AMM 9-00-00 1.0.0.0TOWING AND TAXIING 1. General This chapter deals with aspects of: - Towing. Refer to 9-10-00, pb201. - Taxiing. Refer to 9-20-00, pb201. These procedures will be required by personnel engaged in manoeuvring the aircraft on the ground. The aircraft may be towed forward or pushed aft on hard surfaces using a yoke type towbar which is connected to the aircraft nose wheel by a special towing axle. The nose wheel steering disengages automatically from the steering rack when a towing angle of 55 either side of the aircraft centre line is exceeded. With the nose wheel at the maximum turning angle (90 ) the aircraft may be turned around in a radius of 37 ft. 4.1 in. Refer to 9-10-00, Figure 1 Details of how the aircraft should be towed in abnormal conditions i.e. flat tyre/s, in soft mud or snow is contained in the Aircraft Recovery Manual. The aircraft may be taxied and manoeuvred using the nose wheel steering control. With the nose wheel set at the maximum steering angle (55 ) the aircraft may be turned around in a radius of 53 ft. 10 in. Refer to 9-20-00, Figure 1 9-00-00 Page 1
AMM 9-10-00 2.0.0.0TOWING - DESCRIPTION AND OPERATION 1. General The aircraft is normally towed (forward) or pushed (aft) employing a suitable towing vehicle (tug) with a tow-bar attached to the nose wheel axle. Under towing control, the nose wheel steering automatically disengages from the steering rack at 55 either side of the aircraft centre line. 2. Tow-bar Refer to Figure 1 Shear pins in the approved tow-bar ensure that the maximum allowable towing loads are not exceeded. One shear pin, painted white and labelled SHEAR PIN No. 1 at the forward (tug) end of the tow-bar is designed to fail if the towing load exceeds 3800 lb. The aft end of the tow-bar incorporates two shear pins, painted red and labelled SHEAR PIN No. 2, which act as a torque weak link. Failure of either of these pins occurs when a side load of 295 lb. or more is applied at the tug end of the tow-bar. The failing load limits the induced torque at the nose gear to 33,300 lb. in. Spare pins are stowed on the tow-bar and the forward and aft pins are not interchangeable. 3. Interphone Communication between ground personnel and the flight compartment can be established using the interphone system. A jackpoint for microphone and headset connection is provided adjacent to the ground service electrical connection. 4. Aircraft controls Prior to towing, a suitably qualified operator in the 1st pilots seat should check that the flight controls gust locks are engaged. Gust locks are engaged as follows:- A. ELECTRICAL MASTER switch (panel 4P) to INTERNAL B. RIGHT BATTERY switch (panel 4P) to ON C. RIGHT ESSENTIAL SERVICES switch (panel 4P) to NORMAL D. GUST LOCK lever (panel 3P) to LOCKED E. Flight controls centralied Raise the emergency brake pressure to 2,500 p.s.i. (panel 7P) and select EMERGENCY BRAKES by pulling T-handle adjacent to 1st pilots' right knee. 5. Operational precautions 9-10-00 Page 1
SD3-60 AIRCRAFT MAINTENANCE MANUAL A. The approved tow-bar should always be used unless circumstances do not permit. B. Ensure that only the shear pins supplied with the tow-bar are used for towing. C. The tug driver must ensure that all three aircraft landing gear ground locking pins are inserted. D. The landing gear shock absorbers and tyres should be at the correct inflation pressures. E. Brake pressure (panel 7P) should be raised to 2500 p.s.i. F. A minimum of two operators must be used to tow the aircraft : one qualified operator in the 1st pilots seat to operate the aircraft brakes and another to drive the tow vehicle (tug). G. Clearance must be obtained from airport control before towing the aircraft across the runways or taxiways. H. Ensure that personnel performing towing operations are familiar with procedures and limitations relevant to SD3-60 aircraft. I. The tug driver should avoid sudden starts and stops. J. The aircraft brakes should only be applied on command from the tug driver, guideman or in the event of tow-bar failure. K. The aircraft should never be towed in congested areas without the assistance of guidemen to ensure that there is adequate clearance. L. The aircraft engines should not, under normal circumstances, be running during towing operations. However, the procedure used by some airlines of pushing aircraft away from terminal gates is an exception. If the engines are running during towing, precautions should be taken to keep personnel from the rotating propellers and out of the wash/ exhaust area. 6. Limitations A. The nose wheel towing angle is restricted to 90 either side of the aircraft centre line. B. Maximum fore and aft loads is 3800 lbs. C. Maximum side load at tug end of tow-bar is 295 lbs. D. A maximum towing speed of 10 M P H is recommended for all conditions i.e. any permutation of crosswind speed and towing angle. E. Maximum gradient up which the aircraft can be towed (or pushed) using the approved towbar is 1 in 10. F. The maximum towing speed with engines is 4 mph., with no sudden accelerations. G. Minimum towing radii. Refer to Figure 2. 9-10-00 Page 2
