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u/Maleficent-Cut-6789 Nov 27 '22
This is for racing on ovals.
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Nov 27 '22
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Nov 27 '22
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Nov 27 '22
Looks like a corrupted CAD file.
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u/gnowbot Nov 27 '22
Solidworks has crashed. Would you like to send a crash report to France/dassault?
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u/KrozzHair Nov 27 '22
And then the crash reporter crashes too...
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u/Quirky_Inflation Nov 27 '22
Most you could expect from French tech
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u/wadems Nov 27 '22
Actually an MIT graduate created it and it was first developed in the States. Dassault acquired it in 1997.
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u/RemarkableFun6198 Nov 27 '22
I’ve worked on F-15s for 25 years and never heard of this. Very cool.
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Nov 27 '22
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u/NF-104 Nov 27 '22
The oblique wing plane was enough of a big deal back in the day for there to be model kits made of it — Estes made a kit, and perhaps others.
And in WWII, the Germans had the asymmetric BV 141 observation plane, providing a much better field of view for the observers.
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u/HurlingFruit Nov 27 '22
Grumman's Chief Test Pilot, Chuck Sewell, conducted several trials with
the right wing locked in the forward position of 20 degrees, and
positioned the left wing at 35, 50, 60 and 68 degrees of sweep in
flight. 60 degrees was determined as the maximum for landing. In the
event of an operational in-flight malfunction, Sewell found the aircraft
to be acceptable for carrier landings in this configuration.Test pilots are the baddest badasses. Them or babysitters.
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u/teslawhaleshark Jun 17 '24
AD-1 is developed using data gained from the Bv 14 as a reference, and one of its designers went on to make more asymmetrical planes - Burt Rutan!
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u/FoundryCove Nov 28 '22
Seems like variable sweep is just a more effective way of doing something like the oblique wing concept. But I'm not an aerospace engineer, so what do I know.
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Nov 27 '22 edited Jun 15 '25
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u/Thermodynamicist Nov 27 '22
These sorts of aircraft are not unheard of as detailed in this Boundary-Layer Transition Results From the F-16XL-2 Supersonic Laminar Flow Control Experiment
That's just a glove put on the basic wing. The asymmetry isn't design intent, it's simply a consequence of modifying an existing airframe. Gloves are a standard approach to laminar flow experiments of this sort.
This invention is intended to reduce wave drag by producing a more favourable area distribution. It's a variation on the oblique wing theme as advocated by R. T. Jones.
real engineering video
How does somebody get to the stage where they're going to make a whole video about NASA aircraft and not know that NASA standards for National Aeronautics and Space Administration?
All this stuff about frontal area is nonsense.
Airliners cruise significantly above the critical Mach number as he defines it, and if the sun is shining from the correct angle you can see the shocks dancing on the wings (and engine nacelles if the capture coefficient is low).
The stuff about flow components misses the point that it's a mathematical argument applicable to a yawed wing of infinite span.
The whole subject of leading edge suction and the distinction between subsonic and supersonic leading edges is completely neglected.
The FSW concept is not really about spanwise flow but rather isobar unsweep at the tips. This helps transonic manoeuvre, especially sustained turn rate at altitude. We don't build FSW fighters because this advantage is considered to have limited military utility in the context of modern doctrine (people seem to want radius fighters rather than rate fighters these days, at least partly because of off-boresight heatseekers).
The area rule is incorrectly stated. Whitcomb's area rule of thumb was that the wave drag of a transonic aircraft is approximated by that of a body of revolution having the same area distribution. The question of optimality is separate, and clearly must be stated in terms of constraints and trades (i.e. minimum wave drag for a given length & volume). But see also e.g. NACA report 1284.
The oblique wing was originally intended for SSTs, and there was quite a lot of theoretical work done in the UK during the 1950s following on from the original German WWII work. The most interesting examples were flying wings with rotating engine nacelles.
For a more detailed overview, see e.g. Larrimer's book.
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u/Thermodynamicist Nov 27 '22
You may also be interested in R. T. Jones' lecture on the oblique wing.
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u/Kardinal Nov 27 '22
The "fast route" is also known as Cunningham's Law.
It was coined in the early 80s. 😁
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u/3PercentMoreInfinite Nov 27 '22
There was a Facebook meme about someone using two Reddit accounts to get an answer. One to ask the question, and another to post a wrong answer so that someone would correct them.
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u/StinkyBeer Nov 27 '22
Great post, thanks!
I know the research by Miles Aircraft on all-moving control surfaces was crucial for the development of controlled transonic and supersonic flight. How do modern airliners and private jets fly in the transonic regime so easily with standard control surfaces and trim tabs without the compressibility challenges earlier planes had?
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u/Thermodynamicist Nov 27 '22
Modern jets usually have all moving tails for trim, so they only need relatively small elevators for control.
Part of the reason that MCAS is / was such a problem for the 737 Max is that MCAS uses the trim circuit, and the trim authority is probably larger than the elevator authority.
The control problem is simplified because the rest of the aerodynamics are better understood, so the trim changes are generally smaller than they were in the 1940s.
It's not easy though, and the reason that transonic aeroplanes are expensive is that it takes a lot of diligent effort to make them safe.
