Go Back  PPRuNe Forums > Aircrew Forums > Rotorheads
Reload this Page >

V-280 wins US ARMY FLRAA contract

Rotorheads A haven for helicopter professionals to discuss the things that affect them

V-280 wins US ARMY FLRAA contract

Old 15th May 2023, 18:39
  #241 (permalink)  
 
Join Date: Mar 2005
Location: Land of the Angles
Posts: 359
Received 2 Likes on 2 Posts
A good point.

Although, the precursor to FLRAA was JMR/FVL and in the early days, it was not so much about speed and range (I believe 230kn and a combat radius of 263nm were the original JMR-Medium requirements), but about getting a solution that provided a broad range of advanced capabilities, technologies and efficiencies.

At the point of having to choose a preferred solution in late 2022, I'm not convinced either TD provided what the US Army had envisioned way back in the early days of JMR, but the move away from Europe to the Pacific, with range and speed being two key factors, certainly for any USMC solution, kinda left X2 behind.

That and Team Defiant were clearly not on the same page when it came to interpretating the requirements the way the author had intended.

JMR-Medium was initially an $80Bn program for some 4,000 machines, but it does not look like the FLRAA solution will end up anything like being that big, which for me, backs up my 2nd paragraph, but time will tell.
Hilife is offline  
Old 16th May 2023, 01:11
  #242 (permalink)  
 
Join Date: Dec 2010
Location: USA
Posts: 246
Received 23 Likes on 19 Posts
Originally Posted by noneofyourbusiness
Commando Cody
Tiltrotor wins on speed and range, which is what the Army wanted. So why did Sikorsky bid what was likely to be a losing design? People rightfully questioned whether the X2 could be scaled up to a larger size. Defiant proved the answer is yes.

You are right regarding engines, the Honeywell engine on Defiant was going to be scaled up to provide 7500 hp each compared to the demonstrator 5000 hp, giving a total of 15000 hp, which would provide more lift. Given larger engines and more time, hitting 260 knots, matching the X2, seems plausible. Though fuel burn rate might be very high.

Raider is intriguing regarding its low max speed, it had plenty of engine. Maybe Boeing or Sikorsky figured out how to solve the problem for Defiant? But I don't see how they would have been able to significantly improve aerodynamics. So maybe improving vibration control was the solution?
To my mind Sikorsky was hoping the problems that had plagued X2 so far could be worked out and at a lower cost than a Tilt-Rotor. They may also have felt that if performance of the two competitors was close, Army's familiarity with them plus their political influence would pull them through. Keep in mind X2 was all they had and they had spent some significant money on it over the years. I don't think it can be said that Defiant proved X2 technology could be scaled up to this size. At best it would have to be a profound, "Maybe".

You know, one of Sikorsky's complaints in filing the protest was their claim that Army had always wanted a Tilt-Rotor and this was reflected in their original requirements which they said were later changed, to allow others to compete. I take this to be referring to the original anticipated speed requirement of 250 knots which in the final specs was lowered to 235 knots. Given that Sikorsky said that on Defiant they had lots more power they hadn't yet used, I don't believe more power would have gotten them any more speed or they would have claimed that. . The X2 demonstrator briefly hit 260 knots, but was grounded after that. I think that like Bell, it was the hot and high HOGE requirement that drove ultimate power required.

Vibration control undoubtedly would have been a big factor in higher speeds, but with what we've seen so far is it fair to say that the problem was solved? They came up short in a number of other areas as well.
Commando Cody is offline  
Old 16th May 2023, 01:58
  #243 (permalink)  
 
Join Date: Dec 2010
Location: USA
Posts: 246
Received 23 Likes on 19 Posts
Originally Posted by Hilife
A good point.

Although, the precursor to FLRAA was JMR/FVL and in the early days, it was not so much about speed and range (I believe 230kn and a combat radius of 263nm were the original JMR-Medium requirements), but about getting a solution that provided a broad range of advanced capabilities, technologies and efficiencies.

At the point of having to choose a preferred solution in late 2022, I'm not convinced either TD provided what the US Army had envisioned way back in the early days of JMR, but the move away from Europe to the Pacific, with range and speed being two key factors, certainly for any USMC solution, kinda left X2 behind.

That and Team Defiant were clearly not on the same page when it came to interpretating the requirements the way the author had intended.

