What's the latest news of the V22 Osprey?
zd,
I would love to see the what the 22 will hover out-of-ground effect at 10,000 feet would be...in the summer? Then....compare that to both the 47 and 53 both in raw numbers and as a percentage of MAUW for vertical takeoff at sea level.
I would love to see the what the 22 will hover out-of-ground effect at 10,000 feet would be...in the summer? Then....compare that to both the 47 and 53 both in raw numbers and as a percentage of MAUW for vertical takeoff at sea level.
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"Allison in the V22 and the PT6 variant in the 609 ... LTC1K-4K variant of the T53 (XV-15) and the T800 (US-2) ... vertical-capable."
I'm suprised they haven't got a 3 or 4 engine version on the drawing board, to push up payload. This would also help with the eng-failure during transition problem, which i imagine could be a real problem with low speed low level work over unfriendly territory.
There is going to be some good competition once Sikorsky aim their coaxial development towards V-22 performance figures. A lot of research will be needed to get the rotors to be as efficient as a fixed wing at speed though, requiring active twist and variable RPM. Much better in hover efficiency though.
Mart
I'm suprised they haven't got a 3 or 4 engine version on the drawing board, to push up payload. This would also help with the eng-failure during transition problem, which i imagine could be a real problem with low speed low level work over unfriendly territory.
There is going to be some good competition once Sikorsky aim their coaxial development towards V-22 performance figures. A lot of research will be needed to get the rotors to be as efficient as a fixed wing at speed though, requiring active twist and variable RPM. Much better in hover efficiency though.
Mart
Last edited by Graviman; 14th Jul 2005 at 19:45.
There once was a competition was there not....ABC versus Tiltrotor? Seems I recall hearing of some flying going on over at Mother Rucker or somewhere betwist the two machines.
As I recall...a kind of squatty, curly headed Greek looking fella was in the ABC.
Just testing the waters....."Mark Twain!" (In the mail Nick....)
As I recall...a kind of squatty, curly headed Greek looking fella was in the ABC.
Just testing the waters....."Mark Twain!" (In the mail Nick....)
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The 4-engine version is the quad tilt rotor or QTR - a good summary is at AHS QTR page.
Lots of fun stuff on Bell's other tilt studies at AIAA unbuilt VSTOL. Pretty rare so see concept work like this released for public consumption.
I/C
Lots of fun stuff on Bell's other tilt studies at AIAA unbuilt VSTOL. Pretty rare so see concept work like this released for public consumption.
I/C
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Coincidentally I just got done reading a writeup about the V22 in the July Wired magazine (of all places!). It's actually a pretty good article, other than its title ("Saving the Pentagon's Killer Chopper-Plane"!).. It covers the program's history, some details about the four crashes that I hadn't seen elsewhere, and focuses on the work that's gone on since those accidents.
I have been very critical of the tiltrotor in the past - at least for tactical military stuff (I have to admit that I think the BA609 is a helluva nice looking ship and would love the opp to fly one!). I will still be watching with great interest as they deploy the aircraft in large numbers, but I came away from the article thinking that it's not *as much* of a boondoggle and terrible idea as I thought before. But at $105M per copy (this is GlobalSecurity.org's estimate of the *real* cost), every one they lose due to "whatever" is going to hurt.
Dave Blevins
I have been very critical of the tiltrotor in the past - at least for tactical military stuff (I have to admit that I think the BA609 is a helluva nice looking ship and would love the opp to fly one!). I will still be watching with great interest as they deploy the aircraft in large numbers, but I came away from the article thinking that it's not *as much* of a boondoggle and terrible idea as I thought before. But at $105M per copy (this is GlobalSecurity.org's estimate of the *real* cost), every one they lose due to "whatever" is going to hurt.
Dave Blevins
The MH-47E...fanciest version and equivalent to the CSAR version of the Osprey goes off the lot for about 40 Million Dollars vice the 105 million Dollar price tag of the Osprey. Price creep is bound to happen on the Osprey....so we can assume about a 3:1 ratio of top line Chinooks for the price of one Osprey based upon purchase price alone. The Sea Stallion would be about the same price....and again about a 3:1 advantage in numbers.
In the first six months of the war against terrorism, Night Stalker Chinooks flew more than 200 combat missions totaling about 2,000 flight hours. The Chinooks flew as high as 16,000 feet (which forced crews to use oxygen systems) for as long as 15 hours. More than 70 of these missions, flown in the war's first three months, involved infiltration or removal of special operations troops behind enemy lines. Throughout, the Chinooks maintained a 99-percent mission readiness rate.
Again...know where my vote goes....sorry Bell....no Osprey for this guy.
