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Defiant first flight slips

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posted on Apr, 21 2017 @ 10:32 PM
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Boeing has announced that the first flight of their SB-1 Defiant, being built with Sikorsky, has slipped into 2018. Boeing insists that there isn't a problem with the program, but things just aren't coming together as expected. Boeing is still planning to acquire fuselage assemblies for more aircraft even as they test the prototype.

Meanwhile, Sikorsky is still flying the S-97 Raider demonstrator. They have flown at 150 kts without the pusher prop engaged. They're planning on a 220 kt flight in the coming quarter.


Sikorsky-Boeing’s SB-1 Defiant has fallen months behind its scheduled first flight in the US Army’s Joint Multi-Role Technology Demonstration (JMR-TD), even as Bell Helicopter’s V-280 Valor marches toward its first flight in September.

The army’s JMR-TD serves as the precursor to the service’s Future Vertical Lift competition, which will replace the UH-60 Black Hawk, AH-64 Apache and CH-47 Chinook. Sikorsky-Boeing is pushing its coaxial rotor-pusher propeller Defiant. The Valor offers a tiltrotor that resembles an improved V-22 Osprey.

The Defiant was expected to fly this fall, but Boeing has pushed first flight until early 2018. The company did not encounter a significant issue that caused the delay, says Boeing’s Defiant programme manager, Pat Donnelly.

www.flightglobal.com...




posted on Apr, 22 2017 @ 05:34 AM
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a reply to: Zaphod58

As 'copters move further along toward being more versatile and airplane like, what is being done to make crew survivability more equal to other aircraft given a systems failure?

All fighters have ejection seats, larger craft have other engines while helos have nothing but auto-rotation which requires quick responses and have a minimum altitude in which to be employed.

I can imagine combat helos with ejection seats that tip over to eject out to the side under the blades but that would not be a solution to a typical transport 'copter.



posted on Apr, 22 2017 @ 06:19 AM
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a reply to: Aliensun

The Russians have ejection seats in at least one of their helicopters. The main rotor ejects, followed by the seats.



posted on Oct, 12 2017 @ 12:44 PM
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Great video on the Defiant and the flight control system.




posted on Oct, 12 2017 @ 12:53 PM
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a reply to: Zaphod58

I sure as hell hope so...

Otherwise that's a messy way to die.



posted on Oct, 12 2017 @ 12:56 PM
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a reply to: seagull

That used to be one of the running jokes when it first came out that they had ejection seats.



posted on Oct, 2 2018 @ 08:44 PM
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a reply to: Zaphod58

breakingdefense.com...

Slip and side more. Earliest flight is december. They are suggesting it will be later.

Tick tock, guys...



posted on Oct, 4 2018 @ 09:27 PM
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Also:

breakingdefense.com...

www.flightglobal.com...
edit on 4-10-2018 by anzha because: added another link.



posted on Oct, 6 2018 @ 09:08 AM
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a reply to: anzha

As a big Sikorsky fan, a couple years ago I never in my wildest dreams would have guessed that their warmed-over Kamov rip-off designs would end up getting wrecked in the development timeline game by a god damned Bell tiltrotor.

Now, I'm eating a bunch of crow and quietly hoping that US army soldiers will once again ride into battle on a Bell.



posted on Oct, 6 2018 @ 10:05 AM
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a reply to: Barnalby

Well, it certainly looks like Blackhawk replacement is likely to be the Bell. Though I am sure Radio Robert will show up and dispute that momentarily.


OTOH, it also looks likely the Kiowa replacement will be a Sikorsky. The requirements are not nearly as friendly to the tilt rotor tech and the army wants something that seems to have been flown at size already. The Raider is really close to what they want, sooo...

we'll see. The army have been amazing for fscking up its procurements for 20 years now though. They could do this one again.



posted on Oct, 6 2018 @ 11:45 AM
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a reply to: anzha

Yeah, I can totally see the Kiowa replacement going to Sikorsky and it would be utterly foolish for the eventual Apache replacement to go to anything but an SB-1 derivative.



posted on Oct, 6 2018 @ 12:09 PM
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Depends on if they can get the subs in line. They sorted out the transmission issues. Still having quality control problems with the rotor rigidity last I heard. There is a limit to the ability to scale this up, and they are pushing the boundaries on material science for the loads the rigid rotor is designed for. They seem confident they can get them to deliver though.


