Dawes Posted April 9, 2023 Share Posted April 9, 2023 The Army may throw Sikorsky a consolation prize in the form of a FARA award. Presuming that Bell doesn't have a world-beating design. Link to comment Share on other sites More sharing options...
shep854 Posted April 9, 2023 Share Posted April 9, 2023 1 hour ago, Dawes said: The Army may throw Sikorsky a consolation prize in the form of a FARA award. Presuming that Bell doesn't have a world-beating design. While it may look like corporate welfare, it makes sense to maintain some competition, to keep at least a degree of honesty and accountability. Link to comment Share on other sites More sharing options...
Olof Larsson Posted April 9, 2023 Share Posted April 9, 2023 On 12/29/2022 at 8:15 PM, TrustMe said: That's a problem with all tilt-rotor aircraft, as the door gunner can fire into the rotors. It's the reason why tilt rotor aircraft are a failed design concept. Tilt rotors have far more issues than that. The primary being that they are far inferior for the bulk of helo missions, i.e. short range hauls on our side of the FLOT. The V-280 & V-22 for instance have power similar to a CH-47, but only half the capacity in VTO. Tilt rotors also have issues with poor longitudal stability because of the small rotorprop diameter (especially compared to a tandem rotor helo) making them less suitable for sling loads. On top of that there is also the propwash, that makes whiteout, greyout & brownout a bigger problem. This in turn makes tilt rotors less suitable for CSAR & operations in arid & snow covered terrain. So in my opinion they are not suitable as replacements for eigther the CH-46 or the UH-60. The C-2, E-2, S-2, VH-60N Whitehawk & so on, on the other hand... Link to comment Share on other sites More sharing options...
Stuart Galbraith Posted April 9, 2023 Share Posted April 9, 2023 If you want a light or medium lift aircraft, buy a chinook or a Blackhawk. If you want a fast lift vehicle, buy a shorts sherpa. I can only hope this mess will leave Leonardo in a favourable position to clean up when they figure out its not going to work. Link to comment Share on other sites More sharing options...
Olof Larsson Posted April 9, 2023 Share Posted April 9, 2023 8 hours ago, Stuart Galbraith said: If you want a light or medium lift aircraft, buy a chinook or a Blackhawk. If you want a fast lift vehicle, buy a shorts sherpa. I can only hope this mess will leave Leonardo in a favourable position to clean up when they figure out its not going to work. If you want to compare the V-280 to a helo with the same power, you have the Chinook (2-4 times the capacity over shorter ranges and with the ability to take of and land at three times the altitude), if you want to go faster, the V-280 uses similar power to the C-27J (2-4 times the capacity but faster & further than the V-280). Â There are large parts of the world, where a V-280 cannot hover & therefore cannot do any meaningful operations, including fairly sizeable parts of the US, Latin America, Africa & Asia. And there are even larger areas of the world, where the V-280 would be greatly limited in it's capacity. Â I think (well, I have a vague recollection) it was Igor Sikorsky that said something to the effect that you should never pick a helo, for at job a conventional aircraft can do. For a tiltrotor I would say that you should never pick a tiltrotor, for at job that a conventional aircraft or a helo can do. Link to comment Share on other sites More sharing options...
Dawes Posted April 9, 2023 Share Posted April 9, 2023 The US Army presumably did a thorough comparison and evaluation of both competitors, knowing that their selection would be put under the microscope. There must have been some factor(s) that tipped the scales in favor of the tiltrotor - speed, price, range, load capacity, etc. Link to comment Share on other sites More sharing options...
Olof Larsson Posted April 10, 2023 Share Posted April 10, 2023 9 hours ago, Dawes said: The US Army presumably did a thorough comparison and evaluation of both competitors, knowing that their selection would be put under the microscope. There must have been some factor(s) that tipped the scales in favor of the tiltrotor - speed, price, range, load capacity, etc. It probably was given the set requirements. I question the entire project, for the same reasons I questioned the EFV, the V-22 & the LCS. Â Link to comment Share on other sites More sharing options...
seahawk Posted April 10, 2023 Share Posted April 10, 2023 9 hours ago, Dawes said: The US Army presumably did a thorough comparison and evaluation of both competitors, knowing that their selection would be put under the microscope. There must have been some factor(s) that tipped the scales in favor of the tiltrotor - speed, price, range, load capacity, etc. Simple, the speed requirement. If you desire a certain cruising speed and range the tilt-rotor becomes the only solution, as the compound helicopter does not enjoy the benefit of lift created by the wings. And both solutions are equally complex. Link to comment Share on other sites More sharing options...
