I'm astonished and uplifted by the astonishing amount of interest aroused by this potentially 'damp' topic. Since my original enquiry - a kind, erstwhile colleague has lent me his Trident manuals which; up until then, had been an integral part of his loft insulation.
Reading the manuals without the impending threat of a sim-check was 'quite' interesting. However they did not cover the whole story, or answer all my questions. That surprised me as I had always believed the gaps in my knowledge to be self inflicted.
Nevertheless here are the snippets of information, and for the truly anal; references of where they can be found.
- Taxying checks item 15) Water injection master switch ... off (Ops manual Vol 1 Drills 2)
- Weights MTOW ...65,320 Kg. MTOW injection water added...65,770 Kg i.e. 450 KG increase. (Ops Vol 1 Flight Management - Handling Limitations (a).
- FAILURE OF UNUSED INJECTION WATER TO DRAIN. Symptom: Contents gauge not reading empty. Action: .1) Injection Water Master Switch....Drain. 2) If remaining water does not drain, reselect master switch to prime and open any throttle to TO posn switch for a short time. 3) f remaining water does not drain, revise flight plan and keep below freezing level. This seems to confirm that the H2O was demineralised water not water meth. (Ops F.M. Fuel 3&4)
- All further references are from (Ops Technical)
- (Fuel 10 & 14) Servicing points....Water injection filling point (pressure connection) adjacent to rear equipment bay door. Provides for pressure filling the injection water system at a rate of 50 gal/min. The capacity of the tank is 145 imp. gallons.
- Ditto : Injection water drain valve test button...... Provides a test on the ground that the pump and drain valve are not frozen. When pressed the drain valve should open and a full flow of water should drain from the outlet.
- (Engines 7) SPEY 512 TO perf. sea level dry......12,600 lb thrust until 23 degrees C. My copy of a R.R. book: "The Jet Engine" promises an extra 7 degrees of max thrust if water is used and this is the real benefit of water injection (if it works).
- Lastly, (Loading 1) The TO weight can only exceed 65,320 Kg if the excess is in the form of injection water. The max quantity of injection water is 145 imp. gallons (658 Kg).
I hope that will either be of interest or help you travel to the land of nod.
Anyways it will help my quest for accuracy and authenticity in the book. So be warned your aircraft VC 10; Vanguard; Viscount; Comet; Concorde; Britannia; may be next.
Happy landings!