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Search: Posts Made By: SplineDrive
Showing results 1 to 35 of 236
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Forum: Rotorheads
7th May 2024, 03:29
Replies: 13
Views: 1,506
Posted By SplineDrive

Downfall: The FLRAA Edition...

Downfall: The FLRAA Edition (https://www.captiongenerator.com/v/2284390/hitler-reacts-to-the-bell-v-280-winning-flraa.)

Prescient for late 2022... watch the strategizing at the very end.
...
Forum: Rotorheads
7th Apr 2024, 19:34
Replies: 15
Views: 3,999
Posted By SplineDrive

Lockheed has zero institutional memory of what it...

Lockheed has zero institutional memory of what it takes to support a commercial customer and the Sikorsky of today is well into its Lockheed brain-transplant.
Forum: Rotorheads
29th Mar 2024, 13:33
Replies: 186
Views: 38,937
Posted By SplineDrive

So... how long until the Army decides that an...

So... how long until the Army decides that an armed, crewed scout helicopter is worth having and launches a new competition? If history holds, a program will appear in the 2028-2029 timeframe. Anyone...
Forum: Rotorheads
27th Mar 2024, 11:51
Replies: 186
Views: 38,937
Posted By SplineDrive

If the competitive prototypes got to flight test,...

If the competitive prototypes got to flight test, I don't think the award would have gone to Sikorsky. The Bell was poised to be faster and would have undoubtedly marched through its flight test...
Forum: Rotorheads
21st Mar 2024, 15:38
Replies: 100
Views: 7,224
Posted By SplineDrive

There’s not new concepts in this thread… this is...

There’s not new concepts in this thread… this is basic stuff out of a rotor dynamics textbook.
Forum: Rotorheads
20th Mar 2024, 02:20
Replies: 100
Views: 7,224
Posted By SplineDrive

On a teeter rotor with no pitch flap coupling and...

On a teeter rotor with no pitch flap coupling and no hub spring rate, the first flap frequency is at 1/rev, i.e resonance with the rotor rpm. A system in this state has a phase lag of 90 degrees....
Forum: Rotorheads
28th Feb 2024, 17:51
Replies: 13
Views: 1,506
Posted By SplineDrive

Having the rotor diameter similar to the wing...

Having the rotor diameter similar to the wing span can help with the deep stall and drag, depending on the rotor wash velocity. Still, there are other reasons tilt wings haven’t been successful....
Forum: Rotorheads
28th Feb 2024, 16:02
Replies: 13
Views: 1,506
Posted By SplineDrive

My point is that the point of the aircraft is...

My point is that the point of the aircraft is more about the aero-elastic, mechanical, and performance characteristics of a wing and flapping rotor rather than a hybrid power system. They’re 50+...
Forum: Rotorheads
28th Feb 2024, 11:44
Replies: 13
Views: 1,506
Posted By SplineDrive

Notice what's missing? An X-2 configuration....

Notice what's missing? An X-2 configuration. Sikorsky management must realize that after a billion+ dollars invested in a dead end technology, they need to play catch up on winged configurations with...
Forum: Rotorheads
17th Feb 2024, 14:08
Replies: 186
Views: 38,937
Posted By SplineDrive

Personally, FARA was always strangely...

Personally, FARA was always strangely incompatible with FLRAA, particularly the range and thus speed requirement. If one of the goals of FLRAA was giving the Army a credible Pacific combat capability...
Forum: Rotorheads
16th Feb 2024, 00:52
Replies: 186
Views: 38,937
Posted By SplineDrive

There haven't been but a handful of posts since...

There haven't been but a handful of posts since the cancelation on this or other Rotorheads threads. Thanks for the link.
Forum: Rotorheads
15th Feb 2024, 16:48
Replies: 186
Views: 38,937
Posted By SplineDrive

PPRuNe has been strangely silent on the recent...

PPRuNe has been strangely silent on the recent demise of FARA and the fate of the last X-2 aircraft.
Forum: Rotorheads
11th Feb 2024, 15:14
Replies: 2
Views: 1,416
Posted By SplineDrive

Video of 1972 wind tunnel test Bell has been...

Video of 1972 wind tunnel test

Bell has been pursuing stop fold tilt rotor technology for almost as long as the tilt rotor itself. The link above is an unpowered XV-15 sized stop fold rotor in the...
Forum: Rotorheads
20th Jan 2024, 17:15
Replies: 9
Views: 1,748
Posted By SplineDrive

Bell has publicly done/announced that the 525...

Bell has publicly done/announced that the 525 will have de-ice capabilities and showed photos of the 525 flying with the HISS test system. When the 525 gets certified and how long after the initial...
Forum: Rotorheads
22nd Dec 2023, 15:18
Replies: 2
Views: 1,315
Posted By SplineDrive

It's the stiff out of plane rotor head that is...

It's the stiff out of plane rotor head that is wholly impractical for a two bladed rotor on a passenger carrying aircraft. While a stiff out of plane rotor can be trimmed with cyclic for various...
Forum: Rotorheads
4th Nov 2023, 13:25
Replies: 186
Views: 38,937
Posted By SplineDrive

I gently disagree... X-2 aircraft do have a...

I gently disagree... X-2 aircraft do have a commercial application, just not the one Sikorsky intended: they will all make good museum pieces.
Forum: Rotorheads
28th Oct 2023, 18:18
Replies: 186
Views: 38,937
Posted By SplineDrive

John, for all of my Google-Fu, I cannot find such...

John, for all of my Google-Fu, I cannot find such a document, if it's public.

