What is the Håkan "Stall Vane"? - & First Flapped Landing - Flt 9 - Hakan Modified Lancair Aircraft
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- Опубліковано 24 чер 2024
- What is the "Stall Vane". The first landing with the new custom "fowler" type flaps. And a hydraulic problem.
Check out Håkan's "stall vane" a lower drag alternative to the VGs we saw on flights 7 & 8. You may recognize the idea from the SR22 Cirrus (they call it a fuselage vortex generator). On this flight, we evaluate the handling qualities of the "stall vane".
Thank you for coming along with us. We at Wasabi feel so fortunate to have customers like Håkan willing to share their work and a vibrant community to share that work with. Thank you for your support.
Website: www.wasabiaero.com
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Outline:
00:00 Opening
00:14 Introduction
01:11 Maintenance Briefing
20:15 Test Card Generation
24:52 Ingress, Engine Start, and Taxi
25:35 Preflight Briefing
29:54 Takeoff
30:12 Stalls 45° Flaps, Gear Down
35:51 Stalls 35° Flaps, Gear Down
41:16 Stalls 45° Flaps, Gear Down
44:26 Climb Rate Check - WOT, 45° Flaps, Gear Down
46:37 Climb Rate Check - WOT, 45° Flaps, Gear Down
46:05 Hydraulic Leak
48:17 Slow/Fast Cloverleaf
49:54 Simulated Flapped Approach
51:07 1st Flap Landing 35°/85 KIAS
52:20 Debrief
1:01:46 Outro
---Beginning Test Report---
Flt 009 Flight Report
Summary
Flt Date 12/30/2020
Engine Start: 9:28 LCL
Engine Shutdown: 11:04 LCL
Flt Time: 1.6 HRS
Landings: 1
Fuel State Takeoff: Full Tanks
Total Time After Flight: 7.8 Hrs
Chase: None
Data:
Takeoff MAP 26.2" at 2780 RPM. The throttle/mix/prop levers did not move with the nose gear retraction.
Three stalls at 45° flaps w/ gear down, ~48 KIAS.
Three stalls at flaps 35° w/ gear down, ~50 KIAS.
Three stalls at flaps 45° w/ gear down, ~48 KIAS.
All stalls found to be comparable to the wing/body VG stalls. Perhaps slightly lighter elevator forces w/ the stall vane, but not a problem.
Rate of climb check flaps 45° w/ gear down - WOT @ 2750 RPM and 80 KIAS, 275 FPM.
Rate of climb check flaps 45° w/ gear up - WOT @ 2750 RPM and 80 KIAS, 325 FPM.
2 cloverleafs at 55 KIAS (53 and 56 KGS) at 6,000' and 5°C, 48 KCAS. (indicating high by 15%).
2 cruise cloverleafs at WOT (19.4") and 2500 RPM, ~140 KIAS or 134 KCAS (indicating high by 4%).
The landing was flown w/ 35° flaps and an approach speed of 85 KIAS. The resulting landing was fast with the nose wheel touching first and an associated bounce.
The inner gear door actuator started leaking after the stalls.
After flight, it was determined that the altimeter and MAP indicator were both indicating in error. The altimeter showing ~1,000 feet low, and the MAP showing 1" high as well.
Power Settings/Limits:
Take Off WOT/2700
Climb WOT/2500
Cruise WOT/2500
CHT Limit - 440°F Climb
420°F Cruise
Oil Temp - 215°F
Airpseeds
VS0 - 48 KIAS (42 KCAS)
VS - 55 KIAS (70 KCAS)
Vrot - 83 KIAS (75 KCAS)
VFE - 110 KIAS (100 KCAS)
VLE - 134 KIAS (122 KCAS)
VA - 157 KIAS (143 KCAS)
VNE - 259 KIAS (235 KCAS)
LLF - +3.8g/-1.52g
(flaps up)
+2.0g
(Flaps Down)
Bailout altitude:
Out of control below 5,000
If less than 50% of control remaining RTB
If we can't fly at or below 150 KIAS at 1.5 G with more than 10% of control remaining, bail out.
