PDA

View Full Version : 747 Gear Disagree


Cat in a Hat
9th Aug 2004, 23:48
Would anyone know if it's possible to tow a 747-400 with one gear leg stuck up e.g. a wing gear?

If not, what would the engineers have to do to prepare for towing and how long would it take? Would they have to secure the gear up in its bay or somehow jack up the a/c and extend the gear before towin?

Thanks

r304ndy
11th Aug 2004, 14:25
I'm sure the 747 has been designed to be towed with one (maybe even two) gears retracted, provided the aircraft weight is not over a specified limit. Somewhere in the AMM must tell operators to pin the gears up properly before towing.
For info, the A340-200/300/500/600 can be towed with the centre gear pinned up, provided the aircraft is not over a specified weight limit.

spannersatcx
12th Aug 2004, 18:40
From the Boeing MM: (just noticed you were talking about 744 this is for the classic) (just check the 744 MM and it is the same).:O

9. Tow Airplane (Maximum Weight 500,000 Pounds) Supported by Nose Gear and Body Gear
A. Center and deactivate body gear steering.
(1) When body landing gear trucks have been parked in steered position
and hydraulic power is available, tow airplane with nose gear
straight or set for same direction turn as steered trucks to center
and lock trucks.
(2) When body landing gear trucks have been parked in steered position
and hydraulic power is not available, tow airplane aft with nose
gear steering angle set for the same direction turn as steered
trucks to center and lock trucks.
B. Check that nose gear steering linkage is connected.
CAUTION: UNDER THIS WEIGHT AND GEAR CONDITION, ONLY STRAIGHT AHEAD OR STRAIGHT BACK TOWING IS RECOMMENDED. IF TURNING IS REQUIRED,
ALWAYS START IN A STRAIGHT LINE AND USE MINIMUM TURNING
ANGLE, MAKING TURN WHEN AIRPLANE IS IN MOTION. DO NOT EXCEED 15 DEGREE TURN UNDER ANY CONDITION.
C. Check that nose and body gear are fully serviced (Ref 12-15-03, 12-15-04, 12-15-05) and that tire pressures are in accord with requirements of 12-15-06, Tire Servicing.
D. With above conditions satisfied, tow airplane as required.
CAUTION: DO NOT USE AIRPLANE BRAKES TO AID IN TURNING OR FOR STOPPING AIRPLANE AS STRUT VERTICAL LOADS WILL BE EXCEEDED AND STRUCTURAL DAMAGE MAY RESULT.
10. Tow Airplane (Maximum Weight 360,000 Pounds) Supported by Nose and Wing Gear ________________________________________________
A. Check that center of gravity is not aft of 24% MAC.
B. Check that nose gear steering linkage is connected.
C. Check that nose and wing gear are serviced (Ref 12-15-03, 12-15-04, 12-15-05) and that tire pressures are in accord with requirements of 12-15-06, Tire Servicing.
D. With above conditions satisfied, tow airplane as required.
11. Tow Airplane (Maximum Weight 500,000 Pounds) Supported by Nose and Wing Gear ________________________________________________
A. Check that center of gravity is not aft of 24% MAC.
B. Check that nose gear steering linkage is connected.
CAUTION: UNDER THIS WEIGHT AND GEAR CONDITION, ONLY STRAIGHT AHEAD OR STRAIGHT BACK TOWING IS RECOMMENDED. IF TURNING IS REQUIRED,
ALWAYS START IN A STRAIGHT LINE AND USE MINIMUM TURNING ANGLE,
MAKING TURN WHEN AIRPLANE IS IN MOTION. DO NOT EXCEED 15
DEGREE TURN UNDER ANY CONDITION.
C. Check that nose and wing gear are fully serviced (Ref 12-15-03, 12-15-04, 12-15-05) and that tire pressures are in accord with requirements of 12-15-06, Tire Servicing.
D. With above conditions satisfied, the airplane can be towed.
CAUTION: DO NOT USE AIRPLANE BRAKES TO AID IN TURNING OR FOR STOPPING AIRPLANE AS STRUT VERTICAL LOADS WILL BE EXCEEDED AND STRUCTURAL DAMAGE MAY RESULT.

NSEU
13th Aug 2004, 02:39
Spanners..... Do you have an MM reference for this... I can't seem to find it in ours.

Also, there doesn't seem to be any mention of securing the gear in the up position. You wouldn't want the gear suddenly freeing itself and dragging on the ground during towing... or, more importantly, injuring someone.

Thanks.
Rgds.
NSEU

spannersatcx
13th Aug 2004, 10:09
Chpt 9 taxy & towing.

NSEU
13th Aug 2004, 10:19
Thanks! Found it.

Best regards.
NSEU