VTOL commercial aircraft....

nsaspook

Joined Aug 27, 2009
13,315

Thread Starter

cmartinez

Joined Jan 17, 2007
8,257
It scares me just to look at that thing. I have a perfectly justified (in my mind from flying with people who loved to play games with your lunch) fear of VTOL craft and helicopters.
I'd really like to hear what aircraft you've been into
 

nsaspook

Joined Aug 27, 2009
13,315
Was never in any jet fighter aircraft.
I spent two tours on WestPac on a Helo carrier and flew in everything but the Cobra gunship.
The ship in Guam.

The 53 and 46 but never fast roped one. They hook you to the rope and fly away, you don't go inside.

And last but not least the Huey.

I know the sound of that bird from miles away.


Even got up close and personal with a few Ruskie models. We mooned this guy because he was taking pictures of an operation. Somewhere in the Kremlin there is a picture of our asses.

Had a chance once to ride the outside open hatch 'seats' once. but I respectfully declined.

We had some of the AV-8 Harriers a few times but it looked like a flying death trap.

Due to my job I traveled a lot in the fleet on just about every aircraft from a C5, to carrier CODs, to an OV10 bronco,
For some reason that didn't scare me but it should have.

 
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Thread Starter

cmartinez

Joined Jan 17, 2007
8,257
relatively low payload
I agree. The craft would need a disproportionate amount of power to perform with high payloads

high maintenance
Not sure about that... advances in materials technology could improve maintenance issues.

Of course, that is only my humble opinion. I've never worked or designed anything connected to aircraft. But I'm a mechanical engineer, and I more or less understand the issues that you've mentioned.
 

nsaspook

Joined Aug 27, 2009
13,315
Not going to happen.
Like the V-22 has proven to be high maintenance, relatively low payload.
No kidding, it looks cool in a sci-fi movie but only the military could afford what it costs to run one. At least it's not killing people in crashes anymore but that took 15 years.

 

shteii01

Joined Feb 19, 2010
4,644
I agree. The craft would need a disproportionate amount of power to perform with high payloads


Not sure about that... advances in materials technology could improve maintenance issues.

Of course, that is only my humble opinion. I've never worked or designed anything connected to aircraft. But I'm a mechanical engineer, and I more or less understand the issues that you've mentioned.
I hang out with military and former military peeps. V-22 is high maintenance right now.
 

shteii01

Joined Feb 19, 2010
4,644
Do you know the particulars regarding maintenance annoyances?
That is the impression I got from what people wrote, but no, I don't have specific details. So let us assume that my earlier statement is wrong. I apologize for misleading you.
Some related stuff: http://www.wired.com/2012/10/air-force-silenced-general/all/

The V-22 is flying. It does useful work. In this sense it is a successful aircraft.

The question becomes. Is it successful enough to be attractive for wider use? I am not so sure.

On the other hand. This thread is not about V-22. It is about some future aircraft. While the "solution" is elegant, I am not sure it is worthwhile.
 

Thread Starter

cmartinez

Joined Jan 17, 2007
8,257
... I apologize for misleading you...
On the contrary... I think you gave me an important tip when you said the thing is high maintenance... Here's my guess in the dark as to why that's the case: The only way I can think of that a craft like that is able to be operate is by cyclically and collectively controlling the pitch of each of its two propellers, exactly like a helicopter's rotor... the mechanism for doing that is a very complex one, and also quite delicate and high in its number of components... hence it would require extremely frequent inspection and change of its more fatigue-prone parts.
Helicopters already are high-maintenance machines... I can easily imagine this one being more than twice as much a pain in the backside to keep safely operational

EDIT: Good article, thanks for sharing... sad about the General, though
 

shteii01

Joined Feb 19, 2010
4,644
On the contrary... I think you gave me an important tip when you said the thing is high maintenance... Here's my guess in the dark as to why that's the case: The only way I can think of that a craft like that is able to be operate is by cyclically and collectively controlling the pitch of each of its two propellers, exactly like a helicopter's rotor... the mechanism for doing that is a very complex one, and also quite delicate and high in its number of components... hence it would require extremely frequent inspection and change of its more fatigue-prone parts.
Helicopters already are high-maintenance machines... I can easily imagine this one being more than twice as much a pain in the backside to keep safely operational

EDIT: Good article, thanks for sharing... sad about the General, though
This is the info I was looking for regarding V-22:
"The V-22 has not just one engine but three. There's the two engines, turbo shafts (jet engines that put most of their power out via a shaft rather than thrust) in the nacelles, and there's an APU in the center (provides power on the ground for main engine start and during wing fold/unfold). They're all connected by a cross shaft so that if there is an engine failure they can still land. The left (or right) engine can provide power to the other engine and thus it's prop rotor.

On top of the fact that the engine pods rotate through ~90 degrees, the controls, fuel, and power feeds (electrical and hydraulic) from the engines have to feed through the rotating pivot point which also has to move freely AND support the weight of the aircraft.

And on top of that, the rotors and wing has to fold and stow so it can be struck down for storage on a lower deck of a carrier. That means that controls and power feeds (electrical and hydraulic) need to go through a third pivot point that also must be strong enough to handle the weight."
 

Thread Starter

cmartinez

Joined Jan 17, 2007
8,257
This is the info I was looking for regarding V-22:
"The V-22 has not just one engine but three. There's the two engines, turbo shafts (jet engines that put most of their power out via a shaft rather than thrust) in the nacelles, and there's an APU in the center (provides power on the ground for main engine start and during wing fold/unfold). They're all connected by a cross shaft so that if there is an engine failure they can still land. The left (or right) engine can provide power to the other engine and thus it's prop rotor.

On top of the fact that the engine pods rotate through ~90 degrees, the controls, fuel, and power feeds (electrical and hydraulic) from the engines have to feed through the rotating pivot point which also has to move freely AND support the weight of the aircraft.

And on top of that, the rotors and wing has to fold and stow so it can be struck down for storage on a lower deck of a carrier. That means that controls and power feeds (electrical and hydraulic) need to go through a third pivot point that also must be strong enough to handle the weight."
And to all that, I'd add a rather complex computer-aided control system... since I doubt that a normal (or even skilled) pilot can handle the demands of each individual rotor simultaneously
 
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