S97 Raider

[keesje]

Sikorsky has placed a $15 million price tag on its S97 Raider, as it attempts to convince the US Army that the aircraft is a low-risk replacement for the Kiowa Warrior.

Heli-Expo 2013: Sikorsky reveals S97 price tag - News - Shephard (http://www.shephardmedia.com/news/rotorhub/heli-expo-2013-sikorsky-reveals-s97-price-tag/)

The Pentagon has set a target range of $13 million to $15 million per aircraft for the AAS project.

For reference, a AH-64 Apache costs about three times as much. After many hundreds have been produced, for decades.

Real price, of course, depends on costs included, excluded, spare parts, training etc. etc. Still for a brand new innovative design $15 million seems on the optimistic side in my opinion.

http://images.24ur.com/media/images/600xX/Mar2013/61159940.jpg

[212man]

Yeah right! If they do sell for 15 million, I wouldn't like to see the spares and support costs...

[heli1]

Obviously no avionics !

[carsickpuppy]

$15 Million does seem a bit optimistic, especially considering the USAF (insert very reluctant US taxpayer here) is willing to give $20M+ per for either 20 of the Super Tucano or Beech's AT-6 Texan II turboprop for Afghanistan's Air Force, whenever that legal battle is over. (See beechcraft-sues-air-force-over-las-contract, if you've a mind to.)

[Helilog56]

I've got my check book out to buy a dozen at that price.....:*

[Lonewolf_50]

Does the cost include the engines? :confused:
I've seen a few procurement documents from decades past that identify airframe cost and engine cost separately.

Is that bit of bookkeeping being resorted to here?

Is mission kit included?

What sized production run is that based upon, I wonder. :p

[Turkeyslapper]

especially considering the USAF (insert very reluctant US taxpayer here) is
willing to give $20M+ per for either 20 of the Super Tucano or Beech's AT-6
Texan II turboprop for Afghanistan's Air Force


20Mper copy for a single engined turbo prop...you have to be taking the piss...sure it has some extra gear but come on!!! :ugh:

[SansAnhedral]

$15 million must be for the green plywood and carboard mockup from the photo above.

Maybe they will throw in the blue painted PVC rocket tubes for an extra $50k

[Lonewolf_50]

Turkey Slapper, IIRC there is an armed variant, and support costs involved in that T-6 Texas II dust up. Recent article in the latest challenge in court from Beechcraft (Raytheon?, here (http://www.kansas.com/2013/03/21/2726196/beechcraft-files-lawsuit-in-latest.html).)

[Hilife]

What sized production run is that based upon, I wonder. :p

Well you could start by counting the number of OH-58 Kiowa’s the US Army has in inventory. ;)

[busdriver02]

(supposed shell game of cost, mentioned by whoever)

What you're referring to is GFE (government funded equipment) if for example a certain engine is already in the government supply system and is directed to be used. As an example, one version of the UH-1 that the AF bought was directed to use the same engine as the HH-3, since there were already plenty of engines bought but the HH-3 was being phased out in favor of the HH-53.

[The Sultan]

Hilife

You would be able to buy 1000 advanced 58's for 125 of the 97's and with the 58 you can see behind you. Following the Comanche and Cyclone price escalation to the 100 to 200 mil range per the 97 will be unaffordable.

Just ask the Canadians.

The Sultan

[tottigol]

Sultan, just how can you see behind you in the 58 any better than any other helicopter?
We'll see if Sikorsky can beat Bell to the bank accounts of the decision makers.

Let's get real, if it was for Bell we would still be flying UH-1Hs to a hot LZ, they would only cost 25 millions a pop.

[robin303]

I got out of the US Army in 1996. The prices I was aware of then was.

AH-1F $4 mil
OH-58D $4 mil
UH-60L $12 mil
AH-64 $18mil

So my guess 6 mil for a EC-135 and 4 mil for a 407 a S-97 sounds cheap.

[keesje]

Other, more conventional competitors in the Army's Armed Scout requirement


** EADS is offering a AAS-72X+ for the same competition. Build in Columbus, Mississippi and backed by LM
http://www.eurocopter.com/publications/img_wsw//AAS_72X+.jpg


** A re-engined Bell OH-58F Block II
http://www.helihub.com/wordpress/wp-content/uploads/oh58-block-ii-1-2x.jpg


** A stretched Boeing AH-6S Little Bird
http://files.abovetopsecret.com/files/img/dy50ba446c.jpg

The OH-68F Block would offer the best commonality with the current Kiowa's and maybe be the cheapest (?)

EADS US Columbus shocked the DoD/Army by delivering the UH-72 Lakota's on spec, on price and slightly ahead of schedule and the pilots seem to like it. So they might have a chance.

The Boeing AH-6S Little Bird, while a capable aircraft seems small to me, limited for future derivatives and moving people (inside).

[SansAnhedral]

Let's get real, if it was for Bell we would still be flying UH-1Hs to a hot LZ, they would only cost 25 millions a pop.

You mean like the USMC who fly the UH-1Y into hot LZ on a daily baisis? Or maybe the most technologically advanced rotorcraft in service in the V22?

I don't see your point here, just self-contradicting Bell-bashing.

Sultan factually pointed out that Sikorsky has a very recent history of going way overbudget with what was supposed to be a low cost OTS option for the MoD in Canada. Not to mention that the CH53K is already late and overbudget as well.

Anyone in the Army needs to look at that $15 million S-97 quote with a 5 pound bag of salt.

[Lonewolf_50]

Well you could start by counting the number of OH-58 Kiowa’s the US Army has in inventory.
No, I don't think you could. I don't think Army and NG are merely replacing one for one if you look at out years. More likely reducing pilot manpower and airframes by the time IOC arrives.

On the other hand, a decent ball park figure to work with/form.

With potential conversion of some A/C to F without stopping at D ... not sure how tired those airframes are ... about 600. If only assuming the D, 350 or so.
What you're referring to is GFE (government funded equipment) if for example a certain engine is already in the government supply system and is directed to be used.
Thanks, that rings a bell.
Sultan, I am not sure what you mean by this.
Following the Comanche and Cyclone price escalation to the 100 to 200 mil range per the 97 will be unaffordable.
Do you refer to unit cost, or cost with 20 years of support and spares?

robin:
numbers look close to what I remember. Thanks for the refresh.

keesje:
None of the other three have the S-97's speed feature. That appears to be Sikorsky's ace in the whole, in terms of "what I offer you now, while your OH-58 fleet matures and heads to 2025 retirement, is speed that none of the others can offer." Not sure how that sales pitch would go down with the Army. The Marines went with it for V-22. This isn't as technologically risky. (Well, I don't think it is. I may be wrong.)

Consider this: can S-97 answer the mail on who is fast enough from an amphib to fly armed escort for Marine V-22? Think Joint Ops and the Special Ops angle. They have CV-22's that may need escort ... for certain missions ...

If the Army chooses S-97 ... a big IF ... might not the Marines/Navy eventually order (Block II, or Lot 8, or whatever) a "marinized" version?

They did it with the Cobra, way back when.

Given the comparatively small buy of the AH-1Z ... It's not beyond reason.

But I doubt it. AHIPs worked on some USN vessels, so maybe for special missions a detachment of Army might embark ... and learn how to do actual corrosion control if they want to keep their birds flying! :8

[SansAnhedral]

The problem with that mentality is that the AAS platform isn't in need of a "speed transformation". Sikorsky answered a call no one placed for this particular contract, and it will undoubtedly cost far more than $15 million a copy.

With OTH (as has been discussed ad nauseum in the V22 threads), the speed of a tiltrotor was key to that paradigm.

Recall Sikorsky used to show marketing videos of the X2 (before they started trying to shoehorn it into something for AAS) escorting V22s in flight in airplane mode. Seems the timing of everything is a bit off for those chaps, and offering the S-97 for AAS was just what was on the table at the time.

[keesje]

Lonewolf_50, the S-97 is no doubt the game changer, but also the most expensive and risky option.

In one of the last big competitions (KC-X), congress changed the selection requirements (after EADS won) into meeting minimum requirements (~767 capabilities) at minimal costs, to sideline the better value for money KC30.

Wonder what congress members will try come up with, to steer the deal away from the AAS-72X+, without disqualifying the Boeing and Bell offerings, apart from the usual national interests/ jobs.

[Lonewolf_50]

keesje, you need to learn something. American military aircraft are no longer assigned a bureau number or tail number, they are assigned a zip code. ;)

It is more politically practical to support a program that fills jobs in America than to quibble over a marginal performance advantage. In rotary wing, engineers have been pushing back the performance margins inch by inch for the last twenty years, with diminishing returns.

What makes the Sikorsky sales pitch difficult is that even their low ball cost estimate puts them well out of either domestic option's range, so their major advantage is performance.

The ball is still in play ...

[Lone_Ranger]

Rule 1. Dont believe anything written by a Salesman
Rule 2. Dont believe anything written in the last 10 years
Rule 3. Dont believe anything .............everyones at it

[bhawkh60]

$15 Mil sounds about in line for a 200ish aircraft order for around 2020 delivery. Trying to compare this to CMHP is ridiculous though. While CMHP started as as an OTS program, the delays are the direct result of the Canadian government deciding to completely overhaul the design requirements every 6mos to 2 years and send engineers scrambling to redo everything. :ugh:

[SansAnhedral]

the delays are the direct result of the Canadian government deciding to completely overhaul the design requirements every 6mos to 2 years and send engineers scrambling to redo everything

:=

At the same time, Mauer acknowledges that it was Sikorsky's problems developing the software for the CH-148 Cyclone fleet that led to the delays and the need to re-compete the contract.

"The issue we have in terms of the programme is that our software is behind on the mission system," he explains. "The contract doesn't allow us to deliver the aircraft that kind of disconnect."

HELI-EXPO: Sikorsky (http://www.flightglobal.com/news/articles/heli-expo-sikorsky-hopeful-on-resolution-of-canadian-helo-contract-impasse-383078/)

[bhawkh60]

While our head of military systems may publicly acknowledge resposibility for PR purposes to avoid blaming a customer, I assure you that's not what is discussed internally. The morons who negotiated the CMHP contract allowing the Canadian govnt. to change the specs at will and without cost associated have more to do with the delays in that program than anything.

[Commando Cody]

bhawk60:

What? A customer changing specs at will without regard for cost? Who would believe such a thing could happen!


...Can you say, "VH-71"?

('course that worked out well for Canada, they got all nine of those dirt cheap to be used as parts birds)

[Harry O]

The new co-axial Sikorsky Raider. Very nice :ok:

Quad A 2013: Sikorsky stands by its AAS aircraft - News - Shephard (http://www.shephardmedia.com/news/rotorhub/quad-2013-sikorsky-stands-its-aas-aircraft/)

http://www.shephardmedia.com/static/images/article/SAM_0187.jpg

Sikorsky has defended its offering for the US Army’s Armed Aerial Scout (AAS) programme, saying that it will be ready in time for the requirement and will match the expected price point set by the DoD.

Speaking to Shephard at the AAAA Professional Forum and Exposition in Ft Worth on 12 April, Steve Engebretson, director of AAS at Sikorsky, said that it will adhere to the $15 million per aircraft budget, as well as offering a greater saving in the long run because of the nature of the company’s AAS platform.

‘The affordability question is more than “what can I afford today?” he said. ‘Of course you can’t ignore the upfront cost today, so we took a very bold step…to say this is a $15 million fly away aircraft. To do that absent of a requirement takes a lot of courage and conviction for a company to stand by a new product and say “here it is and it’s going to cost you $15 million”.

‘The reason we did that is because frankly our leadership was getting frustrated with the misperceptions that were in defence and the rotorcraft industry in general. It’s a very natural misperception.’

Sikorsky is offering the Raider co-axial rigid-rotor platform for the requirement, which derives from its X2 technology demonstrator that has undergone 23 flight tests. Two aircraft are being built, the first of which is expected to fly at the end of 2014.

‘If you take a look at what the X2 technology aircraft can do…we’re going to fly the Raider in 18 months and we’re going to do some very impressive things with that aircraft,’ he continued. ‘The natural inclination is that, if you believe we can do it, it must be a very complex and expensive platform.’

Engebretson admitted that X2 technology is more expensive than conventional helicopter technologies, although this is balanced out in the performance.

‘When you compare our price point to others we think we may be as much as 25% more expensive than conventional helicopters of the same sized aircraft for initial acquisition, but you get 100% more capability.’

He said that the army hasn’t published a requirement yet, so when looking at the replacement for Kiowa Warrior the army has to look at how long it will be in service and what capabilities it wants.

‘Do you really want the aircraft out there extended for another service life, another 20-30 years?’ he said.

If the DoD plans to remanufacture the current Kiowa Warrior the life of the aircraft will only be another 20 years or so, Engebretson stated. If this is the case it will end mid-way between the predicted life of the Future Vertical Lift programme also underway, and in turn will not be saving the DoD money in the long run.

‘Again, if you buy something off the shelf and it’s only an incremental improvement of what you have today, and again you have to replace it right in the middle of the largest DoD programme, where is my affordability challenge? You’re better with a new start platform,’ he added.

‘If you go for a new start programme that will get forty years and lay it across a 4,000 aircraft replacement, all of a sudden you realise you don’t have to replace your Kiowa Warriors now until you have finished your Future Vertical Lift replacements.’

He also said that the presidential budget sent to Congress this week did not indicate that the AAS would go ahead this year, which gives more time for Sikorsky to develop the Raider to meet the expected army programme timeline.

[The Sultan]

HO

Are these the same sources that said a CH-53K would be $18M per unit? The blades alone on the 97 will cost more than the most advanced 58D upgrade proposed. Add to that the maintenance cost for replacing fodded pusher blades every time you take off from an unprepared surface or shoot a Hellfire this does not look viable (if it makes it back). Remember the pusher killed the Starship.

The Sultan

[IFMU]

Sultan,
According to this:
Sikorsky S-97 RAIDER? Aircraft Overview (http://raider.sikorsky.com/raider-overview.asp)
They have a clutched propeller. That would imply that FOD should not be an issue.
Did the pusher actually kill the Starship? Will it kill the Piaggio Avanti too? My recollection is not the best but I thought it just was not that competitive with the old iron, the king air, especially when price was considered and the relatively small difference in performance.