Tow-bar Figure 1 9-10-00 Page 3
SD3-60 AIRCRAFT MAINTENANCE MANUAL Minimum Towing Radii Figure 2 9-10-00 Page 4
AMM 9-10-00 3.0.0.0TOWING - MAINTENANCE PRACTICES 1. General This section details the procedures for nose gear towing under normal conditions. 2. Equipment Item Name ITEM Ref. Manufacturer 1 Tow-bar T360-09-01 SHORTS 2 Main landing gear ground T360-10-08 SHORTS locking pin 3 Nose landing gear ground locking pin T360-10-09 SHORTS 3. Towing procedures A. Tow the aircraft. (1) Check that all three landing gear locking pins are fitted, complete with pennants (Items 2 and 3). (2) Station a qualified operator in the pilots seat. (3) Check that the flight controls gust locks are engaged (Refer to 9-10-00, pb201. para 4.). (4) Remove all obstructions from proximity of the aircraft. (5) Ensure that the landing gear shock absorbers and tyres are at the correct inflation pressures. CAUTION: TO PRECLUDE POSSIBLE DAMAGE TO NOSE GEAR CENTRING CAMS, ENSURE DISENGAGEMENT BY CHECKING THAT VISIBLE PARALLEL LENGTH OF NOSE SHOCK ABSORBER PISTON IS NOT IN EXCESS OF 5 INCHES. (6) Attach the tow-bar (item 1) to the nose wheel axle (Refer to 9-10-00, Figure 1) using the shear pins provided. NOTE: If pins other than those specified are fitted, it could result in damage to the aircraft structure. (7) Check that an emergency brake pressure of 2500 p.s.i. is available. System pressure may be raised. Refer to 32-40-00, pb201. (8) Select the EMERGENCY BRAKES by pulling the T-handle adjacent to the 1st pilots right knee. 9-10-00 Page 201
SD3-60 AIRCRAFT MAINTENANCE MANUAL (9) In congested areas, station wing and tail guidemen to ensure adequate clearance from obstructions. (10) If necessary, establish liaison between tug driver and aircraft brake operator by connecting the interphone system. (11) Radio contact with air traffic control should be established to obtain clearance for towing on taxiways, take-off or landing areas. (12) When towing in darkness or poor visibility, or when otherwise required by local airport regulations, switch ON the aircraft navigation lights, anti-collision lights, flight compartment and instrument panel lighting. (13) Remove all wheel chocks and mooring ropes (if fitted) and release the aircraft parking brake. (14) Tow the aircraft, ensuring smooth acceleration and deceleration and remaining within the limits. Refer to 9-10-00, pb1. para 6. WARNING: APPLY THE AIRCRAFT BRAKES IMMEDIATELY IF THE TOW-BAR BREAKS OR BECOMES UNCOUPLED, OR IN ANY EMERGENCY. (15) On completion of towing, centralie the nose wheel, check emergency brake pressure and pressurie if necessary (Refer to 32-40-00, pb201.). Apply aircraft parking brake and chock the aircraft wheels. Remove the tow-bar from the nose wheel. If the aircraft is to be parked or moored, Refer to 10-00-00, pb1. Restore aircraft electrics to OFF, or as required. B. Manhandling the aircraft When manhandling the aircraft, the relevant procedures detailed in para. A (towing the aircraft) again apply. WARNING: (1) TO PREVENT DAMAGE TO THE NOSE GEAR WHEN MANHANDLING BACKWARDS, IT IS ESSENTIAL (DUE TO THE TRAILING NOSEWHEEL) TO GUIDE THE AIRCRAFT WITH THE TOWBAR. (2) TO OBVIATE POSSIBLE INJURY TO PERSONNEL, THE TOWBAR (IF FITTED) MUST BE HELD SECURELY WHILST THE AIRCRAFT IS MOVING. THIS WILL PREVENT SUDDEN TOWBAR 'WHIP ACTION' DUE TO CASTORING. 9-10-00 Page 202
AMM 9-20-00 4.0.0.0TAXIING - DESCRIPTION AND OPERATION 1. General This section provides information for ground personnel engaged in taxiing the aircraft. Directional control is afforded by nose wheel steering and application of either right or left wheel brakes. If nose wheel steering is not available, selective engine thrust may be used. When taxiing at high speed, rudder pedal control may be used to supplement directional control. 