General statistics
List of Youtube channels
Youtube commenter search
Distinguished comments
About

Tara Raboomdiay
Defense News
comments

Comments by "Tara Raboomdiay" (@tararaboomdiay7442) on "Sikorsky challenges US Army's helicopter award" video.

For accuracy, Defiant-X didn't crash, it's never even been built, only the Defiant demonstrator and it didn't crash. Raider crashed due to software error.
7
@Will-W Two things to consider: First a Tilt-Rotor is wider than a comparable helo but it's shorter because the rotors don't go as far out in front. When you consider the size of the Army specified LZ and the Army specified distance between rotor tips, you can fit as many V-280s in that LZ as UH-60s. Even if you couldn't get quite as many,it's a tradeoff because you're gaining speed, range and agility , among other things.
3
@kiabtoomlauj6249 Again, Defiant demonstrated no great agility advantage over Valor, and in some areas Valor demonstrated more agility. As regarding an attack version, if Army wanted one, Valor could easily offer an option in their version which the attack crews would love that would be Very hard to do on Defiant; off-the-shelf ejection seats. This is because on a Tilt-Rotor, the blades never go over the fuselage. Before anyone gets incredulous, the XV-15 had off-the-shelf ejection seats, and the first few V-22 test aircraft had them as well. Obviously the production Ospreys didn't have them--not exactly confidence building in the troops knowing the flight crews could punch out, leaving them behind.
2
@dct124 First time I've ever heard that Defiant had greater range. Sikorsky certainly doesn't tout it. What do you mean third prop? They've already got a pusher and they only hoped to get to 288 mph, and didn't quite make it (I believe for the production version they were talking 270 mph). Bell promised 322 mph and deceiver 351.
2
@dct124 The survivability of either getting hit depends on how much damage is done. What they are accurately pointing out is that they don't have the problem that a loss of a tail rotor causes in a conventional helicopter. In the article you refer to they say, "...fly home at speeds higher than helicopters fly today" they don't say, "faster than any helicopter today ". In a February 2020 article, Sikorsky said without the pusher, they can do 150 knots. There's a re quite a few helos that can do that including even the giants CH-53 and CH-47. Both aircraft can run off one engine, but it doesn't necessarily mean it's more efficient, given the load that one engine has to shoulder and what you have to give up. . How many twins do you know that routinely shut down one engine in normal operations?
2
@dct124 Sikorsky has said the they could potentially get 280 knots with a new engine in an X2. Not all Sikorsky flights have been done under combat loads, simply because these are demonstrators and have limits on what they can do compared to production versions. Bell didn't hide that it's flight was empty. It's a demonstrator too. When has a Defiantt "currently" flown 700nm? Don't forget Valor gets new engines too...
2
@dct124 The Bell demonstrator has shown more in tests at the hover whereas SB>1 hows its agility at 60 knots. When you're moving it's easier to get agility.