Bryan

[JohnDixson]

Sultan,

Please take a look at:

CH-53K: The U.S. Marines? HLR Helicopter Program (http://www.defenseindustrydaily.com/ch53k-the-us-marines-hlr-helicopter-program-updated-01724/)

There was a note published recently regarding a 53K maintenance facility contract that was at the $15M range figure. Could that have been what was being discussed?

[Ian Corrigible]

Back in 2000 the original CH-53E-to-X upgrade plan had a projected unit cost of $21M. When Milestone B was approved in 2005 the new-build unit cost was stated as $56M, a figure that has since grown to $76M excl. R&D (or $102M with).

'Course, Bell originally claimed the V-22 would cost only 25-50% more than a 214ST (http://www.flightglobal.com/pdfarchive/view/1982/1982%20-%202698.html)! :E

I/C

[keesje]

'Course, Bell originally claimed the V-22 would cost only 25-50% more than a 214ST!

Bell hopes to produce JVX for $5-6 million a copy, compared with $3.9 million for its Model 214ST transport helicopter.


:eek:

I guess you have to name an acceptable price to get into the next phase of acceptance / funding.

As long as everyone has an interest in continuing and no firm commitments have to be made everyone is ok if further (public) money is spend.

The un-knowledgeable parliament/Senate / Congress needs to be neutralized until the point of no return.

[Lonewolf_50]

The un-knowledgeable parliament/Senate / Congress needs to be neutralized until the point of no return.
What are you talking about?

Where do you think the money comes from for any major aircraft purchase? :confused:

[500 Fan]

It looks like the goal posts are moving in favour of the S-97.

U.S. Army decision on new armed helicopter delayed again | Reuters (http://www.reuters.com/article/2013/05/08/army-helicopter-idUSL2N0DP35E20130508?goback=%2Enmp_*1_*1_*1_*1_*1_*1_*1_*1_ *1_*1)

500 Fan.

[Savoia]

Sikorsky S-97 Raider Begins Final Assembly

WASHINGTON — Sikorsky will begin final assembly of its S-97 Raider helicopter prototype this week, according to company officials.

http://cmsimg.navytimes.com/apps/pbcsi.dll/bilde?Site=M6&Date=20130923&Category=NEWS04&ArtNo=309230020&Ref=AR&MaxW=640&Border=0&Sikorsky-S-97-Raider-begins-final-assembly

That puts the helicopter manufacturer — which is competing for the Army’s Armed Aerial Scout program — on track for a first flight at the end of 2014.

“It’s just a really exciting foundational milestone for us, and it’s great to be leaving the design phase of Raider and getting into the build phase,” Chris Van Buiten, Sikorsky Innovations vice president, said.

Sikorsky S-97 Raider begins final assembly | Army Times | armytimes.com (http://www.armytimes.com/article/20130923/NEWS04/309230020/Sikorsky-S-97-Raider-begins-final-assembly)

qy-Xb3X-bC0

[Graviman]

Interesting that even with rotor scaled up from X2 the advancing blade technology on S-97 is still capable of 220kts. Nr will have gone down a little, so the longer blades will still have a comparable effective hinge offset.

Impressive machine - I'll be following this one.

[Boudreaux Bob]

Cost among other issues have nearly killed the V-22 Program several times.

But, Sultan skips over that in his commentary.

[The Sultan]

BB

Last time I checked the V-22 is proceeding with new orders coming in. A dedicated scout/light attack heli appears dead to justify the existence of the 64's. Even if the 97 has useful capabilities the Army's Attack mafia will ignore it as it makes early retirement of the 58D a bad decision.

In the future long ranges/fast cruise will be the game changer. The 97 will not be able to do both.

The Sultan

[Lonewolf_50]

Sultan, the Apache doesn't need justification. It's already there. Just to give you an idea on how multi purpose platforms arrive from specialized platforms, the Navy finally decided that the F-14 could indeed be a ground attack platform ... and sure enough, it became one. Apache will do what it needs to do, and as I've suggested in some other discussions on this topic, some of the "scout" function is already being done by various UAVs. The OH-58D is not leaving behind a vacuum of capability. The Army deploys with a mixed bag of tools.

The decision to retire OH-58D looks like a done deal. Whether or not that is a "bad" decision depends on subjective criteria. I don't see the Army reversing that, since decisions on force structure reduction in aviation must be viewed in context with all Army force structure reductions from top to bottom. Something had to go, so Aviation let go of OH-58D because the Other Programs were deemed to be a more pressing requirement to fund and support. I doubt anyone was happy with being forced to make that call.

On your last point: will X-2 demonstrated capability be able to scale up to the size and performance demands on S-97? It looks like Sikorsky is about to find out.

[busdriver02]

The OH-58 is primarily a MK1 Eyeball scout; UAVs and the Apache w/ MTADS has largely replaced the old school. It isn't necessarily better or worse, just different. Except, the sensors don't have to get close to things, so they have reduced risk.

As to the X-2 concept, the upper limit of scalability is a very closely held Sikorsky secret, but from what I've inferred from industry types the S-97 is easy. Something significantly bigger than a Blackhawk gets troublesome.

[SansAnhedral]

Not too much of a secret

X-2 Maxes Out in Medium-Sized Role: Sikorsky Executive | Defense News | defensenews.com (http://www.defensenews.com/article/20110914/DEFSECT01/109140306/X-2-Maxes-Out-in-Medium-Sized-Role-Sikorsky-Executive)

The real dirty secret is that even the traditional medium class is a stretch. I've said before, I would say you're looking at 12,000lbs max.

[busdriver02]

Curious, where are you deriving the 12k number from?

[SansAnhedral]

It was just a swag I came up with on a proverbial napkin some time ago, based on disc loading and FM, limited by rotor radius due to minumum hub spacing for high speed forward flight.

I have no doubt you could increase the GW and manufacture larger heavier rotors, however the requisite disc spacing increase sees exponentially diminishing returns in Vmax due to drag.

Also, consider the XH-59A/S-69 tipped the scales at 9,000 lbs and one of the primary goals of its unfunded successor XH-59B was a "significant weight reduction", which ended up eventually yielding a 5,300 lb X2 TD.

[Jack Carson]

I have to question the level or risk when proposing the S-97 Raider as a true competitor for the US Army’s AAS program. Having flown the XH-59A and viewed many of the X-2 videos it is apparent that at this point both aircraft have demonstrated only limited flight envelopes. Straight line speed was first and foremost in both programs. However, I believe that the XH-59A did perform limited maneuvers at altitudes up to 20,000 ft MSL. I am sure that AAS program maneuverability and agility requirements with be very demanding.

[Lonewolf_50]

I am sure that AAS program maneuverability and agility requirements with be very demanding.
So too were the similar requirements for Comanche. Oops, look what happened there! :eek:

[IFMU]

I like the source that says the scaling is limited. Any company exec is always the go-to source for technical information.
Bryan

[busdriver02]

Thanks Sans, as with everything helicopter it's a trade off between weight and ___________. I imagine that if they think they can scale this up to something Blackhawk sized they're banking the effectiveness of the yet to fly hub fairing and some kind of advanced composite construction techniques? Composites scare me, they're why I chose to go the thermo route rather than structures in college.

[SansAnhedral]

I like the source that says the scaling is limited. Any company exec is always the go-to source for technical information.

I wonder what motivation a government business development executive would have to sandbag and potentially depress stock prices. If anything, it would be to do precisely the opposite.

[John Eacott]

S97 Raider rollout (http://raider.sikorsky.com/rollout_tab.asp) scheduled for 2nd October in West Palm Beach, Florida.

http://canalpiloto.com.br/wp-content/uploads/2014/03/S97_Canal_Piloto.jpg

[IFMU]

Pics of the real thing are out - looks great!
http://defensetech.org/2014/10/02/sikorsky-unveils-s-97-raider-light-attack-helo/
Bryan

[busdriver02]

Interesting to note based on previous discussion, I plopped those photos into power point to compare it against the X-2. Proportionally they're basically the same, disc spacing being the factor I was curious about.

[riff_raff]

The most interesting feature shown in these new pictures is the engine cowl. Nice clean installation of the single T706. Hard to tell, but it looks like they route the exhaust aft and disharge it just ahead of the pusher prop. Seems like it would be a good compromise between weight, thrust and IR suppression.

Nice detailing around the hubs and mast too.


http://aviationweek.com/site-files/aviationweek.com/files/imagecache/galleryformatter_slide_penton/gallery_images/photo7.JPG

[SplineDrive]

Sikorsky is making progress! Aircraft is chained to the ramp and they've released a video of the first engine starts.

CdBBwg0_hKg

https://www.youtube.com/watch?v=CdBBwg0_hKg&spfreload=10

[IFMU]

S97 Raider Journey to first flight video:

DHUc-rueOcQ


http://youtu.be/DHUc-rueOcQ

[SansAnhedral]

Still waiting to see a sail fairing in action on a spinning ABC rotor head

[Ian Corrigible]

...and a first flight. :E

[skadi]

First flight!:

https://www.facebook.com/verticalmag/photos/a.85054751660.81526.51515866660/10153338287101661/?type=1&theater


skadi

[chopper2004]

Congrats to Sikorsky and Team Raider,

Cheers

(Photo courtesy of Sikorsky)

http://i57.photobucket.com/albums/g209/longranger/11336956_10152834532940770_1554523935517599968_o_zps5tp3t4xw .jpg

[SplineDrive]

Still waiting to see a sail fairing in action on a spinning ABC rotor head

On the videos, check out the stationary fastener pattern between the rotors. I think they solved that problem on RAIDER.

[whoknows idont]

It appears to have the side-stick for the copilot on the left side? That would be a rather odd design "feature". Especially highly experienced pilots better be really careful to trick their muscle memory into using the left hand for cyclic control. Could be difficult (read hazardous) in hairy situations.
What's the collective, cyclic up and down? :ooh:

[Ian Corrigible]

See time index 1:17 for an explanation of the side-arm controller (collective), cyclic stick (yaw, pitch & roll) & pedals (brakes & comms), c/o Advanced Programs PM Jim Kagdis.

hwusQWZBXjg

Kudos to Sikorsky on achieving their FF.

I/C

[IFMU]

Congratulations to the Raider team! Very cool! The video looked great.
Bryan Cotton
Sikorsky/X2 Alumni

[whoknows idont]

Seems to me like they changed the layout on the flying prototype.
From the video above ("Sikorsky S-97 RAIDER Journey to First Flight"), 1:26:

http://i.imgur.com/zadO25b.png?1

[SansAnhedral]

On the videos, check out the stationary fastener pattern between the rotors. I think they solved that problem on RAIDER.

That is the same as the X2. It was the weathervane apparatus (of which they patented 3 implementations on their patent) which proved troublesome.

Congratulations to the Raider team! Very cool! The video looked great.
Bryan Cotton
Sikorsky/X2 Alumni

So you have seen the video! Hopefully they didnt make the same miscalculation with the control gains as the X2 maiden (I am sure you remember that having been so involved in the FBW). Bredenbeck had the thing dancing on him that afternoon.

edit

Here is the video, pretty stable this time

j3njDrUtT8k

[IFMU]

Sans,
I watched the vid and I think SplineDrive is right on the sail fairing provisions. Not the same as X2. The X2 was a good aircraft but I think the workd will see that Sikorsky has stepped things up a notch or two for the Raider.

The initial gains did look a lot better! Or Bill is steadier. :8

Bryan

[SplineDrive]

30 seconds into the retrospective video http://youtu.be/j2CJP78WkGs you can see an entire composite skeleton above the lower rotor that isn't rotating. I bet the fairing bolts to that.

Nice video, too.

[NickLappos]

What a gas to watch the next generation of Sikorsky pilots take to the sky in a new design! Raider (and its big brother Defiant) are the new boys on the block, with a nice blend of low speed agility (akin to the BK-105) and high speed load factor and cruise payload efficiency (much better than helicopters, approaching that of Tilt Rotors, and much better than winged compounds.)

The Raider is a rapid prototype, but it is a practical aircraft, akin to a Y plane as a pre-production prototype. It has many prime components that can go straight to production, saving much time if a customer requires fast delivery.

The flight was terrific, all as expected. Here is some info on the aircraft:

Sikorsky S-97 RAIDER? (http://www.raider.sikorsky.com/raider_technology_demonstrator.asp)

Sikorsky S-97 Raider - Concept Light / Attack Helicopter - History, Specs and Pictures - Military Aircraft (http://www.militaryfactory.com/aircraft/detail.asp?aircraft_id=1074)

Sikorsky S-97 Raider Specification & Technical Data | Defence Aviation (http://www.defenceaviation.com/2014/10/sikorsky-s-97-raider-specification-technical-data.html)

For those with sharp eyes, like SplineDrive, the space between the heads has a standpipe that is stationary, allowing a nice fairing to be fitted to fill in that area, and dropping drag by quite a bit. The transmission design team in Ft. Worth thought that up, it could be worth an additional 5 to 10 knots.

[SansAnhedral]

the space between the heads has a standpipe that is stationary, allowing a nice fairing to be fitted to fill in that area

Does that imply its a fixed fairing and they dropped the weathervane design I read so much about?

One thing I am curious about is the expected efficiency of the Defiant in cruise. To date, all ABC ships have buried the QCA/transmission in the middle of the fuselage, keeping that massive drag out of the freestream - and simultaneously eating up almost the entirety of the cabin.

In order to regain useful payload space, that entire assembly has to be mounted on top of the pylon (to avoid what would otherwise be immense CG issues), which probably almost doubles frontal area.

What happens to Vcruise and efficiency in this case?

[exwessex]

Can anyone explain the pilots controls we can see in the picture above-it appears that each pilot has just an outboard side-stick.How is this used?

[SplineDrive]

Sans, yup, it looks like the lawyers made good money processing patents for fairing anti-drive units when the production solution is to mount the fairing to a stationary shaft. Sounds more robust to me.