I think I've already danced the dance about "Kamov ripoffs", so I'm just going to roll my eyes and move on haha


Raider is quietly humming along again.


Assuming they can deliver on the Defiant-scale up, it all probably depends on how much of your expected mission profile is in cruise or hover, and how you weight those requirements. A lot safer and easier to put down in the weeds or in an urban environment with a coax's smaller footprint, less vulnerable to vortex ring state, smaller losses from fuselage/wing being washed in hover, etc, etc. It'll also almost certainly have faster accel and decel in hover with greater agility than the tilt-rotor.

Since at the operator end, the hover phases are frequent and often the most hazardous phases of flight, it makes sense to me over the tilt-rotor compromise which (probably) will outperform X2 in cruise phase. The tilt-rotor system is a lot more mature than X2 work, so it come down to what is actually delivered.



posted on Oct, 7 2018 @ 12:19 AM
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a reply to: RadioRobert

You're right, it's not warmed-over Kamov leftovers, it's the bastard spawn of a Kamov and an AH-56 Cheyenne!



posted on Oct, 8 2018 @ 08:21 PM
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The aircraft was supposed to have flown for the first time last year, but the composite blade manufacturing process has delayed this. At the request of the US Army, Sikorsky-Boeing used an automated fiber placement machine to manufacturer the helicopter’s blades.

“To set the precedent for the future of being a low-cost aircraft we went right in with an automated approach,” said Ken Eland, Future Vertical Lift programme manager for Boeing. “As I put it to someone in the Army, the first spar took us two years to build; the last spar took us 11 days.”


www.flightglobal.com...

That's a different story than I've been hearing and a bit of an odd one, too.



posted on Oct, 8 2018 @ 08:47 PM
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a reply to: anzha

They were going to hand build for the prototype (most composite blades are built with a manual lay up process) but the Army wanted them to seed the process to reduce risk if they are selected. There have been some issues regarding the required stiffness and rigidity. Noone has built a rigid rotor designed for these flight conditions and at this size. I'm struggling to name a compound this size, even. There definitely hasn't been anything like this industrial process for the blades. They also had to retool to eliminate sag because of a material used in the tooling to layup the blades (which contributed to some of the earlier quality control problem).



posted on Oct, 9 2018 @ 06:41 AM
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I am apparently behind the times. Rotor blades have been delivered. They are running the powertrain once more without rotors prior to install.



posted on Oct, 9 2018 @ 03:16 PM
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a reply to: RadioRobert

Does the Fairey Rotodyne count? Other than the aforementioned Cheyenne, that is...



posted on Oct, 9 2018 @ 03:18 PM
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a reply to: RadioRobert

I am very familiar with composites since I've worked with them.


What was meant was the story I had heard over and over was there was a power train issue given its complexity as the root cause of the delays.



posted on Oct, 9 2018 @ 04:58 PM
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a reply to: anzha

They had a materials problem with the transmission that was quickly fixed by changing the hardness of certain elements in the transmission. The story for over a year has been predominantly the automated layup process and having to retool. They had problems with layup because the tool sagged (It's relatively long, like the blades and spars it is laying). If you're at the bleeding edge of mat science already and your tooling is cross-laying a smidge out of spec at both ends, the blades/spars are going to have a hard time reliably falling within tolerances because the patterns are off. So your product might be fine or it might be #. Not delightful.



posted on Oct, 10 2018 @ 04:35 PM
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a reply to: RadioRobert

Defense News is now reporting it was the tranny and the composites for the rotors that have delayed the Defiant flight.

The Valor has broken 250 kts. They're saying they can go faster.

www.defensenews.com...




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