Info on CH-47 landing gear design

Hey fellas.  I was reading one of the other -47 model threads about the ramp , & someone brought up the question about the change in the aft landing gear design from  dual wheels to a single wheel.  I went out into the hanger to find some guys who I know would know.  These three guys have a combined 120 years experience working on all models of the -47.

1. The singe wheel unit was stronger than the dual.  One guy remembered when a pilot snapped of both aft gears during a roll on landing.

1. The addition of power steering.  The duals were free to castor around, just like on a shopping cart. The swivel lock actuator designed changed also, from a round pin to the big locking mechanism that is on there today, which incidentally, can still be snapped with a standard tow bar if its tried to turn with the lock engaged.   Taxiing the aircraft back then had to be accomplished while in a semi-hover, with the front wheels off the ground, but the back wheels on the ground.  According to my guys, it took a fair degree of piloting skill & a good amount of clear ramp space to 4-wheel taxi with the dual aft design. They could only recall two pilots that could routinely do it on a regular basis.

1. The size of the tire had an effect as well.  The small, narrow tires dug into the ground. Remember this was an army aircraft which could expect to spend time out in a field environment.  The current tires are considered to be high flotation tires, but I have seen plenty of aircraft sunk 4 or 5 inches into the dirt, especially when the ground is wet. I remember leaving two good trenches on the parade field at Ft. Sam Houston on a VIP pax haul.   The early tires were actually recapped jet trainer tires that were unusable for the high speed applications of fixed wing aircraft, but plenty good most of the time for slow helo landings.  The crew recounted some instances where the tires came apart during a fast roll on landings.   Lastly, the current size of the tire (8 X 10) is a pretty standard aircraft tire size.  I remember myself looking at the gear of a CH-53 parked next to us at an air show & noticing they had almost identical wheels & tires as we did.

1. The current wheels & tires are identical, & can be put on any position on the aircraft, which simplifies maintenance & supply concerns.  The dual afts were not the same as the front, so you had to stock 2 different types of tires & wheels.

Hope this helps.

Chris Ish