As for Defiant, the public artwork shows the rotor to be a little higher from the cabin, proportionately, than on RAIDER, but the twin engine installation might also affect that. In any case, I see no evidence that the transmission needs to be completely on top of the cabin structure and it does not appear that is the layout. Looks like the passenger cabin is forward of the transmission bay. Also helpful is that larger helicopters typically have a higher cruise speed than their smaller relatives for a given aircraft layout. I have no doubt that Defiant will be fast and a significantly lower L/De than a conventional helo.

When it comes to balancing CG, few rotors in the world will have the moment generation cabailities of the Defiant main rotor ;-) If they want to fly level body I'm sure they can.

[NickLappos]

SansAnhedral,
The faring doesn't weathervane, that was decided to be impractical. The transmission standpipe runs up to keep the fairing in place.

I think you are under the misapprehension that something about the transmission is "massive" and a real problem to house and a real drag issue. The preconception fills your questions, as if we hadn't yet stopped beating our wives. That is not the case with the X2 transmission, and I believe it is not the case with the Kamov transmissions that I am familiar with.

Frankly, the transmission diameter of most helos is sized by the main "bull" gear diameter, which establishes the basic diameter of the box, and the coaxial transmissions with a double shaft tend to fit within that basic bull gear diameter without a problem. Fitting it within the fuselage is no big deal, frankly, and doesn't take up much internal space, as your question says. I found a shot on a public source that shows the Raider's cowing off, here it is: Sikorsky S-97 Raider - Concept Light / Attack Helicopter - History, Specs and Pictures - Military Aircraft (http://www.militaryfactory.com/aircraft/detail.asp?aircraft_id=1074)


Anything orange in there is test instrumentation. Note that the transmission is "normal" in size and width, and that plenty of internal space is left to carry stuff, which is why we build these machines!

[riff_raff]

...Frankly, the transmission diameter of most helos is sized by the main "bull" gear diameter, which establishes the basic diameter of the box....I would agree with this point. A torque split configuration should help reduce the plan view profile of a (intermediate or final) bull gear stage. One major consideration when sizing a bull gear stage is the L/D limit of the bull pinions. A spur gear pinion is limited to an L/D of around 1.0 or less. If more pinions are used to drive the bull gear, each mesh will need to transfer proportionally less torque. This means the diameter of the pinions and bull gear can be reduced while maintaining an appropriate L/D and the required stage gear ratio. A coaxial counter-rotating MRGB configuration would have the same effect on plan view profile (vs. a single rotor config) since there is an additional torque split at the two output drives. The drawback with this configuration is that the vertical length grows due to the extra space required for the dual coaxial outputs.

I was not familiar with the term "standpipe" as used in NickLappos' posts. I had always heard such a device referred to as a "static mast". So out of curiosity I did a search of recent published US patent applications from Sikorsky using the term "standpipe", and sure enough I found a couple documents (http://pdfaiw.uspto.gov/.aiw?Docid=20150125299&homeurl=http%3A%2F%2Fappft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO2%2526Sect2%3DHITOFF%2526p%3D1%2526u%3D% 25252Fnetahtml%25252FPTO%25252Fsearch-bool.html%2526r%3D1%2526f%3DG%2526l%3D50%2526co1%3DAND%2526d %3DPG01%2526s1%3Dsikorsky.AS.%2526s2%3Dstandpipe%2526OS%3DAN %2Fsikorsky%252BAND%252Bstandpipe%2526RS%3DAN%2Fsikorsky%252 BAND%252Bstandpipe&PageNum=&Rtype=&SectionNum=&idkey=6926CA2FF5AA). Interesting stuff.

[SansAnhedral]

Nick, to be fair I never said the transmission itself alone was large, or of large diameter. Note I mentioned QCA, which as a Sikorksy alum I am sure you know the acronym.

You have deftly danced around the issue I was trying to get at; a not-insignificant increase in frontal area. As has been published through many whitepapers during G-LYNX days, XH-59 days and so forth, its well understood that a major contributor to profile drag has always been frontal area, specifically the rotor head. I have read it mentioned that approximately 40% of drag on an edgewise flight helicopter is driven by the head/mast.

So lets take the X2, XH59 and S97, all of which were designed to have negligible payload within the cabin. This allows for a very clean installation using the area below the top deck to be used to house the QCA attachment along with the single engine power pack. Now, if you must reclaim this area due to the payload and egress requirements of FVL-M, you have 2 options:


Mount the QCA and twin engines above top deck in pylon
Mount the QCA and twin engines fully aft of cabin below the top deck a la X2/XH59/S97


The latter of which would almost certainly cause extreme CG issues, as I mentioned before.

It would stand to reason that this was realized by the Sik-Boeing design team as it would appear from they have chosen the former (over time the main gear has migrated in concept art as well, likely due to cabin rearrangement for CG):

http://www.uppic.com/uploads/14328247781.png

So, in addition to all of this new area in the freestream due to dynamic systems, we have a larger diameter rotor, which increases rotor spacing. From layouts of the SB>1, the overall height looks something near 20 feet.

For small GW tatical aircraft like the S97 where you can use the fuselage itself to fair the dynamic system, and keep the rotor spacing low, the ABC concept works well.

I have a hard time fathoming how installed power is going to overcome the apparent large increase in drag from both pylon mounted engines+QCA and increased rotor spacing in edgewise flight on a larger version. I think this is even well-understood by SAC, considering the amount of lobbying done on the FVL IDRR in an attempt to keep the speed requirement closer to 170kt than what was settled on for MPS @ 230kt.

[NickLappos]

Sans,
There is surely more drag due to the extra rotor head, but you went on about lost cabin area due to volume, so I answered that misimpression.
Your worldview of helicopter drag seems drawn from airplanes, where "presented area" and cross section drag are dominant. Rotorcraft are far different, and need a fresh way of examining their efficiencies. Mostly, you must look at the entire package, especially the power consumed by the rotors to produce the lift and thrust, and the hover performance lost when large wings lay within the rotor downwash field.
A twin rotor head design carries an inherent drag penalty, for sure, mostly driven by the extra head but also vastly compounded by the tall mast and space between the rotors. Mikheyev of Kamov published several papers that described his estimate at 10% extra for his designs, I have no reason to doubt that.
The fairing we were talking about on the X2 designs, and the much reduced X2 rotor separation (which drops the upper rotor height substantially) help limit the frontal area drag to very reasonable numbers relative to older coaxials. The head separation on a Kamov is about twice as much, because the low hinge offset rotors have to be kept apart (to prevent self-midair collisions). The very rigid ABC/X2 rotors have almost no flapping, so they can be kept closer together, and with the ensuing lesser drag.


The most important power loss/drag increaser at speed is not the frontal area, but the large power penalty of the retreating blade stall. The rotor alone consumes a vast amount of the power at higher speeds, You could reduce the presented area to a point in space and the rotor blades will consume 3/4 of the power anyway. Helicopters must have balanced lift on both sides of the disk, so the retreating blades, operating at very high angle of attack, and in some reversed flow, are famously inefficient. This is while the advancing blades are approaching Mach 1 and consuming power due to drag divergence. Can't slow them down, or the retreating side gets worse!


The X2/ABC basically tilts its swash plates to dump the angle of the retreating blades, and making sure the advancing blades tote the lift needed while the retreating blades reduce their angles and loaf along. As Mach 1 is being reached, the rotors are slowed down as well, which keeps the high speed drag under control.


What this means, SansAnhedral, is that the X2/ABC design has much lower drag at high speed than helicopters. Its L/D is very attractive, especially when you compare its hover efficiency. Added benefits over other high speed configurations include: efficient helicopter rotors for good payload and good altitude hover performance, fantastic handling with low inertias and nimble pitch, roll and yaw handling, compact design so it fits into small areas.


This was all examined when the FVL was being considered by the Army, and speed, range and altitude performance were all part of the new way of doing business. Need independent proof of these comparisons? Boeing took months to examine tilt rotors, compounds and X2s, and came to Sikorsky to join the team, even though they have a great deal invested in tilt rotors, and know them very well. Defiant is very much a 50-50 partnership with a company that makes 50% of the V22, and chose to spend their effort and money on the X2/ABC configuration.


BTW, another misimpression is the mistaken belief that Sikorsky tried to hold back the speed goals of JMR/FVL. I have no idea who told you that, my suggestion is that if they tell you it is 2 o'clock and your watch agrees, throw your watch away! Sikorsky and Boeing are spending a ton building a machine (Defiant) that will be far, far faster!

[SansAnhedral]

All very good talking points that we have heard about ABC since circa 2005-6 (when Sikorsky was still showing what they considered a feasible 737-fuselaged ABC!). Since there is no precedent at this size, the proof is in the pudding, and I think it will be very difficult for a > 30,000lb GW ABC coax to achieve much more than 200kt. If an SB>1 actually gets built by late 2017, which I still have my doubts based on things I have heard from various industry suppliers on the program, I will be surprised.

Need independent proof of these comparisons? Boeing took months to examine tilt rotors, compounds and X2s, and came to Sikorsky to join the team, even though they have a great deal invested in tilt rotors, and know them very well. Defiant is very much a 50-50 partnership with a company that makes 50% of the V22, and chose to spend their effort and money on the X2/ABC configuration.

Agree to disagree on this point. From the grapevine, the real story is that Boeing intended to partner with Bell on FVL, but it seems Bell had learned the lesson that the 50/50 split on the V22 was far from their best interest to repeat, especially with the specifics of the requested FVL work split.

I still maintain that both Sikorsky and Boeing want nothing more than for FVL-M to go away, hence the teaming. Sikorsky wants to sell S97 as FVL-L or as something "off the shelf, ready to go" to replace Kiowa and AAS. They both subsequently convince Uncle Sam that the capability in the medium class can better be accomplished (read: cheaper) with next gen UH-60X and AH-64X to keep those revenue streams alive.

[IFMU]

Mount the QCA and twin engines above top deck in pylon
Mount the QCA and twin engines fully aft of cabin below the top deck a la X2/XH59/S97


The latter of which would almost certainly cause extreme CG issues, as I mentioned before.


But, it was not a problem on X2. CG was good. Though what SpineDrive says is correct, you still need a forward enough CG for stability. This is a basic aircraft fact that is true for both helicopters and fixed wing.

On Raider, as you load up the cabin, the CG moves forward.

[NickLappos]

SansAnhedral,
Your beliefs are interesting, and many seem to be based on zero facts! Also, the more than a little conspiracy theory nature of those beliefs makes you suspect as a pilot flying passengers. Those who think we have money to burn spending millions on vehicles that we don't think will work are way past crazy.

[SansAnhedral]

It was not a problem because there was no payload on X2, and little on S97. The issue is exacerbated on a 30,000lb utility version.

From the layouts of SB>1, with empty payload, it looks to have little to counteract an aft CG condition if it is trimmed for a nominal payload way out in front as shown.

[NickLappos]

I guess you didn't read the info that I posted about the payload range and speed of the Raider.

[SansAnhedral]

SansAnhedral,
Your beliefs are interesting, and many seem to be based on zero facts! Also, the more than a little conspiracy theory nature of those beliefs makes you suspect as a pilot flying passengers. Those who think we have money to burn spending millions on vehicles that we don't think will work are way past crazy.

Fear not, as flying passengers (unless you count the odd bug-smattered windscreen) is not my meal ticket

But I digress. Nobody claimed that the aircraft "wouldnt work", but we all know that the program we are referring to is intended to "drive requirements" for a future program of record. To present an aircraft that is deficient in a category like cruise speed hardly qualifies as a reason not to try and influence your customer that his requirements are out of bed, and your product is still best for the job.

Having been a part of as much of the S-92 program as you were, surely you can attest to the politics involved in these sorts of things.

[The Sultan]

Nick

Your partisan attacks which denigrated the V-22's speed, range, and payload which have been shown by V-22 operations to be false makes you a poor source of aircraft performance numbers.

The Sultan

[NickLappos]

Sultan
Show me one fact that I misrepresented. One.

Tilt rotors are faster, and more efficient in cruise than other high speed configurations. The L/D of the V22 is fine, and I bet the V280 will be even better. For that greater speed, Tilt Rotors have less payload (given the same power and empty weight) and are not as nimble at low speed. Those are facts, much as we might try to wish them away.

That being said, the V280 is a viable configuration, and a worthwhile competitor for FVL missions. The V22 is successful, and meets most of its promises handily.

[SansAnhedral]

Tilt Rotors have less payload (given the same power and empty weight) and are not as nimble at low speed. Those are facts, much as we might try to wish them away.

Generically, I dont think you can say that tiltrotor payload is always less for a given power unless you specify a mission or some parameters. The ability to perform STOL maneuvers means that you are not necessarily limited to rotor/hover performance for payload calculation.

For low speed maneuverability, ADS-33 is a pretty dated spec, and new tiltrotor designs seem to have designed remedies for the V22 yaw sluggishness with much higher flapping capability.

Nick, weren't you the one chiding Weiner's team that if they wanted to hit their speed target on X2, they just needed to push it out of the ramp on a V22? But that was in your Bell days :}

[SplineDrive]

Sans,

I suspect when Nick is referring to lower payload for the same power and empty weight, he's referencing the higher disc loading tilt rotors have always had (at least up through the 609 and Model 916/918 aircraft). The V-22 has famously poor disc loading (wing/blade fold being a huge design driver), but even the better balanced 609 is still higher than an X-2 would typically be.

Looking at the V-280 concept art, it does appear that they are looking to improve the disc loading and thus hover efficiency over the V-22, but I doubt they will get down to ~12 lb/ft^2 like the RAIDER (and presumably SB>1).

None of the tilt rotor heads that I have experience with has a dramatically higher flapping capability than the V-22. Certainly the two production intent designs flown after the V-22 don't. So if there's enhanced low speed maneuverability, it isn't coming from there. In VTOL mode, these aircraft are very G limited vehicles until they get significantly wing borne.

[SansAnhedral]

None of the tilt rotor heads that I have experience with has a dramatically higher flapping capability than the V-22. Certainly the two production intent designs flown after the V-22 don't.

True, I should have said "design studies". In fact, remember that 609 has no lateral cyclic flapping, and gets roll through DCP in hover and flaps almost identically to the V-22 despite not being underslung.



So if there's enhanced low speed maneuverability, it isn't coming from there.