Maintenance Before Flight
1. VGs removed from wing/body fillet.
2. Installed "Stall vane" fwd of the wing on both sides of the fuselage.
3. Carb heat cable adjusted and cleaned.
4. Intake gaskets replaced and mating surfaces refinished on cylinder 2, 3, and 4.
5. Throttle replaced w/ push-pull style. Routing changed to clear nose gear.
6. Idle adjusted down to 6-800.
7. Fuel drain leak addressed.
8. Half aileron VGs removed.
9. Ipad Cable replaced.
Planned Flight Profile
Engine Start
Take Off
Initial climb 100 KIAS
First Power Reduction WOT/2500
Climb 125 KIAS to '10.5K MSL
45° Flap Extension
3x Flaps 45°-Gear Down Stalls
3x Flaps 35°-Gear Down Stalls
Rate Of Climb check at flaps 45° gear down, WOT 2700 RPM 80 KIAS.
Rate Of Climb check at flaps 45° gear up, WOT 2700 RPM 80 KIAS.
2 Cloverleafs at 1.1 VSO (Gear Down)
2 GPS Cloeverleafs in cruise configuration 8k press altitude, WOT, 2500 RPM.
RTB
Normal approach
Flaps DN landing (35° 85 KIAS)
Squawks:
Recommend different engine monitor with more display area
Recommend different airspeed indicator w/ only knots
Recommend different airspeed indicator ~40 Knots
Brakes Soft
2800 RPM prop governor setting
Inner Gear Door Actuators Leaking
Next Steps:
Start opening the landing envelope with slower approach speeds and more flaps. - Авто та транспорт
“Essentially all models are wrong, but some are useful.” George E.P. Box, one of the great statistical minds of the 20th century.
Spot on, thank you for the comment!!
"To make a long story short because you guys have been sitting here for 50 minutes..." yeah, and? This was awesome!
Very pleased that vane worked so well. It's a cool idea. Watching the tufts along the fillet section was very cool. If I recall right, that section is under a lot of turbulence before the stall, and now it's good flow all the way to the stall. Quite an incredible improvement.
Man, I was really geeking out with you and Hakan discussing how he came up with the stall vanes and located them on his aircraft. And amazing watching how his mod was validated! And the "cool hand" dealing with the hydraulic emergency (and when it's soaking into your backside I'd count that as an emergency!). Yet another great hour spent!
if for only one reason this video is EPIC...if you want to show your students what a stall looks like--HERE IT IS. to watch the wing stall root to tip demonstrating the wing's washout is simply AMAZING
I think I'm going to get some of those sunglasses and the parachute , maybe just wear them in the car to look cool. Good to know where to get them. Great video, the insight into the test program has me glued to the screen every time.
I appreciate that
An hour?! Wow, time to grab a full cup of coffee! Primer is still drying on the wings, so this is a perfect way to pass the time. :-)
Really cool to see the stall progress across the wing.
Thanks man
Took a BASIC cfd class. The model and the setup is a HUGE if. Elliot is very correct in asking questions here!
Love your videos man i believe you are one of the smartest, most level headed pilots alive today. Thanks for sharing with us.
Thanks for saying that
These long format videos are great, thanks for making them
Thanks for saying that
As an engineer and pilot your excitement about this project is infectious. Keep up the rad work!
Thanks man
Thanks for another great video! The blend of test point video, ground ops/briefing, and your post flight elaborative discussion with the camera is a fantastic formula.
I was foot tapping a 4/4 beat with your head tic for the 1 kt/sec deccel rate. Looked good!
Hakan designed a fantastic mod and his list of mx performed between test flights is always a jaw dropping amount of hard work.
The tuft below the stall plate at it's rear was blown over the top of the plate and FORWARD much of the time. The shots of span wise flow when a panel is stalled was extremely illuminating.
Sitting down with a nice cup of tea, I've been looking forward to this since your post.
Thanks man, good to have you along!!
Good to see these numbers behaving as they should, with Håkan's design engineering validated. Was initially concerned that this flight balled up too many new variables with VGs repositioned, stall vane, control linkages, et cetera, but you made it through with the bird only pissing on you. Looking forward to your pattern work and final v speeds. In addition, I'm pretty sure that Håkan's working on how to enhance the top end.
