PART I-DESCRIPTIVE

                 has failed, the wheels will lower under normal hydraulic
                 pressure.  If the hydraulic system has failed, the main
                 wheels will fall free and the nose gear is lowered by
                 means of a small accumulator.

	    (iii)Emergency raising
                 If it is necessary to collapse the undercarriage in an
                 emergency, the ground safety lock can be overridden by
                 setting the normal control handle to UP and pressing the
                 EMERG.-UP pushbutton (4) mounted above the
                 handle.
                 NOTE.-For servicing purposes, the ground crew may
                       operate the undercarriage emergency release
                       (129) to open the undercarriage doors.  The doors
                       will close again when the engine is started pro-
                       vided that the GROUND DOOR CONTROL
                       switch in the port mainwheel well is at CLOSE.
                       The nosewheel emergency selector must be reset
                       by opening a panel on the starboardside of the
                       nose, pulling the plunger fully down and then
                       returning it to the up position.

	    21.  Undercarriage position indicators                       
                       
	    (i)  Three indicators (55) are provided, one for each wheel,
                 on the left forward console.  The word UP appears in
                 each indicator if the wheel is locked up, a miniature
                 wheel shows when it is locked down, and parallel red
                 and yellow lines show if the wheel is unlocked or when
                 the electrical supply is switched off.
A.L.1                (ii)  The wheel portion of the undercarriage control handle (1) lights
Para. 21 (ii)               up when any wheel is unlocked or any of the undercarriage doors
  and (iii)                      are not closed with the wheels locked up.  It also shows if the
Para 20 	                 throttle is closed below minimum cruising r.p.m. with the under-
                                 carriage locked up.
                        |        The handle light can be checked by pressing the warning horn
                        |        cut-out button (54).
                        |  (iii) A warning horn is fitted and sounds if the undercarriage is not
                                 locked down when the throttle is closed beyond the minimum
                                 cruising position.  A horn cut-out switch button (54) above the
                                 undercarriage indicator is provided to silence the horn.  Opening
                                 the throttle resets the horn circuit.

  	       22.  Nosewheel steering

	             Hydraulic pressure is supplied to the nosewheel steering
	             unit through a solenoid valve operated by a pushbutton
	             (72) on the control column.  To engage the unit, the
	             switch is held depressed and the rudder pedals moved to
	             pick-up" the steering mechanism.  The nosewheel must

20