Olof Larsson Posted April 10, 2023 Share Posted April 10, 2023 17 minutes ago, seahawk said: Simple, the speed requirement. If you desire a certain cruising speed and range the tilt-rotor becomes the only solution, as the compound helicopter does not enjoy the benefit of lift created by the wings. And both solutions are equally complex. Undoubtedly. It's just that the V-280 will suffer (or rather the US Army's economy) during the >90% of the missions where the speed is of little to no use, or where hovering at high altitude, over water, sand of snow is desired. Â You need to slingload a pallet of 155mm ammo 50km, to get around a congested section of road? The UH-60 would have done it as well. You want to do a CASEVAC at 6500 feet. Well, now you need to send in a CH-47, because the V-280 is unable. You want to set up a FOB for your infantry at a 4500 feet hill. Well, the V-2800 could supply the base, but at greatly reduced capacity, so lets set up the base in the valley below. You want to do a raid against some assholes compound in Abbottabad? Well it's at >4000 feet, so the V-280 might not have enough margin, so mayby you need more V-280's, use CH-47's, use the land route, or forgett about getting intel & positive ID on the guy, and just JDAM him, risking collatteral damage. You need to rescue a hostage in a remote house in arid terrain. Brown out is to much of an issue, for a quick unloading a surprice, so now you need to unload 15 miles away the night before the rescue & approach on foot, hoping that you are not detected by someone. Â There are certainly situations where that speed is useful (say island-hopping in and around the South China Sea), but as a general replacement for the UH-60, I think it's the wrong way to go. Not because it's to little of an improvement, but because it will be no improvment in most cases, a inferior solution in many cases, and it will drain money, that could have been used for other things. Link to comment Share on other sites More sharing options...
seahawk Posted April 10, 2023 Share Posted April 10, 2023 Imho the war in the Ukraine has shown that speed is not important for a helicopter. The ability to fly ultra low is and you do not fly ultra low at high speeds. I still get the operational concept behind the V-22, I do not get if for the FLRAA. And I surely hope they either scrap FARA or go with the Bell solution, because reconnaissance with a helicopter already seems like a questionable idea, but if you do it, you do it slow, ultra low level and kind of hide and seek style. So the extra costs for high speed can be dropped. Link to comment Share on other sites More sharing options...
Stuart Galbraith Posted April 10, 2023 Share Posted April 10, 2023 16 hours ago, Olof Larsson said: If you want to compare the V-280 to a helo with the same power, you have the Chinook (2-4 times the capacity over shorter ranges and with the ability to take of and land at three times the altitude), if you want to go faster, the V-280 uses similar power to the C-27J (2-4 times the capacity but faster & further than the V-280). Â There are large parts of the world, where a V-280 cannot hover & therefore cannot do any meaningful operations, including fairly sizeable parts of the US, Latin America, Africa & Asia. And there are even larger areas of the world, where the V-280 would be greatly limited in it's capacity. Â I think (well, I have a vague recollection) it was Igor Sikorsky that said something to the effect that you should never pick a helo, for at job a conventional aircraft can do. For a tiltrotor I would say that you should never pick a tiltrotor, for at job that a conventional aircraft or a helo can do. Yeah, I was thinking exactly the same thing. Link to comment Share on other sites More sharing options...
Stuart Galbraith Posted April 10, 2023 Share Posted April 10, 2023 4 hours ago, seahawk said: Imho the war in the Ukraine has shown that speed is not important for a helicopter. The ability to fly ultra low is and you do not fly ultra low at high speeds. I still get the operational concept behind the V-22, I do not get if for the FLRAA. And I surely hope they either scrap FARA or go with the Bell solution, because reconnaissance with a helicopter already seems like a questionable idea, but if you do it, you do it slow, ultra low level and kind of hide and seek style. So the extra costs for high speed can be dropped. Im not sure even the V22 stands up. I was looking at it on that Documentary about HMS Queen Elizabeth, and they crossed decked one. The amount of surface area it covered was incredible. That and the take off look incredibly clumsy when he was doing sideslip. I thought he was going to touch the deck with his blades. If people want a light aircraft, buy one. If people want a heavy lift helicopter, buy one. But I think there is a lot of evidence, trying to shoehorn both into the same airframe ends up with something not as good as either, and several times the cost. Link to comment Share on other sites More sharing options...
