Sikorsky Raider X - FARA contender
 

Today Sikorsky announced the Raider X for FARA competition ..

https://www.lockheedmartin.com/en-us...-raider-x.html

Sikorsky AUSA FARA Press Release
 

That’s needlessly harsh... if they didn’t want us to think of S-97 Raider, their FARA CP wouldn’t be named Raider-X with a video full of Raider flight clips. That said, it’s still too many rotors and unnecessarily complex and expensive to meet the mission requirements. It is notable they never actually stated an MCP cruise speed and amount of payload at range and time on station. Just lots of promises of future growth potential... like it maybe needs a bigger engine now.

isn't CGI wonderful.

True, but adding more power to Raider-X will increase the top end speed and that appears to be what Sikorsky is selling, and they’re right in a way. With additional installed power, Raider-X can achieve speeds that the Model 360 cannot because the wing/rotor combination will cease to become an effective source of forward thrust long before the prop does. Of course, at the Army’s target cruise speed of 180 knots, this isn’t true, and a well designed single main rotor is sufficient.

The mass and cost penalty of a lift sharing wing and SPU is likely far less than an entire additional main rotor and controls, a high power clutched propellor, and the additional structure/systems required to sustain and mitigate the loads from the rigid rotors. In other words, the empty weight of Raider-X is bound to be higher than Model 360. Since the Army has requested a max gross weight and limited the rotor diameter, Sikorsky’s ship likely has less payload/fuel than the Model 360 at the customer requested max gross weight. To carry the full payload at the desired range, they’ll have to fly Raider-X at higher gross weights and disk loading which then incurs additional structural penalties unless they choose to have lower maneuver margins at those gross weights. Adding more power just compounds those issues.

Seems like a lot of downside for a little more speed.

Philosophies, Bell vs. Sikorsky
 

This is interesting.

It looks like Bell believes the Army will go for low risk and cost )and not give a ton of credit for performance much beyond the threshold and objective levels. They design for the cruise requirement and use the SPU to boost speed for the short dashes.

Sikorsky apparently believes the opposite.

Speed isn’t the only metric to get credit on...

Understood. I just used speed as an example of how these two contractors were looking at it differently. Bell going for low cost by not trying to do 205 knots for the entire flight. The basic question is overall how much credit will be given for how much performance. A bid could have better performance promises than another less expensive one, but if the extra credit given is not enough to overcome the difference in cost, it'll still lose. We've seen this happen in contracts awarded of the last decade or so.

Yes, there are more requirements than can all be met by a real aircraft, so the Army will have to evaluate each competitors performance and capability trade offs. Also, I doubt Raider-X can cruise at 205 knots... they only stated they think they can beat 205. Bet that’s a dash speed and not sustained MCP cruise speed.

Sultan (or other learned respondents)...

Thanks for the input on speed requirements.

Can you weigh in on the FARA life cycle cost requirements?

I have never seen a calculation, but I imagine LCC increase exponentially with speed. You raise the point that increased speed means little when applied over a short radius of action. So if you stack these two factors together, it indicates that the speed requirement is very costly... (nothing new here). Taking your point one step further, will the FARA increased speed requirement compared to conventional helicopters be similarly insignificant, i.e. will any operational benefit be realized given the complexities and uncertainties of the real world?

Increased speed incurs weight and/or fatigue life penalties, higher maintenance, lower Time Between Overhaul and others that don't come to mind immediately. Compared to current generation aircraft, these penalties will be somewhat ameliorated by health and usage monitoring and prediction.

Fuel consumption will also be increased, and this also presents at least a geometric if not exponential increased cost versus speed as you track it backwards in the supply chain (fuel burn by various modes of transportation from source to user). The fuel burn penalty due to speed is only there when you go fast, but the attendant fuel consumption due to increased weight is always present.

Fuel cost is one thing, but availability in a critical time of need is more important.

And of course none of the above touches on development and production cost deltas derived solely from speed.

Thanks,

DS

One thing the Bell 360 does not have going for it is the fact it can't carry anyone. Neither could the OH-58 (well in a pinch). The Karem, AVX, and Sikorsky Raider (and possibly the Boeing XX-XX) all have what seem to be a 3-4 person cabin, but then again they use more advanced/expensive/intricate propulsion methods than the conventional-like tandem-seat B360. It makes you wonder if there will be a program to replace the MH-6 troop lifter... since FARA is to (more or less) replace the OH-58D.

Thankfully, your paycheck is not governed by your communication skills, but rather your technical skills.

As to your points/criticisms on this PR release-I share most of them. (Bell Ringer's post made me chuckle).
This press release reminds me of the guy who thinks that foreplay is telling her how great of a time she's about to have.

For Spline Drive:
Thanks for that post. The Raider (S-97) as a follow up to what was achieved by X2 has intrigued me. Will it or won't it fulfill it's promise/potential? We simply don't know.

As to the Acquisition angle on this:
I am reminded of something from about 40 years ago, the infamous 'Hi-Low" mix for a Fighter program, which ended up with F-15 and F-16. And a by product of that was the F-18. Maybe, someone will finally accept a low risk, truly "low cost" for the Low in a proposal like this.
Not everything one buys needs to be bleeding edge. Cost is a variable in any acquisition decision.

But let's look at how deployable the FARA candidates are.
How many 360's fit into a C-17? How many Raiders?
What is the notional "self deployment" capability. (See V-280 for a comparison)

As one of you above said, Speed isn't the only metric.

You know,LW,going down that road has just a few former SA folks asking why then didn’t SA simply ( airframe/drivetrain/rotors/power plant -wise ), simply update the RAH-66. Bell has to do development testing whereas the Comanche, aircraft wise, was developed.

The RAH-66 was a joint Sikorsky/Boeing program
 

The RAH-66 was a joint Sikorsky/Boeing program. So Sikorsky would need to either re-team with Boeing, or Boeing would need to sign over the rights. Neither which are likely to occur. Especially after teaming on the SB>1 Defiant was not as amicable as what is portrayed in the press.

The Boeing AH-6S Phoenix (Little Bird with 15 inch fuselage extension) would appear to be a very good candidate to replace the current Little Bird fleet if the 160th would rather stay with a traditional helicopter design. The extended fuselage would allow more room for additional fuel or perhaps even two additional seats in the rear cabin as well as the two external benches. Unfortunately the AH-6S never made it beyond the mock-up stage but with a new rotor, perhaps scaled down from the AH-64E Guardian (a possible consideration for the MELB if it is enhanced further beyond the Block III upgrade) it might be a slightly larger Little Bird with improved performance. Boeing haven't indicated any desire to resurrect the Phoenix project recently though.

I'm not sure being seated on a bench externally at FARA speeds would be appreciated by the bench-riders!

500 Fan.

This seems to be the consistent opinion on teaming with Boeing in the VTOL industry for the last several decades.

I agree and I have heard the same comments. RAH-66 was a ~165 knot (cruise) machine and certainly with some more modern aerodynamics in the rotor, a drag clean up, small wing, etc. could be pushed to 180+ as Bell has done. Yes, it would be a clean sheet design and not a resubmission of RAH-66 due to the Boeing-Sikorsky teaming, but the knowledge base inside SAC to do so is still there, for now. Assuming an analysis of options was performed, I deeply suspect a strong X-2 "thumb" was placed on the scale. I think the company leadership is "all in" on the X-2 platform, even if it isn't the best match for the customer requirements.