2
@dct124 If I recall, int hose articles Sikorsky talked about what happens if the pusher got shot off, unlike a conventional helicopter, it can still function. Now if you're hit hard enough to blow a major portion of the tail off, pretty much anything is going down. Carrying an external load will slow anyone down, including Defiant. Yes, although Valor can lift an external load operatic in rotorborne configuration (mighty handy for takeoff and landing), it will probably operate in intermediate configuration if they want max speed while carrying a load faster. BTW, the V-22 hold's the world's record for speed when carrying an external load. Frankly, though moving a decent external load at speeds above 100 knots is not that operationally useful because of the loads placed o the cargo and effects the hanging cargo place onthe carrier. Well, another reason was lower risk. Valor just got out there and did whatever was asked of it whenever it was asked of it while Defiant had a troublesome t demonstration record, and kept missing achieving datapoints on their announced schedules.. Here's just one example: the original JMR-TD for FLRAA called for first flight in 2017, a year of flight test/demonstrator in 2018, a year of data reduction and analysis in 2019, with selection of who would proceed to the next phase, viruatl and real world prototypes [remember, these were demonstrators.not prototypes) in late 2019/early 2020. 2020. Valor flew in 2017, did the demonstrations on time and the flew beyond what was required. Defiant not only didn't fly in 2017, they couldn't even get it into the air until March of 2019. And then it had to be grounded for problems a few flights after that. Its demonstration program was troubled and caused the whole program to slip. So it's not too surprising that they'd lean towards for Valor even on just perception of lower risk, even discouraging the performance differences
2
@dct124 Remember, Valor and Defiant are both technology demonstrators, not even prototypes. Their purpose is to demonstrate the probability that EMD and production versions will fully meet or exceed Army's requirements. From the results of the demonstration, Army would pick who they'd fund for prototyping and development. Valor demonstrated more and had far less problems than Defiant, which was probably why it was chosen: greater potential performance and higher likelihood it would meet or exceed requirements in the production version. I suspect that's why it was chosen.
2
@legallyfree2955 $$$, both for development and operational costs prevent adopting both. Basically what you've got to do is decide which-one overall gives eh Army the best voice for its mission and money.
2
@Ohhiohh If you mean engine you're completely wrong. If you mean proprotor, what helo won't crash if you blow the rotor off?
2
@yolo_burrito Better do more research. Raider wasn't in this competition. Valor dramatically outperformed Defiant in actual flight test.
2
@yolo_burrito They never give out all the details until after they see what's in the protest. However it might have been something like, "Valor did better in demonstrations, was more reliable and delivered on its promises better and so we have greater confidence Bell will actually be able to deliver more of what they promised"..
2
@robertgregory6778 From what we've seen so far, there's nothing to indicate that Raider and Defiant launch or accelerate faster. Where do you get the idea that any of these aircraft, including Valor, are "stealthy", or that the downwash from the V-280, which has been measured, is as bad as you say?
2
@markbrockman9859 There was no requirement for Valor or Defiant to fit in a C-17. The plan is that either they go ovoer by ship or fly themselves over. That was one of the reasons for the ferry range requirement.
2
There was no requirement for either aircraft to fit in a C-5. They would either be shipped over or flown using a route that did not require AAR (Army never asked for that capability, although I'm sure both aircraft could add it if someone specified that.
2
@irvhh143 You might want to apologize, because Mike Love's right.
2
@irvhh143 Again, regarding short takeoff, go look for yourself at what happened in the demonstrations.
2
@irvhh143 The driveshaft is normally unloaded. When an engine fail, the difference in power mechanically loads up the shaft to power both proprotors. It's designed for that purpose and has the necessary strength. As far as the rest of your post, everything in it is simply wrong. Remember, it was demonstrated in flight for over three years, and if anything you said was true, someone would have noticed.
2
@irvhh143 still uses the crosshaft for engine out.
2
@irvhh143 Hmm, twice the speed, far greater range, faster accel/decel, larger payload, much greater ability to HOGE in hot and high conditions, etc. Sounds like more than a "minor" increase in performance to me. Actually, the Chinook is a surprisingly good autorotator, especially given its size. I should point out that every autorotation does not necessarily mean you end up with a soft, gentle landing. How much autorotation capability is one of the tradeoffs in design. For example, the UH-1 reportedly autorotated better than the UH-60, but no one says we should have stayed with the Huey. As to what's Valor's autorotational performance, all we know for sure at this point is that Bell says it has the capability. We'll have to wait for a prototype to see. The aircraft flown so far was just a technology demonstrator,. Come to think of it, what's Defiant's performance? AFAIK, Sikorsky has never even addressed the issue. The statement that FLRAAi is the selling point for Valor is self-evident. FLRAA is the whole reason for Valor's existence. In fact, it's the whole reason for Defiant's existence as well.