'Sports-car' Performance Promised for Bell V-280 | Defense: Aviation International News (http://www.ainonline.com/aviation-news/defense/2015-02-27/sports-car-performance-promised-bell-v-280)
The Army wants to focus on low-speed agility, so the V-280 will have about 50 percent more flapping capability in its rotor system than the V-22. That’s going to enable an even greater level of agility in all axes–pitch, roll, and yaw–so that you have that sports-car type of helicopter performance in the landing zones and objective areas. That’s a focus for the Army customer.

[SplineDrive]

Sans,

Interesting article mentioning the higher flap capability, I hadn't seen that one. Thanks. If the hubs still have elastomeric gimbals and CF bearings, that will be a life challenge, but rubbers are always getting a little better and the life of the demonstrator is short :-)

[riff_raff]

One major difference between the V-22 and V-280 is that all of the rotor moments/forces in the V-22 had to pass thru the gearbox structure.

[SplineDrive]

Saw this on Sikorsky's Facebook page... Photos of the RAIDER flying with the full set of fairings installed including the elusive fairing between the rotor heads.

https://www.facebook.com/SikorskyAircraft/posts/10153129023280770

Looks good!

[The Sultan]

So four months to put fairings on, not impressed. I was waiting for a press release where they with great daring and skill expanded the flight envelope above 10 Knots.

The Sultan

[Collective Bias]

Sultan

You seem to have a big personal problem with Sikorsky, and Nick in particular. My guess is that I am not the only one on this forum getting a bit tired on this. It is one thing to be supportive for a product, but also realise that other manufactures can also build helicopters that can fly.



CB

[SplineDrive]

Sultan, it's a small industry, I'd keep the snarky comments down... I know other manufacturers have gone months between flights at the beginning of flight test on internally funded programs.

In the meantime, I'm quite sure they've done more than 'installed some fairings'...

[The Sultan]

Collective/Spline

From the original Sikorsky first flight press release:

Sikorsky chief pilot Bill Fell and co-pilot Kevin Bredenbeck completed three take-offs and landings during the hour-long sortie and evaluated the aircraft’s handling in all four cardinal directions at speeds up to 10kt.

“It was quite the aggressive first flight for a helicopter,” says Bredenbeck, who piloted the X2, the S-97’s proof-of-concept demonstrator.

I was mocking Sikorsky's own words about how doing ten knots was aggressive. They probably did nothing except hover over a point in a ten knot wind and do control inputs, standard but not aggressive. Typically it would be a couple of days to get to a respectable 60 knot-ish envelope to fine tune the FBW system which, with Sikorsky's PR, would have been released. No fairings needed for that. Once fine tuned, fairings would be needed to push past the speeds of a 50 year old 53. That also would have resulted in a press release. I am sure they will make their 220 knot goal, but they are 4 months into their year long program. I grant that it took Bell over two months to expand the envelope of the 525 beyond 160 knots (near design speed) with a totally new privately funded FBW aircraft, but they at least waited to annouce something announcable, Adding fairings is like touching up paint if all you are doing is hovering.

The Sultan

[SplineDrive]

Sultan,

I won't try and justify the use of the term 'aggressive', though from watching the longer videos, it looks like they did more than hover over a point making control inputs. Looks like the translated in all directions and made control pulse inputs to check stability/response, etc. I agree standard stuff, though pulses aren't always on a first flight test card. To be fair to Sikorsky, they haven't even made an announcement regarding additional flights beyond a few photos posted to social media... The fairings are only a visible change.

Glad to hear the 525 flight program is proceeding... that's an aircraft Bell has sorely needed for many, many years.

SD

[Lonewolf_50]

Sultan

You seem to have a big personal problem with Sikorsky, and Nick in particular. My guess is that I am not the only one on this forum getting a bit tired on this.
Indeed. I suspect that a whole lot of test points and data not widely discussed were the topic of the test, if my exposure to a developmental program about 20 years ago is any guide.

[CTR]

A week article today reported S-97 program manager statement that flight testing is being halted again for another 9 to 12 weeks. Reason is to wait for more hours to be accumulated on the gearbox test stand units.

It appears first flight of the S-97 followed the course of the majority of new aircraft programs. Get it in the air as quickly as possible to meet a executives milestone, just so he or she will get their bonus. Does not matter if very little real data is aquired or if the flight test schedule is actually delayed by a flight only for the press. Not picking on Sikorsky, especially not the people busting their ass getting it done. Just stating that the S-97 followed the old aerospace adage I was told 35 years ago; "First flight only has to be high enough to pass a piece of paper under the wheels". Then you push the aircraft back in the hanger and finis the job.

[IFMU]

CTR,
I am sure you are right on. I am not part of the S-97 inner circle, as I left Sikorsky when they closed Schweizer down. But your words ring with truth that I have seen firsthand before.
Bryan
Sikorsky/X2 Alumni

[SASless]

Actually I think Sultan is suffering from a case of Intellectual Penis Envy when he opines re Nick. I suppose when he peers at his own "I love Me!" display on his Cubicle wall....he feels quite small thinking of what Nick's must look like after all these many Years in the Industry, Awards, Trophies, Patents, and the other Memorabilia he has accumulated as an Army Pilot, Engineer, Test Pilot, and Senior Executive heading up Research and Development Operations at several Aerospace Firms.

But....we should be tolerant of those fighting the Green Eyed Monster that lurks in some.

[IFMU]

I think anybody who has really accomplished something can look at the accomplishments of others and recognize that they have done something good. I am not a tiltrotor guy, however clearly they have kicked ass to get the V22 to where it is today. Why badmouth them? When I was younger I did not always behave as such, but maturity is a good thing.

[riff_raff]

A week article today reported S-97 program manager statement that flight testing is being halted again for another 9 to 12 weeks. Reason is to wait for more hours to be accumulated on the gearbox test stand units.I recall reading somewhere a comment from Sikorsky saying with the S-97 they wanted to accumulate a certain number of hours of drivetrain bench test for each hour of planned flight test. Seems reasonable given the relative complexity of the drivetrain and that it is an all new design. Being internally funded there are no contract schedule milestones to meet, and any flight test failures will reflect poorly on Sikorsky's JMR-TD effort which relies on the same technology. So Sikorsky has very good reason for taking their time getting everything right before continuing with S-97 flight testing.

[CTR]

I Seems reasonable given the relative complexity of the drivetrain and that it is an all new design. Being internally funded there are no contract schedule milestones to meet, and any flight test failures will reflect poorly on Sikorsky's JMR-TD effort which relies on the same technology.

The point is why not wait until after the required testing is complete to start real flight testing. Instead of rushing first flight to meet some artificial date for a press release.

[IFMU]

The point is why not wait until after the required testing is complete to start real flight testing. Instead of rushing first flight to meet some artificial date for a press release.

I think the artificial date is for execs to get a bonus. If we could just get back to engineers running these companies then this silliness would go away.

[SansAnhedral]

I thought it was already late from the initial "fly by the end of 2014" commitment?

[The Sultan]

Actually I think Sultan is suffering from a case of Intellectual Penis Envy

Sasless

You know how those with the biggest gun are compensating for private part issues. Well anyone driving by south Arlington on I-20 can see the structure Nick had built for his ego for an significant cost to Bell and the taxpayers. Some day it will be torn down never being used. Nick does know how to spend money. When at Bell these expenditures had near zero return.

The Sultan

[The Sultan]

from riff-raff

A week article today reported S-97 program manager statement that flight testing is being halted again for another 9 to 12 weeks. Reason is to wait for more hours to be accumulated on the gearbox test stand units.

Riff this is a very wise move especially after the CH-53K transmission embarrassment. Not sure what the issue would be to keep them from doing moderate 60-100 knots flights, after being released for flight, while isolating problems before pushing to the higher load maneuvers.

The Sultan

[JohnDixson]

And what is the building all about, Sultan? Design Spaces? Test Labs/Rotor Test Stands?

John

[SASless]

Sultan's Ego perhaps....if it can be squeezed into the building.

[riff_raff]

Riff this is a very wise move especially after the CH-53K transmission embarrassment.The 53K MRGB is also a fairly complicated design, but in a different way than the S-97 MRGB. The 53K has three engines driving a single main rotor, while the S-97 has a single engine driving two main rotors.

I would not necessarily consider the development problems with the 53K MRGB an embarrassment. It is a (12 way) torque split configuration designed for very high power (>16,000hp) and low specific weight (over 500lbs less than planetary config). Torque split designs are notoriously difficult to get right because the multiple load paths present a very complex analysis case. The 53K MRGB relies on torsionally compliant quill shafts and precision assembly to provide the required balance of torque distribution among 12 pinions driving the bull gear. Anyone that has experience working with this type of gearbox would agree that getting the torque balance correct requires a detailed analysis effort plus several cycles of bench test/design modification.

The only reason Sikorsky might have to be embarrassed is if they failed to fully appreciate the level of development effort this type of gearbox has historically been shown to require. I also would have expected NAVAIR to foresee these kinds of development issues. NAVAIR has some very competent people and have lots of experience in this field.

[Lonewolf_50]

The 53K MRGB ... It is a (12 way) torque split configuration designed for very high power (>16,000hp) and low specific weight (over 500lbs less than planetary config). Torque split designs are notoriously difficult to get right because the multiple load paths present a very complex analysis case. The 53K MRGB relies on torsionally compliant quill shafts and precision assembly to provide the required balance of torque distribution among 12 pinions driving the bull gear. Anyone that has experience working with this type of gearbox would agree that getting the torque balance correct requires a detailed analysis effort plus several cycles of bench test/design modification. If you compare it to the 53E main gear box, is it an order of magnitude more difficult or within the same order of magnitude in difficulty ... given the weight target?

[riff_raff]

I would not consider the split torque design to present an "order of magnitude" greater difficulty than that of the CH-53E. However, simply growing the existing CH-53E configuration to accomodate a 30% increase in power presented some serious design challenges, even without weight concerns. The 53E MRGB uses a spiral bevel 1st stage and planetary 2nd/3rd stages. Early in the 53K program NAVAIR asked Sikorsky to perform an MRGB trade study comparing an improved planetary design to a split torque design. NAVAIR wanted to determine if the advantages of the split torque configuration were enough to justify the greater development risk. Among the advantages provided by the split torque configuration were lower weight, more space for increasing the main rotor shaft diameter, and a more efficient main housing structure.

If you are interested in reading more about the 53K MRGB design trade study work done by Sikorsky, there is an excellent AHS technical paper from 2008 (https://rotorcraft.arc.nasa.gov/Rotorcraft_Bibliography/index.php/component/joodb/article/3/5778-he-s-gmirya-y-mowka-f-leigh-l).

[Lonewolf_50]

I would not consider the split torque design to present an "order of magnitude" greater difficulty than that of the CH-53E. However, simply growing the existing CH-53E configuration to accomodate a 30% increase in power presented some serious design challenges, even without weight concerns. The 53E MRGB uses a spiral bevel 1st stage and planetary 2nd/3rd stages. Early in the 53K program NAVAIR asked Sikorsky to perform an MRGB trade study comparing an improved planetary design to a split torque design. NAVAIR wanted to determine if the advantages of the split torque configuration were enough to justify the greater development risk. Among the advantages provided by the split torque configuration were lower weight, more space for increasing the main rotor shaft diameter, and a more efficient main housing structure.

If you are interested in reading more about the 53K MRGB design trade study work done by Sikorsky, there is an excellent AHS technical paper from 2008 (https://rotorcraft.arc.nasa.gov/Rotorcraft_Bibliography/index.php/component/joodb/article/3/5778-he-s-gmirya-y-mowka-f-leigh-l).Many thanks, riff raff, this is the kind of post one comes to PPRuNe for. Thanks also for the link. :ok:

[riff_raff]

Lonewolf_50- Just a couple final comments regarding the challenge of designing a split torque gearbox.

First, back in 2003 under the AATD RDS-21 program, Sikorsky demonstrated they could get load sharing within 1% in a split torque gear drive using their torsionally compliant quill shaft concept (somewhat similar to what is used at a larger scale in the 53K MRGB). I can tell you from experience that getting load sharing within 1% in any split torque gear drive is pretty impressive. Apparently they were not able to achieve anywhere close to the same result with the 53K MRGB in testing, since they are currently going thru a major redesign. In fact, I would speculate the bull pinion load sharing variation they saw in bench testing of the 53K MRGB was much more than "an order of magnitude" greater than 1%. In my opinion, even a 10% variation in load sharing between the 12 bull pinions would be quite acceptable.

Second, in case you don't get your hands on a copy of the AHS paper I linked, here's the most interesting quote:
"Summary and Conclusion A trade study on two different design configurations of the CH-S3K main gearbox, a new split torque MGB vs. an improved planetary MGB, was performed. The three focusing parameters of the trade study include performance, cost and risk. The advantage and disadvantages of both design configurations were thoroughly studied. The geartrain systems, mounting bearings, and supporting housings of the two different MGB‘s were designed and analyzed for detailed weight calculations. Results of the trade study are summarized below.
1.The split torque MGB design has a significant weight saving (more than 500 lbs) over the improved planetary.
2. The Split torque MGB can save millions of dollars per aircraft in total cost which includes development and production cost.
3. The Split torque design bears slightly higher risk than the improved planetary design due to Sikorsky’s lack of production experience in split-torque gearboxes. But the risk-reduction test of the quill shaft lowered the risk level of the split-torque MGB to the same level as that of the improved planetary.
In conclusion, the split torque main gearbox is a better design and was chosen for the new CH-53K."

[Lonewolf_50]

Second, in case you don't get your hands on a copy of the AHS paper I linked, here's the most interesting quote: All that link got me to was a cover page. Thanks for the meat and potatoes summary. :ok:

[SansAnhedral]

I'm wondering if there are any implications for LoL situations with a split torque design

[riff_raff]

Lonewolf_50- here's a later AHS paper on the same subject if you want to spend $30.

https://vtol.org/store/product/load-sharing-test-of-the-ch53k-split-torque-main-gearbox-2474.cfm

[The Sultan]

John D

I never said building, that would at least be useful for storage.

