The Royal Air Force has been flying  the Boeing CH-47C designated Chinook HC1 since December 1980, further improvements lead to the HC1A. The CH-47D enter service with the US Army in 1982 and likewise the RAF began to upgrade theirs as well to the HC2. The Special Forces fly the HC3 which are similar to the MH-47E.
There are plans to upgrade the HC2, HC2A and HC3 helicopters to HC4, HC4A and HC5 standard. Further development based on the CH-47F has led to the HC6 which includes digital flight-control systems.
The main rival is the Sikorsky CH-53K King Stallion, although the CH-53 has been flown by the German Air Force who had evaluated the CH-47 Chinook. Another contender could be the Mil Mi-26 or the newest variant the
Mi-26T2V.
The largest helicopter ever built was the Mil V-12.

On the Whiffing front I have attempted to build a twin rotor variant of the Fairey Rotodyne,  using parts from the Italeri MH-47E kit. The fuselage was made from two Airfix kits 'spares and repair 'as advertised.
I've even tried using the Mach2 Super Frelon with the Italeri EH-101 Merlin rotor and tail,  although the Merlin parts can be adapted for the Airfix Fairey Rotodyne if you have enough filler/puty to hand.
My biggest build was the Heliplane; which used a 1/72 C-130H with the tail from the Heller Lockheed Constellation and rotor stack of the Mil Mi-26. The nose was replaced with the Cammett BAe Nimrod AEW.3 front radome. The only real problem was that the rotor blades kept breaking off every time I moved it. I solved this by adding a pair of wing stubs with a pair of twin jet pods from the Monogram B-36 Peacemaker.  The jet engines were able to rotate and lift the Heliplane off the ground into the flight position. The wing stubs were for the weapons and drop fuel tanks. I did manage to find another set of rotor blades and produced a contra-rotating Heliplane.  Flight testing concluded that the fuel tanks didn't last very long with the combination of the four jets but proved that the Heliplane could use the rotors to lift  or land and the jets for propulsion.
A larger V-22 Osprey could be another option.

That's interesting.

I read an article where some scientist argued that only a very well funded force could afford such a compromise as the MV-22 in service as it's payload is significantly less than a correspondingly big helicopter while it's range and speed is considerably lower than corresponding aircraft, and in fact, a well-judged combination of the two would be cheaper not only to run, but also to buy.

The fact that the Osprey hasn't been exported might speak for this, but it's still a uniquely cool machine in its own right, in particular for an engineer as myself.. 

Tbh, I think RAF is right in replacing a Wokka with a better Wokka. The design is very well proven and found to work almost whatever you throw at it. But that's in the real world. In whif-world, I would probably look at a good but somewhat general looking transport fuselage, then marrying it to a set of scaleoramaed Osprey power packs/rotors.

I also think that the MV-22 only fits a special operational niche - you can get light equipment close to the theatre of operations, fast, ideal for commando troops, or as an SAR vehicle. However, if that's not a major mission focus, a "simple " helicopter will do, anfd probably at much lower operational costs. And when you want to haul heavy/big ordnance around, either internally or as an external load, the MV-22 fails, too, and a big heli is certainly the better option. Japan is AFAIK the only export customer, and there it replaces the vintage CH-46 helicopters.

How about Rotodyning a Chinook ?

Quote from: tigercat on January 21, 2021, 01:24:59 AM

How about Rotodyning a Chinook ?

Boring already did that, and quite a while ago too.

There was a prototype Chinook flown with some socking great wings sticking out of the fuselage. The wings could rotate through 90 degrees, presumably to lessen the drag when going vertically up or down, but it didn't have any extra engines on them, as the 'dyne had.

Think of all the hard points you could fit .

Quote from: tigercat on January 21, 2021, 04:18:07 AM
Think of all the hard points you could fit .

Going back to the old A/ACH gunship concept... the trouble with that, is that back in the day they worked out you need 2 per mission for mutual support, and it removes the lift capability of X-number of transport choppers.

I'm now thinking of the Lockheed C-27 Spartan with either tilting wings or tilting engines although the F27 Friendship might be nearer the size with tilting engines at the wingtips. The main landing gear would store in blisters along the fuselage.
I've always run into problems building the Airfix model but this would make a great whiff.

