Originally Posted by Zoom
Didn't KC-135s and B-52s with turbojets rather than turbofans use it as well? Otherwise even the earth's curvature wouldn't have got those beasts airborne.
The KC-135A with the J-57s did indeed use water when the temps were above 40F if I remember correctly. We carried 5600lbs of distilled water that you used in 120 seconds. It was timed by the nav on takeoff with a call when nearing water exhaustion to make sure you got the nose down.
When I first got into tankers the system was set up with LEFT and RIGHT water injection. Finally some wizard realized that with a little different plumbing, you would NOT have assymetric thrust if one of the pumps failed and they went to an INB and OUTB system. (well, DUH!) The injection pumps had a very high electrical load and at times you could not get the engines to 'take water' so various methods were used including running the engines up to about 2.00 EPR and then turning the water pumps on (helluva shock on the engines). 'wet' EPR for takeoff was 2.85.
A 'wet' takeoff was standard out of Thailand when carrying 165,000lbs of fuel for the fighters going north. Takeoff gross around 280 when added water and Vr speed around 170kts.