Design exercise: next generation carrier onboard delivery airplane for US Navy

[Nicknick]

So most of the 600 hp was used to heat up the rubber, not the drive train, this would be exactly the same with electric propulsion. It is also clear, that four wheels burn more power than just two.

 

[Richard N]

U.S. Navy Surging Last C-2 Greyhound Squadron As CMV-22 Osprey Remains Grounded

The last 15 C-2As are surging to meet the carrier onboard delivery mission after all Ospreys were grounded in December, with DOT&E meanwhile reporting

theaviationist.com

 

[yasotay]

Reasons that the CMV-22B was chosen were that it could deliver to other ships of a Task Force while dispersed. It can also stay aboard the carrier and provides the Task Force with other options ranging from CSAR to humanitarian relief. So, at a minimum I would think that a replacement would; a. be VTOL, b. fold sufficiently to go underdeck, c. provides increased payload or cost efficiency to warrant the replacement.

 

[Scott Kenny]

Reasons that the CMV-22B was chosen were that it could deliver to other ships of a Task Force while dispersed. It can also stay aboard the carrier and provides the Task Force with other options ranging from CSAR to humanitarian relief. So, at a minimum I would think that a replacement would; a. be VTOL, b. fold sufficiently to go underdeck, c. provides increased payload or cost efficiency to warrant the replacement.

Agreed. So while it might be a second (third?) generation tilt-rotor, it'll still look a lot like an Osprey. It might get stretched about 10ft 5ft fore-aft and have a 10ft 5ft wider wingspan with bigger proprotors, though (back to the original planned dimensions before the LHA clearance forced a shorter wingspan and smaller props).

Edited because I got the dimension wrong.

 

[yasotay]

@Scott Kenny - size growth might reduce the number of ships that would be accessible. It would also have to auto-fold per USN shipboard requirement. If "the juice is worth the squeeze" for the expense I would agree larger more productivity to the fleet would be warranted.
I think that the Bell tilt/fold might be a logical next step.
Interestingly Sikorsky has just announced a return to the tilt-wing concept. That might produce an option as well.

 

[Scott Kenny]

@Scott Kenny - size growth might reduce the number of ships that would be accessible. It would also have to auto-fold per USN shipboard requirement. If "the juice is worth the squeeze" for the expense I would agree larger more productivity to the fleet would be warranted.
I think that the Bell tilt/fold might be a logical next step.
Interestingly Sikorsky has just announced a return to the tilt-wing concept. That might produce an option as well.

I missed the dimension. It's only a 5ft stretch to wings and fuselage, to allow for proprotors +5ft in diameter.

And with some composite construction of the fuselage, I think it'll work, weight wise.

 

[Mike OTDP]

If I were starting from scratch, I'd design from the ground up for an ASW, AEW, and COD variant. Possibly tanker as well.

For the pure COD mission, though, I might talk to Shin Meiwa about a seaplane. Much simpler than wrestling with V/STOL systems, and it can be made much larger.

 

[Scott Kenny]

If I were starting from scratch, I'd design from the ground up for an ASW, AEW, and COD variant. Possibly tanker as well.

One minor nuisance is that ASW is (generally) conducted at low altitude, while AEW/COD/Tanker are mid-to-high altitude jobs (20-30kft or more).

Which makes your aerodynamic optimization a bit of a pain. (and IIRC why P-3s have round tipped props and C130s have square tipped props)

But hey, that's what you pay engineers a lot of money for!

For the pure COD mission, though, I might talk to Shin Meiwa about a seaplane. Much simpler than wrestling with V/STOL systems, and it can be made much larger.

But then you'd need a crane on every ship to haul the cargo up from the seaplane to the quarterdeck.

While an Osprey can land on any helipad and deliver 20klbs to the hangar deck.

 

[TomS]

For the pure COD mission, though, I might talk to Shin Meiwa about a seaplane. Much simpler than wrestling with V/STOL systems, and it can be made much larger.

It's called "Carrier Onboard Delivery" not "Water Alongside Delivery" for a reason. If you are happy putting the cargo (including passengers) in the water somewhere kinda near the destination ship, we already have C-130s that can do that without even landing. Stuff does tend to get a bit waterlogged, though. And the pickups are hell.

OK, more seriously, the point of COD is that you can receive (and send) cargo more or less in stride. Trying to get cargo from a seaplane to a ship would be much more of an involved evolution. Consider, for example, the mechanisms developed for rearming the P-6M SeaMaster seaplane bomber. That was based on getting one roughly 3-ton atomic bomb at a time from the ship into a seaplane alongside, in calm water, likely in an anchorage. The necessary boom makes an UNREP kingpost look small.

https://www.secretprojects.co.uk/threads/martin-p6m-seamaster.334/page-2

Trying to deliver cargo from a seaplane in a higher sea state, as one might find in the open ocean, is likely to be impossible under many conditions where a plane or tiltrotor would be fine.

 

[1635yankee]

One minor nuisance is that ASW is (generally) conducted at low altitude, while AEW/COD/Tanker are mid-to-high altitude jobs (20-30kft or more).

Which makes your aerodynamic optimization a bit of a pain. (and IIRC why P-3s have round tipped props and C130s have square tipped props)

But hey, that's what you pay engineers a lot of money for!



But then you'd need a crane on every ship to haul the cargo up from the seaplane to the quarterdeck.

While an Osprey can land on any helipad and deliver 20klbs to the hangar deck.

I believe every ship already has at least one crane. They may not be very big.

On the other hand, I don't think the Shin Meiwa US-1 (or any variant of it) has a large roof hatch. Adding that would be somewhat non-trivial, as it would likely need to cut through where the wing structure is located.

We could, of course, think about bringing back the XC-142 or something similar (enlarge the CL-84!)

 

[Scott Kenny]

I believe every ship already has at least one crane. They may not be very big.

I'm not sure they have a 10 ton crane on anything smaller than an LHA/LHD.

On the other hand, I don't think the Shin Meiwa US-1 (or any variant of it) has a large roof hatch. Adding that would be somewhat non-trivial, as it would likely need to cut through where the wing structure is located.

Could probably stick one just aft of the rear spar of the wing. Wouldn't be too far aft of the CG limit for flying.

We could, of course, think about bringing back the XC-142 or something similar (enlarge the CL-84!)

Isn't that basically the Osprey already? (yes, I know, different mechanical system, but still props and VTOL)

 

[uk 75]

I suppose that simply building and updating C2s is not an option?
At least as an insurance against the more complicated Osprey.

 

[TomS]

I suppose that simply building and updating C2s is not an option?
At least as an insurance against the more complicated Osprey.

Probably not building new ones, since the line had been closed for ages. Around 2013, Northrop was proposing to reengine them, retrofit them with the glass cockpits from the E-2Ds, and then rewing them to keep them flying past 2030.

The Future COD Aircraft Contenders: The Northrop Grumman C-2A Greyhound | Defense Media Network

An article about potential Carrier Onboard Delivery (COD) aircraft for the U.S. Navy, with a focus on the C-2A Greyhound.

www.defensemedianetwork.com

But in the end, the Navy preferred the flexibility of VTOL and selected the CMV-22B. There simply isn't money to do both.