Re: Old 707's

Date:         26 Dec 97 03:28:49 
From:         tyler@plk.af.mil (David Tyler)
Organization: Air Force Phillips Lab.
References:   1 2 3 4 5 6
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hackettNO*SPAM@southwind.net (Kim Hackett) writes:

>>My father used to talk about "water wagons" -- early 707s which used
>>water injection for additional takeoff thrust.  Despite keeping my ears
>>open for any tibits about these beasts, I've heard nothing about them.
>>
>>Were they real?  Can anyone provide details about them?

>The early 707s, the KC-135A with J57 engines, and the B-52G use water
>injection for additional takeoff thrust.  The B-52G has a water tank in
>the fuselage forward of the wing.  The water injection lasts about 45
>seconds.  Not all takeoffs use water injection.  On takeoffs with water
>injection, all of the water must be used, otherwise it would freeze at
>altitude.  I think the water capacity on the B-52G is about 3000 lb, if
>I remember correctly.

an interesting bit of apocrypha that used to circulate amongst tanker
drivers was that the original configuration for the -135 water injection
was one pump for the left engines and one pump for the right...  after
someone realized just how dicey it was during a max togw takeoff when
one pump suddenly failed, the configuration was changed to one pump for
the inboards and one for the outboards...  :)

we AWACS crews used to watch with raised eyebrows as water-wagon tankers
would take off in the middle a hot afternoon in riyadh, carrying nearly
a full load to the orbiting E-3.  they'd put out a furious amount of smoke
and noise, and roll, and roll, and roll...  finally, out where we were
sure the runway must be running out, they'd waddle into the air.  whew.

dave
______________________________________________________________________
-David W. Tyler               "It seems you feel our work is not
-USAF Phillips Laboratory         of benefit to the public."
-Albuquerque, New Mexico
-tyler@plk.af.mil                         --Rachel