Aviation of WWII
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Pilot`s Notes Wellington Pilot`s Notes



January 1944.


13. Flying controls.—These are of the conventional type. The rudder bar is adjustable for reach by means of a star-wheel (35) at the rear of its mounting. This can be rotated in flight by the feet, clockwise rotation shortening the reach. Dual controls, coupled to the main controls, can be mounted on a special floor extension forward of the starhoard seat.

14. Trimming tabs.—The elevator and rudder trimming tabs are operated by a single control (59) which works in the natural sense. There is a fine adjustment control (60) for the elevator tabs to the left of this control. The aileron trimming tab (port only) control is a rotatable handle (65) with a lock-release grip, immediately outboard of the elevator and rudder trimming tab control, and works in the opposite way to the natural, i.e. turning clockwise raises the starboard wing.

15. Interconnection of elevator trimming tabs and flaps.— When the flaps arc fully lowered they cause the aircraft to become "tail-heavy"; the flaps are, therefore, interconnected with the elevator tabs so that lowering of the flaps automatically raises the elevator tabs and counteracts the "tail-heaviness".

It is essential that the elevator trimming tab control should not be forward of the central position before the flaps are lowered, or damage to the tab control mechanism may result. On most aircraft a spring catch is fitted which allows the pilot to feel the central position on moving the control.

16. Undercarriage control.—Raising and lowering of the undercarriage and tailwhee! is controlled by a lever (31) in the centre of the instrument panel which has automatic safety catches locking it in the UP or DOWN positions. These catches must be freed by the catch release before the lever can he operated, Each main wheel unit u provided with mechanical up and down locks which automatically lock the unit in the UP or DOWN position as soon as it is fully retracted or lowered. The locks are automatically released by hydraulic power immediately the undercarriage selector lever is moved to the UP or DOWN position. Correct operation of the locks is indicated by the normal undercarriage indicator, with the electrical circuit of which they arc interconnected.

17. Undercarriage indicator.—On Mk. III aircraft the indicator (u) shows as follows:

All units locked DOWN ... Three green lights

All units unlocked ....... No lights

All units locked UP......... Three red lights

but on the later Marks the indicator shows as follows:

All units locked DOWN ... Three green lights

All units unlocked .... Three red lights

All units locked UP ... No lights

The indicator switch (49) is interlocked so that it must be on when the ignition switches are on. The indicator DOWN lights are duplicated (on Mk. III aircraft the red lights are also duplicated, but not the tailwhccl light), and in the event of failure of a lamp the duplicate set can be brought into circuit by pulling out (or pushing in) a knob in the centre of the dial case. In addition, counterclockwise rotation of this knob operates a dimmer screen.

18. Undercarriage warning horn and light.—An electric horn behind the pilot's scat sounds and a red light beside the undercarriage indicator lights up if both throttles are closed and the undercarriage is not locked down. The horn can be tested by pressing the test pushbutton (8) with the indicator switch closed. The light goes out when the horn stops. The light is not fitted on Mk. III aircraft.

19. Flap control.—The flap control lever (29) is retained in its neutral position by a spring-loaded catch which is released for operation by depressing the knob. The flaps are interconnected with the elevator tab control (tee para. 15). The flap indicator (36) is switched on by the undercarriage indicator switch.

20. Wheel brakes.—Twin operating levers (40) for the pneumatic wheel brakes are provided on the control column handwheel; they are compressed cither singly or simultaneously to apply both brakes. The brakes can be applied in the fully locked position for parking by engaging the locking slide (41). The system provides for differential braking by virtue of rudder bar movement when taxying. A triple pressure gauge (18). showing the main supply pressure and the pressure at each brake, is fitted on the right of the instrument panel.

21. Flying control locking gear.—The flying controls can be locked in their neutral position by means of a triangular spring-loaded frame, hinged beneath the window ledge on the port side of the cockpit, and a detachable hinged nuisance bar. When not in use, the former is secured by a strap and pin to the side of the cockpit, and the latter is stowed on the starboard side of the cahin gangway.


22. Throttle and mixture controls.—The two throttle levers (46) are interconnected with the corresponding mixture control levers (53) so that if the throttle is moved out of the weak mixture cruising range, the mixture lever will, if in the WEAK position, return to the rich (NORMAL) position. On Hercules XVI and XVII installations there are no pilot's mixture control levers, control being fully automatic. An economical mixture strength is obtained by keeping at or below +2 lb./sq.in. boost. Pending the introduction of a warning light to indicate the economical cruising boost position of the throttle levers, a white line is painted on the quadrant and the levers. On certain modified engines a position midway between the climbing and economical cruising boost settings gives better economy on the climb after the boost has fallen to + 4 Ib./sq.in., and this position will be indicated by a second white line. A friction lever (47) is provided for clamping the throttles in any position to prevent movement due to vibration.