2
@irvhh143 As the Army has repeatedly made clear, neither the Valor nor the Defiant that have flown are prototypes. They are Technology Demonstrators, hence the name of their program Joint Multi-Role Technology Demonstrator. Their purpose was to demonstrate their respective advanced technologies and the Army would evaluate the results to decide which concept offers greater potential not only for meeting or exceeding the Army's requirements but also greater potential for achieving its promises. Army only has enough money to operationally develop one of them for the FLRAA (there are actually two "A"s in the program name) program. The next step involves actual prototype(s). Of course the seller is talking about expected performance. That's wast everyone talks about until you actually build the thing. Both bidders gave their expected performance estimates for production models. That's what was being demonstrated, how likely it was that their concepts could achieve their promises. On that basis, Valor clearly demonstrated more and inspired more confidence than Defiant. I wouldn't be surprised if that was the pivotal factor in the decision. What is your basis that a production Valor cannot take off vertically at operational weight? Even Sikorsky has never claimed that! Regarding hover capability, I would estimate that it could hover for as long as required. Not as efficiently as a regular helicopter, but Bell has always acknowledged that. However, it should hover for as long as the Army has specified (otherwise it would have been rejected). For one thing, it is required to HOGE at mission weight at 6000'/95°, which strikes me as somewhat more than "limited" hover capability. Is the whole aircraft armored like an A-10? No. One good hit on a Chinook's driveshaft and down she goes. All aircraft are vulnerable to enough hits in the right place a the right time. That's just the cost of doing business. But I would opine an aircraft doing 250 kn is less likely to be hit than one traveling at 125. Your objection to FLRAA is an objection to the UH-60, UH-1, H-35,H-19, etc. [not to mention CH-47 and H-53], or any transport helo. What is your alternative? Have the troops walk or ride in trucks? Last time I checked, no helo in flight has been knocked out by an underground mine or IED. One other thing about FLRAA. Personally, I am not sure that as things stands neither a production Valor or Defaint can meet their original range estimate. The reason is that Army told both contractors to base their production aircraft estimates on the Army delivering the advanced FATE engine. It's become apparent in the past year or so that Army will not be able to deliver that engine to meet the FLRAA schedule, so the contractors were told that for the production aircraft they should select a more current techcnology engine. If the engine(s) chosen turn b out to be heavier or burn more fuel than what Army promised for FATE, the designs are going to take a hit there and Army won't be able to hold them to their original estimates. For the record, the exact same thing happened to Osprey
2
Actually, a naval Valor could operate from a DDG as well as flat deck ships. Such a variant would fold up for going into the hangar to a size smaller than that of a UH-60. No one has said how a Defiant could fold and reduce its mast height to go on a DDG. Sikorsky hasn't even discussed it.
2
Air Force on its own went out and bought their own version, eh CV-22. They wanted to get more, but other programs had higher priority for the $$.
2
Defiant -X is not a scout andr light attack aircraft and was never intended to be one. You are confusing it with Raider-X
2
@DeathlordSlavik 1. How do we know this with the current technology V-280? 2. Defiant is not a conventional coaxial rotor. It is a much more advanced, but also more complex technology.
2
@DeathlordSlavik Defiant is an X2, not a coaxial, and how do you know that thr V-280 will be harder to martian than an old technology coaxial (which agian Defiant is not)?
2
@DeathlordSlavik I was actually giving credit to Sikorsky for their in technology through X2. Maybe it would have been more accurate to say the X2 is not a conventional coaxial, since any stacked rotors wold be coaxial. Sikorsky's are advances are using rigid rotors for more flexibility in maneuver, reducing the distance between the rotors which reduces drag (although Defiant is still pretty tall) the ability to synchronize and use the opposing blades to offset the problem of asymmetric lift, slowing the rotors at higher speed to avoid retreating blade stall and to keep the tips from going supersonic. These are all significant advances over conventional coaxial rotors such as Kamov uses. Note that Kamov, who has more experience with conventional coaxial than anyone, doesn't produce any craft that go faster or farther than regular helicopters. Sikorsky deserves credit for working on advancing the technology, but as of now it looks like they're not there yet.
