PART 1 - DESCRIPTIVE

          36.   Hood jettisoning
          
          (a)   The hood is jettisoned by gas pressure from a jettison
                gun acting on two pistons which release the hood rails
                and then push the hood upwards.  This is initiated by
                pulling the handle (34) on the port shelf.  This action also
                operates a micro-switch which, if electrical power is
                available, automatically lowers the gunsight.
                
          (b)   An external emergency release ring is inside a break
                panel on the port side of the fuselage below the cockpit.
                When the release ring is pulled the jettison gun is not
                fired but the hood rails are released.  The hood may then
                be lifted clear manually.

          (c)   The hood is also jettisoned automatically whenever either
                the ejection seat blind handle or the seat-pan alternative
                firing handle is pulled (see para. 40(a)(iv)).  In this case
                the G.G.S. is not automatically lowered 
 
          35.   Cockpit pressurization, heating and demisting

                NOTE.-The system is inoperative whenever the hood is
                      open.
          (a)   Hot air under pressure is bled from the engine compressor
                to supply the heating, pressurization and demisting
                system.  The air supply to the cockpit terminates in spray
                pipes which provide for windscreen, side panels and hood
                demisting.
          
          (b)  The master ON/OFF switch (3) controls the flow to the
               cockpit.  The temperature control lever (2) permits the
               selection of AUTO or manual HOTTER-COLDER.  The
               TEMP. SELECTOR (1) is for use in AUTO to preselect
               the desired temperature, which is then maintained by a
               thermostat.  In the manual range, temperature is con-
               trolled by first setting the lever to HOTTER or COLDER
               and then, when the desired temperature is reached
               engaging the lever in the central gate.

          (c)  The cockpit altimeter (74) should indicate in accordance
               with the following table.  Should the cockpit pressure
               differential drop by more then ½ lb./sq.in a red light
               (73) on the right of the instrument panel comes on.

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