The Sultan

[The Sultan]

AUSA 2015: Sikorsky?s big plans for Raider (video) - News - Shephard (http://www.shephardmedia.com/news/rotorhub/ausa-2015-sikorskys-big-plans-raider/)

Interview with Sikorsky at AUSA on the S-97. Not very impressive. The one guy did not get the script, he went beyond the vague press release and stated they got to only 20 knots in forward flights instead of putting no number on it so people could dream of higher speeds.

The other amazing thing stated was the SB-1 would benefit from the S-97 testing. Short of the 97 already uncovering a major design flaw (which is plausible based on the stagnation of the test effort) the SB-1 design is fixed by now. One year ago, at the original schedule, the 97 may have had an impact, but not now.

The Sultan

[Lonewolf_50]

I'm wondering if there are any implications for LoL situations with a split torque design Loss of lubrication in any gear box is going to have implications. I wonder if they are using ISF (a super-finishing process for gears) as an alternative design strategy.

[IFMU]

Did the VS300 and R4 have any impact? Of course not, they were Sikorsky machines, right? I thought it was a great interview and video, thanks for the link!

[JohnDixson]

You are correct, Sultan, you used the term " structure ".

My question remains as posed. Just imagine I had used " structure " instead of " building ".

John

[HeliTester]

I am also Curious. What is this self-aggrandizing structure? Perhaps someone could post a photo of it.

[IFMU]

http://www.bizjournals.com/dallas/news/2014/04/07/a-look-inside-bell-helicopters-new-corporate.html

Perhaps this is what sultan speaks of. Looks ok to me.

[riff_raff]

I'm wondering if there are any implications for LoL situations with a split torque designSA- That's actually quite an interesting question.

The answer to your question would depend on the specific configuration of split torque transmission. And since the number of potential split torque configurations is quite large, let's just compare the split torque and improved planetary designs considered for the 53K in terms of LoL operation.

First, compare two well known cases where LoL caused overheating and structural failure of a gearbox component, which resulted in loss of MRGB function, and finally loss of the aircraft with everyone aboard. There is the 1982 CH-47 accident in Mannheim and the 2009 S-92 accident in St. John's. What both accidents have in common are the components that failed first after LoL - a spiral bevel pinion and the tapered roller bearings supporting it. With the CH-47 MRGB, the spiral bevel pinion was part of the interconnect drive between the F/R rotors. With the S-92 MRGB, the spiral bevel pinion was part of the tail rotor drive. However, where these two cases differ is the extent of the LoL condition. With the CH-47, there was only LoL at one point in the circuit. The oil jet for the failed spiral bevel pinion bearings became clogged with debris. With the S-92, there was a filter housing leak that resulted in loss of all lube oil.

When comparing the two 53K MRGB configurations, it's important to note that they both use spiral bevel gear meshes for the engine inputs and tail rotor drive. So one design characteristic that has proven to be an issue with LoL conditions is still present in both gearboxes.

The two gearbox components most affected by LoL are bearings and gears. During LoL conditions the greatest concern is scuffing/scoring producing excess heat buildup at the contact surfaces, locally weakening the material, and causing local yielding or structural failure. Lots of design/analysis effort goes towards addressing this issue. The overheating problem can be especially difficult with the bearing inner race surfaces and rolling elements since they have very limited conductive heat transfer ability to surrounding structures. The outer bearing races are usually not an issue since they are in contact with large/cooler housing structures.

The one advantage I can see with the split torque design vs the improved planetary in terms of LoL performance is elimination of the highly loaded planet gear bearings. These planet bearings are mounted in a rotating carrier structure and are fairly well thermally isolated. On the other hand, all the gearshaft bearings (outer races) in the split torque design are mounted in fixed structures with good conductive heat transfer paths.

Designing a helo MRGB to provide the necessary operational capability under LoL conditions is no simple task. It involves expertise in heat transfer, metallurgy, tribology and kinematics. Things would also be much easier if weight wasn't such a big concern.

[SansAnhedral]

RR, good summary.

Sikorsky designs in particular tend to utilize numerous tapered roller bearings, which seem to be rather intolerant of insufficient lubrication relative to non-tapered versions.

[NickLappos]

John, I know "Sultan" well, in spite of his on line bluster, he is really a fine person, and quite knowledgeable within his particular field,, which has nothing to do with the care and feeding of propulsed, rigid coaxial rotors. Like some folks, anonymity helps increase his expertise, confidence and self-aggrandizement.

He is not qualified to make about half the pronouncements he makes.
Regarding the Sikorsky rigid coaxial designs that are revolutionizing helicopters, he has no practical knowledge at all. Like Percival Lowell's intricate maps of Martian canals, Sultan's intricate pronouncements on details of Raider or Defiant will prove to be pure bull.

[JohnDixson]

Actually, Nick, I was interested in what " structure " ( that you single handedly got Bell to build ) could possibly lead to dissatisfaction by both Sultan and the taxpayers. The post by IFMU and link make it sound like a very overdue project to provide more modern and industry competitive facilities for the Bell employees. Good for Bell, one would think. So, I remain interested in the explanation.

John

[SansAnhedral]

I would assume he was referencing the high whirl tower at the XworX facility that has seen less use than anticipated.

[Self loading bear]

Some background:
Xworx (http://www.ainonline.com/aviation-news/aviation-international-news/2009-12-29/bells-xworx-studying-improved-rotor-blades)
Could it be that Sultan is implying the whole Xworx business unit is not performing?

SLB

[SASless]

Perhaps we might get a HUMs expert to investigate the vibrations emanating from a set of Lips down in Texas.....as there must be a pair fluttering at an awful rate.:ouch:

[riff_raff]

Sikorsky designs in particular tend to utilize numerous tapered roller bearings, which seem to be rather intolerant of insufficient lubrication relative to non-tapered versions.What you note about tapered roller bearings is essentially correct. The sliding contact between the inner race shoulder and roller end faces generates quite a bit of heat, especially on high speed shafts. The main reason a pair of tapered roller bearings might be used to support a spiral bevel pinion is because it is attractive from a weight and packaging standpoint.

In the AHS paper I linked there is a table (table 7) showing scoring results from the trade study Sikorsky conducted comparing split torque and improved planetary designs. For the "technical risk - oil out" attribute, the split torque design scored 7.5/0.75 (raw score/weighted score) and the improved planetary design scored 5.0/0.50. A raw score of 10.0 is best and 0.0 is worst. So based on the results of this trade study Sikorsky seems to conclude the split torque design is superior overall to the improved planetary design in LoL performance.

One other interesting thing I noted about both designs described in the Sikorsky trade study was that they appear to use a duplex angular contact ball bearing/cylindrical roller bearing arrangement to support all of the spiral bevel pinons, rather than a pair of tapered roller bearings. The 3 bearing arrangement is larger, heavier and more expensive than a 2 bearing (tapered roller) arrangement, but it should perform better in LoL conditions.

[SansAnhedral]

In that case, it would certainly appear they have heeded some lessons learned, which is a good thing.

One wonders if this sort of change was working it's way into the S92 IDMGB before it essentially vanished.

[The Sultan]

From Avweek:

There are two industry-funded Raider prototypes. The first took to the air in May 2015 and is being used for envelope expansion.

What envelope expansion?

The Sultan

[SansAnhedral]

Does anyone know if the 2nd ship has even flown yet? I cant imagine SALMC (did I get that right?) would not be shouting it from the mountaintop like the 1st flight from nearly a year ago.

[The Sultan]

Hilife

Sikorksy's PR dept would put out a glowing release if they hovered again with increased tire pressure. No press release at HAI would tell the tale. Maybe they will actually have one. Whatever they do the 97 is too late to fix any issues with the Defiant.

The Sutlan

[riff_raff]

Sikorsky is going through a change in ownership, and the S97 project is internally funded. So it would not seem unusual for the project to be idled until the business situation at Sikorsky is all ironed out.

Sikorsky also has its hands full getting the SB-1 flight demonstrator ready for testing by mid-2017. They are under contract to fly this JMR aircraft, so it would have priority over the S97 project.

[SansAnhedral]

However, Sikorsky claims S-97 is risk reduction for SB-1.

Only thing that is certain about the Defiant is that it appears to be a full year behind the Valor from a schedule standpoint.

Thus one would imagine they would be flying the pants off the S-97 as risk reduction since it has been "complete" (or so we were led to believe) for over a year.

[Ian Corrigible]

From Sikorsky reports progress with demonstrators (http://www.ainonline.com/aviation-news/aerospace/2016-02-29/sikorsky-reports-progress-demonstrators):
Since its first flight in May last year, the S-97 has performed “a number of flights,” including one on February 4 ... Sikorsky is planning up to 60 hours of flight tests on the aircraft for 2016.
I/C

[The Sultan]

IC

So did announce at least another flight that's good. The wording suggests they are still getting a handle on hovering and air taxing.

Interesting in less time the Bell 525 privately funded with FBW has surpassed 200 it's, and it can actually carry a meaningful load.

The Sultan

[riff_raff]

In the past two weeks the Army has issued RFI's for the FVL small variant (CS1) (https://www.fbo.gov/utils/view?id=a5565b60f76fb235432f6779d0a9c97d) and medium variant (CS3) (https://www.fbo.gov/utils/view?id=30d9477b774fd2e196779f3a65fb934b). Definitely worth a read. Some of the desired capabilities are interesting. For example, the small variant RFI (CS1) lists "5.1.9. Aerial refuel capable."

Sikorsky definitely has put themselves in a good position for FVL so far. They now have the massive resources of L-M available, and they have two related flight demonstration aircraft efforts with S97 and SB-1 (JMR TD). Most likely SB-1 & Bell's V-280 will be parked after the test phase of JMR wraps up at the end of FY19. But probably the most important benefits to Sikorsky from the S97/SB-1 programs are a greatly increased technical knowledge base of their concept and an established team of suppliers for all critical subsystems, which will be invaluable for their FVL effort.

[CTR]

Riff-Raff,

The LM Sikorsky & Boeing team are very well positioned both politically and with legacy products. But technically?there is not enough accumulated flight hours to really claim anything. Especially reduced development risk.

After FVL, the Defiant may very well be parked. But the Valor is already being marketed by Bell as a low cost alternative to the V-22. And based on the commercial 525 FBW technology and manufacturing experience, Bell is well positioned to control costs.

My crystal ball sees the Valor flying in 2017 and the Defiant being 6 months to a year late. This will not matter to the US Army because they will move the first flight requirement date to keep the Defiant in play.

As the Army conducts a decade long evaluation, Bell will obtain Valor buys from the USMC, USAF and foreign military buyers. Because the aircraft is heavily based on commercially developed technology, export restrictions are not an issue.

Meanwhile using their enormous political clout, the Army will continue to fly Blackhawks and Apaches for another 40 years.

As far as the Scout mission? Armed UAVs and legacy platforms will be the choice for cost.

[riff_raff]

CTR- I agree that Bell was smart to place a big emphasis on cost reduction with their V-280 design. Things like a non-tilting engine and a straight, single piece wing structure reduce both manufacturing and maintenance costs. I also think tiltrotors are likely the best approach for most of the FVL requirements.

However, there are still a couple other potential contenders for FVL besides Bell and Sikorsky. Airbus Helicopter with their compound concept is one example.

[CTR]

I ask this question seriously, without any bias. Can any experienced Army pilots explain what old, new or future role the S-97 would fill?

The OH-58 was old and under powered. But it was cheap and reliable.

The Army also is dumping all their TH-67 trainers. Stating all future platforms will be 2+ engines. The S-97 is single engine in a platform that will cost an order of magnitude more than an OH-58.

Will appreciate an explanation that makes sense.

[evansb]

http://i1047.photobucket.com/albums/b477/gumpjr_bucket/sikorsky-s97-raider.jpg

[riff_raff]

CTR- I hope you'll pardon the fact that I'm not an Army pilot, but here is how Lockheed-Martin-Sikorsky management apparently sees the S-97 being applied to the US Army's future rotorcraft needs.

https://www.flightglobal.com/news/articles/heli-expo-lockheed-sikorsky-raider-could-answer-fvl-422666/

"The 5,00kg (11,000lb) pusher-prop assault platform – which achieves speed and agility via Sikorsky’s X2-derived advanced rigid rotor and drive system – is already flying at West Palm Beach, Florida, and would be Lockheed’s go-to offer if the army were to launch an Armed Aerial Scout follow-on through its next-generation first future vertical lift (FVL) rotorcraft acquisition plan.......Sikorsky president Dan Schultz told Flightglobal after a media briefing at the Heli-Expo show that the Raider fits nicely within CS1, and that Lockheed-Sikorsky will respond in kind."

[Lonewolf_50]

@CTR
F-16 is single engine
F-35 is single engine.


To answer your question in part, engine reliability appears to have gotten to where the risk is at an acceptable level from the "whole system" design perspective. Kicking a few thoughts around, Comanche had two engines. How that figured into the ultimate decision to cancel that program I do not know (if it figured at all).

[CTR]

RR and LW,

Thank you for your responses, but really would like an Army pilot POV. Especially in light of the Army's dropping all single engine training helicopters and auto to ground training.

As far as any comparisons with fighter aircraft, the missions and environments are completely different. The S-97 will be down and dirty where a momentary engine failure and contact with said dirt are a seconds away. With the exception of the Ti tub A-10 (with two engines), even in ground support the F-16 and F-35 live up high where there is time to relight an engine failure.

Also, the S-97 will not be equipped with six ejection seats for the passengers in economy seating.

Cheers

CTR

[Lonewolf_50]

RR and LW,
Thank you for your responses, but really would like an Army pilot POV. Especially in light of the Army's dropping all single engine training helicopters and auto to ground training. Since I mostly flew in the Navy, and really appreciated the second engine due to being over water, we may share sentiments on a number of things -- we didn't have ejection seats either.

Hooah, and such.

[CTR]

Since I mostly flew in the Navy, and really appreciated the second engine due to being over water, we may share sentiments on a number of things -- we didn't have ejection seats either.

Hooah, and such.

Lone Wolf, since you flew for the USN, you may already know the Navy is keeping their TH-57 single engine trainers and continuing to teach autorotation to ground techniques. Seems smart.

