Re: V22 Osprey fails OPEVAL
 

Here's where i get confused:

The pure helicopter speed record still stands at 400 kph, set by the Westland Lynx G-LYNX in 1986. The machine is, so i'm reliably informed, due to be shipped from the Helicopter Museum in Weston-Super-Mare back to Yeovil for a factory restoration to it's record setting livery. The real trick was using the BERP tips to allow faster rotor speed, and improved retreating tip lift at high AOA (and high dAOA/dt - ie vortex shedding).

Now 400 kph works out at 216 kts, which is pretty good for a pure heli. The V-22 demonstrated speed at OPEVAL II is 240 kts which is only an 11% improvement in speed. For the target of 300 kts, the problem is really just one of avoiding the retreating rotor limitations. This is bread and butter for any of the counter rotating heli configs, previously discussed on many threads.

Surely wouldn't a design based on coaxial, such as the proposed Sikorsky X-2 make much more sense!?! More particularly, since the S-69 ABC is a proven design concept a program could be put together reasonably quickly. At this stage, even as a practical back pedaling excercise, i'm amazed this doesn't get the attention it deserves...

Mart

Re: V22 Osprey fails OPEVAL
 

Graviman,

The demo'd MV-22 cruise speed during OPEVAL was actually 255 kts (against a 240 kt target). Not bad when compared to the 150 kts cruise speed of the today's helos (e.g. US101), but I agree it'll be interesting to see how the X2 and the other alternative high-speed designs do.

(The other tricks used by G-LYNX included red-lined donks (Gem 60s with water-methanol), reprofiled exhausts and aerodynamic refinements)

I/C

Re: V22 Osprey fails OPEVAL
 

The payload of the record-setting Lynx was the pilot's clipboard, with a full cargo load, the speed would have been less than 200 MPH. Any comparison of the stunt of one type to the bread and butter capability of another is just not proper.

Re: V22 Osprey fails OPEVAL
 

I thought the X2 was the next generation of the S-69 technology. And, they announced at AHS last year that they are putting it together quickly. Maybe it is getting the attention it deserves. What I wonder is what will happen to potential military and commercial tilt-rotor customers if Sikorsky succeeds, and can deliver a high speed rotorcraft, with a sensible disk loading, and autorotation capability. Will people stick to their tilt rotor guns, or run screaming?
-- IFMU

Re: V22 Osprey fails OPEVAL
 

IC,

A 105 knot advantage as demonstrated is still far less than two times the speed of the helicopter and for the V22 to carry the same payload as the Sikorsky or Chinook....it will take three sorties not one. (That is for small cube loads internally as well) Please remember the cube inside the cabin is much smaller on the V22.

I have also heard that the V22 engine removal and replacement has to be done on the flight deck because it is too tall for the hangar deck when in the required configuration. Factor that into a tactical situation requiring light discipline not to mention the howling gale that usually blows along the flight deck.

This is one of those situations that only gets worse with effort.

Bluntly....it is a Boondogle! In the Army we would call it FUBAR!

Re: V22 Osprey fails OPEVAL
 

IFMU,

Apparently, much of the S2, which Sikorsky is currently building, is an assemblage of components from various existing craft and outside companies. For instance, the blades are to be supplied by Emitt Wallace, the person who brought out the AirScooter http://www.eagleaviationtech.com/airscooter.htm The S2 may be just a 'teaser' for government funding on the heavy lift contract.

I can envision a situation where Bell submits the V-44 quadrotor.
Then Sikorsky submits the S2 coaxial, and Bell chokes.
Then Boeing submits the interleaving configuration, and Sikorsky and Bell both choke. :D

Perhaps we will know a bit more next week after the AHS Vertical Lift Aircraft Design Conference. http://www.vtol.org/vla06program.html

Re: V22 Osprey fails OPEVAL
 

The Heavy Lift is not at all related to this Dave. That program is precisely what it appears to be and what the USMC is paying for, an upgrade of the CH-53E.

The X2 is a company funded small demonstrator that will explore high speed vertical lift, and is championed personally by Sikorsky senior management, with no current government funds.

Re: V22 Osprey fails OPEVAL
 

Nick. Thanks.

It may have been the; Joint Transport Rotorcraft (JTR), or the Future Transport Rotorcraft (FTR), or the Air Maneuver Transport (AMT). :rolleyes:

Whichever, it is the program where Bell is proposing the V-44, Sikorsky is proposing two versions of the X2, and Boeing is proposing two craft, one of which is by its newly acquired small rotorcraft company.

My understanding is that the government is spliting 20 to40 million dollars between the five projects, for the companies to develop their proposed concepts.

Re: V22 Osprey
 

The local helicopter medivac company here had two crashes that destroyed both ships in just one month (last October). Considering that the cost per hour to operate the helo is about ten times(just a guess) what a land based ambulance would be, an unbiased observer might wonder why helicopters are used at all.