2
@DeathlordSlavik Sorry,it was a semantics thing, I was trying to differentiate between Sikorsky's more advanced concept and regular coaxials , so technically I was wrong and should have said X2 was a very advanced subset of the overall concept of coaxials/stacked rotors. Look at Kamov's masts, distance between rotors, shape of blades, hub thickness of mast, etc. Those are not intended for high speeds. Kamov was designing craft that were compact and avoided tail rotor issues. Even the KA-50/52 stays well under 200 knots They've been doing coaxial designs since the early '50s. It's their signature concept, just like tandem rotor technology was Piasecki's. you can see the ultimate expression of Piasecki's concept in the CH-46 and-47, which were designed by Piasecki and were acquired when Boeing bought the corporation (which was called Vertol) in 1960. The S-69 was a research aircraft designed to test and demonstrate Sikorsky's Advancing Blade Concept, which was not a conventional coaxial and was the precursor the the X2 technology. This also was the time of the XV-15 Tilt-Rotor demonstrator. Without going into too much detail, it was half the speed of the XV-15. They eventually hung two turbojets on it, which raised the weight to the point it could no longer HOGE, but even with those blasting away and the aircraft in a shallow dive, its top speed was still 69 knots slower than the XV-15. Sikorsky is already where? Just look at how many of their self set schedules and goals they missed on both S-97 and SB>1. They are higher risk
2
Both the XV-15 and test models of the V-22 had ejection seats. You won't see them in the Valor the Army is presently planning to buy because that wouldn't instill a lot of confidence in the two door gunners and 14 troops also inside. If an attack version with just two crew came about, though, off-the-shelf ejection seats would be a good idea and easy to do..
2
Even if that's true, that's one point for Defiant and still many, many more points for Valor.
1
@dct124 Defiant promised certain speeds and agility with the engine they have now, but didn't demonstrate them. Bell achieved its promises with the engine it has now. Both craft were to get new engines in their production version. Valor is probably more agile at speed at any altitude. The speed and range figures the Army wants in production aircraft and the performance promises made are at loaded weights. I don't get where people keep saying that the figures are only without load. Even if that were true, the Valor still demonstrated more.
1
Remember Defiant is pretty big itself and it's really tall.
1
The two aircraft were intended for the exact same purpose, FLRAA. Even if Defiant and Valor were to achieve all their promises (and Valor looks more likely to be able to do that based on the demonstrations so far), their performance is not different enough overall to justify developing and operating both even if the Army could afford it, which it can't.
1
I suggest you look at the V-22's actual flight and combat history (none has ever been shot down). V-280 is by design a smaller aircraft and couldn't reparable V-22 even if anyone wanted to. Regarding 30 knot speed difference, Defiant touched2 47 knots on one flight.Valor demonstrated cruise at 305 knots. BTW, Lockheed would make more money if Defiant won, because they own Sikorsky. On Valor, they're just a subcontractor tasked with integrating the avionics.
1
@andrewanderson3472 If you're talking about an engine going out, noting, except for lowered necromancer. If you're taking about a proprotor actually being physically destroyed, unless they can glide on the wing, pretty much the same as any c'opter with a rotor blown off
1
@markbrockman9859 No requirement for FLRAA to fit into a C-17 without disassembly. You either ship them transoceanic distances or fly them, with intermediate stops as necessary. That's Army's announced plan and why they wanted such a great ferry range
1
@FLORATOSOTHON What happens if the rotor is blown off on a conventional helicopter such as Chinook or evenUH-60?
1
@FLORATOSOTHON Actually the counter-rotating blades hit each other in the S-97 Raider crash.
