Russia’s new Mi-38 transport helicopters to start arriving for troops in 2019
Wow, that was a bit quicker than I expected... will be interesting to see how quickly they can get other variations out too.
Not sure if this is the right place for this?
General parameters of the future high speed helo
Now I can see it... hmm... with the tail pusher blades and the angle of the blades out the sides you could only safely approach this helicopter from the front, and on a ship it would be a very stupid design because on a ship the biggest danger with a helo is the tail rotor, well with this helicopter it is not just the tail rotor it is also the main rotor blades out to the sides... so a shift in wind direction has that tail rotor swinging around on the deck but also those main rotor blades swinging low over the deck in all directions.
I rather suspect this is for land based only ops and is probably one option... they will normally put up multiple designs so they can properly evaluate advantages and disadvantages directly before making their decision.
x_54_u43 mentions electric motor direct drive rotors, but that would actually be an advantage for the coaxial arrangement... with intermeshing blades you need to seriously control rotor speed because both sets of blades cross arcs and could therefore hit the other set of blades if they were running faster than the other set.
With fully coaxial blades like they normally use speeding up or slowing down one set of blades is yaw control and it is vastly superior to conventional helicopters because above about 50-60km per hour the tail rotor has little to no effect as the aerodynamic forces of the air flowing over the helicopters shape has vastly more effect on where the nose is pointing. In comparison the Ka-50 or any other coaxial rotor helo can turn at will by speeding up or slowing down one set of rotors as obviously each set of rotors has enormous momentum and can turn the aircraft against the force of wind flow up to about 100km/h in any direction... for a transport that is not important but for an armed helo being able to point your nose at a target in most flight conditions is very useful... like a fighter aircraft... it was a feature they talked a lot about with the Commanche design... until the figures for the Hokum were revealed and then the Americans shut up about how useful it was.
The reason the Hokum has limited rotation of its gun was because its pedal turns at low speed were so fast and responsive... they didn't need a turret so they could locate the gun mount near the cg and get a much much more accurate weapon because it shakes the aircraft around much less when firing... even compared with the Havoc which is a similar aircraft weight and the same gun.
The main problem with coaxials is of course the height to keep the blades apart, and a complex and heavy gearbox to manage rotor speed and rotation.
With electric motors you don't need gearboxes and just regulate electrical power to change blade rotation speed and blade angle etc etc.
I suspect they will reveal this design in the hope of getting a foreign partner to help develop it and give it a chance if it loses the competition for the Russian programme... for the same reason the Mi-28 was revealed about 4-5 years before the Ka-50 because the Ka-50 was the hot favourite and won the competition for the replacement of the Hind... of course later on requirements for night ops meant a two seater was needed, hense the Ka-52. (night and bad weather flying is a full time job for the pilot so you need another crew member to hit targets etc)