Very nice, great work of Hakan on the Stall Vane. Looking forward to the Flt 10 / "Stol" episode :P
I skipped a few videos in the series, this is such a cool solution to the problem. Glad you it got figured out, I remember seeing his disappointment in the ineffectiveness on the first flight
Lots of work to get here. Glad you came along
Amazing how a small addition can make such a difference. So cool.
Very interesting content, thanks for sharing! I suggest to also put a single tuft right on the tip/trailing of the stall vane. The direction and intensity of the swirling of this tuft could then be used as an indicator to estimate the local incidence with the flow. Ideally it would stop swirling in cruise if the vane incidence is set correctly.
I love to learn so much about aerodynamics on this series, this is just fascinating stuff! Thanks! 🤙🏻
I love this series. They'll end at some point in time so I can only hope you find another great subject to document! GREAT STUFF is COOL!
Loving this series Elliot from an engineering perspective its compelling, Bowers Pony probably a cooler aeroplane but Hakan and yourself are working so well together its awesome
I'm rewatching waiting for some new content, I am still gobsmacked by the difference between this program and the raptor, one guy gets it, the other is penny pinching and a handful to deal with, I know which plane I would trust with my life
What a great project this is turning out to be. Good work!
Absolutely
Very cool! Dream job right there!
A good time for sure
Great vid!
Thank you
The stain is hydraulic fluid.......sure Elliot. You go with that.
This is some Cool Stuff with a Cool Airplane.
I agree!!
Keep on with these awesome videos! Love watching and learning about the process and the science behind it.... currently building an rv 10 in your home state of mi if your ever back around would love to buy you a meal and talk cool stuff.... thanks for all that you do
Sounds like a plan
I like he is modifying it! 👏🏻👏🏻👏🏻
Cool stuff for sure
Hey Elliot. Thanks Bro.
Rich.
Thank you!!
Looks like a great flap set up, those and some VG's on my "Legal Eagle" I could slow flight like a falling feather.... COOL............ always great to get the inside scoop on testing,
hope to see ya at RENO some time........ for your UA-cam followers how about a Quality bright Orange Ball Cap with the Wasabi logo ( you could pick us out in the stands as you flew by .. lol ).
You just be careful young fella , that thing will take off backwards with any more drag
Orange? Why orange? Wasabi is green!
Not sure Green would stand out in the stands at 200 mph... and Sthil is the sponsor ( Stihl Orange ) ... after giving it some more thought............ I like Orange.
@@robertlafnear4865 make it bright and fluorescent enough it will.
Elliot, these are great videos! Thank you for sharing all these. Interesting with the "stall vane" installed, I noticed less air disruption along the aft fuselage the closer you got to the stall. Or at least when the tufts began to flip around a lot closer to the stall break. At least compared to the other videos pre stall vane.
PS) Your cooling video (FLT 4 I think) gave me some great ideas for solving my high CHT issues on my -7A. Especially the cowl flares!
Thanks man. Hakan is a pretty smart fella. Glad you dig!!
That new trim tab will be a beast! Maybe a trim tab for the trim tab is in order 😎
Keep up the great work, I can't wait to see Hakan take her out for a spin! It seems like the right main was slow/hesitant going both up 30:07 and down 30:16 on take-off.
Thanks
Great video series. Keep it up! Interesting names for the "thingy" like stall vane, and Cirrus calling it a fuselage vortex generator. On the big jets the name that seems common is a chine. Like the nacelle chine on a 737 or C-17. Sometimes I see it called a strake. They often play with the size of the chine can help create a stronger vortex to lower stall & approach speeds and for characteristics, but at some point you start taking a hit on cruise drag.
I suggest you guys call it the "Gonkulator". I just wanna hear Håkan say the word Gonkulator.
"oh shit"..............lots of those moments on this channel ;)
Thanks for coming along.
Really interesting to watch the discussions. What kind of engine? Apologies if it's in another video - I have not seen them all. The climb performance seems like it's a bit underpowered, but perhaps it's an o-320 and the aircraft is heavy. Impressive you could get the stall speeds so low. Enjoyed the video!
🤣 I totally get it! If I hear "well it worked in the computer model" one more time at work, I am going to lose my shit! I am a mechanic in an industrial environment and sometimes I swear my job is to overcome engineering shortcomings 😬
It’s a whole thing
“All models are wrong, but some are useful.”