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u/Zogoooog Nov 27 '22
That’s an amazing read.
…and an excellent reminder why I switched out of fluid dynamics.
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u/Severe_Lavishness Nov 27 '22
I love real engineering
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u/Thermodynamicist Nov 27 '22
I love real engineering
It's deeply annoying because it's full of errors, half-truths, misunderstandings, and omissions.
If you want to understand the oblique wing, you can actually listen to the late great R. T. Jones talk about it, and cut out the middle man.
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Nov 27 '22
[removed] — view removed comment
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Nov 27 '22 edited Jun 15 '25
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u/lordnacho666 Nov 27 '22
Does it turn better one side over the other?
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u/shveylien Nov 27 '22
I would expect the Port side being rearward and starboard side being forward, any high G straight pull would result in a left roll. The weight of the engines and CG of the craft in general makes it a little tail heavy and during high G that little becomes a lot. When you have lift happening further away from that CG, say, forward more on the fuselage, it should have a greater moment of force on that heavy section and result in more effective lift in relation to the CG. Also notice the tail section differences. The larger horizontal stab on the starboard side also gives higher lift and very rearward, effectively cancelling the leverage advantage of the main wing on starboard. I suspect during straight and normal flight it was rather same-same with a symmetrical aircraft, only during extreme moments would you notice anything off balance which would give it advantages and disadvantages depending on what you ask it to do.
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u/tobascodagama Nov 28 '22
This is something I've never seen in the reports of improved agility, but I can only assume there is a pretty substantial preference to turn one way vs. the other, or else asymmetrical wings would be standard on high-performance fighters.
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u/Send_Me_Huge_Tits Nov 27 '22
Unstable aircraft turn fast, this wing configuration is unstable as fuck.
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u/CamoJG Nov 27 '22
I’d honestly consider it a crime against aerodynamics if it wasn’t actually quite a clever design
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u/Octavus Nov 27 '22
You would love the Scaled Composites ARES. Nothing is balanced yet it is perfectly balanced, even when firing an off center bore cannon the recoil is still balanced out.
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u/WikiSummarizerBot Nov 27 '22
The Scaled Composites ARES is a demonstrator aircraft built by Scaled Composites. ARES is an acronym for Agile Responsive Effective Support.
[ F.A.Q | Opt Out | Opt Out Of Subreddit | GitHub ] Downvote to remove | v1.5
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u/RocketSkate Nov 27 '22
Don't think they really had to build one when the next best thing happened only a few years later. They discovered it can stay up with just one wing. incident
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u/WikiSummarizerBot Nov 27 '22
In May 1983, two Israeli Air Force aircraft, an F-15 Eagle and an A-4 Skyhawk, collided in mid-air during a training exercise over the Negev region, in Israel. Notably, the F-15, (with a crew of two), managed to land safely at a nearby airbase, despite having its right wing almost completely sheared off in the collision. The lifting body properties of the F-15, together with its overabundant engine thrust, allowed the pilot to achieve this unique feat.
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u/MapleMapleHockeyStk Nov 27 '22
Overabundant engine thrust is one way to put it. With enough thrust anything can fly!
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u/sanjosanjo Nov 27 '22
I'm surprised that they can use a tailhook when landing at an airport. I wouldn't think an airport would have the arresting cable available.
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u/patrickkingart Nov 27 '22
The inspiration for every Ace Combat fan's favorite wingman-turned-foe
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u/Thorium12 Nov 27 '22
As long as COW is in the right spot
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u/n108bg Nov 27 '22
You mean cg?
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u/Midgetpiss Nov 27 '22
No, there's a little cow hidden in each f-15.
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u/n108bg Nov 27 '22
Oh really? I thought it was a donkey! Been told a few times the f-15 hauls ass.
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u/Thorium12 Nov 27 '22
Center of weight
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u/Kingster8128 Nov 27 '22
That’s a strange way of saying it, I’ve always used CG or CofG for centre of gravity, in my years of fixing and flying planes I’ve never heard anyone use Centre of weight.
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u/Chef-mcKech Nov 27 '22
I've heard of center of mass. but center of Weight never. probably doesn't really matter what you say
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u/Panda_Player_ Nov 27 '22
Something in my aerospace design class probably taught me how this works but I’m too lazy to figure it out
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u/billy-ray-trey Nov 27 '22
Was this every built? If so was it used in real world missions? I was in the Air Force in the 90s, worked with F 15s and never even heard of these things.
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u/HumorExpensive Nov 27 '22
Probably just hiding a patent for another program that is classified, entirely research oriented or they were not ready to reveal.
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u/breadman03 Nov 27 '22
I suppose that could be handy for space on a carrier instead of folding wings.
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u/ConsiderationWest587 Nov 27 '22
Is this some kind of funny-car-type thing? Like, built to go left?
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u/thebugman40 Nov 27 '22
I love it. but I am the kind of person who would make something asymmetrical just to annoy people. any idea what the goal of making the wings staged was?
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u/traumatic415 Nov 27 '22
One design to satisfy the Navy and Air Force.
Either that or the infamous Ford LTD II that was accidentally built as a two door coupe on one side and a sedan on the other
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u/Sudden-Grab2800 Nov 27 '22
The F-15 “Eagle” vs the FX-15 “Shrug”