To expand on Art Field's post #32. The Vaiant used water meth for take off only.
When initiated it increased the RPM by 300 from 8,000 to 8,300 with a constant JPT adding an extra 1,000 lbs. thrust to each engine..
The water meth tank was in the rear of the fuselage, held 1410 lbs. of W/M and lasted for one minute.
Precisely at the time the mainwheels left the runway at Nairobi International.