A better tilt rotor.

steingar said:
Dunno about that. Some pretty basic aerodynamics working against it.
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Well my main gripe was always the HOGE capability of the Osprey. There's no way we could've fulfilled our mission in Afghanistan with an Osprey. As indicated by a former 160th commander, it doesn't meet their needs either:

http://www.g2mil.com/qalat.htm

Apparently, Bell has worked that out with the V280 by reducing weight and increasing disk size. Lighter disk loading = greater HOGE. Still, I think with a coaxial they'll have even greater hover capability and the ability to auto if necessary.
 
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Velocity173 said:
Well my main gripe was always the HOGE capability of the Osprey. There's no way we could've fulfilled our mission in Afghanistan with an Osprey. As indicated by a former 160th commander, it doesn't meet their needs either:

http://www.g2mil.com/qalat.htm

Apparently, Bell has worked that out with the V280 by reducing weight and increasing disk size. Lighter disk loading = greater HOGE. Still, I think with a coaxial they'll have even greater hover capability and the ability to auto if necessary.
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Why couldn't you do full down autos? Transmissions and connected.
 
Unit74 said:
Why couldn't you do full down autos? Transmissions and connected.
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The rotors can't maintain sufficient rpm during an auto (low inertia). Some are appalled that it has no autorotational capability but I see it as low on my importance meter. Odds of duel engine failure slim. It would be nice to have that capability (coaxial) to touchdown at 10 kts vs 100 + kts glide (tilt rotor) but not a deal breaker to me.

If Bell addresses some of the problems I've read on the Osprey such as HOGE, defensive weapons, weight, vortex ring state, formation landings, cost and reliability, I think they're have a good replacement for conventional helos. Obviously the greater range and speed can be a huge benefit in most missions.
 
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Someone who actually knows the answer, no speculators, please.
Why on earth would you put all the weight of the engines, and the transmissions way out on the end of the wings?
Wouldn't it make more sense to put the engines and transmissions above the fuselage and just run a shaft out to the propellers?
Just wondering.
 
Shepherd said:
Someone who actually knows the answer, no speculators, please.
Why on earth would you put all the weight of the engines, and the transmissions way out on the end of the wings?
Wouldn't it make more sense to put the engines and transmissions above the fuselage and just run a shaft out to the propellers?
Just wondering.
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Passenger comfort. Quieter cabin. :D
 
Sorry, you didn't say no sarcasm.

Putting the engine and transmission out away from the cabin, eliminate the possibility of those items entering the cabin in a hard landing.
 
Velocity173 said:
Sorry, you didn't say no sarcasm.

Putting the engine and transmission out away from the cabin, eliminate the possibility of those items entering the cabin in a hard landing.
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It's a lot easier to build a stronger cabin than a stronger wing. Also every helicopter on the planet has the engines and transmissions on top of or inside the fuselage.
It' makes no sense to me.
 
I don't understand why they don't use 4 smaller rotors on each corner.
 
ktup-flyer said:
Idk, I'm not an aerospace engineer. Boeing has had a concept quad tiltrotor for a while.
View attachment 45386
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Holy crap that looks expensive and big! Marines can barely keep their Ospreys flying at low OR rates. I can't imagine how much it would cost for four engines and transmissions to go with them.

In a perfect world without fiscal restraints, I suppose that concept would work. Problem is, the Army isn't looking to replace 360 helos with a tilt rotor like the Marines with their Osprey. This Valor is going to replace at least 1,500 Black Hawks. They have to do everything they can to keep costs down.
 
Actually the Ruskie helos are far better in high hot conditions. Sad but true. That's why we rebuilt the Afghan Air Force with them instead of our stuff.
 
That Qalat article actually seemed halfway decent right up until he wrote "ISA (in still air)" after that it was hard to take it seriously. I'm not saying the article is all wrong (EDIT: Nevermind, the article is almost completely wrong, so many details about the incident are just not correct...) but it makes a lot of very bad assumptions, and I think his conclusion is, at minimum, highly flawed.

I was actually out flying that night. We were ferrying an Mi-17 and flew past Qalat twice. The first time we went by we saw the three Ospreys flying around (it was a training mission, not a combat mission), but on the way back we flew over a huge fire and saw several Black Hawks in the area (found out they were CASEVAC birds) and when we landed at Qalat for gas, there were only two Ospreys. The other crew chief in my aircraft went to talk to the crew (since they were blocking the refuel spots for us) and that's when we found out that the fire we flew over was their other Osprey. It was eerie listening on the radio to the Black Hawks bringing in the injured to the medical facility there at the FOB.
 
Conventional helicopters in the Army have no problem with hot and high in Astan. 58s had major issues but they'll all be gone soon. 64s had minor issues but the E model has taken care of that. If the enemy was in a habitable place, we could easily get to them.

Plenty of times we dropped off soldiers well above the V-22s 5400 ft HOGE limit.
 
So I've been under the impression that the Osprey's Achilles heel was a vortex generated by the rotors at low altitude. I don't think anyone really knew about it before they started flying the thing. Resulted in a couple crashes and fatalities.

I really don't see how the new design can avoid this. And if it can't come in hot and fast I don't see its utility in a war zone.
 
steingar said:
So I've been under the impression that the Osprey's Achilles heel was a vortex generated by the rotors at low altitude. I don't think anyone really knew about it before they started flying the thing. Resulted in a couple crashes and fatalities.

I really don't see how the new design can avoid this. And if it can't come in hot and fast I don't see its utility in a war zone.
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They modify their approaches to stay out of vortex ring state now. Believe they're limited to 800 fpm.
 
Velocity173 said:
They modify their approaches to stay out of vortex ring state now. Believe they're limited to 800 fpm.
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Which means you can't come in hot and fast like a helicopter. Means you come in slow, giving the bad buys more time to shoot at you. Sounds like a bad thing, if I'm reading this right.
 
I wonder if electric motors powered by a generator on the engine(s) would be a possibility.

Rich
 
steingar said:
Which means you can't come in hot and fast like a helicopter. Means you come in slow, giving the bad buys more time to shoot at you. Sounds like a bad thing, if I'm reading this right.
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Yeah but 800 fpm, less that 40 kts is no slouch though. We used to come in hot, probably well over 1000 fpm the last few hundred feet. Definitely nothing at Impact over 500 fpm. It's really not the descent rate but touch down speed anyway. I'd say the majority of my friends have ripped something off the 60 during assault landings.:(

I the think the bigger issue is formation landings. I knew that would be a problem before even reading about it. Guy I work with flys Ospreys and confirmed it as well. The amount of distance required between aircraft is excessive in my opinion. Plenty of LZs won't support that size.
 
On the Osprey, putting the engines on the wingtips simplifies the transmission, adds to the stability, and frees up room in the center section. It also makes it easier to fold the whole thing up and put it below decks.
 
At least on the mock up, it doesn't look like you can land in airplane mode.
 
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