PART III - HANDLING
tanks, resulting in a slow decrease of the reading of the
fuel contents gauge. When the fuel flow has been
reduced to less than 4,000 lb./hr. the level of the internal
tanks will be slowly restored. By the time the drop tanks
are empty, the readings of the contents gauge and the
totalizer will be about equal and will decrease together
thereafter, both showing approximately the same
reading.
(v) The contents gauge must always be regarded as the
master instrument in so far as fuel contents is concerned,
the totalizer being used only for checking.
50. Engine handling
(i) Whenever the throttle is opened, the initial movement
must be slow until the engine is definitely accelerating.
Thereafter the throttle may be opened rapidly at any
altitude up to 40,000 feet. Above this height all throttle
movements must be made with care to avoid the pos-
sibility of a compressor stall and possible flame
extinction.
(ii) While the engine is running on the main fuel system
the emergency system should be switched OFF, other-
wise if the throttle ia opened rapidly, the emergency
system will override the normal system causing a com-
pressor stall or flame extinction.
(iii)Rapid acceleration to full power immediately after
starting a cold engine will usually result in excessive
j.p.t.
(iv) Compressor stall is recognised by a pulsating roaring
noise accompanied by heavy vibration coupled with little
or no increase in r.p.m. and a rapid rise in j.p.t. The
throttle must be closed until these conditions disappear
and a slower acceleration attempted.
(v) Engine noise and roughness may occur in flight especially
when at high power above 15,000 feet; this can usually
be overcome by changing the r.p.m. If the roughness
continues irrespective of height and r.p.m., a mechanical
failure is the probable cause and a landing should be
made.
51. Engine starting
NOTE.-Extreme care must be taken when moving the
throttle while starting, until idling r.p.m. are
obtained. Small movements result in large
changes in fuel flow and excessive temperatures
may easily result. It is recommended that until
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