PART I-DESCRIPTIVE

          oxygen, an air inlet NORMAL-100% OXYGEN switch,
          an emergency three-position switch and a combined flow
          and blinker unit.

     (c)  When the ON/OFF valve is on and the inlet switch is at
          NORMAL, an air/oxygen mixture is fed to the pilot's
          mask, up to a height at which 100% oxygen is auto-
          matically delivered. When the inlet switch is at 100%
          OXYGEN no air is added irrespective of the height.
A.L.3/57  This position should normally be selected if any symptoms of
          anoxia are present. The emergency switch when moved
          to either right or left admits oxygen under greater
          pressure. Normally it should be central, but in the event
          of loss of cabin pressure should be offset.

     (d)  The mask may be tested before flight by firmly pressing
          in the EMERGENCY switch, when in the central posi-
          tion. Oxygen is then supplied under pressure, the firmer
          the switch is pressed the greater the pressure (up to 5
          times that obtained with the switch in either side posi-
          tion). The mask can then be adjusted until no leaks are
          apparent.
          
     (e)  Emergency system

          A manual control (94) on the starboard shelf operates
          the emergency oxygen bottle in the seat well, providing
          the safety pin on the bottle is withdrawn.

     40.  Internal lighting
     
     (a)  Cockpit lamps

          The lamps are controlled by five on-off dimmer switches
          (80) (87) on the starboard wall.

     (b)  Emergency. lamp

          The emergency lamp, powered by a separate battery, is
          controlled by an on/off switch (77) on the switch panel
          on the starboard wall.

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