JMR-Medium was initially an $80Bn program for some 4,000 machines, but it does not look like the FLRAA solution will end up anything like being that big, which for me, backs up my 2nd paragraph, but time will tell.
As always when the Gov't is involved, there's an alphabet soup. JMR/JMR-TD was the technology demonstration phase and it provided data to FVL, which was for operational vehicle; FLRAA and FARA are two of the operational vehicle categories for which one aircraft will be selected for each. The Marines my choose to leverage FLRAA technology, but it's not a guarantee that they'l just l buy a marinized version of the V-280. Regarding FARA, USMC does not have the kind of mission for which it is designed..

Nothing is ever simple.
Commando Cody is offline  
Old 16th May 2023, 11:15
  #244 (permalink)  
 
Join Date: Jul 2018
Location: Indianapolis
Posts: 87
Received 9 Likes on 7 Posts
Originally Posted by Commando Cody
To my mind Sikorsky was hoping the problems that had plagued X2 so far could be worked out and at a lower cost than a Tilt-Rotor. They may also have felt that if performance of the two competitors was close, Army's familiarity with them plus their political influence would pull them through. Keep in mind X2 was all they had and they had spent some significant money on it over the years. I don't think it can be said that Defiant proved X2 technology could be scaled up to this size. At best it would have to be a profound, "Maybe".

You know, one of Sikorsky's complaints in filing the protest was their claim that Army had always wanted a Tilt-Rotor and this was reflected in their original requirements which they said were later changed, to allow others to compete. I take this to be referring to the original anticipated speed requirement of 250 knots which in the final specs was lowered to 235 knots. Given that Sikorsky said that on Defiant they had lots more power they hadn't yet used, I don't believe more power would have gotten them any more speed or they would have claimed that. . The X2 demonstrator briefly hit 260 knots, but was grounded after that. I think that like Bell, it was the hot and high HOGE requirement that drove ultimate power required.

Vibration control undoubtedly would have been a big factor in higher speeds, but with what we've seen so far is it fair to say that the problem was solved? They came up short in a number of other areas as well.
Matching X2 performance just means achieving high speed for a short time. X2 never demonstrated anything else. It may have been shaking like a son of a gun. If vibration was the problem, then Sikorsky or Boeing solved the problem well enough to allow Defiant to nearly match the X2 demonstrator speed. We do know Defiant flew few hours, and as far as I know, never allowed Army pilots to fly the Defiant. The last Defiant video released appeared pretty impressive, which occurred after the final proposals were turned in.

Lol - Sikorsky whining the Army wanted a tiltrotor all along. Reply to Sikorsky: Is water wet? Of course dummy.

Last edited by noneofyourbusiness; 16th May 2023 at 12:35. Reason: untangling my word salad
noneofyourbusiness is offline  
Old 16th May 2023, 11:31
  #245 (permalink)  
 
Join Date: Jul 2018
Location: Indianapolis
Posts: 87
Received 9 Likes on 7 Posts
Originally Posted by Hilife
A good point.

Although, the precursor to FLRAA was JMR/FVL and in the early days, it was not so much about speed and range (I believe 230kn and a combat radius of 263nm were the original JMR-Medium requirements), but about getting a solution that provided a broad range of advanced capabilities, technologies and efficiencies.

At the point of having to choose a preferred solution in late 2022, I'm not convinced either TD provided what the US Army had envisioned way back in the early days of JMR, but the move away from Europe to the Pacific, with range and speed being two key factors, certainly for any USMC solution, kinda left X2 behind.

That and Team Defiant were clearly not on the same page when it came to interpretating the requirements the way the author had intended.

JMR-Medium was initially an $80Bn program for some 4,000 machines, but it does not look like the FLRAA solution will end up anything like being that big, which for me, backs up my 2nd paragraph, but time will tell.
Interesting, thanks. Sikorsky engineering management just did not have the cojones to bid a tiltrotor for FLRAA. I imagine they **** a brick when they saw the speed and range requirements. Boeing is just plain clueless.

Last edited by noneofyourbusiness; 16th May 2023 at 12:14.
noneofyourbusiness is offline  
Old 16th May 2023, 13:36
  #246 (permalink)  
CTR
 
Join Date: Oct 2007
Location: Texas
Posts: 288
Likes: 0
Received 39 Likes on 22 Posts
Originally Posted by Commando Cody
To my mind Sikorsky was hoping the problems that had plagued X2 so far could be worked out and at a lower cost than a Tilt-Rotor. They may also have felt that if performance of the two competitors was close, Army's familiarity with them plus their political influence would pull them through. Keep in mind X2 was all they had and they had spent some significant money on it over the years. I don't think it can be said that Defiant proved X2 technology could be scaled up to this size. At best it would have to be a profound, "Maybe".