[riff_raff]

Lonewolf_50 brings up a good point in post #143 about improved engine reliability. The S-97 currently uses the YT706, but I'm sure Sikorsky intends to use the ITEP engine (GE3000 (http://www.geaviation.com/military/engines/ge3000/) or HPW3000 (http://www.dualspoolrules.com/why-we-need-a-new-engine/#view-resources)) when it becomes available. The ITEP engine is designed to replace the T700 on existing airframes.

Two goals of the ITEP engine program were improved performance at a wide speed range, and greater tolerance to ingestion of debris/sand. Page 2 of this ATEC white paper (http://www.dualspoolrules.com/wp-content/uploads/2015/08/ATEC-Dual-Spool-White-Paper_PDF.pdf) briefly discusses these issues.

[CTR]

Riff-Raff,

Thank you for posting the link on the dual spool engine technology. I believe the section on page two you are referencing is
" Because there are two rotating assemblies that can vary in speed,
the engine more capable and better at handling sand ingestion than a single spool engine, which would incur much greater degradation to engine components. As a result, a dual-spool design fosters greater time-on-wing and less down time for maintenance."

However what the text is referring to is Maintenance Reliability, versus Critical Failure Reliability. Maintenance Reliability covers mean time between overhauls and required scheduled maintenance. Critical Failure Reliability is a measure of the probability of a failure that can cause the loss of an flight critical component. In a single engine aircraft, loss of engine function classifies as a critical failure for many flight conditions.

[Lonewolf_50]

Lone Wolf, since you flew for the USN, you may already know the Navy is keeping their TH-57 single engine trainers and continuing to teach autorotation to ground techniques. Seems smart.

I am also aware that NAVAIR has not done the greatest job ever of finding a follow on helicopter trainer even though Bell support is getting more expensive all the time ... but that's a different topic. The TH-57 is in some ways a victim of its own success: the way they fly them in Milton, with hot pumps and multiple student events per cycle, they get fantastic output for input. Nothing that follows them is likely to be even close to as inexpensive per flight hour. With the Navy's pilot force 50% and greater being helicopter sorts, boosting that system cost has some unattractive impacts on budgets that keep shrinking. Sorry for the derail. I learned to auto in a TH-57. Good bird.

[Jack Carson]

It is amazing how the conversation tends to make a full swing back to a discussion of single vs twin engine. In the early phases of the LHX program, that later became the AH-66 Comanche program there were many discussions surrounding the required number of engines. I for one supported the side that would have opted for a single. Having flown more than 3 and a ½ years and many flight hours at HT-18 in the venerable H-1 series and many day and night operations in the B-206L-4 I have more than enough confidence that robustly designed single engine aircraft would be a safe cost effective solution for many missions. After almost 20 years in development the Comanche had grown in complexity and cost that ultimately resulted in its extinction.
The governments and military’s desires for aircraft requirements that do much more than what is typically required for 90+ percent of missions drives cost and complexity to unattainable levels. The Canadian S-92 and the VH-71 are two examples where extreme mission requirements resulted in program delays or cancellation. In the meantime day to day operations continue safely in 30 and 40 year old VH-3s OH-58s and even the OH-6 single engine Little Birds. The big question is when is enough enough?

[riff_raff]

CTR- In your post of March 7, you voiced concern about "momentary engine failure" when the S-97 would be flying close to ground level. What type of event do you see causing a momentary engine failure? All of the flight critical systems/components in a rotorcraft drivetrain are designed for a level of operational fault tolerance that takes into account operating conditions and crew safety.

If you have time I'd recommend reading the RFP solicitation docs for the ITEP engine. Lots of stuff on what the Army wants with regards to the engine FMEA (Failure Modes and Effects Analysis) and identifying Critical Items.

https://www.fbo.gov/utils/view?id=916a2beb09f418ece7274ed48b9acad6

https://www.fbo.gov/utils/view?id=e257237d2b98d65beee8fea63b103d57

[The Sultan]

The S-97 should be blasting through the skies by now. Anyone have a link to the Sikorsky Quad A press release?

The Sultan

[The Sultan]

Now well into August and 5 months since even a whisper of progress. Has Lockheed given up?

The Sultan

[IFMU]

Sultan,
As an ex-Sikorsky guy I had also wondered. It has been pretty quiet even from my old X2 buddies. I recently heard they have been quietly making progress. No doubt they are keeping it under wraps to protect themselves from your scathing criticism. It is an awesome machine.

[The Sultan]

IFMU

Sikorsky was putting out press releases if they painted it or added a new fairing. I think if they flew beyond the boundaries of the field it would be splashed everywhere for meer mortals to behold. Getting old, I forgot first flight was May 2015, so 15 months with no reported progress.

The Sultan

[CTR]

Perhaps envelope expansion for the S-97 is currently pretty low on the list of Sikorsky priorities?


Engineering manpower is a choke point for all aerospace companies.


The CH-53K, Canadian Cyclone, and FVL SB>1 are all government funded programs with contracted progress payments and performance penalties.


The S-97 is not part of any government contract, currently has no customers, and is fully funded by Sikorsky and teaming suppliers.


It is no surprise to me that the S-97 is on hold. If I were Sikorsky management, all of the S-97 engineering possible would be redeployed to money generating programs.


The real question on my mind is where are the expected press releases for the SB>1 build progress? But that could be it's own thread.

[IFMU]

CTR,
Quietly making progress is not the same as on hold. I have no idea what they are up to on the Defiant.

[Ian Corrigible]

I have no idea what they are up to on the Defiant.

From Sikorsky-Boeing wrap up SB-1 design review as Defiant takes form (https://www.flightglobal.com/news/articles/sikorsky-boeing-wrap-up-sb-1-design-review-as-defian-422091), 02/2016:
Boeing Future Vertical Lift chief Pat Donnelly said most components of the rigid-rotor coaxial compound helicopter are already under construction and will start coming together later this year.

Donnelly says Swift Engineering of San Clemente, California will ship the core composite structure to Boeing's AH-64 Apache production plant in Mesa, Arizona by mid-year for design limit testing, before it continues east to Sikorsky’s rotorcraft facility in West Palm Beach, Florida in the September timeframe.

“The aircraft will be stuffed with all the hydraulics and mechanical components,” says Donnelly. “It’ll undergo final assembly and we’ll fly it down there.”
And from Boeing outlines plans for JMR demonstrator (https://www.flightglobal.com/news/articles/boeing-outlines-plans-for-jmr-demonstrator-426189/), 06/2016:
“We’re in the process of building a one-off flying demonstrator," says Jeff Shelton, senior manager for JMR/FVL global sales and marketing. "We are in the manufacturing stage now, and will start assembling later this year at West Palm Beach in Florida, where the flight testing will also take place.”

The aircraft will be flown at the end of next year and into 2019.

I/C

[CTR]

I have see the words. But are there any photos of Defiant hardware?


"Quietly making progress is not the same as on hold" I concur, I have been on programs where company priorities robbed me of most of my team. The hand full of us that remained achieved many innovations while leadership concentrated their micro managing and demands for daily status reports on priority programs. But our program schedule became greatly stretched. I believe the same is occurring on the S-97.

[SansAnhedral]

7 is not part of any government contract, currently has no customers, and is fully funded by Sikorsky and teaming suppliers.

Wouldn't the fact that S-97 is not a program of record anywhere compel Sikorsky to use it as a marketing tool and therefore get some return on the investment? I am very puzzled by the lack of information and progress.

Occam's razor suggests technical issues.

[Hilife]

CTR makes several valid points on post #155 and to add to this, Sikorsky is now wholly owned by LM, whose share price has risen impressively these past few years in-spite of major US defense spending cut-backs and is a very different beast from UTC (whose share price took a major hit following the decision to sell or spin-off Sikorsky, and has yet to recover).

What makes me smile is that for the current FVL JMR-TD Medium/Utility program, the SB-1 is a 50/50 JV with Boing (:)) and Sikorsky (a company wholly owned by LM) and the Bell V-280 Valor has LM as a major partner.

Were it a 50/50 JV on both programs, then one would think the DoD would raise competitive pricing concerns, as one company could be seen as a win/win bidder whatever the outcome, but not knowing what value share there is on the Valor program (but likely less than 50%), then one could question whether this bidder has a preferred platform solution :).

As for the S-97 Raider, I still don’t see anything else to compete with it on the JMR-Light option, so I don’t suppose either Sikorsky or LM is that worried about any lack of Raider press releases just now and logically any of the data coming out of the Raider program is being fast tracked to the Defiant platform.

[The Sultan]

Hilife

The main reason for the 97 was as a demo/risk reduction for the Defiant when it was to fly in 2014. To meet the JVL schedule Defiant's design had to proceed without any 97 input. So now Lockheed has decided it is irrelevant and appears to have defunded it. Makes the Defiant program very risky compared to the V-280 which is building off of XV-15, V-22, and the 609.

The Sultan

[Ian Corrigible]

The latest copy of Av Week provided a brief program update:

Nine flights to date (since May 2015)
Latest flight was performed with the gear retracted, for the first time
Meanwhile, the B-21 (http://www.pprune.org/military-aviation/575340-lrs-b-b-21-a.html) has appropriated its name... :E

I/C

[IFMU]

Excellent, we were due for some news! I'm off to Udvar-Hazy for the X2 induction, hope to hear more in person.

[Lonewolf_50]

The latest copy of Av Week provided a brief program update:

Nine flights to date (since May 2015)
Latest flight was performed with the gear retracted, for the first time
Meanwhile, the B-21 (http://www.pprune.org/military-aviation/575340-lrs-b-b-21-a.html) has appropriated its name... :E

I/C
There's also a football team in Oakland who may wish to have a quite word on the subject ... :8
http://upload.wikimedia.org/wikipedia/en/thumb/9/9d/Oakland_Raiders.svg/500px-Oakland_Raiders.svg.png

[SansAnhedral]

AC1
Maiden flight (1.0hr): 5/22/15

4 month hiatus

Second flight (1.2hr): 9/29/15

Hiatus to accumulate 200 hours on PTSB (15-20 hr/wk) @ 32 hours 9/29/16 = 9 weeks?

7 total additional flights in 12 months

AC2
No flight time?

[The Sultan]

Sikorsky posted new video. Looks like still limited to low speed runway work after 18 months when they stated full envelope by summer 2016 in their last program delay update.

The Sultan

http://www.dodbuzz.com/2016/11/07/watch-s-97-raider-flies-wheels-up/?ref=yfp
Link added

[Lonewolf_50]

Sultan, it might be possible that they are taking a cautious approach with new tech, a caution possibly reinforced by the tragic loss of that 525 a few months ago in Texas.

[SansAnhedral]

New tech

https://upload.wikimedia.org/wikipedia/en/d/dd/Sikorsky_XH-59A.jpg

http://imgproc.airliners.net/photos/airliners/1/7/7/1902771-v40-15.jpg

https://vtol.org/images/dmImage/StandardImage/sikorskyx281710.JPG

https://lh6.googleusercontent.com/-L9ikp_H32N4/UfLgsdomHaI/AAAAAAAAhXg/4y890ZXbI4g/s400/Sikorsky%2520X2%2520Demonstrator.JPG

[Lonewolf_50]

@SansAnhedral Making it work to a modern spec and modern requirements is indeed reliant on new tech, and new materials, as well as making them work together effectively. Likewise, requiring "new" is the effort to scale up from the X-2. You will note that those vintage efforts each was not successfully pursued at the time. Tradeoffs, etc.

[SansAnhedral]

Oh I know, I was just being pedantic :}

[SansAnhedral]

Is this really another 4+ month hiatus?

Are there MGB issues? Vibration? Are the supplier-built composite blades or flexbeams delaminating/cracking/failing?

My money is on the latter.

Approaching 2 full years since first flight, this is beyond suspicious.

[Lonewolf_50]

Sans, what might be going on is that (with being part of LM now) the focus on design work is being directed to the next size up aircraft that is to compete with V-280 Valor. Maybe. No idea.

[The Sultan]

Lone

Your hypothesis is unlikely. The 97 has not left the airport grounds that I know of as Sikorsky would drop another video of that great achievement. After all the money spent if it was safe to fly anyone would take the opportunity to shake down the flight controls, basic design concept, or get PR. It was originally a concept demonstrator and risk reduction tool. The fact that it has done none of these points to major design issues.

[SplineDrive]

Or they are just flying over the swamps of Florida using it as a risk reduction tool for SB>1. It seems likely that they haven't met their flight test goals yet (I would expect a video and announcement, too), but I suspect progress is being made and they're just radio silent.

I know the flight test programs I've been associated with never made progress as public as I would have liked, lol.

[SplineDrive]

You won't find me being a huge champion of outsourcing critical dynamic components :-/

[IFMU]

I bet if somebody at Sikorsky made a decision to do that they came from another company!

[SansAnhedral]

I bet if somebody at Sikorsky made a decision to do that they came from another company!

The X2 and S97 blades (and some other S97 rotor components) were designed and built at a supplier in Virginia (http://eagleaviationtech.com/rotor-blades-propellers/2031263)

[IFMU]

Built, yes. Designed, no. They did a nice job on the X2 blades. The decision to send them out did not come from a life long Sikorsky employee!

[SansAnhedral]

Designed, no.

Ashish did the aero layout, yes, but the Eagle guys will tell you they did the detail design.

[IFMU]

Funny, I thought that was Dave who did the structural design. We had many Daves on the program but one was the rotors structural designer. Ashish's aero design was a masterwork.

[SansAnhedral]

Dave Darrow, he did the rotor head, including the very clever tailored blade grips.

I suppose it all comes down to semantics of concept design versus detail design.

[retoocs]

This just got posted by Lockheed.
https://youtu.be/yuStvGT1aFA

yuStvGT1aFA

[SansAnhedral]

This just got posted by Lockheed.
https://youtu.be/yuStvGT1aFA

Wow, so the rotor fold at 1:22 and 3:08 doesn't come anywhere near functioning as shown. The blade grips are crashing straight through the fairings.

[The Sultan]

Notice they never mention the S-97 as if it never existed.

[riff_raff]

Blade fold systems always seem to add a significant amount of complication. Not easy to do cleanly.

[SansAnhedral]

Blade fold systems always seem to add a significant amount of complication. Not easy to do cleanly.

Indeed. If you're going to tout it in your promo video, you ought to show something that actually works at least in virtual space.