The reason is speed might save a life.
A similar argument could be put forth in support of the tiltrotor. If the extra speed saves lives then maybe some would want to spend the money.

It is odd that the helo people on this forum are so against a new technology that has advanced performance. I think Sikorsky probably had a hard time promoting helo capability in the early development days as well. The naysayers must have said helos were too dangerous and cost to much.

On the other hand, the Bell V-22 may be poorly designed and overweight because of folding mechanisms. I agree with 3top.
The technology needs to evolve with better ideas from multiple designs.
slowrotor

Just a joke. ~ Maybe
 

For fast response;-

How about buying high lift dirigibles and taking the hospital to the accident?

Re: V22 Osprey
 

Nick, impressive numbers. However, I'm quite certain the V22 was meant to be used for more than ONE 200nm trip. :ooh:

Re: V22 Osprey
 

Matthew,
I was not specific enough, it is a $2,000,000 investment per minute, which could buy a waterfront mansion in Miami for the USMC for each V22 dispatcher if that guy saved 1 minute per call.

Re: V22 Osprey
 

Nick, if the V22 makes 1000 trips during its service life, then the time savings would be 30 000 minutes, making the value of one minute $2,000. You're right that it costs a lot, but it's a good idea to avoid "the distortion of the COST of that speed ".

Re: V22 Osprey
 

Are there any cost or payload estimates for the Sikorsky X-2 approach yet? I realise S-69 was a prototype machine with associated costs, and X-2 is not yet directly comparable. Since S-69 has already demonstrated 269 kts, and the X-2 pusher prop will reduce hub/trim drag, this has the time saving capability of V-22...

BTW good point well made about comparing stunt with bread-and-butter capabilities, Nick.

Mart

Re: V22 Osprey
 

Graviman,
The cost for an X2 might be 10% more than a regular helo of the same general size, and the payload might be 10% less, due to the increased empty weight for the "extra" rotorhead and the auxiliary propulsion/propellor.
Also, the cruise fuel flow at 240-ish would be higher than a tilt rotor because the rotor is just not as efficient as a wing at high speed.

So the X2 would take off with about 50 to 75% more payload than a tiltrotor, but would burn more fuel per mile, so the range would be no better, and maybe worse. Devilish tradeoffs, these.

Re: V22 Osprey
 

Nick, how to generate a statistic is entirely in the hands of its creator. However, it is important to ensure that everyone using the statistic understands it fully. I don't think your $2 million minute will be well understood after a few iterations along the grapevine.

For example, consider a comparison between a $40 million helicopter and a $100 million Osprey, which has had its initial 200nm flight. The $60 million difference was paid for at $2 million per minute. Now however, with the difference gone, the V22 is faster with the only cost of that speed being the increased incremental costs (ie fuel, maintenance, etc).

Another way to look at it is if the first flight wasn't 200nm but was 400nm. Then the V22 comes in at the cut rate price (50% off) of $1 million per minute.

Either way you run it, those numbers are just shocking statistics that aren't based on any business sense. Nobody would buy a V22 for one flight, and nobody would spread the initial purchase price completely over a single flight.

Re: V22 Osprey
 

Nick,

You better head for the bunker, grab yer Kevlar underwear.....sully the "Concorde"? Yikes...."Incoming!"

Re: V22 Osprey
 

Nick,

How would the X2 stack up if there was any amount of hovering in the mission?

-- IFMU

Re: V22 Osprey
 

Nick, I'm beginning to see your approach. When planning the machine, if you seperate the procurement costs from the operating costs, it doesn't matter if you spread procurement costs over one mission or over the life of the machine.

However, I doubt an operator would ever work that way. I was comparing a North American built sporty family sedan to a similiar performing German one. Operating costs (mostly mileage) were approximately the same, but the German one cost twice as much. However, the safety and reliability of the German car and the quality of the engineering convinced me that it was worth more than twice the North American one. The first trip home would have been safer but (using your statistic) that would have cost me $4,000 per mile for that safety. Had I considered your statistic rather than the decrease in the long term operating costs due to the reliability I wouldn't have ever thought that the German was the better choice.

Not a very good story because in the end I bought the North American one because my wife liked the color choices better.

If by some miracle the V22 proves to need $1 of maintenance for every 900 flight hours, then that fact would never appear in your stats, but would be very influential in choosing a machine.

The point is that the decision of which machine to procure should ultimately compare overall performance and suitability with average hourly cost of operation over the vehicle's lifetime. That average hourly cost would not have a $120 million increment (60 minutes x $2 million/minute) due to the purchase price of $100 million.

Re: V22 Osprey
 

IFMU,
I am not privy to the latest info, but flew the ABC back when, and understand the concept well. The counter rotating coaxial design is at home in the hover, and is very efficient, as well as having unlimited yaw control. Dave Jackson can go on from here!

It is optimized for hover, except for the +10% lost payload it suffers from carrying the propulsor and shroud that allow it to go to high speed.