23. Propeller controls

(i) The speed control levers (56), common to all three types of propeller, arc at the rear of the engine control quadrant and arc moved forward to increase r.p.m. The feathering pushbuttons (6 and 15) for the hydraulic types are on the instrument panel.

(ii) The controls for the electric propellers (if fitted) are on the instrument panel and arc as follows:

(a) Safety switches.—These should always be ON in flight as they control the supply to the propeller pitch mechanism and feathering circuits. If an excessive load is applied during any operation, the safety switch is automatically thrown to OFF. If this happens the switch should be reset to ON at the end of about half-a-minute.

(b) Selector switches.—Each switch can be moved to three different positions other than the central one, in which the propeller operates in fixed pitch. The two lower positions are for manual INCreasc and DECrease of the r.p.m. respectively, and when the switch is moved to either of these positions it must be held there until the desired r.p.m. are attained; on being released it will return to the central position. In the upper (AUTO) position, the propeller operates under constant speed control.

(c) Feathering switches.—These are moved upward for rapid feathering and will function whatever the position of the propeller selector switches. Feathering can be effected slowly, but using substantially less current, by holding the corresponding selector switch down to the left in the DECrcase r.p.m. position.In either case, when the propeller is fully feathered the selector switch should be set to central.

24. Supercharger control— The control (54) aft of the throttle levers may be locked in either the MEDIUM (M ratio) or FULL (S ratio) positions by a spring catch which is released by depressing the lever. On Mk. XI, XII, XIII and XIV aircraft the control is locked in M ratio.

25. Carburettor air intake control.— The lever (55) at the side of the supercharger control may be locked in cither the COLD or WARM positions by a spring-catch which is disengaged by depressing the lever. The shutters arc hydraulically operated.

26. Cowling gill controls.—The gills arc opened and closed by handles (37) which are turned anti-clockwise to open.

27. Oil cooler shutters (Mk. III aircraft only).—The oil cooler shutters arc operated by "Exactor" hydraulic controls to the right of the pilot's seat.

28. Slow-running cut-outs.—The controls (57), which are spring-loaded handles, arc aft of the engine control box and each must be pulled and held out to stop the corresponding engine after the throttle is closed and before switching off the ignition.

29. Pruning pumps.—An induction system priming pump, for use when starting, is mounted in each engine nacelle. A three-way priming cock inside each undercarriage wheel housing allows for priming with high volatility fuel from an outside source.

30. Engine-starter and booster-coil pushbuttons.—These (5 and 17) arc on the centre instrument panel.

31. Boost gauge reversal control. - If one of the boost gauges fails, the boost gauge of the other engine can be used in its stead by pulling out the boost gauge reversal control (28).


32. Bomb doors.—The bomb doors are operated by a handle (43) which can be moved to the OPEN or CLOSED position, after releasing the lock, by depressing the spring-loaded thumb-knob. The handle is coupled with the bomb release master switch (45) so as to prevent the release of bombs until the control is in the OPEN position.

33- Bomb/deptn-cnarge release control.— The pilot can release the bombs or depth-charges by means of the pushbutton (42), provided that they have been selected by the bomb aimer and the master switch is on. (For jettisoning of bombs and depth-charges see para. 67.)

34. Torpedo release controls (Mk XI and XIII aircraft only). Two pushbuttons (39), for port and starboard torpedoes, are provided on the control column handgrip. Each is covered by a safety shield.

35. Heating controls. -Exhaust-heated air is supplied from both engines via ducts, from which branch pipes supply the various crew stations. The main supply is controlled by a push-pull rod at the wing spar extensions on each side of the fuselage. The pilot's supply is controlled locally by a knob (83) on the diffuser (58) below and slightly forward of his seat.

36. Landing lamps.—Two retractable landing lamps in the port wing are raised and .lowered by an "Exactor" hydraulic control lever (66) which can be locked in any desired position by a spring-loaded catch which is released at the top of the lever. Either lamp can be lighted, the other acting as a reserve, by operating the three-position switch (44) on the port side of the cockpit.

37. Reconnaissance flares.—From three to eleven Hares arc stowed vertically in racks on the starboard side, immediately aft of the cabin, and the launching tube is mounted amidships on the starboard side of the fuselage. An alternative arrangement of three or six loaded flare chutes in the mid-turret position is fitted in certain aircraft and a flare launching switch panel is fitted in the bomb-aimer's compartment..