Issued with A.L.1
                            PART 1 - DESCRIPTIVE

                 same stick movement aileron travel in Manual is approxi-
                 mately two-thirds of that obtained in Power.
          
          (b)    This automatic changeover is provided for by the insertion
                 of a hydraulic jack in the aileron control linkage.  When
                 hydraulic pressure is fed to the jack (via the aileron
                 Power selector cock) the jack extends to alter the linkage
                 effective arm.  When hydraulic pressure is lacking the jack
                 retracts under spring pressure.

          25.  Engaging power controls on the ground
          
          (a)    Pre-mod. 452
                 
                 When hydraulic power and electrical power are available the
                 power selector switches should be switched ON and the
                 control column moved to engage the power controls
                 locking pawls.  If, as is likely the locking pawls are not
                 opposite their slots, they clamp on the side of the piston
                 rods; considerable force is then required to slide the
                 piston rods and engage the pawls in the slots.  When all
                 pawls are correctly engaged the control column can be
                 moved freely over its full travel in all directions, and is
                 felt to come up against positive stops at the extreme end of its
                 movement.  The indicators (43) will then show black.
                 
          (b)    Post-mod. 452
                 
                 To engage Power hold the appropriate switch to POWER
                 with the left hand and move the stick with the right hand,
                 laterally when engaging aileron and fore-and-aft when
                 engaging elevator, until the corresponding magnetic indi-
                 cator goes black.  The switch an then be released.  To
                 engage aileron power more easily it is advisable to
                 either:-                
                 
                 (i)   Select POWER with the stick held hard over to star-
                       board and then move it to port, or 
                       
                 (ii)  Attempt engagement immediately after light up be-
                       fore hydraulic pressure builds up

28B