Olof Larsson Posted April 10, 2023 Share Posted April 10, 2023 4 hours ago, Stuart Galbraith said: Im not sure even the V22 stands up. I was looking at it on that Documentary about HMS Queen Elizabeth, and they crossed decked one. The amount of surface area it covered was incredible. That and the take off look incredibly clumsy when he was doing sideslip. I thought he was going to touch the deck with his blades. If people want a light aircraft, buy one. If people want a heavy lift helicopter, buy one. But I think there is a lot of evidence, trying to shoehorn both into the same airframe ends up with something not as good as either, and several times the cost. Yes. The V-22 takes up more space on the deck & far more in the hangar (70-80% more) than a CH-47. For the Wasp-class, the switch from CH-46 to MV-22, ment going from up to 42 CH-46's to up to 22 MV-22's, despite all the early claims that the V-22 would be as small on the outside & as large on the inside as the CH-46. Link to comment Share on other sites More sharing options...
bfng3569 Posted April 10, 2023 Share Posted April 10, 2023 19 hours ago, Dawes said: The US Army presumably did a thorough comparison and evaluation of both competitors, knowing that their selection would be put under the microscope. There must have been some factor(s) that tipped the scales in favor of the tiltrotor - speed, price, range, load capacity, etc.  I don't do gov speak, the bolded seems like a pretty strong statement...... ineligible for award.... thats pretty damming. "Sikorsky challenged the agency’s assignment of a rating of unacceptable to its proposal under the engineering design and development evaluation factor, architecture subfactor, which ultimately rendered the proposal ineligible for award. Sikorsky also argued that the agency should have found Bell’s proposal to be unacceptable. Finally, Sikorsky challenged the agency’s evaluation under the engineering design and development factor and the product supportability factor; the cost/price evaluation; and the best-value tradeoff decision.  Link to comment Share on other sites More sharing options...
Ivanhoe Posted April 10, 2023 Share Posted April 10, 2023 It is pretty easy to game the procurement system with performance specs. And procurement people are not always the sharpest bowling balls in the shed. For me, the death-knell for FLRAA is the simple fact that the Congressional/Military Complex has run almost every large procurement project into the ground. Just as the Osprey turned out to be a weak replacement for Phrogs overall, this thing will turn out to be an overall weak replacement for Blackhawks. Before going for the "Buck Rogers" airplane-after-next, I'd like to see the Congressional/Military Complex just buy a medium-lift conventional helo with similar performance to Blackhawks but with dramatically lower maintenance costs*. Likewise for heavy lift. Our remaining manufacturers can do it, but only if the customer wants such.  * The Army's current recruitment nightmare is going to severely impact high-skill MOSes such as aircraft maintainers. Somebody who can score high on ASVAB is going to find civilian employment pretty lucrative.  Link to comment Share on other sites More sharing options...
DB Posted April 11, 2023 Share Posted April 11, 2023 The argument for a "better Blackhawk" seems fairly compelling. I'm astonished that this thing apparently can't hover out of ground effect above 6500ft. The V-22 weighs a lot more, uses the same engines and has only the benefit of bigger rotors to compensate and manages 10,000ft apparently. Just how much do you want to sacrifice for the speed? Link to comment Share on other sites More sharing options...
Ivanhoe Posted April 11, 2023 Share Posted April 11, 2023 The V-22 has a substantially lower disc loading (roughly 10 lbf/sq ft at max gross for VTO) than the Valor at about 16 lbf/sq ft. The engineers at Bell certainly know better than to do this, so there is something stupid or dishonest going on here. XV-15 has disc loading of about 13 lbf/sq ft, and the flight test team was super careful not to do anything crazy (as opposed to what Army helo pilots do on the daily). Â Link to comment Share on other sites More sharing options...
Ivanhoe Posted April 11, 2023 Share Posted April 11, 2023 p.s. the king of high altitude ops, the Aerospatiale Lama, has a disc loading of about 5 lbf/sq ft. Service ceiling of about 17,000 ft ASL, though the Nepalese do some very cra-cra rescue flights. Stones like grapefruits as the saying goes. MD-500 Defender has disc loading of about 4.7 lbf/sq ft, but has weak high-altitude performance due to the ancient engine. Civvie versions with modern engines have service ceiling up to about 18,000 ft. For a true Blackhawk replacement, with all that implies mission-wise, I'd want to see a helicopter-mode disc loading of no more than the Blackhawk's, around 7 lbf/sq ft. 8 maximum.    Link to comment Share on other sites More sharing options...
seahawk Posted April 11, 2023 Share Posted April 11, 2023 13 hours ago, Olof Larsson said: Yes. The V-22 takes up more space on the deck & far more in the hangar (70-80% more) than a CH-47. For the Wasp-class, the switch from CH-46 to MV-22, ment going from up to 42 CH-46's to up to 22 MV-22's, despite all the early claims that the V-22 would be as small on the outside & as large on the inside as the CH-46. But the general idea to move the amphibis further out to the sea and compensate this with a higher cruising speed, at least made some sense. For the Army I do not see it. Ukraine has shown that helicopter assaults into enemy territory do not work if the enemy has manpads, a functioning command and artillery. Link to comment Share on other sites More sharing options...