You know, one of Sikorsky's complaints in filing the protest was their claim that Army had always wanted a Tilt-Rotor and this was reflected in their original requirements which they said were later changed, to allow others to compete. I take this to be referring to the original anticipated speed requirement of 250 knots which in the final specs was lowered to 235 knots. Given that Sikorsky said that on Defiant they had lots more power they hadn't yet used, I don't believe more power would have gotten them any more speed……
CC,

I concur your analysis, but I believe Sikorsky had dual path to winning in their strategy.

One path, was as you stated, hope that you can work out the X-2 technology for a Defiant size aircraft adequately enough to compete. Also, Sikorsky’s and Boeing’s combined corporate ego believed Bell could not succeed in producing a viable demonstrator aircraft.

The second path, was ensuring that the FLRAA program would be either canceled, or so underfunded, it would fail to succeed. This would allow Sikorsky and Boeing to continue building their legacy aircraft as long as possible.

Following Sikorsky’s lack of success of the first path, this second path of insuring FLRAA fails is now Sikorsky’s main strategy . This is best illustrated by the following video of Connecticut senator Chris Murphy questioning the Secretary of the Army.






Last edited by CTR; 16th May 2023 at 18:03.
CTR is offline  
Old 16th May 2023, 17:50
  #247 (permalink)  
Thread Starter
 
Join Date: Nov 2010
Location: Earth
Posts: 700
Received 15 Likes on 10 Posts
Originally Posted by CTR
Following the failure of the first path, this second path of insuring FLRAA fails is now Sikorsky’s main strategy . This is best illustrated by the following video of Connecticut senator Chris Murphy questioning the Secretary of the Army.
The mental gymnastics required by the messaging senator Murphy continues to espouse is really quite remarkable. To be making the argument that a new tiltrotor will be unaffordable simply because the first-of-its-kind production tiltrotor predecessor (designed to insanely costly maritime requirements) was expensive and difficult to develop, while the entirely unproven competing platform that has never even had a remotely successful demonstrator predecessor is somehow the less risky and a more rational selection...well that pretty much beguiles logic.

The V-280 was designed from inception to incorporate all the lessons learned in design and manufacturing from XV-3, XV-15, 609, and V-22. It also contained specific design details (eg straight wing) to meet cost targets that the Army specified early in the JMR programme. The maturity of tiltrotors in general is now essentially beyond reasonable question, yet senator Murphy's "parochial" interest in pushing what is pretty blatant propaganda continues.
SansAnhedral is offline  
Old 16th May 2023, 20:02
  #248 (permalink)  
 
Join Date: Jul 2018
Location: Indianapolis
Posts: 87
Received 9 Likes on 7 Posts
Sikorsky strove to be second best. Pick us, we're kinda good. But it isn't about what Sikorsky wants to build, it's about what the customer wants. When Bob Lutz was at Chrysler, he saved Chrysler by replacing the fading K cars with modern cars, which were well received. Lutz said that you wouldn't sell many cars if you were everyone's second choice.
noneofyourbusiness is offline  
The following users liked this post:
Old 18th May 2023, 14:12
  #249 (permalink)  
 
Join Date: Jul 2018
Location: Indianapolis
Posts: 87
Received 9 Likes on 7 Posts
Next up will be FARA. The Army will pick what is best for their soldiers, as their lives depend on this equipment. This will override jobs in Connecticut concerns. The clutched pusher prop on Raider X is a potential problem. Sikorsky will be very careful, most of the parts in the clutch will be flight safety parts. Still, anything mechanical can fail, even if it only happens once. Unlike a Cessna where everyone knows to stay away from the prop, people will become careless because they think the prop will never be turning on the ground, until one time it is. This is insidious.

There is no significant reason to select the underpowered Raider X unless it is substantially faster than Invictus. Even then, it depends on whether this increased speed is considered to be much of an advantage by the Army, if Invictus meets the required speed. Simplicity improves reliability, safety and maintainability, and Invictus is simpler than Raider X.

