Some of the above posts seem to muse that the CH-47 would be a better choice over the CH-53K for even the USMC. While I do agree the CH-47 is a great choice for most land based forces, and much cheaper than the CH-53, it is important to talk about more than just cost, and talk about the implications of a CH-47 aboard ships- which is an extremely important factor for the USMC.
-The 53 is marinized properly. The 47 is not.
-The 53 has a powered fold system, and a surprisingly small (if you can call anything about the 53 small) spot factor when folded for such a large aircraft. The 47 blades can be folded, but not quickly or easily. A proper powered blade fold would likely require a new rotor head? And would you still need the blade support "rack" on the center fuselage?
- Would a 47 fit on the elevators and hangar bay of a US Navy LHA/LHD? I do know they can fit on a Nimitz class lift/hangar, but the USMC rarely operates heavy helos from CVN's.
- Do 47's fit behind the foul line on the forward flight deck of the LHA/LHD? This is where heavy/medium helos are usually parked when folded. The CH-53 is nosed towed and can hang its rear out over the water. The 47, as it is towed by the rear wheels would likely have to have the cockpit hang well out over the water. Acceptable?
- How many CH-47s would you need to replace the lift capacity of the 53's? Both troops and equipment? Is there space for the larger number of aircraft required?
- Spot factor of the CH-47?
- Capability. Can the CH-47 lift some of the big USMC loads required? LAV, multiple Hummers, etc. The 47 has a smaller capacity for trooping, supply and tactical recovery missions.
Please I'm not a hater of the CH-47, it is a great aircraft, but when you want heavy maritime lift, the 53 might be the only (expensive) choice for the USMC. Yes the 47 has worked aboard ships, and will do so wit the UK, but it is not tailor made for maritime heavy lift. A maritime CH-47 would be more expensive than a land based one. Yes you could lessen USMC requirements, but would need to make doctrinal changes as well.