[Ian Corrigible]

If the S-97 program does end up being shelved, it raises the interesting question of that $50 million or so funded by the 35 companies in the supplier team (http://www.prnewswire.com/news-releases/sikorsky-announces-supplier-team-for-s-97-raider-helicopter-program-137192098.html) (responsible for 25% of the program's $200 million cost (http://aviationweek.com/paris-air-show-2015/sikorsky-s-raider-should-raise-helicopter-performance)). Did this contribution buy all 35 of the suppliers a seat on the SB>1, or will some of them just have to write it off as a lottery ticket that didn't pay out this time around?

I/C

[SansAnhedral]

I can say for certain that some of those listed suppliers were already entirely shut out of SB>1 regardless of the fate of the Raider.

[IFMU]

Blade fold systems always seem to add a significant amount of complication. Not easy to do cleanly.

Nifty marketing video aside, hard to imagine a folding rigid rotor. I doubt interference with the fairing would be the biggest technical challenge. With no articulation the loads there are elevated.

[SansAnhedral]

Nifty marketing video aside, hard to imagine a folding rigid rotor. I doubt interference with the fairing would be the biggest technical challenge. With no articulation the loads there are elevated.

Dave and Frank are still at it

SINGLE ACTUATOR BLADE FOLD LINKAGE (http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=/netahtml/PTO/srchnum.html&r=1&f=G&l=50&s1=20170073068.PGNR.)

NON-LOADED MANUAL BLADE FOLD ASSEMBLY (http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=/netahtml/PTO/srchnum.html&r=1&f=G&l=50&s1=20160214711.PGNR.)

[retoocs]

Guess the program is still going. This just got posted.

HncZgouxt9k

[IFMU]

Cool video! I guess sultan's last dig must have hurt, so they had to post something.

[etudiant]

Guess the program is still going. This just got posted.

HncZgouxt9k

Can anyone more familiar with the situation clarify whether this video shows additional flights or is it a creative montage of images from the initial flight?
I've heard nothing about any additional S-97 flight testing, so was surprised by this release.

[The Sultan]

As it shows being beyond the airport perimeter it must be very recent flights. Looks like they finally met their May 2015 objectives. The "high speed" flyby looked pretty slow and the maneuvers minimal.

With SB1 reported to be at least a year late and the Bell V280 approaching being readied for ground and flight tests this year they had to do something.

[SplineDrive]

It seems safe to assume that they haven't met the speed goal yet, otherwise it would be more prominently advertised. Still, the program continues. Looks good with the gear up and the slick engine installation. Video shows perhaps a bit over 45 AoB? Not really aggressive but demonstrating more maneuverability than the X2TD did. Not sure what the XH-59A demoed back in the day.

Blade fold on a rigid rotor is certainly possible... just a pain. But anyone who has done blade fold knows it's always a pain.

Remember when the comments were that they'd never get that inter rotor fairing to stay straight? :-)

[SansAnhedral]

creative montage

Interesting thought, especially with the tactically interspersed CG.

[SplineDrive]

http://www.defensenews.com/articles/defiant-delayed-joint-multi-role-demonstrator-wont-fly-in-2017

Article admits what we've all suspected, Defiant is behind schedule. States Raider flew in March, so there's opportunity for what appear to be off airport property flights since the last acknowledged flights from last fall.

[CTR]

Defiant delayed: Joint multi-role demonstrator won?t fly in 2017 (http://www.defensenews.com/articles/defiant-delayed-joint-multi-role-demonstrator-wont-fly-in-2017)

Article admits what we've all suspected, Defiant is behind schedule. States.

Defiant is a year late to scheduled first flight? Sikorsky and Boeing must have known they were falling behind schedule for a long time before today's official announcement. Contracted first flight is only a few months away.

I don't think S and B upper management were in the dark about this. They are a good company with smart people in charge.

I can only guess that Defiant management was playing the equivalent of a starring contest with the Bell V-280 program. S and B hoped Bell would blink first and ask the government for an contract extension first. Problem for the Defiant program was Bell appeared to be meeting schedule.

With only months remaining before the truth would be obvious to all Sikorsky and Boeing blinked.

Running into technical or procurement difficulties is understandable. Holding back information that your program is a year behind schedule until a few months before first flight is unacceptable contractor behavior.

[etudiant]

The schedule is pretty flexible, as this is a long term fleet renewal oriented development.
So I think taking time up from to make the right decisions is very appropriate. Costs are largely determined by these early choices, so this is the best chance for getting it right.

These rationalizations aside, it is also a reality that Boeing has been late and over budget on almost all its developments, both civil as well as military, throughout this century. So it would be surprising if this project, which is projected to scale a concept from a 6,000 pound vehicle to something in the 30,000 pound class, were not to experience substantial slippage and cost growth.

[The Sultan]

ET

You forgot Sikorsky(CH-148, CH-53K) and L-M(F-35) all of which are years behind schedule and obscenely over budget. The 97 and SB-1 are already well down the same path.

[SplineDrive]

We can also add the V-22, 609, 525, and even the relatively straightforward 429 to the late list. In fact, its a rare aircraft these days that comes in on time and even rarer to come in on time, on budget, and not overweight :-)

I do agree that the Defiant team should have been more forthcoming to the public, though I doubt the announmence is a surprise to the contracting agencies.

Bell definitely had the easier design task when it comes to the JMR demonstrator (relative to their technology base at the start of the program), so I would have always expected them to be closer to hitting schedule targets.

[The Sultan]

Spline

The V-22 flew basically on time six years after contract award. Fielding was delayed by budget cuts which starved the program for years. As to prototype crashes which further caused delays it is of interest to note that the two lost were Boeing's responsibility. Bell did not loose one of its prototypes. As to 609 and 525 they are commercially funded and not germane to the discussion.

[CTR]

Spline,

I hate to agree with Sultan, but trying to make JMR contract performance comparisons to any previous programs (especially commercial) are flawed. Every program has its own unique issues. These include; changing customer requirements, delays in funding, bad teaming agreements, and many more.

But the JMR demonstrator competition provides a clear and honest comparison of performance to contract.

Both the SB>1 team and Bell committed to the same performance and schedule requirements. Excuses by SB>1 managers that meeting the first flight date was not as important as their system integration and propulsion system testing being completed is a diversion from the truth. Bell also has to perform these tests to allow for First Flight.

As far as the SB>1 team facing greater technical challenges, Pat Donnelly the Boeing Defiant program manager clearly stated this was not the case. In his words "Things are not happening as quickly as we would like".

If Bell succeeds in flying on schedule, it will be a true David versus Goliath story.

[SplineDrive]

Fair enough, but regardless of what the Defiant managers claim, that is the more technically ambitious design compared to the relative maturity of the tiltrotor platform. It's not a surprise they're behind.

Given that Bell has the incumbent high speed VTOL platoform, you can argue that Defiant is the David in that analogy.

[CTR]

Bell AND Boeing share all technology on the V-22.

The combined engineer manpower of Boeing Vertol and Sikorsky is more than three times that of Bell.

The combined yearly revenue of Boeing and Lockheed is ten times more than Textron, Bell's parent company.

To perform to schedule primarily takes two things, people and money.

Who is the little guy in this story?

[The Sultan]

Spline

The concept demonstrators for the 280 (XV-15) and the SB1 (XH-59) were created and tested at the same time. Claiming the SB1 is behind because of the lead tilt rotors have in successful application is ignoring the facts. Both concepts were competed and the tiltrotor won. The 97 was suppose to be a risk reduction/confidence builder for SB1, but that proved to be a bust for those objectives.

[SansAnhedral]

A very good point. An oft repeated claim with regards to SB1 and V280 is that "the Army wont buy a tiltrotor because they didn't buy one before"

Well the same could be said about the ABC and the XH-59!

Lest we forget...from ca 1973

http://www.combatreform.org/H59family.jpg

[SplineDrive]

Y'all are not trying to claim that the ABC and tiltrotor concepts are at equivalent levels of maturity, are you?

Because THAT would be silly.

[The Sultan]

Y'all are not trying to claim that the ABC and tiltrotor concepts are at equivalent levels of maturity, are you?

By the end of the XV-15 v XH-59 demo effort similar effort had been expended on each concept. The ABC was inferior in all aspects and had numerous design issues and was shelved in favor of the superior tilt rotor.

[SplineDrive]

By the end of the XV-15 v XH-59 demo effort similar effort had been expended on each concept. The ABC was inferior in all aspects and had numerous design issues and was shelved in favor of the superior tilt rotor.

Right... and as a result, in the intervening years, several generations of tiltrotors have been designed, with some being qualified and placed into service. The tiltrotor is obviously the more mature design concept, hence my position that the Sikorsky Boeing team, despite their theoretical resources, can be viewed as the underdog. The onus is on them to show that the conclusions of the XH-59A and XV-15 programs has been overcome.

[CTR]

The tiltrotor is obviously the more mature design concept, hence my position that the Sikorsky Boeing team, despite their theoretical resources, can be viewed as the underdog.

Spline,

Theoretical? We are not talking "Alternate Truths". The financial capital and engineering bandwidth of the SB>1 team is a well documented fact. They are part of the two biggest military contractors in the world!

Sikorsky and Boeing project management have stated that technical issues are not causing the delay. Are they lying like Sultan thinks? Well they provided an alternate truth last December when they stated they were on schedule.

But look at the facts presented clearly. I agree that tiltrotor flight technology is more proven than for the X-2. But what does that have to do with failure to meet schedule to build a demonstration aircraft?
It is once reaching flight test that the tiltrotor will have an advantage.

Both aircraft have advanced composite structures, FBW technology and complex propulsion systems. In the race up to flight test both aircraft had the same challenges.

The Defiant is late because the tremendous resources of Sikorsky and Boeing were either not allocated or mismanaged. I would have a lot more respect for the management at both SN>1 companies if the just came out and said "We screwed up!" Instead of "Things are not going as quickly as we would like".

Great engineering and capabilities on the SB>1 team. I put the onus on their management.

[SansAnhedral]

Fundamentally, the delay of Defiant in addition to the extremely protracted flight testing of Raider makes the issues seem far less likely due to management and much more technical oriented - totally contrary to the statements made by management of Sikorsky/Boeing/Lockheed. Occams razor.

But would we really expect them to be transparent if they hit design roadblocks? No, rather we get to enjoy the PR blitz of fancy movies in lieu of actual progress.

For example, The SB1 team has had their fuselage for 4 months now, and they have released precisely one photo of it on delivery day and included zero images of any physical hardware whatsoever in their latest marketing video. We saw S97 touted widely during construction.

Part of downselect for FVL is the ability for a team to manufacture on time and on budget. So to keep everything hidden if there really is no technical issue would be quite puzzling.

[etudiant]

Fancy management techniques and flashy videos are very effective tools for marketing, but are no substitute for hard nosed engineering assessments.
Unfortunately, the evidence suggests that in aerospace, corporate decision makers have lost sight of this. Because no one, corporation or manager, is held accountable when there is huge cost growth or delay (F-35, KC-46), there is no pressure to behave differently.

[SplineDrive]

CTR, I agree with Sans assessment of the situation.

As far as finances, both the helo divisions of Lockheed and Boeing are tiny compared to the entire corporation and in different divisions from the larger fixed wing communities. The resources aren't shared across the entire enterprises. The JMR programs are also not entirely gov funded, there's very significant vendor investment and I would be surprised if being put for sale and bought didn't hamstring internal funding on the Sikorsky side.

I'm also glad to not be on the legal team that developed what I can only assume is 30,000 lb of legal papers firewalling the various Lockheed, Boeing, and Sikorsky interests into their proper buckets. :-)

[CTR]

Spline,

Even just looking at the helicopter divisions, based on sales of Blackhawks, Apaches, and Chinooks Sikorsky and Boeing dwarf Bell. There is no financial reasons the Defiant should be late.

Unless Sikorsky and Boeing just want to delay any JMR follow on contact as long as possible. Or even kill it if possible. That way they can continue to sell the Army Blackhawks and Apaches as long as possible.

Regardless if it is technical or a financially tactical delay, I believe the numeric for the SB >1 should be changed to SB<Bell.

[riff_raff]

The justification for these flight demonstrators was risk reduction and minimizing schedule delays in the production aircraft program. Both Bell and Sikorsky have the financial/manpower/manufacturing resources to meet the JMR schedule. I think there may be reasons other than those mentioned for Sikorsky delaying their flight testing until next year.

[rjsquirrel]

I enjoy all the sniping about schedule here, as if the aircraft for the year 2030 will be decided by 5 months in 2017!
I do note that the fans of tilt rotors don't specify the tremendous difficulty the Osprey is having in the real world.
I wonder if the JMR design requires the aircraft to both arrive at the destination and also come home. If so, is a "proven" tilt rotor at a disadvantage? Does the US Army require aircraft that can do a round trip?

US Marine Osprey crashes off Japan, 5 rescued, US officials say | Fox News (http://www.foxnews.com/world/2016/12/13/us-marine-osprey-crashes-off-japan-5-rescued-us-officials-say.html)

https://theaviationist.com/2017/01/29/u-s-mv-22-osprey-tilt-rotor-aircraft-crash-lands-in-yemen-during-special-ops-raid-on-al-qaeda/

[SASless]

RJ,

You are going to cause the Sultan to seek a "Safe Space" if you keep injecting facts into the discussion.....and that is so unfair of you!

[The Sultan]

Rj/SAS

You guys are pushing weak S these days. The V-22 off Okinawa was damaged by what is reported to be a refueling hose/receptical into a rotor. Though damaged the ship continued to fly and was purposely ditched to avoid flying over populated area. No aircraft fault and the V-22 probably survived the strike better than any helicopter would taking such a piece of hardware into the main or tail rotors.

As to Yemen I have not seen a cause, but whatever it was it was not the national embarresment of the 53's in Cambodia and Desert One, or the 60's in Grenada.

[rjsquirrel]

Sultan, the Yemen "self-crashing" Osprey was a national embarrassment, you just are immune.

[CTR]

Let's try an stick to the facts.

Two companies/teams were selected by the DOD to build JMR demonstrator aircraft, Bell and the Sikorsky-Boeing team.

By customer requirement BOTH contract recipients committed to flying their aircraft by the last quarter of 2017.

