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-   -   Sikorsky X Wing video (https://www.pprune.org/rotorheads/636526-sikorsky-x-wing-video.html)

SLFMS 3rd Nov 2020 05:11

Sikorsky X Wing video
 
Spoiler
 

Here's a link to a short video on the X Wing project I thought was pretty interesting. It's a good little tube channel with some other non related fixed wing projects as well.


Commando Cody 3rd Nov 2020 18:51

The video gets a lot of stuff wrong.

First the S-72 was not an X-Wing. It was the Rotor Systems Research Aircraft (RSRA), whose purpose was to test various rotors. Here's a picture of the S-72 with an X-Wing mounted, you'll see it's much differnt from what's in the video.

Second, those wings are there to provide a fallback in case there were issues with whatever rotor was being tested. The goal of X-wing was that the rotor would be stopped in flight and itself act as a conventional wing.

Third, the X-wing never flew on the RSRA (note that isn't an X-wing rotor in the flying shots) . An earlier version did make a takeoff on a highly modified Kaman Seasprite, but it just lifted into a tethered hover and made no attempt to attempt any horizontal motion, because the flight control system couldn't handle that.

That last factor is why X-Wing never went anywhere. The required flight control system and supplying the varying bleed air to the rotor would have been hideously complex and the craft would require a lot of power, especially during transition (It was speculated that an X-wing would not be able to start/stop the rotor for transition and maintain level flight). It would be very expensive but wouldn't offer much advantage over, say, Tilt-Rotor. It might dash maybe a hundred knots faster, but its cruise would actually be lower. While the V-22 doesn't have the world's greatest autorotation characteristics (due to a unique USMC requirement for deck spacing, other tilt-rotors are better) it beat the heck out of X-wing which would have the characteristics of a brick.

It was an interesting concept that just didn't pan out.

https://cimg4.ibsrv.net/gimg/pprune....969ca06d9b.jpg

The Sultan 3rd Nov 2020 20:31

CC,

You just burst the bubble of the BS team’s plan to replace the failed SB-1 Defiant with a “slightly” modified paper production proposal where the twin rotors are replaced with an X-wing. Similar approach to what Boeing tried to pull on their JSF with a switch from delta wing to a conventional wing/stabilizer layout.

Commando Cody 3rd Nov 2020 23:41


Originally Posted by The Sultan (Post 10918184)
CC,

You just burst the bubble of the BS team’s plan to replace the failed SB-1 Defiant with a “slightly” modified paper production proposal where the twin rotors are replaced with an X-wing. Similar approach to what Boeing tried to pull on their JSF with a switch from delta wing to a conventional wing/stabilizer layout.


Must admit hadn't heard that. If they tried that, you might as well just hand the production contract to Bell now. Aside from the fact that X-wing would be a far worse technology for FLRAA (at least X2 aircraft can fly), it would be radically different from the technology that was the basis for their award for the competition. Bell and all the non-selectees would have a very good case that Sikorsky was now proposing something completely different from what they said they were going to build.

In the case of JSF, Boeing changed their design because they realized their configuration could not easily fly the required carrier approach. It's worth noting that Lockheed found themselves in the same boat, but they realized it earlier and so changed their design before they actually cut metal (or composite ;) ).

Keep in mind that Boeing is somewhat handicapped. Their last military aircraft of their own design entered service in the 1950s. Their JSF was the first (and only) aircraft of theirs to fly that had an afterburner or was designed to fly supersonically. They've never had a helicopter of their own design enter production and in fact have only flown five airframes of one design in total.

SLFMS 4th Nov 2020 03:12

Thank you for contributing all those corrections Commando Cody. I didn't really know anything about the program but it's very interesting.
i guess in the techtubers defence it's very specific details.

IFMU 4th Nov 2020 04:55

I don't think any Sikorsky people want to bring back the X wing.

JohnDixson 4th Nov 2020 11:38

Perhaps IFMU was referring to the guy who was going to push the STOP ROTOR button?

sycamore 4th Nov 2020 14:41

JD,or perhaps the `bigger` `get out of here` button...!!

rudestuff 4th Nov 2020 14:46

The first blueprint showed an S67 Blackhawk..

SplineDrive 4th Nov 2020 14:58


Originally Posted by IFMU (Post 10918356)
I don't think any Sikorsky people want to bring back the X wing.

Oh, I’ve heard a few wistful dreams and “what-ifs” about X-Wing over the years, but I think Sultan is just having fun, though... Sikorsky is “all-in” on X-2 technology. Not a wise strategy, but it is what it is.

Less Hair 4th Nov 2020 16:30


Their last military aircraft of their own design entered service in the 1950s. Their JSF was the first (and only) aircraft of theirs to fly that had an afterburner or was designed to fly supersonically.
To be fair Boeing inherited MDD (plus others) so they have more like 1950s experience with very fast jets.

