(2)
Remove external electrical power (Ref 24-22-0). The APU may be operated if the engines are not operating, or the engines are operating but no electrical power changes are made while towing.
WARNING: ENSURE HYDRAULIC SYSTEM A IS COMPLETELY DEPRESSURIZED AND DO NOT MAKE ANY ELECTRICAL POWER CHANGES WITH TOW BAR CONNECTED. AN INTERRUPTION OF ELECTRICAL POWER COULD CAUSE MOMENTARY PRESSURIZATION OF ENGINE DRIVEN HYDRAULIC PUMPS WHICH COULD PRESSURIZE SYSTEM A AND CAUSE NOSE GEAR TO ALIGN WITH STEERING WHEEL POSITION. DAMAGE TO EQUIPMENT AND INJURY TO PERSONNEL COULD OCCUR.
H. On airplanes with nose gear steering depressurization valve, depress button and install nose gear steering lockout pin in steering depressurization valve (Ref 32-00-01).
CAUTION: TO AVOID DAMAGE TO STEERING COMPONENTS OR TOWING
EQUIPMENT, THE DEPRESSURIZATION VALVE BUTTON MUST BE
DEPRESSED AND HELD WHEN LOCKOUT PIN IS INSERTED.
NOTE: Nose gear steering depressurizing lockout pin can be installed and removed without entering wheel well from aft of right nose wheel well door.
I. Connect interphone system between control cabin, tow tractor operator and towing ground crew.
J. Check that ramp area is cleared of all stands and equipment in the towing path.
K. Connect tow bar to tow tractor and to airplane.
L. Remove airplane static ground wires.
M. Close the fan cowl panels, thrust reverser (Ref Chapter 71).
CAUTION: MAKE SURE ALL ENGINE COWLS ARE CLOSED AND LATCHED BEFORE THE AIRPLANE IS TOWED. DAMAGE TO EQUIPMENT CAN OCCUR.
N. To tow the airplane with the entry or lower cargo door open is optional.
5C9
9-10-0 Page 202 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. Feb 01/95
4. Tow Airplane from Nose Gear
A. Position wing, tail, tow tractor operator and ground crew so that all are in visual contact.
B. Check that cockpit man, ground crew, and tow tractor operator are in intercom communication.
C. Check that wheel chocks are removed.
D. Check that hydraulic brakes are released.
E. Tow airplane. Begin towing slowly and straight ahead before attempting to turn.
CAUTION: MOVE AIRPLANE FORWARD BEFORE STARTING SHARP TURNS. AVOID SUDDEN STARTS AND STOPS.
IF TOWING IS BEING DONE UNDER HIGH LOAD CONDITIONS, SUCH AS TOWING WITH BOTH TIRES FLAT ON ONE MAIN GEAR, TOWING ON SOFT TERRAIN, TOWING UP INCLINES GREATER THAN 5 DEGREES, OR SIMILAR CONDITIONS, REFER TO MAIN GEAR TOWING, PAR. 5, AS NOSE GEAR TOWING STRUCTURAL LIMITATIONS MAY BE EXCEEDED.
F. Limit brake applications to minimum use within safety limitations. Fully charged accumulators are capable of approximately three brake applications.
CAUTION: IF YOU USE A TOW BAR, YOU CAN CAUSE THE SHEAR PINS TO SHEAR IF YOU USE THE AIRPLANE BRAKES WHILE YOU TOW THE AIRPLANE.
MOST TOWBARLESS TOW VEHICLES DO NOT HAVE A SHEAR PIN TO LIMIT THE LOADS IF AIRPLANE BRAKES ARE USED DURING TOWING. IF AIRPLANE BRAKES ARE USED WHILE TOWING WITH A TOWBARLESS TOW VEHICLE ATTACHED TO THE NOSE LANDING GEAR, PERFORM THE “HARD LANDING OR HIGH DRAG/SLIDE LOAD LANDING” INSPECTION FOR THE NOSE LANDING GEAR AREAS (REF 5-51-51).
5C9 Aug 01/96 9-10-0 Page 202A/202B BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
G. Maximum normal turning angle is 78 degrees as indicated by red stripes on nose gear doors. If a greater turning angle is required, disconnect torsion links on nose gear. If an angle in excess of 90 degrees is required, disconnect nose gear taxi light wire. When disconnected, support lower torsion link against dragging to prevent damage to lubrication fittings. See Fig. 202 for turning dimensions. See Fig. 203 for wingtip turning radius for various turning angles. See Fig. 204 for ground turning techniques.
H. Finish towing in a straight path for a minimum of 10 feet to relieve turning stresses remaining in tires and shock struts.
I. At end of towing, position wheel chocks fore and aft of a main gear wheel on each main gear.
J. Disconnect tow bar and remove nose gear steering nulling pin.
5. Tow Airplane under Abnormal Loads (Main Gear Towing)
A. Preparation for towing and towing the airplane under abnormal loads is the same as towing airplane from the nose gear except for the following:
(1)
Eyebolt assemblies are installed in place of the jacking cone on each main gear and locally fabricated cables attach the gears to the tow tractors. The nose gear tow bar is not used.
(2)
Hydraulic system A is pressurized and airplane is steered during towing by the nose wheel steering system by directions from the ground crew.
(3) 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：737 AMM 飞机维护手册 TOWING AND TAXIING(2)
