PART I-DESCRIPTIVE
on the port wall. A temperature indicator (19) on the
port shelf registers whenever the master switch is ON
and electrical power is available.
(b) When the master switch is ON, air is bled from the
engine compressor and fed to three entry points in the
cockpit. One at the extreme rear end of the port shelf
can be blanked off at will: the same feed line supplies air
to a small louvre (44) on the port side of the instrument
panel. The quantity of air entering the cockpit via this
louvre will depend on whether the inlet port is blanked
off or not. The third entry point is a larger louvre (78)
on the starboard wall, above the oxygen regulator.
(c) The cockpit pressure control valve limits the pressure
differential to 3½ lb./sq. in. at 27,000 ft. and above. If
the pressure differential falls below a predetermined
minimum, a warning light (53) on the instrument panel
comes on. Should the differential fall still further a
warning horn sounds. The horn may be silenced by the
operation of a guarded switch (76) on the starboard wall.
An altimeter (68) which shows the equivalent cockpit
altitude is on the starboard shelf.
(d) A manually operated vent (7) on the port wall
admits air at atmospheric pressure, and may be opened
when the pressurization system is OFF or to release
pressure in an emergency.
(e) The hood seal and the cartridge starter access door seal
are inflated by air direct from the engine compressor.
35. Hood and windscreen de-misting
(a) Hot air for de-misting the windscreen interspace is fed
direct from the engine compressor.
(b) Hot air supply to the windscreen and hood gallery pipes
is controlled by a DEMIST switch (12) on the port wall.
The air supplied is very hot at high power and low
altitude and in these circumstances should only be used
if mist has already formed. It should be used at high
altitude and, to reduce the possibility of mist forming.
it should be left on for the descent. 36 |