Shortround6
Lieutenant General
Has anyone ever heard of a designer of a different looking aircraft ever saying his design was stall and spin prone?
Foo Fighters
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John Frazer
Airman
- 43
- Apr 21, 2018
Do any of you have any reason, besides ignorance and skepticism, to doubt the word of Wainfan? He stated as much in the NASA report he authored after they commissioned a study on it.
I challenge anyone to prove he lied and that NASA accepted it or said it was wrong.
The Arups were also stall and spin proof, as was the Nemeth "parachute plane".
In his NASA funded report, Wainfan writes about the "Vortex lift" such very low-aspect ratio planes can use.
They do _NOT_ always drag around a burden of heavy induced drag due to wing-tip vortices. That is the most common myth about the type (they do not and never did need outward-turning exaggerated-size, plane-changing props to "counter" vortices).
The pilot may elect to use "parachute lift" or "vortex lift", at around 50% power to stay aloft at super-slow speeds. The wing-tip vortices capture the airflow over the top of the leading edge and keep it from separating. The plane does not stall, even if it's flying too slow with the nose held up, that it descends.
The airflow stays on top of the wing, and the vortices "capture a "bubble" of low pressure above-behind it, giving it increased lift.
This is science, not tall tales by braggart plane designers.
The same thing reported for the Nemeth, the Arups, the Little Bird, the Facetmobile.
I challenge anyone to prove he lied and that NASA accepted it or said it was wrong.
The Arups were also stall and spin proof, as was the Nemeth "parachute plane".
In his NASA funded report, Wainfan writes about the "Vortex lift" such very low-aspect ratio planes can use.
They do _NOT_ always drag around a burden of heavy induced drag due to wing-tip vortices. That is the most common myth about the type (they do not and never did need outward-turning exaggerated-size, plane-changing props to "counter" vortices).
The pilot may elect to use "parachute lift" or "vortex lift", at around 50% power to stay aloft at super-slow speeds. The wing-tip vortices capture the airflow over the top of the leading edge and keep it from separating. The plane does not stall, even if it's flying too slow with the nose held up, that it descends.
The airflow stays on top of the wing, and the vortices "capture a "bubble" of low pressure above-behind it, giving it increased lift.
This is science, not tall tales by braggart plane designers.
The same thing reported for the Nemeth, the Arups, the Little Bird, the Facetmobile.
GregP
Major
About the XF5U-1 never getting airborne, all the references I have ever seen to it say that the program was behind schedule and over budget, and that the Navy saw that jets were going to be the coming thing. They decided to cancel it rather than fund it to completion, and the prototype was transferred to Smithsonian for display. The V-173 flew in 1943, and the two XF5U-1s were cancelled in 1946.
Apparently, they never solved the vibration issues and the only completed XF5U-1 made several "hops" down the runway, but never true flight. It was apparently VERY structurally strong. I have always wondered why they never flew at least a test programs on it. Many designs where the power had to change direction from the crankshaft suffered from vibration. The P-39 / P-63 series comes to mind. The U-joint make a distance noise and vibration. The Osprey comes to mind, as do the experimentals with titlrotors.
The XF5UI-1 was basically a tiltrotor aircraft configuration that did not tilt. That is, the configuration was very similar to later tiltrotors when they were in fixed-wing flight, but the props were small enough to not require tilting for ground clearance.
Apparently, they never solved the vibration issues and the only completed XF5U-1 made several "hops" down the runway, but never true flight. It was apparently VERY structurally strong. I have always wondered why they never flew at least a test programs on it. Many designs where the power had to change direction from the crankshaft suffered from vibration. The P-39 / P-63 series comes to mind. The U-joint make a distance noise and vibration. The Osprey comes to mind, as do the experimentals with titlrotors.
The XF5UI-1 was basically a tiltrotor aircraft configuration that did not tilt. That is, the configuration was very similar to later tiltrotors when they were in fixed-wing flight, but the props were small enough to not require tilting for ground clearance.
John Frazer
Airman
- 43
- Apr 21, 2018
Funny they never asked boat designers to make gearboxes/drivetrains. Aviation around that time never seemed to get it right.
As for jets taking over, this is at best a convenient excuse.
The Navy and AF continued using piston/prop planes for combat into the '70s and for support roles into the 80s. Still operating props. a 5500 horsepower powerplant (like on the A2D Sky Shark)for a single contra-prop on a body like the XF5U would have been amazing and still STOL.
A flapjack like the Sikorsky designs would have been awesome with jets -far passing anything for another 20 years. They distracted things with Zimmerman's pet theories about shaping the slip-stream, discarded everything about the Nemeth, Arup, Eshelman, and struggled on trying to make decent STOL planes.