In the first six months of the war against terrorism, Night Stalker Chinooks flew more than 200 combat missions totaling about 2,000 flight hours. The Chinooks flew as high as 16,000 feet (which forced crews to use oxygen systems) for as long as 15 hours. More than 70 of these missions, flown in the war's first three months, involved infiltration or removal of special operations troops behind enemy lines. Throughout, the Chinooks maintained a 99-percent mission readiness rate.
Again...know where my vote goes....sorry Bell....no Osprey for this guy.
Last edited by SASless; 14th Jul 2005 at 23:49.
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"The 4-engine version is the quad tilt rotor or QTR"
With a shaft required from front wing/rotor set to rear wing/rotor set, that would have to be some drivetrain - unless they "assume" no total front/rear eng failure...
"Lots of fun stuff on Bell's other tilt studies at AIAA unbuilt VSTOL."
Interesting stuff here. I guess they opted early on for a distributed powertrain to keep drivetrain mass down (torque limit on one engine operation). I still bet that G/Box and Drivelines make up a significant proportion of the empty weight.
"MH-47E ... 40 Million Dollars vice the 105 (plus creep) million Dollar price tag of the Osprey"
Tandems have been around a while now since Piasecki's "Flying Banana". I imagine that time will (eventually) see this technology cheapen too, as it proves itself (or otherwise
).
"Chinooks maintained a 99-percent mission readiness rate."
That's an impressive statistic!
Mart
With a shaft required from front wing/rotor set to rear wing/rotor set, that would have to be some drivetrain - unless they "assume" no total front/rear eng failure...
"Lots of fun stuff on Bell's other tilt studies at AIAA unbuilt VSTOL."
Interesting stuff here. I guess they opted early on for a distributed powertrain to keep drivetrain mass down (torque limit on one engine operation). I still bet that G/Box and Drivelines make up a significant proportion of the empty weight.
"MH-47E ... 40 Million Dollars vice the 105 (plus creep) million Dollar price tag of the Osprey"
Tandems have been around a while now since Piasecki's "Flying Banana". I imagine that time will (eventually) see this technology cheapen too, as it proves itself (or otherwise
)."Chinooks maintained a 99-percent mission readiness rate."
That's an impressive statistic!
Mart
Think of the engineering it took to design the Osprey for shipboard service....and either engine drive of the rotors...with rotor translation and blade fold capability. Someone probably has an ulcer by now.
One look at the CH-46 heads or the CH-53 heads with blade fold will give you headaches too.
One look at the CH-46 heads or the CH-53 heads with blade fold will give you headaches too.
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The $100M price tag for a vanilla MV-22 sounds high - most estimates are closer to $71-74M, with NAVAIR demanding a reduction to $58M by 2010. The mission-equipped CV-22 is probably closer to the $100M mark (just as SOAR's birds cost $20M to upgrade from Ds or Fs).
The oft-quoted 99% mission readiness rate for the MH-47E (during 72 missions over a three month period in OEF) indicates a carefully-planned schedule and a hard-worked ground crew ! Publicly-released mission capable rates for the CH-47D in OEF are closer to 60%, and 80% for OIF.
That said, the Chinook’s achievements in-theater have been spectacular, and the uprated donks have substantially improved the fleet’s performance (it wasn't that long ago that Congress and the media were taking pot shots at the MH-47E for its lack of high-alt performance).
SASless - you're spot-on with the blade folding comments. While it does meet the Corps' spotting requirements, that little trick doesn't come cheap, and the weight penalty is significant.
Graviman - it'll really get interesting once the electric drive systems now entering mass production for automotive and marine applications begin to improve in efficiency, reliability and weight. That then opens up the possibility of a mission-optimized powerplant located on the aircraft's fuselage driving motor-driven proprotors, thereby doing away with the cost and complexity of individual powertrains on each wing.
I/C
The oft-quoted 99% mission readiness rate for the MH-47E (during 72 missions over a three month period in OEF) indicates a carefully-planned schedule and a hard-worked ground crew ! Publicly-released mission capable rates for the CH-47D in OEF are closer to 60%, and 80% for OIF.
That said, the Chinook’s achievements in-theater have been spectacular, and the uprated donks have substantially improved the fleet’s performance (it wasn't that long ago that Congress and the media were taking pot shots at the MH-47E for its lack of high-alt performance).
SASless - you're spot-on with the blade folding comments. While it does meet the Corps' spotting requirements, that little trick doesn't come cheap, and the weight penalty is significant.