The Army probably will not go to a twin engine melt and repour. Keeping the GE engine would give us two 3000 hp engines, or 6000 hp, compared to the Apache 4000 hp. Essentially this would give us a growth Apache, not a scout helicopter. It is unlikely the Army would pull the plug on its new engine and go back to using something like two older technology T800 engines. The new GE engine is a major improvement over previous engines.
noneofyourbusiness is offline  
Old 18th May 2023, 14:57
  #250 (permalink)  
Thread Starter
 
Join Date: Nov 2010
Location: Earth
Posts: 700
Received 15 Likes on 10 Posts
Originally Posted by noneofyourbusiness
The Army probably will not go to a twin engine melt and repour.
Hold onto your butt.

Originally Posted by noneofyourbusiness
The clutched pusher prop on Raider X is a potential problem. Sikorsky will be very careful, most of the parts in the clutch will be flight safety parts. Still, anything mechanical can fail, even if it only happens once. Unlike a Cessna where everyone knows to stay away from the prop, people will become careless because they think the prop will never be turning on the ground, until one time it is. This is insidious.
Remember that the S-97 pusher is wet clutched so it does not stop rotating. Defiant used a dry clutch to attempt to demonstrate the safety aspect of stopping it during ground ops. Unfortunately that clutch sh*t the bed and the Army knows all about it.
SansAnhedral is offline  
The following 2 users liked this post by SansAnhedral:
Old 18th May 2023, 16:55
  #251 (permalink)  
 
Join Date: Jul 2018
Location: Indianapolis
Posts: 87
Received 9 Likes on 7 Posts
Originally Posted by SansAnhedral
Hold onto your butt.



Remember that the S-97 pusher is wet clutched so it does not stop rotating. Defiant used a dry clutch to attempt to demonstrate the safety aspect of stopping it during ground ops. Unfortunately that clutch sh*t the bed and the Army knows all about it.
At a gas turbine company, I sometimes worked on design of high power aerospace clutches. The wet clutch is always superior to a dry clutch. It is possible to design the Raider wet clutch to be unclutched while idling on the ground, so it sounds like the Raider clutch design is a botch job. A brake would still be needed on the prop, and the clutch plates would need to have spring separators, to make sure the plates separated when the clamp force was removed. A dry clutch has a much much greater wear rate of the clutch plates. Therefore the plates have to be very thick. Then the clamp load has to be massively increased because there are fewer plates. So the dry clutch ends up just as large or larger than the wet clutch. Oil must continuously be supplied to the clutch bearings even with a "dry" clutch. Likely Sikorsky did not account for the very high wear rate of the dry clutch plates. Think of needing 1.5 inch thick plates instead of .125 inch thick clutch plates. The thermal management of the dry clutch requires shielding around the red hot dry clutch plates, to keep from coking the bearings oil, or even starting a fire. Cooling air is required, and the best source here is engine bleed air. Do everything right, and the dry clutch still has a much shorter clutch plate life than a wet clutch.

The Sikorsky X-wing clutch design, scaled to size, would work just fine.

Last edited by noneofyourbusiness; 18th May 2023 at 22:58.
noneofyourbusiness is offline  
The following 2 users liked this post by noneofyourbusiness:
Old 19th May 2023, 10:17
  #252 (permalink)  
CTR
 
Join Date: Oct 2007
Location: Texas
Posts: 288
Likes: 0
Received 39 Likes on 22 Posts
Wet versus Dry

Another large benefit of a wet clutch over a dry clutch is more predictable coefficient of friction. The highest risk of damage in this clutch application is during engagement with the main rotors spinning and the propeller stopped. This must be achieved smoothly to prevent damage to the drive system.

With a dry clutch, the coefficient of friction is higher than on a wet clutch, and dry friction can change significantly with wear and temperature. This makes safety engaging a dry clutch in this application much more problematic.
CTR is offline  
The following 2 users liked this post by CTR:
Old 19th May 2023, 11:45
  #253 (permalink)  
 
Join Date: Feb 2015
Location: USA
Posts: 237
Received 47 Likes on 23 Posts
Originally Posted by noneofyourbusiness
At a gas turbine company, I sometimes worked on design of high power aerospace clutches. The wet clutch is always superior to a dry clutch. It is possible to design the Raider wet clutch to be unclutched while idling on the ground, so it sounds like the Raider clutch design is a botch job. A brake would still be needed on the prop, and the clutch plates would need to have spring separators, to make sure the plates separated when the clamp force was removed.