John Frazer
Airman
- 43
- Apr 21, 2018
See also the earlier Payen/Aubrun AP-10, 1935
Much more like these other round planes
from 24 to 107+kts on 40 horsepower. empty 200kg, gross340kg
Attachments
John Frazer
Airman
- 43
- Apr 21, 2018
John Frazer
Airman
- 43
- Apr 21, 2018
John Frazer
Airman
- 43
- Apr 21, 2018
GrauGeist said:
> The Arup S-2... eventually crashed.
That remains unknown. Some reports say it was sold to a stunt-flyer who crashed planes for airshows.
Mid-Atlantic Air Museum in 2015 reported that they received something claimed to be the original S-2, intact. They've not retraced that claim on the post reporting it
By all appearances, the 2 and 4 flew on until age of the airframe retired them.
> The Ford... Model 15-P held solid promise, but the War sidelined the project.
It's crappy performance grounded it, and the war sidelined any future development.
Note that to this day, not a single tail-less all-wing has produced a safe, reliable utilitarian plane that was other than highly risky, experimental, not at all ready for the consumer.
This includes the Horten sport gliders before/during/after the war, the 229, the modern Horten HX-2 with wing-tip fins, and it includes the B-2.
Many designers tried to do so, all gave up on tail-less and on only wing-tip fins, and produced workable planes when they sensibly settled on a center fin/rudder, behind the prop.
The Ford probably would have also.
> The Arup S-2... eventually crashed.
That remains unknown. Some reports say it was sold to a stunt-flyer who crashed planes for airshows.
Mid-Atlantic Air Museum in 2015 reported that they received something claimed to be the original S-2, intact. They've not retraced that claim on the post reporting it
By all appearances, the 2 and 4 flew on until age of the airframe retired them.
> The Ford... Model 15-P held solid promise, but the War sidelined the project.
It's crappy performance grounded it, and the war sidelined any future development.
Note that to this day, not a single tail-less all-wing has produced a safe, reliable utilitarian plane that was other than highly risky, experimental, not at all ready for the consumer.
This includes the Horten sport gliders before/during/after the war, the 229, the modern Horten HX-2 with wing-tip fins, and it includes the B-2.
Many designers tried to do so, all gave up on tail-less and on only wing-tip fins, and produced workable planes when they sensibly settled on a center fin/rudder, behind the prop.
The Ford probably would have also.
Attachments
There might be a few hang glider and powered trike pilots that dispute that.
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
Pretty sure the combat record and performance of the B-2 blows that assumption out of the water...
John Frazer
Airman
- 43
- Apr 21, 2018
Have their planes been certified as airworthy by appropriate authorities, or sold or used long-term by other than the designers and other test pilots, or sport pilots willing to sign waivers and take their chances?
fubar57
General
From here...Hang Gliding Frequently Asked Questions
How safe are hang gliders?
As safe as the person flying them. Like any form of sport aviation, hang gliding can be dangerous if pursued carelessly. Gliders in the US are now certified for airworthiness by the Hang Glider Manufacturers Assn. (HGMA). Also, hang gliding instruction has been standardized and students learn from certified instructors using a thorough gradual training program. Despite these advances, people still make judgment errors and aviation is not very forgiving of such. The majority of pilots fly their entire careers without sustaining a serious injury.
2003...http://www.paraglidingforum.com/files/aw_specs_262.pdf
Germany...https://www.dhv.de/fileadmin/user_u...n/technik/tec_downloads/LTF2009_Eng_final.pdf
How safe are hang gliders?
As safe as the person flying them. Like any form of sport aviation, hang gliding can be dangerous if pursued carelessly. Gliders in the US are now certified for airworthiness by the Hang Glider Manufacturers Assn. (HGMA). Also, hang gliding instruction has been standardized and students learn from certified instructors using a thorough gradual training program. Despite these advances, people still make judgment errors and aviation is not very forgiving of such. The majority of pilots fly their entire careers without sustaining a serious injury.
2003...http://www.paraglidingforum.com/files/aw_specs_262.pdf
Germany...https://www.dhv.de/fileadmin/user_u...n/technik/tec_downloads/LTF2009_Eng_final.pdf
Yes, yes, and yes.
Commercial hang gliding operations are available in many places; maybe not under FAA jurisdiction, but that's not my area of knowledge.
John Frazer
Airman
- 43
- Apr 21, 2018
Hang gliders. Right. "Not under FAA jurisdiction". I did say utilitarian airworthy planes. Ultralights too, though they're not sold as certified planes. Hardly anyone builds lifting bodies or tailed all-wings anyway.