Quote from: Pellson on January 21, 2021, 12:27:45 AMThe fact that the Osprey hasn't been exported might speak for this, but it's still a uniquely cool machine in its own right, in particular for an engineer as myself.. 

I think that the Japanese would disagree with you, along with Boeing



Picture found on the web

Gondor

The Osprey is clearly a compromise between a big helo and a transport aircraft. But when you put it in the assault role it was designed for, let's just say I don't hear the Marines complaining! The one problem is that the Osprey will out run the attack helos so either the attack helos have to launch way before the Ospreys or coordinate with the fast jets to prep the LZ for them. The Marines might not say it out loud but the A-10 is a favorite of theirs.
The USMC evaluated the A-10 but rejected it as it didn't leak enough......,,

Quote from: Gondor on October 23, 2024, 11:23:55 AM

Quote from: Pellson on January 21, 2021, 12:27:45 AMThe fact that the Osprey hasn't been exported might speak for this, but it's still a uniquely cool machine in its own right, in particular for an engineer as myself.. 

I think that the Japanese would disagree with you, along with Boeing



Picture found on the web

Gondor

And confirmed discussed here: https://news.usni.org/2020/07/14/japan-self-defense-force-accepts-delivery-of-first-v-22-osprey

Quote from: scooter on October 23, 2024, 12:15:58 PM

Quote from: Gondor on October 23, 2024, 11:23:55 AM

Quote from: Pellson on January 21, 2021, 12:27:45 AMThe fact that the Osprey hasn't been exported might speak for this, but it's still a uniquely cool machine in its own right, in particular for an engineer as myself.. 

I think that the Japanese would disagree with you, along with Boeing



Picture found on the web

Gondor

And confirmed discussed here: https://news.usni.org/2020/07/14/japan-self-defense-force-accepts-delivery-of-first-v-22-osprey

I happily stand corrected and note that I wasn't aware at the time. 

Quote from: kerick on October 23, 2024, 11:56:59 AMThe Osprey is clearly a compromise between a big helo and a transport aircraft. But when you put it in the assault role it was designed for, let's just say I don't hear the Marines complaining! The one problem is that the Osprey will out run the attack helos so either the attack helos have to launch way before the Ospreys or coordinate with the fast jets to prep the LZ for them. The Marines might not say it out loud but the A-10 is a favorite of theirs.
The USMC evaluated the A-10 but rejected it as it didn't leak enough......,,

Clearly the answer is to make an A-10 version of the Osprey ... I dunno about wing-mounted ordnance, but I could definitely see that big cannon poking out of the nose with a very large ammo drum in the cargo bay ...

Quote from: Scotaidh on October 25, 2024, 04:02:46 AM

Quote from: kerick on October 23, 2024, 11:56:59 AMThe Osprey is clearly a compromise between a big helo and a transport aircraft. But when you put it in the assault role it was designed for, let's just say I don't hear the Marines complaining! The one problem is that the Osprey will out run the attack helos so either the attack helos have to launch way before the Ospreys or coordinate with the fast jets to prep the LZ for them. The Marines might not say it out loud but the A-10 is a favorite of theirs.
The USMC evaluated the A-10 but rejected it as it didn't leak enough......,,

Clearly the answer is to make an A-10 version of the Osprey ... I dunno about wing-mounted ordnance, but I could definitely see that big cannon poking out of the nose with a very large ammo drum in the cargo bay ...

You would have to kick the nose wheel off to one side to make room.

Quote from: kerick on October 25, 2024, 08:05:58 AM

Quote from: Scotaidh on October 25, 2024, 04:02:46 AM

Quote from: kerick on October 23, 2024, 11:56:59 AMThe Osprey is clearly a compromise between a big helo and a transport aircraft. But when you put it in the assault role it was designed for, let's just say I don't hear the Marines complaining! The one problem is that the Osprey will out run the attack helos so either the attack helos have to launch way before the Ospreys or coordinate with the fast jets to prep the LZ for them. The Marines might not say it out loud but the A-10 is a favorite of theirs.
The USMC evaluated the A-10 but rejected it as it didn't leak enough......,,

Clearly the answer is to make an A-10 version of the Osprey ... I dunno about wing-mounted ordnance, but I could definitely see that big cannon poking out of the nose with a very large ammo drum in the cargo bay ...

You would have to kick the nose wheel off to one side to make room.

0

As per the A-10