PART I-DESCRIPTIVE

     (d)  The use of flaps for airbraking is restricted to 35° to
          avoid slight directional snaking which might occur if
          larger flap angles were selected.

     (e)  A position indicator (23) is situated adjacent to the limit
          setting switch.


     28.  Flaps/airbrakes emergency operation

     (a)  If the live-line pressure fails, the flaps may be lowered,
          raised and re-lowered by the hydraulic pressure of the
          two main accumulators, after normal selection, providing
          no other hydraulically-operated system is used, e.g.
          powered controls.
          
     (b)  If no hydraulic pressure is available the flaps may be
          lowered fully down only, irrespective of the position of
          the limit switch, by pressing the emergency button (4)
          on the port shelf.

     29.  Wheel brakes control

     (a)  The maxaret wheel brakes are operated hydraulically by
          means of a lever (71) on the control column and a
          differential relay controlled by the rudder bar. When
          the brakes are applied, the maxaret units auto-
          matically prevent the wheels locking irrespective of the
          rate of deceleration and type of landing surface in use.
          For maximum braking the brakes should be applied
          fully and the maxaret units allowed to vary the pressure
          as necessary. Normally the maxaret units should not be
          allowed to operate (indicated by violent oscillation of
          the triple pressure gauge needles) as this leads to
          excessive brake wear.

     (b)  The available hydraulic pressure (3,150 ± 150 lb./sq. in.)
          is shown on the triple pressure gauge (24) together
          with the pressure at each wheel brake (1,750 lb./sq. in.
          max.).
          
     (c)  When the boost switch (39) on the instrument panel is
          placed up to ON the entire hydraulic pressure is made

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