PART III-HANDLING
H.P. cock should be closed and all unnecessary electrical
services switched off. (See para. 76).
(d) With reheat on. any form of compressor stall is unlikely
to occur but if it does the reheat will cancel automatically
and the throttle should be closed.
54. Management of the reheat system
(a) To operate the reheat, check that the shut-off switch is
at NORMAL and open the throttle to the reheat gate.
Cheek that the j.p.t. exceeds 600°C. at 7,900 ± 50 r.p.m.
and then push the throttle through the gate. The reheat
will light after about three seconds.
(b) When the reheat lights up momentary fluctuation of
r.p.m. occurs but should damp out quickly. If, when
reheat is on at high altitude, a fluctuation of r.p.m.
accompanied by a sympathetic thrust variation sets in, it
is due to malfunctioning of the reheat controller. If the
fluctuation becomes large (more than 100 r.p.m.) reheat
should he cancelled.
(c) Reheat light-up at heights above 25,000 feet is not 100%
certain.
(d) To cancel reheat pull the throttle out of the gate and
throttle back. However at lower altitudes it will be
necessary to pull the throttle out of the gate and then
operate the REHEAT SHUT-OFF switch in order to
prevent r.p.m. falling below 7,600. If the shut-off switch
has been used to cancel reheat it must afterwards be
returned to NORMAL, so that reheat will be available
when next required.
(e) The nozzle position indicator shows white only when the
nozzle eyelids are in the incorrect position for the running
condition selected. It shows white therefore momentarily,
whilst the eyelids are changing position when reheat is
selected or cancelled.
(f) Failure of the reheat system
(i) If the eyelids fail to open after light-up occurs,
pressure will build up in the jet pipe and will auto-
matically cut off the reheat fuel. Reheat should then 49
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