During contract negotiations Bell requested additional schedule time to achieve first flight. The DOD refused however because the Sikorsky Boeing team claimed they could meet the 2017 first flight date.

Now just months before the comitted fly date the Sikorsky Boeing team reveals they are at least half a year behind schedule.

I have good friends at Sikorsky, Boeing and Bell. And in my 40 years in aerospace I have worked for or been a supplier to all three companies.

Sikorsky and Boeing upon being selected for a JMR contract was declared the dream team by the media, and the media questioned how Bell could even compete against the two largest defense companies in the US.

Time will tell which aircraft, if any is ever selected for production. But if I was the US Army I would give preference to the supplier that was open, honest, and busted their tails to meet contract commitments.

[etudiant]

I don't think there is an advanced technology rotor craft without cringe worthy weaknesses. So it is pointless to harp on the various failures, there have been lots, widely distributed.
The issue here is that the Army is trying to advance the performance of VTOL aircraft.
That will take effort, but we all know that without a schedule, nothing ever gets done.
So there is a schedule and SB has failed to meet it.
That will cost them some, no doubt, but that is peripheral. The main question is whether there is some really fundamental flaw inhibiting the scale up of the co axial rotor concept.

[SansAnhedral]

I enjoy all the sniping about schedule here, as if the aircraft for the year 2030 will be decided by 5 months in 2017!
I do note that the fans of tilt rotors don't specify the tremendous difficulty the Osprey is having in the real world.
I wonder if the JMR design requires the aircraft to both arrive at the destination and also come home. If so, is a "proven" tilt rotor at a disadvantage? Does the US Army require aircraft that can do a round trip?

US Marine Osprey crashes off Japan, 5 rescued, US officials say | Fox News (http://www.foxnews.com/world/2016/12/13/us-marine-osprey-crashes-off-japan-5-rescued-us-officials-say.html)

https://theaviationist.com/2017/01/29/u-s-mv-22-osprey-tilt-rotor-aircraft-crash-lands-in-yemen-during-special-ops-raid-on-al-qaeda/

"Tremendous difficulty"

https://i.giphy.com/Vg0JstydL8HCg.gif

rj is just upset that the pprune V-22 thread of years has gone quiet while the aircraft continues to rack up hundreds of thousands of hours of flight time and remains the USMC's most in-demand aircraft and nearly its safest...so he has to try and steer the conversation on the S97 thread to the Osprey for some unknown reason. Even SAS came out of the woodwork after hearing some some good old fashioned V22 trash talk. Its like the halcyon days of 2011 huh guys!

If one wants to get so pedantic and irrelevant...at least the Yemen V-22 went down in combat with no loss of life, while the venerable UH-60 crashes in clear air onto golf courses (http://www.cnn.com/2017/04/17/politics/h-60-blackhawk-crash-ft-belvoir/) killing our servicemen. What a "national embarrassment", or am I just immune?

[SASless]

Sans,

The Marines have hung their hat on the V-22.....of course it continues to rack up flying hours......what else could it do?

That a Blackhawk crash killed a crew member is not surprising as that happens in crashes just as there have been fatalities in Osprey crashes.

So what's your point?

[SansAnhedral]

The point, succinctly (and rather obviously), is that the V-22 is hardly having "tremendous difficulty" nor is it a "national embarrassment".

It also belongs in a discussion of the S-97 about as much as the UH-60.

[SASless]

I was pointing to the schedule slippage and the fact most experimental programs have delays for various reasons......and the V-22 certainly qualified for those criticisms!

Acting as though the S-97 should be immune at this very early stage seems a bit unfair.

I seem to recall the V-22 Program almost being ended due to some very serious deficiencies.....that killed peoplle and that was well into the program.

The 97 has a long way to go yet to get to either point.

[SansAnhedral]

I don't think anyone is claiming the S-97 should be immune to anything. But let's not pretend this is an isolated "slip" in a vacuum.

This is a discussion of a suspicious delay of a flight test programme relative to its stated objectives, its immediate predecessor X2, in addition to a publicly announced delay of a growth version of the same technology with SB1....all under the guise from the manufacturer that there are no technical issues (or more to the point, no scaling issues).

Comparisons to the V-22 program of record are not germane to discussion for myriad reasons.

[SASless]

Why "suspicious"?

In your mind and ,Sultan's ,who as we all know likes nothing with "Sikorsky" labels afixed to it.

[The Sultan]

SAS

One month delay after first flight is normal for instrumentation refinement.

Six month delay points to need to improve parts.

Two year delay looks like a major problem which requires significant design changes.

Since the 97 was to be used for SB1 risk reduction, it explains the major schedule slip of SB1. The question is how many other problems will be encountered growing the concept another factor of three?

[CTR]

Why "suspicious"?

In your mind and ,Sultan's ,who as we all know likes nothing with "Sikorsky" labels afixed to it.

SASless,

So what is your theory for why the SB>1 team is "delayed"?

Currently the choices are as follows;

A) Major technical issues with scaling up the X-2 technology (conspiracy theorieists favorite). But that would mean some very smart people in both the government and Boeing would either have been fooled by Sikorsky or complicit in hiding evidence that X-2 technology was flawed.

B) Sikorsky and Boeing mismanaged the Defiant program, either by under funding it, wasting resources, selecting inadequate suppliers, or a combination of the above. This is the Defiant Program management claim, but their wording is "Things didn't go as quickly as we would have liked". Hard to believe the two biggest defense contractors in the US are that inept.

C) Intentional program delay by Sikorsky and Boeing management to insure continued sales of their existing products to the DOD. Another conspiracy theorists favorite.

D) ?????

Maybe we can have a vote?

Have fun

[SASless]

Perhaps....it is exactly what they say it is.....ever thought of that?

[CTR]

Perhaps....it is exactly what they say it is.....ever thought of that?

So option "B", gets one vote from SAS!

[IFMU]

I'll float an option D. Engineering said "it will take X amount of time." Management said "no it won't."

Just a guess, as I am not part of Sikorsky any longer. Nor do I have any knowledge as to why there are delays. I still think it is an awesome machine. If Bell can fly their machine to their schedule my hat is off to them.

[SASless]

Did the crash of the 525 at Bell cause a delay to that program?

How about the 609 Crash in Italy....any delay there?

I don't hear any concern being voiced over those programs?

How many delays were there in the V-22 Program?

There is no mention of BAE yet....they certainly are known for problems!

[CTR]

I'll float an option D. Engineering said "it will take X amount of time." Management said "no it won't.".

IFMU,

I believe that falls under option
"B Sikorsky and Boeing mismanaged the Defiant program, either by under funding it, wasting resources..."

So 2 for "B"

[The Sultan]

By referencing accidents SAS apparently is voting (A), a concept scaling problem.

[SansAnhedral]

Perhaps....it is exactly what they say it is.....ever thought of that?

Remind me again, what is the official line from SAC regarding the protracted S-97 development? It was late to first flight, late to return to flight, and has yet to demonstrate maneuvering or high speed outside of computer rendering 2 years later.

When there have been persistent questions regarding the scalability of new technology by those in the industry, and subsequently your first upscaled project does not meet its self-imposed timeline by a large margin, followed by the further upscaled project getting "officially" delayed for every reason other than technical - yes that's suspicious to observers.

PS. Did X2 perform any of the high-G maneuvers advertised by SAC with ABC tech in its 23 hours of flight? It, as well as XH-59, did a lot of straight line speeds and sustained turns, but nothing approaching whats shown in all the PR renderings.

[SplineDrive]

Like most programs I've been attached to, my vote is some flavor of B as the largest slice of the truth.

[IFMU]

IFMU,

I believe that falls under option
"B Sikorsky and Boeing mismanaged the Defiant program, either by under funding it, wasting resources..."

So 2 for "B"

I believe that "we need this baby next month, get 9 women on it" would not fall into under funding or supplier mismanagement​. And, it's not a vote, just another possible cause.

[etudiant]

See no reason to dismiss option A
The pool of aerodynamics expertise is pretty shallow and the number of people really conversant with coaxial rotors is single digit at best. Factor in a huge scale up such as this program postulates, it is outside the envelope.
My guess is powerpoint engineering met reality. This seems to happen a lot lately, wonder why.

[jeffg]

RJ, Your article also mentions the H-60 that went down during the bin Laden raid and as others have mentioned there was the 60 on the golf course a few weeks ago. Using your logic is the H-60 also an 'self crashing' aircraft that can't make a 'round trip'? Or are you applying a double standard?

[SplineDrive]

ET, understanding of coaxial rotors isn't as thin on the ground as you suggest... it's not a new configuration, there's wind tunnel data, aeroelastic modeling, subscale rotor testing, and of course flight data for several generations of ABC style aircraft. In addition to that, there is the experience of the Kamov, Hiller, and other designs that are to varying degrees, relavant... certainly more than single digit numbers of people are really conversant.

The design will manageably scale. It may or may not be the best fit to customer requirements, but that's partly what the JMR effort is for :-)

[SansAnhedral]

Aerodynamics are not really the issue when it comes to the scalability of the ABC configuration - its the feasibility of manufacturing a physical rotor head, mast, and blade set that can withstand the exponentially greater loads driven by increases in gross weight, while maintaining overall weight and rotor spacing that keeps drag at a manageable level.

Consider also it is no real mystery why we have not seen any high gross weight conventional rigid rotor helicopters, in spite of the control power and savings in maintenance and component cost (no more hinges, elastomers, bearings, etc) they could provide.

[etudiant]

ET, understanding of coaxial rotors isn't as thin on the ground as you suggest... it's not a new configuration, there's wind tunnel data, aeroelastic modeling, subscale rotor testing, and of course flight data for several generations of ABC style aircraft. In addition to that, there is the experience of the Kamov, Hiller, and other designs that are to varying degrees, relavant... certainly more than single digit numbers of people are really conversant.

The design will manageably scale. It may or may not be the best fit to customer requirements, but that's partly what the JMR effort is for :-)

Honestly, I have no confidence that the designs will scale.
We don't really have a firm grasp even on conventional rotor systems engineering, else we have long since corrected the design flaws that led to the EC225 getting its certificate pulled for North Sea operations.

AFAIK, there are no 30,000 lbs GW ABC vehicles flying anywhere. What there is is much smaller and the development performance to date suggests strongly that the designs don't scale.

[SASless]

What are the issues that exist for the 97 but did not seem to limit the 53,64. and 67 or the Cheyenne?

What is unique to the ABC concept that other Rotor Systems do not share when it comes to size increases?

Did the Russians not have some success with Co-axial Rotor systems?

Then there is the Piasecki X-49 pusher that uses a Blackhawk airframe and Rotor System....how does that compare to the 97?

https://tacairnet.com/2015/08/05/piaseckis-x-49-is-the-fastest-sea-hawk-in-existence/

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19970015550.pdf

[The Sultan]

SAS,

To help you catch up:

- the 53 and 64 are tradional helicopters with 60's performance and abysmal safety records

- the 67 ended up scattered across a field in England due to poor maneuverability and/or pilot error

- the Cheyenne was an expensive failure with design flaws many related to the rotor

As for the Piasecki, this is a joke going nowhere.

[SansAnhedral]

What are the issues that exist for the 97 but did not seem to limit the 53,64. and 67 or the Cheyenne?

What is unique to the ABC concept that other Rotor Systems do not share when it comes to size increases?

:ugh: ABC craft, by definition, utilize a closely spaced high hinge offset rigid rotor system. This means no flapping or lead/lag hinges, and therefore colossal moments through the rotor head and into the mast, even for small diameter rotors and smaller gross weights.

As I alluded to before, why is it that you've never seen a rigid rotor from a Bo105 installed on a helicopter much larger than a light twin (topping out at ~12k lbs), much less in a closely spaced stacked arrangement? Because the loads into the structure increase exponentially, to a point where the required construction to carry them becomes prohibitively sized. The amount of blade flapping also will increase, as there are no materials which maintain the stiffness to weight ratios required at larger radii. This drives greater rotor spacing, which is a poison pill to the ABC concept meeting its stated performance. Then there is also the complex aeroelastic tuning aspect.

The comparison to Kamov is getting tiresome; the only commonality between these designs is the usage of a coaxial drivetrain. The Russian designs are all articulated, hinged rotor systems (hinges and flapping alleviate loads). There is no doubt you can scale something like that up to CH53 size, though to clear flapping it would on the order of 50 feet tall!

[SASless]

Thank you for the explanation.

That does explain the large separation of the two rotor systems on the Kamov as compared to the much smaller vertical separation of the ABC system.

Knowing the Rigid Rotor system is only on the BO and BK did not strike me as notable but in light of what you describe it does make sense. The BK is a derivative of the BO and not much increase in size. I have never heard a conversation about why those are the only two "Rigid Rotor" aircraft.

Sizing of Rotor Systems....diameter, blade chord, and numbers of blades has always seemed a Black Art of sorts....then compound that by adding a second set of Blades and I can see how complex it all becomes.

The Sikorsky ABC competed with the Bell Tilt Rotor back in the early 80's in an Army Test Program....with the ABC concept not getting the Nod.... which resulted with the advent of the V-22 Program.

Did the possible shortcomings of the ABC Concept, as you are describing now, become factors that led to the Tilt Rotor concept gaining acceptance by the Military and the ABC not?

[SansAnhedral]

The ABC versus tiltrotor competition of the 70s used craft (XH-59 and XV-15) sized below what is being compared today (SB>1 and V-280). At the time, Sikorsky used to illustrate larger versions of the rotor system scaled to fit medium lift class aircraft, but as the technology proved toublesome from a vibration and flight control standpoint through testing, they were never put to task proving it was feasible.

Now that FBW and better AVC have addressed some of the shortcomings revealed 40 years ago, the elephant in the room remains the sizing.

Fundamentally, gimballed rotors used on tiltrotors don't have the same concerns with scaling, and whether or not that factored heavily into the JVX decision making process is debatable. That's not to say there aren't other tiltrotor designs that do not make dubious scalability claims - Karem's OSTR to wit. Yet more issues with a large rigid rotor concept, this time with the added challenge of tiltrotor dynamics. Karem seems to believe he can simply just tune high with some rather mythical ultralight and ultra stiff construction material.