AL1 PART IV - EMERGENCY HANDLING
Page 88
back if necessary, that the maximum allowable temperature is
not exceeded. The likelihood of obtaining a successful relight is
increased if the height and airspeed are below the permitted
maxima for relighting.
(ii) If no relight occurs within 30 seconds proceed as follows:-
H.P. cock OFF
L.P. cock Leave on
All non-essential electrics (in-
cluding tailplane) Off
If below 35,000 ft. Relight at once
If above 35,000 ft. Switch off both booster pumps
descend to 35,000 ft. and carry
out relighting drill.
NOTE.-If above 35,000 ft. the decision to descend quickly or glide
at 210 knots will depend on the prevailing circumstances
e.g., weather conditions, distance to travel, etc. The following
should be borne in mind.
1. Relights are more easily obtained at lower altitudes.
2. At best gliding speed the aircraft covers approximately
2 miles per 1,000 ft.
3. With normal services running the batteries cannot be
relied on for very long. (See para. 90(b).) All non-essential
electrics must therefore be switched off to conserve
battery power.
4. Unless Mod. 502 is embodied Manual should be selected
before attempting to relight in case relighting is unsuccess-
ful and the batteries become exhausted.
5. Descending at a speed above 210 knots will increase
windmilling r.p.m. Consequently hydraulic pressure will
be higher and the generators may continue to supply
power. (See para. 90 (d), NOTE 2.)
6. If a glide is to be made at 210 knots the tailplane should
be set to ½° nose-up.
93. Relighting
(a) Check and/or set:-
Maximum altitude 35,000 ft.
Maximum airspeed 0.80M
All non-essential electrics Off (see para.90)
Throttle H.P. cock OFF
Battery master switch ON
Ignition switch ON
Starter master switch ON
Booster-pumps ON
(b) Set the relight switch on for 2 seconds, then set the throttle lever to
the H.P. cock open position. When the r.p.m. rise to idling, increase
power carefully.
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