Flying Pancake aircraft for bush operations

[BJC]

BJC

 

[Pilot-34]

Having done a bunch of practice autorotations in helicopters, they are petty much non event unless there is a tree or fence or rock in the way. Never had to do a real one luckily because I’m sure it would involve a tree or fence or rock. Power off ARUP is going to be planted like a tree.

Oh no it doesn’t work like that I can pretty much guarantee it will be onto a rock between lots of trees and fences.....

Usually on a morning where are you missed your coffee.

 

[Vigilant1]

Was just looking at the Vought `V-173 flying pancake and saw that it had almost identical performance to a Cessna 172 despite having far better takeoff and landing characteristics.

"Almost identical performance"... How many Cessna 172s would have been sold if it had the V-173s useful load of about 500 lbs?
These small GA-sized LAR aircraft can have utility if their wing loading is kept very low. That's how they can achieve noteworthy TO/landing speeds despite an inefficient (draggy) wing planforn. So, build them light and don't put much in them. Maybe the V-173 could have been made into some sort of useful observation/laison/air ambulance niche aircraft, but it was never going to be the basis for an effective fighter or attack aircraft as some breathless write-ups suggest.

 

[Doggzilla]

"Almost identical performance"... How many Cessna 172s would have been sold if it had the V-173s useful load of about 500 lbs?
These small GA-sized LAR aircraft can have utility if their wing loading is kept very low. That's how they can achieve noteworthy TO/landing speeds despite an inefficient (draggy) wing planforn. So, build them light and don't put much in them. Maybe the V-173 could have been made into some sort of useful observation/laison/air ambulance niche aircraft, but it was never going to be the basis for an effective fighter or attack aircraft as some breathless write-ups suggest.

Did you post this in the wrong thread or something?

Not only is the useful load within 50lbs of the Cessna, it was developed into a successful naval fighter prototype which performed extremely well.

 

[Doggzilla]

Theoretical discussion that leads to applied concepts is one of the appeals of this forum. Throwing BS against the wall just to kill time, OTOH, is just mental masturbation.

I'm interested to hear about the experiments in the flying pancake concept, but if this is just killing time, I'll steer clear. Thanks for clarifying that this thread has no technical merit whatsoever.

You mean like the hissy fits you keep throwing which do nothing but harass other members and provide absolutely no technical purposes? Like that?

 

[Kyle Boatright]

Not only is the useful load within 50lbs of the Cessna, it was developed into a successful naval fighter prototype which performed extremely well.

The V-173 was no more of a fighter prototype than the frisbee in my closet (which is also round and flies, but that doesn't make it a fighter prototype). It was a shape. A proof of concept shape. The XF5U was a prototype.

Is there any primary data available that shows the V-173's performance? Not what some guy reading a story in Popular Mechanics copied into Wiki. A USAAC report? A NACA report? Something from Chance Vought?

 

[BJC]

Did you post this in the wrong thread or something?

Not only is the useful load within 50lbs of the Cessna, it was developed into a successful naval fighter prototype which performed extremely well.

If the “successful naval fighter prototype” you are referring to is the XF5U, it never flew. See post #38. If that doesn’t work for you, see The Pancake that Didn’t Fly

BJC

 

[FritzW]

, but if this is just killing time, I'll steer clear.

That would be great, thanks.

it was developed into a successful naval fighter prototype

I read that as "it was developed into a successful naval fighter prototype" not that it was a fighter prototype.

>>>>>>
When did it become a bad thing to talk about ideas on the HBA?

I think the idea of a low AR STOL airplane would make an interesting conversation. Why all the push-back?

 

[BBerson]

Low AR is not the same as "pancake". The V-173 was an attempt at VTOL. It failed at that probably because of weight. For a non-VTOL the optimal AR may be around 3. Even Barnaby is leaning to AR:2, I think.
An airplane designer (Bill Fike) built an AR:3 20 foot span cantilever Cub in Alaska.

 

[BJC]

I read that as "it was developed into a successful naval fighter prototype" not that it was a fighter prototype

Dogg asserted that the V 173 was developed into the XF5U, which he further described as a “successful
naval fighter prototype which performed extremely well.”

I contend that a prototype that never flew can not be accurately described as a “successful naval fighter prototype which performed extremely well.”

I’m through.


BJC

 

[Kyle Boatright]

I read that as "it was developed into a successful naval fighter prototype" not that it was a fighter prototype.

>>>>>>
When did it become a bad thing to talk about ideas on the HBA?

I think the idea of a low AR STOL airplane would make an interesting conversation. Why all the push-back?

1) It wasn't developed into a successful prototype. The prototype was constructed, but never flown.

2) Ideas are great. But I struggle with fantastic claims around things that never happened. The V-173 got off the ground and flew. It apparently demonstrated good short field performance, but you'd expect that with almost any shape that had a wing loading of ~ 5 lb/SF.

3) The push back is that the concept was tried and abandoned for a reason. If you want STOL performance, there are easier ways to get there and to have more performance in other aspects of flight. Why do something weird and complex (two buried engines, running through gearboxes, turning huge props) to underperform something essentially conventional like a C-182 with an STC'd canard?

4) If someone wants to build one, great. I'd love to see it. But justifying it by making inflated claims about the success of Vought's efforts is.... silly.

 

[PagoBay]

They flew it, but other that that, what are the specific engineering accomplishments?
Please provide a citation for that claim. Thank you.
BJC

Thanks. Made some edits. Hope they suffice.

 

[Sockmonkey]

There's always the Nemeth parasol. That one managed pretty good STOL and actually flew.

 

[Sockmonkey]

Now, because the trailing edge doesn't always have to be round, there's this.

The straight center section is being blown by the prop, while the swept tips are out in the open to develop vortex lift. I was too lazy to draw the wheels. The engine has to be in the leading edge rather than in front of the cockpit to make it easier to pitch the fuselage up. Junkers flap of course because you need to maintain full pitch authority during high AOA vortex lift STOL operations.

 

[bmcj]

This video has some good historical footage, including short landings and high AOA testing.

 

[Pilot-34]

Now, because the trailing edge doesn't always have to be round, there's this.

The straight center section is being blown by the prop, while the swept tips are out in the open to develop vortex lift. I was too lazy to draw the wheels. The engine has to be in the leading edge rather than in front of the cockpit to make it easier to pitch the fuselage up. Junkers flap of course because you need to maintain full pitch authority during high AOA vortex lift STOL operations.

If the propeller was significantly above the way wouldn’t it develop greater lift on takeoff?
Think Custer channel wing.

 

[Sockmonkey]

If the propeller was significantly above the way wouldn’t it develop greater lift on takeoff?
Think Custer channel wing.

IIRC the channel wing was basically using the propwash to create vortex lift. Here we have the wing being blown, which gets you much the same effect, plus the vortex from the outer panels.

As I understand it, the props on the pancake rotated outward so the propwash totally countered the tip vortexes.
So you could say that it's STOL was from being a blown wing rather than a vortex generating one. I think they could just as easily made the thing square and gotten the same performance.