Although Bell has shown models and artis' concept of attack V280s, that is aimed more at USMC and other potential customers, although they could certainly could build it if someone was willing to pay, Army is talking more about replacing at least some of the Apache fleet with whatever comes out of FARA.

The pusher won't affect the size of the footprint but main rotor diameter will, I suspect they are being circumspect on purpose.

Without being cynical about supporting the US military industrial base... now that Bell have won FLRAA, Sikorsky will be handed FARA.

Say hello to the new Apache... the Chippewa?

https://cimg7.ibsrv.net/gimg/pprune....799caadf95.jpg

Incredibly it was not until early 2022 that Sikorsky ever publicly disclosed an actual rotor diameter...of Defiant X at 58.5' vs 53.7' of UH-60.

As they never disclosed Defiant's rotor size, we can't be certain if Defiant X is the same.

So could Bell win the FARA comp as well or is it a foregone conclusion that Sikorsky will be handed it ???

What if the Bell product is way better ??

300+…. They will take an A400M or Herc if they want to go fast. 😉

Sik/Lok 's performance on the CH-53K so far, is just embarrassing! That probably played a large role in the decision.

Footprints
 

With all of the unsupported statements being made regarding the V-280 footprint compared to Blackhawk, I decided to lay it out for myself.

Full disclosure, I couldn’t find anything but photographs comparing the Blackhawk to the SB>1 Defiant. Therefore I was forced to use a Sikorsky image of them next to each other to scale the Defiant Main rotor size based on a 53’8” Blackhawk main rotor.


https://cimg5.ibsrv.net/gimg/pprune....36df8c7a8.jpeg
The shaded green areas show where the Valor footprint exceeds the Defiant footprint, while the violet shaded area s illustrate where the Defiant footprint exceeds that of Valor. For reference, a Blackhawk footprint is shown.

For footprint size, it seems to be a case of six of one, or a half a dozen of another. ;-)

Stunning irony if Bell beats SAC with a conventional single main rotor design.

More than ironic if the Bell “Comanche” was selected!

Works fine if you always have a long enough runway with clear enough approach and departure space and a ramp to park the things. But then, if you have those anywhere you might need to go, VTOL makes no sense

Industrial base concerns will no doubt be take into account "off the record", but that'll be part of the decision. It's important to keep in mind that this is Army's fifth attempt to replace the OH-58. They can't afford to fail again.

The contenders are approaching this with different philosophies. Bell is offering an advanced conventional helo that they say will meet or exceed Army's requirements with presumably lower risk and cost. Sikorsky is going to propose a vehicle will likely be higher risk and cost, but they will contend that their bird will have enough advantages in performance to justify paying extra to get it. This competition doesn't look like it's going to be a pure price shootout like the Air Force's. T-X competition mostly was.

Sikorsky can point to the fact that their S-97 has been flying for over seven years and has or more flight hours under its belt. OTOH, it's missed numerous announced goals and Sikorsky admits that it will not reach its promised speed. Fortunately, FARA required speeds are lower than what Sikorsky was hoping for with S-97.

So this looks like a true flyoff will be a big part of the decision. If Sikorsky can deliver what they promised at an acceptable risk and they aren't inordinately more expensive, they stand a good shot. However, if Bell achieves its goals and is dramatically cheaper, that could tip things their way. The fact that Raider-X could easily be built in another version that could include an small internal cabin instead of weapons (it doesn't look like it will be hot swappable; (Bell has a patent where an Invictus' wings are popped off and six people ride in basic seats against the fuselage on the outside) would bee a plus as a tiebreaker, but can't be a deciding factor because the Army never asked for a cabin so the lack of one can't count against a competitor. Invictus looks like it can carry more weapons if it offloads some fuel by using the two store stations on the wings, but that also can't be a deciding factor because both contenders can carry the Amy's specified load.

If both aircraft deliver what they promise and essentially tie overall, industrial base could figure in, but that issue doesn't make it a slam dunk for Sikorsky. Look at it this way (this is an example, not a prediction): If both contenders absolutely meet all their promises but Raider-X with its higher permanence has a program three times the cost of Invictus(unlikely, I'm just trying to make a point), would you award to Sikorsky on Industrial base grounds?

Of course none of this addresses the issue that some time back the Progrram Manger said that an aircraft that meets all the Army FARA specs can't be built.

Have had issues posting the past week, but as it turns out others have said what I was going to say anyway so no great loss. 🤣

The Drive Article is probably the most balanced read I’ve seen about all the discussion on this topic. If you want to read other interesting things related to V-280 I can suggest searching for US patent 10,570,931 B2 where Bell describes the tilting gearbox/prop rotor in great detail, with drawings of the drivetrain.

I found another patent for the possible Hydraulic system as well but I forgot to save it. Will post later when I find it.

FltMech

Welcome Back!

Good to see you posting again.

Thanks, SASless good to be back.

I had mixed up the patent numbers in my last post, that one was for hydraulic system, US 9,174,731 B2 is for the tilt rotor aircraft with fixed engine.

FltMech

Sorry to keep putting stuff up here, but think this patent information is pertinent to the larger conversation.

If you have trouble finding the above patent information you can also copy txt below and paste into google search bar:

EP2837559B1

US20180274563A1

For some reason when you just copy US patent number and search that it doesn’t come very well.

FltMech

Raider-X has to fly well and perform properly first. While the Army asked for a 14,000 lb aircraft for FARA, I deeply suspect both aircraft are thousands of pounds over this target with Raider-X being heavier than Invictus. Raider-X has a ~15% larger rotor diameter but I’d spitball 70% greater mass relative to Raider’s original design point. So it’s not a foregone conclusion that Raider scales well to the Raider-X size. Rotor loads, drag, vibes, clutch, whatever other issue you want to imagine could still end up being an issue and the simpler Invictus could come away as the more practical vehicle.

Its starting to sound like there is a power deficit with a single engine for both camps, however much more of a detriment for Raider X. There was even an unsolicited comment from Sikorsky in an interview regarding the Raider X cruising at 230 kts with a second engine, so if that isn't insight as to what is going on, I'm not sure what is.

The real issue for Sikorsky is that both they and Bell have already basically completed the demonstrator aircraft designed around a single engine. I don't find it unlikely at all, and it would be an immense embarrassment for Sikorsky, if the conventional Invictus actually demonstrates higher speeds and Sikorsky has to try and convince everyone that their platform actually would be faster with more installed power.

Assuming the historical X2 vibration and rotor load woes are magically solved, this would give the Army an "out" if they want to select Raider based on the "industry base" rationale.

Add a second engine on FARA, and you have a Boeing Apache replacement, not a Kiowa replacement (admittedly the original FARA spec is far from a Kiowa).

This will not make Boeing happy. With all the FARA specification changes, Boeing could rightly file a protest to request the FARA competition be reopened.

With the loss of FLRAA, Boeing Helicopter engineers have nothing left but upgrades to 50+ year old designs. To retain the capability to design new helicopters, this time around Boeing might invest in developing worthwhile proposal.

What ability to design new helicopters? Boeing has bought/merged into every helicopter in their suite of offerings, or licensed the design for them. Even the YUH-61 had an MBB derived rotor system.