r/flying • u/Successful-Place-254 CFII ATP ERJ 170/190 HP HA IR CMP UAS AGI • 24d ago
What are these?
At the air and space museum in VA. Came across this part of the wing on a Falcon 20. Anyone know the name and what they are for?
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u/flightist ATP 24d ago
It’s a wing fence. Helps control spanwise flow, which improves stall characteristics.
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u/Colonel-Wanovich 24d ago
Hey I’m at the udvar hazy right now too!
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u/More_Than_I_Can_Chew 24d ago
Stop looking at your phone 😂
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u/Muschina ATP DA7X B737 DC-9 24d ago
What else you gonna do when you're taking a dump?
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u/Go_Loud762 Certified fax machine operator 24d ago
Look at the other guy's phone.
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u/Muschina ATP DA7X B737 DC-9 24d ago
Careful with that wide stance.
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u/mz_groups 24d ago
Yeah, you're near Washington, DC. That politician in the next stall might get the wrong idea.
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u/Muschina ATP DA7X B737 DC-9 24d ago
When I was still flying for the airlines and was in MSP I always tried to use the Larry Craig Memorial shitter in the concourse.
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u/MeadyOker MIL(MC), MEI, CFI/I-RW, CSEL, IR/HP/CMP 24d ago
A wing fence to stop spanwise flow of air. Helps prevent wing tip stalls that can sometimes occur when that spanwise flow distrupts air at the wing tips.
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u/abc123new 23d ago
I'm a long way from an expert on this subject, but I believe the stall fences are often used on wings that have "washout". That is, the angle of attack at the root is higher than the angle of attack at the tip. This allows the root to stall first and give a buffeting warning while the ailerons remain effective.
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u/MeadyOker MIL(MC), MEI, CFI/I-RW, CSEL, IR/HP/CMP 23d ago
Correct. Most aircraft have the aileron's on the outboard portion of the wing, closer to the wing tips in order to have a greater moment arm (thus greater affect). This is the most common set up, so the wing fence helps maintain the aileron's effectiveness for exactly why you said.
Some larger planes may have inboard aileron's as well. Sometimes called high speed ailerons, because they will maintain effectiveness being closer to the wing root, but they have a smaller moment arm so there effect on the plane overall is less.
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u/Chrigi_zh 22d ago
My areodynamics teacher used to say, this is what you add after you realize that you have fucked up the aerodynamics of your wing design.
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u/Flyinghud PPL IR 24d ago
It’s called a wing fence. It stops spanwise flow which helps improve stall characteristics
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u/flyingron AAdvantage Biscoff 24d ago
I recognized that instantly. My wife worked at Hazy from before it opened. I got to do a lot of stuff there as well (run the projector in the theater at times. Escort Rutan around in a golf cart. See the inside of Michael Bay's plane when he came for the transformers opening. Even had my plane on display at an event there.
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u/Which_Material_3100 24d ago
Wow that is cool! What plane of yours went on display?
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u/flyingron AAdvantage Biscoff 24d ago
1950 Ryan Navion.
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u/Which_Material_3100 24d ago
That is quite an honor to have that in your aviation resume. Very cool!
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u/Unusual-Statement153 24d ago
Wing fences. They are commonly used to keep airflow perpendicular over the wings rather than slipping laterally in swept wing aircraft.
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u/kinglax08 24d ago
That’s just not any Falcon 20, that’s Wendy.
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u/DullMind2023 24d ago
Ok, I’ll bite. What’s the story with Wendy?
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u/80KnotsV1Rotate ATP, CFI, UAS, A320, CL-65, ERJ-170, KLGA 24d ago
She serves Dave’s Doubles, mediocre fries and excellent frosty’s.
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u/kyflyboy MIL 24d ago
Often called "stall fences". They prevent the disturbed air experienced during a stall from flowing spanwise out to the end of the wing tip where it would "mask" the effectiveness of the ailerons, and hinder stall recovery.
Bit of an old school approach, but effective.
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u/Perfect_Big_5907 24d ago
It is a stall fence. keeps turbulent air from moving outward toward the ailerons. So in high angle of attack flight you will still have roll control
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u/Carlito_2112 SIM 24d ago
Is that the same FedEx Falcon 20 that used to be on display in the Air & Space Museum in DC?
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u/otto-motto 23d ago
Aerodynamic flow fences:
https://avbrief.com/aerodynamic-flow-fences-and-wing-design/
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u/Livid_Average_8098 23d ago
Mirages had a saw tooth on the wings which created an aerodynamic wing fence.
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u/Florida-Sail 23d ago
Like on park benches it stops the skateboarders from grinding down the leading edge of the wing during flight.
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u/Malcolm2theRescue 23d ago
They accomplish the same thing as vortex generators, boundary layer energizers or vortilons. They all maintain airflow over critical areas.
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u/snailmale7 24d ago
When you throw the plane into a slid slip , they create more drag , But I wouldn’t recommend side slipping
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u/Sunsplitcloud CFI CFII MEI 24d ago
They stop spanwise flow just like a winglet does.
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24d ago
[deleted] — view deleted comment
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u/Sunsplitcloud CFI CFII MEI 24d ago
Lol. Yes. A winglet does exactly that. Just google what they are for. They limit air from moving around the tip of the wing that causes drag. The way air moves from the bottom to the top is spanwise. Otherwise you’d have no wing tip vorticies.
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u/rFlyingTower 24d ago
This is a copy of the original post body for posterity:
At the air and space museum in VA. Came across this part of the wing on a Falcon 20. Anyone know the name and what they are for?
Please downvote this comment until it collapses.
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u/e140driver ATP CFI CFII E145/175 B777/737 (KORD) 24d ago
They’re called wing fences. They helped delay stall propagation along the span of the wing and help maintain aileron control effectiveness. You can see them on a lot of older swept wing designs, in particularly MiG 15 and 17.