PART I - DESCRIPTIVE
(b) In manual
(i) Manual operation of the controls may be selected
deliberately by operating a switch in the cockpit
(see para. 21) provided that electrical power is
available, or will happen automatically if hydraulic
pressure drops below 200 lb./sq. in.
(ii) When operating in manual, control surface move-
ments are achieved through a mechanical linkage.
The spring-loaded hydraulically-operated pawls
automatically disengage and release the anchored
jack piston rods, allowing them and the jack bodies
to move freely with the control surfaces. The con-
trols are heavy in Manual except the ailerons.
(c) Hydraulic power reserve
Accumulators are fitted in the power control circuits
to provide a reserve of power if the main hydraulic supply
fails. This reserve may be sufficient for a maximum of
3½ complete cycles of aileron and elevator operation