Graviman - it'll really get interesting once the electric drive systems now entering mass production for automotive and marine applications begin to improve in efficiency, reliability and weight. That then opens up the possibility of a mission-optimized powerplant located on the aircraft's fuselage driving motor-driven proprotors, thereby doing away with the cost and complexity of individual powertrains on each wing.
I/C
Excellent presentation Nick....I feel vindicated on my comments about the Osprey versus the equivalent helicopters.
The one thing you did not address was the airspeed of the Osprey in the external cargo mode. How does that affect the numbers? Commonsense says the external load being carried will determine the airspeed the machine can fly (in general) and thus any airspeed advantage the Osprey had would evaporate like fried chicken at a family reunion.
The one thing you did not address was the airspeed of the Osprey in the external cargo mode. How does that affect the numbers? Commonsense says the external load being carried will determine the airspeed the machine can fly (in general) and thus any airspeed advantage the Osprey had would evaporate like fried chicken at a family reunion.
Good point SaSless,
But how much forward speed does the V-22 need for it's wings to create the lift needed to stay in the air ?? 70-80knots maybe??
and that speed is over Vne of most external loads.
Is it only able to sling in "hover mode" then??
I think the number would affected then, increasing the helicopters advantage even more. just a thought
Can't help it but sometimes this whole tiltrotor thing reminds me of the movie "Pentagon Wars"
does anyone else remember that one ???
But how much forward speed does the V-22 need for it's wings to create the lift needed to stay in the air ?? 70-80knots maybe??
and that speed is over Vne of most external loads.
Is it only able to sling in "hover mode" then??
I think the number would affected then, increasing the helicopters advantage even more. just a thought
Can't help it but sometimes this whole tiltrotor thing reminds me of the movie "Pentagon Wars"
does anyone else remember that one ???
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Regarding External Load Weight and Speed Capabilities...
OSPREY ESTABLISHES SEVERAL NEW RECORDS
By RICHARD R. BURGESS, Managing Editor
Bell-Boeing's MV-22B Osprey tiltrotor transport has set an unofficial load-carrying world record for rotorcraft by carrying a 10,000-pound external load at a speed of 220 knots. The load was attached to the Osprey's aft cargo hook by a Marine helicopter support team, using procedures developed during 15 prior hookups.
During a series of 20 flights in 10 days, the Osprey eventually had reached the required speed of 220 knots while carrying a load of 6,000 pounds. The 10,000-pound load was carried on a later flight.
"It was basically transparent that there was an external load once the V-22 was airborne from the hookup, into forward flight, and during the transition into the airplane mode," said Bill Leonard, a developmental test pilot. "The V-22 was remarkably easy to operate and handled the 6,000-pound load extremely well."
"The demonstration of the V-22's ability to carry external loads at very high speeds is a significant accomplishment," said John Buyers, Bell-Boeing's V-22 program director at Naval Air Station Patuxent River, Md. "This is the fastest airspeed any rotorcraft has carried an external load, no matter what the weight."
"What is significant about the V-22 external loads testing is not so much the weight ... [the tiltrotor] is carrying but the coupling of the weight and the speed," said Steve Grohsmeyer, Boeing's senior V-22 experimental test pilot. "Helicopters have lifted much heavier external loads but have not reached speeds of 220 knots while carrying these loads." The external load-carrying capability of the MV-22B is considered critical to the amphibious-lift requirements postulated by the Marine Corps for the 21st century.
In a later test flight, Osprey No. 8 carried a 6,500-pound HMMWV (high-mobility multiwheeled vehicle, or "Humvee") in an inverted V-sling at 120 knots and at a 60-degree engine nacelle angle. "The aircraft was very stable in the hover and forward flight," said Grohsmeyer, who flew the test mission with Maj. Bill Witzig. "It was well-damped following acroservoelastic and flying qualities excitations--both the aircraft and the load flew very well. We should feel very confident about taking this load faster if we want to."
"Like previous external load tests, this test went without a hitch and is a testament to the professionalism and efficiency of all those involved," said Phil Dunford, Bell-Boeing's director of flight test for the V-22 program.
Further tests will involve carrying--at 220 knots--15,000 pounds suspended from the forward and aft cargo hooks.
The first time a tiltrotor was used to carry external loads occurred earlier in the decade when an FSD (full-scale development) V-22A carried 4,000 pounds while reaching a speed of 174 knots.
By RICHARD R. BURGESS, Managing Editor
Bell-Boeing's MV-22B Osprey tiltrotor transport has set an unofficial load-carrying world record for rotorcraft by carrying a 10,000-pound external load at a speed of 220 knots. The load was attached to the Osprey's aft cargo hook by a Marine helicopter support team, using procedures developed during 15 prior hookups.