1
I don't think they even made 100 hours on Defiant. Even if they had, that's less than half the number of hours they flew Valor before they grounded it since they had nothing left to test or demonstrate.
1
@FLORATOSOTHON You are correct, the blade intermeshing isn't what caused the crash, it was the software issue. which illustrates that X2 control technology is really complex as NTSB noted in their 2019 report on the accident. My point was that in the severe rolls, the blades did intermesh, something Sikorsky didn't believe would happen. The say they have since modified the software to prevent a occurrence.
1
@FLORATOSOTHON Even if you want to include Raider's hours , Valor flew more hours that both of them. In fact, IIRC, Valor flew more hours that all X2s ever built combined. Of course, if you count Raider hours as experience you've also got to count the XV-15, which 40 years ago flew more hours than Raider and Defiant combined. And there are the hundreds of thousands of V-22 hours...
1
@irvhh143 I note that Chinook engines are not connected to the rotors, especially in the case of the forward one. In fact in CH-47, if the shaft breaks you lose the aircraft. In Valor, if the crossshaft breaks, nothing happens unless you then lose an engine; in which case you glide. It's interesting that almost everyone thinks the Valor proprotor/engine interface is better than previous generations. it wasn't done before because of the lower metallurgy and manufacturing technology of the past. Tilting just the proprotors back the actually turned out to be heavier than tilting both the proprotor and engine.
1
Although flyoffs are great, they're expensive. What this was was each competitor demonstrating their technology and how well it worked and how likely a production aircraft could meet its promises. . Army then decided which technology to go with.
1
They've only built one V-280 and it flew consistently for 3 1/2 years until the demonstration program was complete. Maiden flight crash??? Huh???
1
Depends on what's hit just like any aircraft.
1
@edcox1630 Yes it can, but at a lesser weight. This is true of all helos.
1
One of the Army's requirements is that FLRAA has to fit int the "footprint" of the UH-60 and Army says they both do that. I wish they'd define "footprint" bitter. One of the other requirements is that in a specified LZ, you have to get as many FLRAAs in as Black Hawks maintaining specified separation. Army seems to feel they can both do that.
1
Cost Guard doesn't have the money to take Defaint all the way from a technology demonstrator (not even a prototype) to production, and the relatively small quantity they need would make the unit price astronomical. Coast Guard tends to buy 'copters developed for someone else and then modify them to their needs.
1
Sikorsky and Boeing designed Defiant before Lockheed ate Sikorsky, and Valor is a pure Bell design. Lockheed was brought on board as a subcontractor to handle avionics integration.
1
@stephenwilkens3101 All helos are somewhat predictable in the final landing phase. But Tilt-Rotor does not impose any manuring restrictions during transition, either way.
1
@stephenwilkens3101 Thing is, Defiant advocates keep promising things while Valor actually does them. For example, Defiant promised breathtaking deceleration, but I don't know if it actually flew the promised profile. Valor's demonstrator, which does not have as high a performance as the production version will, has flew decelerations from 220 knots to a hover in 45 seconds. It has met or exceeded every Army specified agility requirement. It isn't going to be the absolute best at absolutely everything (I don't know if this demonstrator did the maneuver you're talking about). For example. if Defiant-X would had me its promises, although Valor met Army's requirement for testing, Defiant-X would have done hot and high HOGE better than Valor. Everything in aircraft design is a tradeoff.
1
The key is whether Defaint can do what it promises in the real world. I admit I haven't seem everything, but I haven't seen where Defaint actually flew that super fast level flight decel to a hover/landing. That decel number I gave for Valor came from a real flight. The key is that if they both fulfill their promises, each will have advantages /disadvantages over the other. Thing is, based on the demonstrations, Valor looks a lot more likely that it'll get to what the Army wants, and that risk factor probably paid a big role in-the decision.
1
They can't afford by themselves to develop it to the point where it would be operational, and wouldn't buy a sufficient quantity to make it practical.
1