And it does fit the B2. Only 20 made, already being phased out and horribly expensive, all are besides the point of aeronautics I was making.
The crew are highly trained highly paid military officers, probably test pilots in their own, and they only ride sealed into ejection seats so that they can get out at any moment. If they have damage or problems & stall and start to spin, there's nothing for it but to get out, and that's not safe, reliable, utilitarian.
The military has no problem putting crews into horrendous death traps and the contractors and military big-wigs sing their praises and throw money at them to keep them flying.
Which aircraft are you classifying as death traps and based on what criteria?
Cheers,
Biff
Obviously, anything without a tail.
I'm just trying to work out if delta-wing aircraft have tails or not...
Shortround6
Lieutenant General
According to some people what makes the B-2 "work" is that it is controlled by computers with control surface deflections rapid enough (and sometimes small enough) that they could not be applied by a human pilot using mechanical/hydraulic means.
However right or wrong this may be as a design philosophy there are a number of modern aircraft with tails that have stability issues (some designed in) that require computers and/or computer controlled control surfaces in order to remain stable even in level flight. The F-16 is one of them.
And as we are finding out with the 737 Max, even conventional appearing (it has a tail) commercial aircraft are flown by computers with 'suggestions' from the crew as to control surface deflections to achieve certain flight goals (like climbing or diving).
However right or wrong this may be as a design philosophy there are a number of modern aircraft with tails that have stability issues (some designed in) that require computers and/or computer controlled control surfaces in order to remain stable even in level flight. The F-16 is one of them.
And as we are finding out with the 737 Max, even conventional appearing (it has a tail) commercial aircraft are flown by computers with 'suggestions' from the crew as to control surface deflections to achieve certain flight goals (like climbing or diving).
John Fazer,
I have to respectfully disagree with you on a few items.
First, while the stated plan is to retire the B-2s by mid 2030s, I wouldn't hold my breath. Military history shows that programs are routinely cut, modified, and or stopped at the whims of the yearly budget or continuing resolution.
Second, fly by wire (FBW), is here to stay. As said by SR6, the F-16 does not fly without it, even though it has a conventional tail. To be clear, the plane is not controllable with out a functioning FBW system. We lost one on an ocean crossing when a mid air resulted in it losing the radome. The AOA sensors are located there. No sensors, no controllable flight. The North Pacific Ocean is cold in the winter time. I would guess the F22 is the same in that it's unfyable without FBW, and the F35, and probably every new fighter design from now on.
Third, to answer your comments about highly trained, test pilots with no other option but to eject should there be battle damage or problems. Yes, highly trained is good. Uncle Sam gets some big dollar items from your tax dollars and wants to keep them for a long time, and good training is a sound investment. Second, we are taught when a situation warrants jumping out of an aircraft, or as we say, giving it back to the tax payer. However not all situations are covered and that is where airmanship and experience come in. Far more guys have died trying to save an aircraft than have punched out when they should not have.
As for the death traps, I haven't seen one yet.
As for the highly paid officers comment. I look at it from two ways. Firstly the DoD determines what pay is and I think in the end it's based on what's affordable inside the confines of the budget. Secondly, regardless of officer or enlisted, attacking an heavily defended target by air or ground is not done for pay. The picture that comes to mind, is from the back of a landing craft off shore from Normandy, with a bunch a 20 year olds who are about to be landed. Or the guys who routinely do patrols in the Middle East right now. Trust me when I say they don't do it for the money, and the pay isn't enough.
Cheers,
Biff
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
To expand a little on the B-2, the primary issue the Air Force has with it, is the stealth coating which needs constant maintenance - otherwise, it is front-line hardware that fits a mission profile that no other aircraft in the Air Force inventory can do.
Additionally, only one B-2 has ever been lost during flight, and it was due to condensation in one of it's sensors, causing an error in calibration which in turn caused erroneous airspeed and AoA during take-off - a condition the pilots couldn't correct...this all being covered in Buff and SR's posts above.
Additionally, only one B-2 has ever been lost during flight, and it was due to condensation in one of it's sensors, causing an error in calibration which in turn caused erroneous airspeed and AoA during take-off - a condition the pilots couldn't correct...this all being covered in Buff and SR's posts above.
John Frazer
Airman
- 43
- Apr 21, 2018
It's not a question about it fitting the mission, it's about it being a safe forgiving aerodynamic design, and without extensive expensive training and especially computerized control maintaining stability and flyability, it isn't.
Wrong handling and no expensive controls or sensors, and it dies. At least in a 747 or Cessna, you have some kind of chance if things are less than 100% peachy.
That there are finned tailed planes that fly only with expensive controls doesn't change my statement about tailless-all-wings.
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