During a series of 20 flights in 10 days, the Osprey eventually had reached the required speed of 220 knots while carrying a load of 6,000 pounds. The 10,000-pound load was carried on a later flight.
"It was basically transparent that there was an external load once the V-22 was airborne from the hookup, into forward flight, and during the transition into the airplane mode," said Bill Leonard, a developmental test pilot. "The V-22 was remarkably easy to operate and handled the 6,000-pound load extremely well."
"The demonstration of the V-22's ability to carry external loads at very high speeds is a significant accomplishment," said John Buyers, Bell-Boeing's V-22 program director at Naval Air Station Patuxent River, Md. "This is the fastest airspeed any rotorcraft has carried an external load, no matter what the weight."
"What is significant about the V-22 external loads testing is not so much the weight ... [the tiltrotor] is carrying but the coupling of the weight and the speed," said Steve Grohsmeyer, Boeing's senior V-22 experimental test pilot. "Helicopters have lifted much heavier external loads but have not reached speeds of 220 knots while carrying these loads." The external load-carrying capability of the MV-22B is considered critical to the amphibious-lift requirements postulated by the Marine Corps for the 21st century.
In a later test flight, Osprey No. 8 carried a 6,500-pound HMMWV (high-mobility multiwheeled vehicle, or "Humvee") in an inverted V-sling at 120 knots and at a 60-degree engine nacelle angle. "The aircraft was very stable in the hover and forward flight," said Grohsmeyer, who flew the test mission with Maj. Bill Witzig. "It was well-damped following acroservoelastic and flying qualities excitations--both the aircraft and the load flew very well. We should feel very confident about taking this load faster if we want to."
"Like previous external load tests, this test went without a hitch and is a testament to the professionalism and efficiency of all those involved," said Phil Dunford, Bell-Boeing's director of flight test for the V-22 program.
Further tests will involve carrying--at 220 knots--15,000 pounds suspended from the forward and aft cargo hooks.
The first time a tiltrotor was used to carry external loads occurred earlier in the decade when an FSD (full-scale development) V-22A carried 4,000 pounds while reaching a speed of 174 knots.
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Interesting presentation Nick. Puts the facts into perspective.
"Someone probably has an ulcer by now."
Certainly looks like some serious engineering has been required...
"... electric drive systems ... improve in efficiency, reliability and weight.... a mission-optimized powerplant located on the aircraft's fuselage driving motor-driven proprotors..."
I'm a complete convert of the hybrid helicopter, primarily for reasons of improved efficiency without mission compromise (generally through v-RRPM). Best power/weight is using NdFeB magnet technology, in a disk motor to reduce the iron reluctance circuit mass. Commercial units already exceed kW/kg by running at very high rpm (couldn't find an exact figure by googling).
My only concern is that you will always need to design for failsafe operation, primarily due to the controller complexity required for brushless DC motors (magnet rotates, while static windings are switched). In a tilt-rotor this means you always need the tip-to-tip driveshaft, in case one motor fails. You can triple up of course, but i will be interested to see which way the technology goes...
Mart
"Someone probably has an ulcer by now."
Certainly looks like some serious engineering has been required...
"... electric drive systems ... improve in efficiency, reliability and weight.... a mission-optimized powerplant located on the aircraft's fuselage driving motor-driven proprotors..."
I'm a complete convert of the hybrid helicopter, primarily for reasons of improved efficiency without mission compromise (generally through v-RRPM). Best power/weight is using NdFeB magnet technology, in a disk motor to reduce the iron reluctance circuit mass. Commercial units already exceed kW/kg by running at very high rpm (couldn't find an exact figure by googling).
My only concern is that you will always need to design for failsafe operation, primarily due to the controller complexity required for brushless DC motors (magnet rotates, while static windings are switched). In a tilt-rotor this means you always need the tip-to-tip driveshaft, in case one motor fails. You can triple up of course, but i will be interested to see which way the technology goes...
Mart
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I think all the lifting, etc arguments are irrelevant - I can see a real niche market for this already and would be more interested in comparisons between a 609 and a 76, or any other typical corporate helicopter.
Phil
Phil
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I understand that the V-22 is capable of carrying external loads at pretty high speed and that is fine but the question is can the load itself survive it? A humvee is not meant to go 200 mph! In fact I recall some problems in testing the Army's new FMTV vehicle doing sling loads. The chinnok pilots were able to cruise along at a pretty good clip with the truck in tow....so fast that it would crack the windshields from wind forces against it. It was decided that the truck should be carried backwards so as to reduce the wind force on the front. This may work for a planned mission but I doubt the marines would want to remove all their tarp and bow kits and put braces on the windows and doors to keep from ruining their vehicles just so the V-22 can sling them into a hot LZ or beach at 200 knots. This would leave a bunch of Marines sitting on the beach trying to put their wheels back together while being shot at....not a good scenario in my mind.