[paragraph removed]

The Sikorsky X-wing clutch design, scaled to size, would work just fine.
Raider's prop is just a foot or so from the YT706 exhaust, so it likely always spins, by design, to prevent excessive heating on the prop blades (if the prop were braked).

"X-Wing"... there's a technological dead end we haven't heard of in a long, long time.
SplineDrive is offline  
Old 19th May 2023, 12:23
  #254 (permalink)  
 
Join Date: Jul 2018
Location: Indianapolis
Posts: 87
Received 9 Likes on 7 Posts
Originally Posted by SplineDrive
Raider's prop is just a foot or so from the YT706 exhaust, so it likely always spins, by design, to prevent excessive heating on the prop blades (if the prop were braked).

"X-Wing"... there's a technological dead end we haven't heard of in a long, long time.
And the clutch design was fantastic, well before my time. Comparing it to some other "modern" clutches. Does JSF ring a bell?

I think is more likely to be an oversight in design to let the blades keep rotating on the ground. Not sure you would get much cooling effect with a relatively slow rpm rotation of the blades. The engine would be at ground idle condition, so maybe the exhaust is relatively cool.

If Sikorsky always needed to have the clutch engaged, there would be no reason to have a clutch.

I am guessing whoever designed the clutch wasn't aware you need spring separators to "unstick" the clutch plates. And maybe Sikorsky did not want to add the weight of a brake.

If Sikorsky needed to always keep the clutch engaged, there would be no reason to have a clutch.

Last edited by noneofyourbusiness; 19th May 2023 at 13:07.
noneofyourbusiness is offline  
Old 19th May 2023, 12:24
  #255 (permalink)  
 
Join Date: Jul 2018
Location: Indianapolis
Posts: 87
Received 9 Likes on 7 Posts
Originally Posted by CTR
Another large benefit of a wet clutch over a dry clutch is more predictable coefficient of friction. The highest risk of damage in this clutch application is during engagement with the main rotors spinning and the propeller stopped. This must be achieved smoothly to prevent damage to the drive system.

With a dry clutch, the coefficient of friction is higher than on a wet clutch, and dry friction can change significantly with wear and temperature. This makes safety engaging a dry clutch in this application much more problematic.
Exactly.
noneofyourbusiness is offline  
Old 19th May 2023, 14:42
  #256 (permalink)  
 
Join Date: Feb 2015
Location: USA
Posts: 237
Received 47 Likes on 23 Posts
Originally Posted by noneofyourbusiness
And the clutch design was fantastic, well before my time. Comparing it to some other "modern" clutches. Does JSF ring a bell?

I think is more likely to be an oversight in design to let the blades keep rotating on the ground. Not sure you would get much cooling effect with a relatively slow rpm rotation of the blades. The engine would be at ground idle condition, so maybe the exhaust is relatively cool.

If Sikorsky always needed to have the clutch engaged, there would be no reason to have a clutch.

I am guessing whoever designed the clutch wasn't aware you need spring separators to "unstick" the clutch plates. And maybe Sikorsky did not want to add the weight of a brake.

If Sikorsky needed to always keep the clutch engaged, there would be no reason to have a clutch.
“Declutching” down to a slow rpm basically eliminates the blade tip noise from the prop which, like a tail rotor, is far worse than the main rotor noise. Being low to the ground, blade tip erosion from a slow spinning prop is also improved. I think for a combat scout there are operational reasons to prefer a clutchable prop. Reduced power loss from prop profile drag as well. Is all this worth the cost/weight/complexity of a clutchable prop? Completely fair question. Raider included the technology as a demonstrator. I guess it’s possible it is eliminated on Raider-X as not being worth the penalties. We’ll have to see.
SplineDrive is offline  
The following 2 users liked this post by SplineDrive:
Old 19th May 2023, 14:54
  #257 (permalink)  
 
Join Date: Jul 2021
Location: Southern United States
Posts: 129
Likes: 0
Received 64 Likes on 32 Posts
With upturned exhaust on H-60 rotor blades need to be positioned on centerline to avoid “charring” during rotor brake starts. I suppose even slowly rotating the pusher prop would help, but seems to be a recipe for disaster for personnel operating around the aircraft.

I’ve heard that the pusher on Raider X is electric driven, I assume clutching of the drive system would still be required?