2. Operational precautions WARNING: TAXIING MUST BE PERFORMED BY SUITABLY QUALIFIED PERSONNEL. FOR INFORMATION ON MANAGEMENT OF THE AIRCRAFT REFERENCE MUST BE MADE TO THE FLIGHT CREW MANUAL. A. Prior to taxiing, ensure that the landing gear shock absorbers and tyres are at the correct inflation pressures. B. Two qualified personnel should be stationed in the flight compartment; one in the 1st pilots seat to manoeuvre the aircraft and one in the co-pilot's seat to assist and act as observer. C. Ensure that all personnel engaged in taxiing are familiar with procedures and limitations relevant to SD3-60 aircraft. D. The guideman should be positioned at a safe distance, forward of the aircraft and within the pilot's view. E. The guidemen should use standard hand signals and in darkness or inclement weather, illuminated or reflective wands. F. Personnel authorised to taxi, should be familiar with airport control communications, procedures and radio frequencies. Clearance from airport control must be obtained before taxiing across runways or taxiways. G. When taxiing aft, the nose wheel must not be allowed to castor excessively, but should be restricted inside the centre band marks on the steering box by small inputs from the steering handle, thus overriding poor runway surfaces. WARNING: TAXIING AFT, MUST ONLY BE PERFORMED ON PAVED OR PREPARED SURFACES. 3. Limitations A. The nose wheel steering angle is limited to 55 either side of the aircraft centre line. B. The minimum turning radii are shown in (Refer to Figure 1). 9-20-00 Page 1
SD3-60 AIRCRAFT MAINTENANCE MANUAL C. The minimum taxi strip width required for a 180 turn using the maximum steering angle (55 ) is 53 ft. 10 in. (16.41 m). D. The main wheel brake heat limitations and cooling times are specified in the Flight or Crew Manual. E. The maximum taxiing speed is specified in the Crew or Flight Manual. NOTE: With gust locks engaged the max taxi baulk mechanism restricts engine power and consequently ground speed. F. Taxiing aft, must only be performed on paved or prepared surfaces. 9-20-00 Page 2
Minimum Turning Radii Figure 1 9-20-00 Page 3
AMM 9-20-00 5.0.0.0TAXIING - MAINTENANCE PRACTICES 1. General This section contains detailed taxiing procedures. 2. Equipment Item Name Number Manufacturer 1 Main landing gear ground locking pin 2 Nose landing gear ground locking pin 3. Taxiing procedure A. Operational precautions (1) Ensure that the nose and main gear ground lock pins (items 1 and 2), are fitted complete with pennants. (2) Chock the main gear wheels and ensure that any mooring cables are removed. (3) Station two suitably qualified persons, one in each pilot's seat. (4) Engage the gust locks by selecting the GUST LOCK LEVER (pilot's centre console) LOCKED and centraliing the controls. (5) Check the brake pressure (up to 1500 p.s.i.) and hydraulic system pressure (3300 p.s.i.) and apply the parking brake. (6) For taxiing in darkness or poor visibility or when otherwise required by local airport regulations, switch ON the aircraft navigation lights, anti-collision lights, flight compartment and instrument panel lighting. WARNING: ENSURE THAT PERSONNEL AND EQUIPMENT ARE CLEAR OF THE PROPELLERS AND WASH/EXHAUST AREA. (7) Station fire fighting personnel and equipment and start the engines - (Refer to 71-00-01, pb501. for PT6A-65R engines). - (Refer to 71-00-02, pb501. for PT6A-65AR engines). - (Refer to 71-00-03, pb501. for PT6A-67R engines). (8) Establish radio contact with air traffic control. B. Taxi the aircraft T360.10.08 T360.10.09 (1) Remove the wheel chocks and release the parking brake. SHORTS SHORTS 9-20-00 Page 201
SD3-60 AIRCRAFT MAINTENANCE MANUAL (2) Obtain necessary clearances from air traffic control and use guidemen to ensure adequate clearances in congested areas. (3) Begin taxiing by applying only enough power to start the roll. Adjust power to maintain required speed. CAUTION: 1. WHEN TAXIING IN WET OR ICY CONDITIONS DO NOT CONTINUE TO TURN THE NOSE WHEEL STEERING IF NO TURNING ACTION IS OBSERVED. THIS IS AN INDICATION THAT THE NOSEWHEEL IS SKIDDING AND, WITH LARGE STEERING ANGLES SELECTED, STRUCTURAL DAMAGE COULD OCCUR IF ROUGH SPOTS ARE ENCOUNTERED. 2. IF STEERING EMPLOYING ASYMMETRIC THRUST, THE TILLER MUST NOT BE HELD (THE HANDLE MOVES AUTOMATICALLY AS A RESULT OF FEEDBACK FROM THE ACTUATOR SERVO VALVE OPERATING LEVER). 3. BEFORE REARWARD TAXIING THE NOSE WHEEL MUST BE CENTRED. SMALL STEERING INPUTS MAY SUBSEQUENTLY BE USED WHEN TAXIING BACKWARDS PROVIDING THE TILLER IS KEPT WITHIN ITS CENTRING BAND LIMITS. (4) If possible avoid small radius turns. When minimum radius turns are necessary reduce speed as much as possible to prevent heavy side loads and tyre scrubbing. (5) On completition of a turn and before stopping the aircraft, centre the nose wheel steering control and continue taxiing to align the nose wheel with the aircraft centre line, thus relieving tyre stresses induced by the turn. (6) With taxiing complete apply the parking brake. (7) Shut down the engines, - (Refer to 71-00-01, pb501. for PT6A-65R engines). - (Refer to 71-00-02, pb501. for PT6A-65AR engines). - (Refer to 71-00-03, pb501. for PT6A-67R engines). (8) Re-select the aircraft lighting, etc., as required and chock the wheels. (9) If the aircraft is to be parked or moored, Refer to 10-00-00, pb1. 9-20-00 Page 202