From the numbers I have read the 609 and the 76 have similar useful loads but the power required is drastically different. You can get (or used ot be able to get) a PT6 powered S-76 which has about 980HP each. The PT6 in the 609 puts out I think somethig like 1680 HP each. I would assume that HP increase would be needed in the helicopter mode but I'm not sure how much less it will be for the airplane mode.
Max
From the numbers I have read the 609 and the 76 have similar useful loads but the power required is drastically different. You can get (or used ot be able to get) a PT6 powered S-76 which has about 980HP each. The PT6 in the 609 puts out I think somethig like 1680 HP each. I would assume that HP increase would be needed in the helicopter mode but I'm not sure how much less it will be for the airplane mode.
Max
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Diversion from the thread
Graviman,
In the thread 'Future rotorcraft control systems' the question was;
"Why could not a reasonably large diameter, linear induction disk motor be an integral part of a special rotor hub...?"
Your reply was;
"Why not, but aerospace motors and generators run at 80'000 rpm regardless of shape. Any less and you are just introducing unecessary weight."
In this thread you say.
"Best power/weight is using NdFeB magnet technology, in a disk motor to reduce the iron reluctance circuit mass."
Back to the thread
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Dave,
That's easy: you need both! Since the application is aerospace propulsion i was making the assumption that the motor/gen would already be geared to run at as high RPM as practical. Having got the most power for a given torque, the ideal design then seeks to reduce the mass for that torque. This is accomplished by minimising NdFeB magnetic circuit length, which is the objective of disk motors.
To get partly up to speed check out www.uqm.com
I have read about higher performance developments for various applications, but couldn't find any of the ones i was thinking of in my quick google session...
For a rotor hub application you would still need to gear the motor down, requiring a serious epicyclic reduction gearbox. In a tiltrotor this drivetrain rotates into the airflow, in an interleaving heli the drivetrain would likely present a serious drag element. Notice i still state that a mechanical drivetrain would be required in the tiltrotor. Your application was also to try to remove the mechanical drivetrain, which i still believe to be impractical.
Mart
That's easy: you need both! Since the application is aerospace propulsion i was making the assumption that the motor/gen would already be geared to run at as high RPM as practical. Having got the most power for a given torque, the ideal design then seeks to reduce the mass for that torque. This is accomplished by minimising NdFeB magnetic circuit length, which is the objective of disk motors.
To get partly up to speed check out www.uqm.com
I have read about higher performance developments for various applications, but couldn't find any of the ones i was thinking of in my quick google session...
For a rotor hub application you would still need to gear the motor down, requiring a serious epicyclic reduction gearbox. In a tiltrotor this drivetrain rotates into the airflow, in an interleaving heli the drivetrain would likely present a serious drag element. Notice i still state that a mechanical drivetrain would be required in the tiltrotor. Your application was also to try to remove the mechanical drivetrain, which i still believe to be impractical.
Mart
Last edited by Graviman; 15th Jul 2005 at 23:36.
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junglyAEO,
Your logic seems to be interesting. I think what you said is that when we find a cheaper, similarly sized vehicle that does better, we are wrong. Or does that mean when the USMC managed to find a machine that had half the efficiency at twice the price that they were wrong?
If your Doctor used the logic you use, he would amputate your feet to cure your hangnail.
With similar logic, several Marines said to me that the 53E is a "heavy helicopter" and a V-22 is a "medium" so they don't compare! Same deck spot factor, half the cost, twice the payload, 150% of the transport capability, but not a better choice.
Paco, Of course we should compare the 609 to an S-76, otherwise we would have no contest! How about comparing it to a 206 to be sure it looks good? Or maybe a Bell 47?
Your logic seems to be interesting. I think what you said is that when we find a cheaper, similarly sized vehicle that does better, we are wrong. Or does that mean when the USMC managed to find a machine that had half the efficiency at twice the price that they were wrong?
If your Doctor used the logic you use, he would amputate your feet to cure your hangnail.
With similar logic, several Marines said to me that the 53E is a "heavy helicopter" and a V-22 is a "medium" so they don't compare! Same deck spot factor, half the cost, twice the payload, 150% of the transport capability, but not a better choice.
Paco, Of course we should compare the 609 to an S-76, otherwise we would have no contest! How about comparing it to a 206 to be sure it looks good? Or maybe a Bell 47?