I used to be pretty solid in the co-axial camp but the more I hear about the challenges associated with maturing the technology the less suitable it appears.

Would be interesting to see the engineering challenges both designs face discussed in detail by some of the members that have engineering backgrounds, think I’ll start a new thread on that in a bit.

FltMech

60FltMech is offline  
Old 19th May 2023, 15:01
  #258 (permalink)  
 
Join Date: Jul 2018
Location: Indianapolis
Posts: 87
Received 9 Likes on 7 Posts
Originally Posted by SplineDrive
“Declutching” down to a slow rpm basically eliminates the blade tip noise from the prop which, like a tail rotor, is far worse than the main rotor noise. Being low to the ground, blade tip erosion from a slow spinning prop is also improved. I think for a combat scout there are operational reasons to prefer a clutchable prop. Reduced power loss from prop profile drag as well. Is all this worth the cost/weight/complexity of a clutchable prop? Completely fair question. Raider included the technology as a demonstrator. I guess it’s possible it is eliminated on Raider-X as not being worth the penalties. We’ll have to see.
Certainly there are good reasons to have a clutched prop. Sikorsky has sold this as a major advantage. Either 1) they did not execute the design well or 2) Your concern, that they may have had to keep the prop engaged for blade cooling reasons.
noneofyourbusiness is offline  
Old 19th May 2023, 15:17
  #259 (permalink)  
 
Join Date: Jul 2018
Location: Indianapolis
Posts: 87
Received 9 Likes on 7 Posts
Originally Posted by 60FltMech
With upturned exhaust on H-60 rotor blades need to be positioned on centerline to avoid “charring” during rotor brake starts. I suppose even slowly rotating the pusher prop would help, but seems to be a recipe for disaster for personnel operating around the aircraft.

I’ve heard that the pusher on Raider X is electric driven, I assume clutching of the drive system would still be required?

I used to be pretty solid in the co-axial camp but the more I hear about the challenges associated with maturing the technology the less suitable it appears.

Would be interesting to see the engineering challenges both designs face discussed in detail by some of the members that have engineering backgrounds, think I’ll start a new thread on that in a bit.

FltMech
They would not necessarily need a clutch. They could drive, with a variable speed motor, the prop pretty much any speed they want down to very low rpm. The lower the rpm they want, the heavier the motor, unless they added a gearbox and clutch to the motor. An electric generator is also required with the electric motor, so this is very energy inefficient (perhaps 70%) compared to a mechanical drive (98-99%), and heavy. Additional cooling would be required the handle the energy losses of the electric motor and generator.
noneofyourbusiness is offline  
Old 20th May 2023, 16:13
  #260 (permalink)  
 
Join Date: Jul 2018
Location: Indianapolis
Posts: 87
Received 9 Likes on 7 Posts
A man named "spyclip" posted this on The Drive. Seems very knowledgeable, probably a former engineering insider at Sikorsky:

Spyclip
1 July, 2022

No vibration issues? Are you serious? The vibration is the entire reason they have flown only a few dozen hours in 3 years of flight testing and only allowed a single sortie flown by Army test pilots at low speed. The AVC system approach has been a complete failure (again, just like S-97), and the dynamics of another insufficiently stiff fuselage for the propulsor drive shaft make the SB1 just as much of a paint shaker as S-97. Pilots can't even read their instruments in these designs due to the vibration. SB1 has hit absolutely ZERO of its own self imposed targets in demonstration. Sikorsky's own target was a cruise speed of 250 kt at MCP, while in the end they could only manage a momentary 247 kt at CRP (130%). Swing and a miss on drag estimates, and vibration levels at high speed put a cap on that. To date they have not demonstrated any Vector Control maneuvers despite touting it in every single mention of the technology. Go watch the videos, there is no level acceleration or deceleration - its always nose down gaining speed like a normal helicopter. And they most certainly have not shown Defiant holding nose high or nose low attitude in hover, much less any ADS-33 level 1 handling maneuvers outside of a lumbering slalom. V-280 demonstrated high rate level 1 hover pitch, roll, and yaw multiple times. Sikorsky hasn't even done a hover pedal yaw turn in Defiant because they have next to no yaw authority with differential torque and it would be embarrassingly slow.

]https://www.thedrive.com/the-war-zone/raider-x-lockheed-martin
noneofyourbusiness is offline  
The following 2 users liked this post by noneofyourbusiness:

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.