The following Hirschberg commentary article reflects the trades and general approach accurately.
...
Forum: Rotorheads
26th Oct 2023, 11:43
Replies: 186
Views: 38,937
Posted By SplineDrive

John... actually essentially the opposite...

John... actually essentially the opposite approach was taken. A mission equipment package was defined... somewhat loosely with respect to ALEs. MOSA was defined. A min speed, max rotor diameter, and...
Forum: Rotorheads
25th Oct 2023, 00:16
Replies: 186
Views: 38,937
Posted By SplineDrive

The odds that Raider-X can keep up with Valor are...

The odds that Raider-X can keep up with Valor are zero... even if a production version had two T-901 engines. Literally zero. Zip. Nada. Oh hell no. Not going to happen.
Forum: Rotorheads
24th Oct 2023, 17:12
Replies: 186
Views: 38,937
Posted By SplineDrive

Several posters here talking about Raider-X...

Several posters here talking about Raider-X having a serious speed advantage over Invictus and Evalu8er mentions closing the gap to a V-280 escort with Raider-X since it will be much faster than the...
Forum: Rotorheads
15th Oct 2023, 14:13
Replies: 186
Views: 38,937
Posted By SplineDrive

Odds on favorite could be program cancellation,...

Odds on favorite could be program cancellation, but let's see what the Army AoA says. Both teams will have their engines very soon and it'll be game on to get in the air. Then we'll see if Raider-X...
Forum: Rotorheads
9th Oct 2023, 11:22
Replies: 186
Views: 38,937
Posted By SplineDrive

Looks like Raider-X is complete enough to put...

Looks like Raider-X is complete enough to put together a sizzle reel for AUSA.
Sikorsky video link
...
Forum: Rotorheads
9th Sep 2023, 14:54
Replies: 10
Views: 2,823
Posted By SplineDrive

Rotor inertia for the win. Nice work on the...

Rotor inertia for the win. Nice work on the pilot, too.
Forum: Rotorheads
5th Aug 2023, 22:30
Replies: 43
Views: 8,459
Posted By SplineDrive

Definitely not the first description of an enemy...

Definitely not the first description of an enemy induced helicopter hydraulic system fire I've heard from that conflict. Glad you weren't forced down in less friendly territory... hope you're...
Forum: Rotorheads
5th Aug 2023, 21:05
Replies: 186
Views: 38,937
Posted By SplineDrive

It likely involves Boeing lobbyists, members of...

It likely involves Boeing lobbyists, members of Congress, and sacks of cash.
Forum: Rotorheads
5th Aug 2023, 16:18
Replies: 186
Views: 38,937
Posted By SplineDrive

The Analysis of Alternatives, currently in...

The Analysis of Alternatives, currently in progress, will either say to add a second T-901 engine and grow the aircraft or kill the program and upgrade the Apache. Easy money and heavy lobbying is on...
Forum: Rotorheads
29th Jul 2023, 21:30
Replies: 23
Views: 8,430
Posted By SplineDrive

I'd never seen this photo before... thanks for...

I'd never seen this photo before... thanks for sharing!
Forum: Rotorheads
4th Jun 2023, 15:53
Replies: 40
Views: 5,576
Posted By SplineDrive

I'll bite, but I'll preface this that my opinion...

I'll bite, but I'll preface this that my opinion is counter to the eVTOL industry trend.

Wisk has moved to the increasingly common "lift + tilt cruise" approach for distributed lift. Their front 6...
Forum: Rotorheads
4th Jun 2023, 15:22
Replies: 40
Views: 5,576
Posted By SplineDrive

Now you've added some of the problems of the...

Now you've added some of the problems of the X-Wing pneumatic rotor system! :)
Forum: Rotorheads
22nd May 2023, 11:57
Replies: 40
Views: 5,576
Posted By SplineDrive

My comment about an X-2 style aircraft losing to...

My comment about an X-2 style aircraft losing to a simple winged helicopter was a reference to the US Army FARA competition where the Sikorsky Raider-X is pitched against the Bell Invictus.

I have...
Forum: Rotorheads
22nd May 2023, 11:40
Replies: 40
Views: 5,576
Posted By SplineDrive

Because people fly aircraft to the point of...

Because people fly aircraft to the point of energy exhaustion and errors/mistakes are made in the energy loading/consumption process. Should we have passenger fixed wing aircraft that can't glide?...
Forum: Rotorheads
21st May 2023, 22:13
Replies: 40
Views: 5,576
Posted By SplineDrive

Yes, Jaunt is pursuing a more conventional...

Yes, Jaunt is pursuing a more conventional certification. As for eVTOL platforms and the common lack of autorotation and/or glide capabilities, why should the flying public tolerate aircraft that are...
Forum: Rotorheads
21st May 2023, 15:30
Replies: 40
Views: 5,576
Posted By SplineDrive

There's a couple of key differences between...

There's a couple of key differences between lifting an aircraft vertically with "blowing air" and pushing it forward via "blowing air". Lifting an aircraft requires generating enough thrust to...
Forum: Rotorheads
21st May 2023, 15:10
Replies: 40
Views: 5,576
Posted By SplineDrive

X-49 as a research platform has been going on for...

X-49 as a research platform has been going on for a while, but not a ton of public data. The configuration adds a wing (which is key to high speed performance with a flapping rotor) and the ducted...
Forum: Rotorheads
20th May 2023, 19:22
Replies: 40
Views: 5,576
Posted By SplineDrive

eVTOL got "high end money" back when interest...

eVTOL got "high end money" back when interest rates were near zero. A cash crunch is coming soon and most of the players won't survive their cash burn rates as certification is delayed. The FAA cert...
Showing results 1 to 35 of 236
 
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