Stuart Galbraith Posted April 11, 2023 Share Posted April 11, 2023 1 hour ago, seahawk said: But the general idea to move the amphibis further out to the sea and compensate this with a higher cruising speed, at least made some sense. For the Army I do not see it. Ukraine has shown that helicopter assaults into enemy territory do not work if the enemy has manpads, a functioning command and artillery. Or looked at another way, they enfranchise the ability of the USMC to do shore assault, at just the same time as they emasculate other parts of it to do shore assault. Id argue that long range air assault was proven not to work in 2003, when that task force got badly shot up over Iraq. And they were armoured. Not easy to armour transport helicopters. If it was me, rather than pissing about with speed, Id put the money into making at least some of them stealthy, or at least make the shape stealthy, and just apply the paint to ones you want for CSAR or SF. After all, there is no helicopter yet built thats going to outrun a manpad. Â Link to comment Share on other sites More sharing options...
seahawk Posted April 11, 2023 Share Posted April 11, 2023 The Marines are a bit more expeditionary, so I can at least understand the reasoning that led them to go for the V-22. It might not have been fully spot on, though. For the Army I can not even see a coherent operational doctrine behind the FLRAA. CSAR is done by the Air Force and for special ops, stealth seems more useful then speed. For general troop and equipment hauling missions, I would also prefer stealth (or at least a very reduced IR signature) over speed. The whole thing screams "We want in on the mission to contain the Chinese. We have no operational experience, doctrine or equipment to be useful, but we want to be relevant." Link to comment Share on other sites More sharing options...
Stuart Galbraith Posted April 11, 2023 Share Posted April 11, 2023 2 hours ago, Ivanhoe said: p.s. the king of high altitude ops, the Aerospatiale Lama, has a disc loading of about 5 lbf/sq ft. Service ceiling of about 17,000 ft ASL, though the Nepalese do some very cra-cra rescue flights. Stones like grapefruits as the saying goes. MD-500 Defender has disc loading of about 4.7 lbf/sq ft, but has weak high-altitude performance due to the ancient engine. Civvie versions with modern engines have service ceiling up to about 18,000 ft. For a true Blackhawk replacement, with all that implies mission-wise, I'd want to see a helicopter-mode disc loading of no more than the Blackhawk's, around 7 lbf/sq ft. 8 maximum.    Does anyone know of a good online calculator to work this out? I was just trying to figure out the rotor loading of an AW139, but the only one I can find doesnt seem to offer accurate calculations. Link to comment Share on other sites More sharing options...
DB Posted April 11, 2023 Share Posted April 11, 2023 3 hours ago, Ivanhoe said: The V-22 has a substantially lower disc loading (roughly 10 lbf/sq ft at max gross for VTO) than the Valor at about 16 lbf/sq ft. The engineers at Bell certainly know better than to do this, so there is something stupid or dishonest going on here. XV-15 has disc loading of about 13 lbf/sq ft, and the flight test team was super careful not to do anything crazy (as opposed to what Army helo pilots do on the daily). Â Assuming that the wikipedia figures for the V-22 and V-280 are correct, this doesn't seem to be correct, or my calcs are off, and so on. V-280 maximum payload is 30865 lb, rotor diameter is 35 ft. V-22 maximum VTO payload is 47500 lb, rotor diameter is 38.1 ft. This yields 16 lb/sqft versus 20.8 lb/sqft. Other figures show the maximum rolling take-off weights as 38,000 lb and 52,600 lb respectively. For Stuart: I assumed that the disc loading is calculated by taking the weight and dividing it by the swept area of the two propellers - i.e. 2*pi*(d/2)^2. This article agrees, more or less:Â https://vtol.org/files/dmfile/JMR_Bell-Vertiflite.pdf#:~:text=The 35 ft (10.7 m,52%2C600 lb (23.6 t). Link to comment Share on other sites More sharing options...
Ivanhoe Posted April 12, 2023 Share Posted April 12, 2023 Looks like I fat-fingered the V-22's VTO max gross. Sorry about that. I should know better than doing calculations after midnight, a lesson I must pay attention to as its federal income tax week here. Your formula for disc loading is correct.  Link to comment Share on other sites More sharing options...
Ivanhoe Posted April 12, 2023 Share Posted April 12, 2023 21 hours ago, seahawk said: But the general idea to move the amphibis further out to the sea and compensate this with a higher cruising speed, at least made some sense. For the Army I do not see it. Ukraine has shown that helicopter assaults into enemy territory do not work if the enemy has manpads, a functioning command and artillery. Given the "do more with less" aspect of 21st century Army infantry, I am reminded of the Vietnam AirCav approach. Fly to an LZ, debus, march to contact, win the battle, RTB for steaks and beer. At least, that was the theory. Link to comment Share on other sites More sharing options...
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