Commando Cody 4th Nov 2020 17:54


Originally Posted by Less Hair (Post 10918740)
To be fair Boeing inherited MDD (plus others) so they have more like 1950s experience with very fast jets.

Boeing didn't inherit MDD, they bought it. Probably the biggest mistake they ever made because it seems like Boeing essentially suffered a hostile takeover using their own money.

In any case, that agrees with my point. Boeing has not had a military design of their own enter service since the 1950s, and have never had a helicopter of their own design (except for those 5-6 airframes I mentioned) even fly. All their military aircraft since the 1950s have been aircraft designed and put into production by someone else.

This is anecdotal, but I've seen narratives that said before Defiant, Boeing and Bell discussed partnering on what would become the V-280. When the talks fell through and it was announced that Boeing would not be working with them, Bell engineers cheered.

FWIW

Commando Cody 4th Nov 2020 18:00


Originally Posted by SLFMS (Post 10918331)
Thank you for contributing all those corrections Commando Cody. I didn't really know anything about the program but it's very interesting.
i guess in the techtubers defence it's very specific details.

Oh there were others but the big thing that chafed me was all the references to the wonders of X-wing while showing videos of something that wasn't an X-wing. They either were really ignorant or deliberately misleading in order to imply the technology was more successful than it was (which was not at all).

SplineDrive 4th Nov 2020 19:02


Originally Posted by Commando Cody (Post 10918795)
This is anecdotal, but I've seen narratives that said before Defiant, Boeing and Bell discussed partnering on what would become the V-280. When the talks fell through and it was announced that Boeing would not be working with them, Bell engineers cheered.

FWIW

Anecdotally, the opposite was true at Sikorsky when engineers learned they’d be teaming with Boeing on SB>1.

CTR 4th Nov 2020 20:22


Originally Posted by SplineDrive (Post 10918823)
Anecdotally, the opposite was true at Sikorsky when engineers learned they’d be teaming with Boeing on SB>1.

Having shared late night drinks with FVL program engineers from both Sikorsky and Bell, I can confirm second hand the veracity of these stories.

IFMU 5th Nov 2020 14:31


Originally Posted by CTR (Post 10918879)
Having shared late night drinks with FVL program engineers from both Sikorsky and Bell, I can confirm second hand the veracity of these stories.

My first reaction was ye gods, did nobody remember Comanche?

SplineDrive 5th Nov 2020 15:39


Originally Posted by IFMU (Post 10919459)
My first reaction was ye gods, did nobody remember Comanche?

Plenty of people remember Comanche... not all engineers remember that teaming fondly.

JohnDixson 6th Nov 2020 12:51

Back to the RSRA for a moment ( then a comment re Comanche teaming ).

The initial idea was not the X-wing, it was to provide a test platform for advanced rotors, open to NASA/DARPA, and OEM’s as I understood. X wing came later.

As to the Boeing/ SA teaming on Comanche. I can only address the flight test aspects and in that regard, the teaming worked well. The Flight test Team leader was a Boeing man of long experience, Clarence Hutchinson, and he was really excellent. In fact, after consulting with our CEO, I/we offered him a job, which he turned down for a number of personal reasons. That test team worked to produce perhaps the best flying machine the vertical flight industry has seen* ( only flew it once, and it was very, very impressive ). I’m talking about the basic helicopter. In the present, cannot comment on the Defiant, as I am not remotely involved.
*Were there development problems to solve? Of course-there always are, and some are more easily solved that others, but as to aircraft problems, they were addressed and resolved.

SplineDrive 6th Nov 2020 14:04


Originally Posted by JohnDixson (Post 10920263)
Back to the RSRA for a moment ( then a comment re Comanche teaming ).
As to the Boeing/ SA teaming on Comanche. I can only address the flight test aspects and in that regard, the teaming worked well. The Flight test Team leader was a Boeing man of long experience, Clarence Hutchinson, and he was really excellent. In fact, after consulting with our CEO, I/we offered him a job, which he turned down for a number of personal reasons. That test team worked to produce perhaps the best flying machine the vertical flight industry has seen* ( only flew it once, and it was very, very impressive ). I’m talking about the basic helicopter. In the present, cannot comment on the Defiant, as I am not remotely involved.
*Were there development problems to solve? Of course-there always are, and some are more easily solved that others, but as to aircraft problems, they were addressed and resolved.

The complaint I’ve always heard was not Boeing’s individual engineers and their contributions, but rather how their program managers assigned to the teams managed risk, schedule, mitigations, etc.

CTR 6th Nov 2020 16:21

Same Impression
 

Originally Posted by SplineDrive (Post 10920307)
The complaint I’ve always heard was not Boeing’s individual engineers and their contributions, but rather how their program managers assigned to the teams managed risk, schedule, mitigations, etc.


This was the same information I was relayed over drinks. This information is also supported by both Sikorsky and Bell’s stealing away many excellent engineers from Boeing.


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