
max gross combat load-outs. The water system was inter-locked in
several ways to safeguard the unstressed water tank which wouldn't
tolerate flight g-loads when loaded. The main interlock was to the
cockpit pressurization system. Normal check list procedure for before
takeoff was to close the canopy, check the roller over the hooks for
security, then move the RAM/Dump/Pressurization control to A/C and
pressurize. When that was done any water (or fuel) would be dumped
automatically on the ramp. It resembled a cow on a flat rock and
happened occasionally with new guys making their first water T/O at
If the intent was a water T/O, then a large toggle switch was
activated ONLY after brake release, throttle outboard, positive burner
light (unmistakeable!). Without a burner light, water would not be
After burner out, the toggle switch was moved to the "dump" position
and cockpit pressurization was chosen.
In other words, normal ops stateside, particularly from a transient
base, would not have used water. If this were a deployed exercise with
heavyweight takeoffs required, there would have been regular F-105
I'm still saying it is a very improbable, if not impossible,
Heh. Never underestimate the ability of a motivated fool!
Never try to win an emotional argument with facts.
I agree with you on that one. But, careful, you are sounding too
close to the "Mythbusters" :)