It'd be REALLY interesting to have tiny flush mounted ports on wing surface connected to pressure/vacuum gauges- I've often wondered HOW MUCH low pressure an airfoil produces.
Elliot, Are any slip test with flaps scheduled? The step stall vane vortex generator is working great!
As an engineer who is interested in getting into FTE, I LOVE your videos. Thanks for all the work you put into these, they're great!
Great to have you along. This series in particular scratches so many great FTE itches. Stoked you ended up here, thanks for the comment!
Such an interesting solution! I think I've seen these kind of vanes too at 737 engine nacelles, I think also to re-attach airflow at high AOA that is disturbed by the engine nacelle before it meets the leading edge.
I'm curious about the shape of the leading edge of the vane. It appears to be round. Why not rectangular? Or a delta-wing shape? Also curious what the vanes do in negative AOA (high speed with too much flap)?
Awesome stuff! I love the level of detail in these. Only problem is that it makes me want to own an experimental instead of the certified aircraft that I have today...
My apologies, :)
I would think that having the VGs that close to the leading edge would kill a lot of the laminar flow in that area.
Me too - I'd start moving them back on the next tufted flights. Believe they could be moved back to 50 - 60 %
There's a few shots where it looks like some fluid is escaping from the right main gear - look at 31:21 and 43:27 for example. Hydraulic fluid? Gas from the wing tanks? Or just dirt falling off the extended gear?
Periodically check any fuel strainers/filters for any blockages from the fuel sealant used on the fuel system. Was on a recovery once and came down to too much sealant used and clogged the carburetor inlet screen.
Thanks
@12:45 - Hey, a Ray Allen stick grip! Made in my childhood hometown... And @18:15 - hey, Dynon; right up the road from my current home! :-)
[Nobody tell Mark Jackson that I mentioned name-brands] ;-D
Way awesome, thank you
Given that the stall vanes and VGs are relatively small relative to the wing area, how do the cameras affect flight performance? (I've certainly learned that position is important.) It seems like the cameras are closer to the wing an elevator tips, so would this affect the asymmetry of yaw you observed? This is fascinating.
Excellent. Haven’t noticed but does he have an emergency drop for the undercarriage?
Yes he does
I'd call it a strake, Concorde had those to initiate the huge barrel vortices over the wing at high AoA; but it's also a vane I guess. Most high-bypass-turbofan airliners have those on the engine nacelles to keep the flow attached in the wake of the large engines at high AoA.
In CfD not only does the model have to be accurate, but there are also gremlins in the numerical stability during the calculation. Yes, there's still a lot of uncertainty, and even Boeing used tufts on the 787 during the first flight to validate their CFD results.
How does the yaw string work in the propwash?
What about using a trip strip at the max thickness point, like on gliders vs VGs?
Do strakes on LongEzes have same function as 'thingie'?
Might be dangerous, try a 'thingie' on one side only. Then, during stall, if it falls off to one side consistently...
The tufts on the fuselage are much more stable ie horizontal then where the large vgs were at/close to stall . I thought that the canopy was totally responsible looks like it was the vgs.i forgot that they were there.
Pretty cool stuff
It would be really interesting to actuate the Stall Vane from the fuselage into and out of the air flow while tied to an AOA. In cruise it could be fully retracted, high AOA fully deployed. Do the benefits outweigh the complexity though?
For these geeks? Complexity is probably not an impediment.
What's the purpose of attaching that vane? To lower stall speed? I wonder about doing that on the inboard part of the wing, since it's desirable to have the stall originate on the inboard section and propagate outward. So it must keep the air from separating out to where the stall strip is? That vane won't make the plane faster, and might slow it down some small amount that may not be noticeable. But I wouldn't install it.
All the testing was performed at one CG and weight with no apparent ballast. How will that translate to something closer to gross weight during the dual checkout?
@Elliot, thank goodness the aircraft uses 5606 for hydraulic fluid rather than Skydrol!
ask me how I know this
@@stay_at_home_astronaut hahaha, well said.
@@stay_at_home_astronaut Got a little close to the organophosphates?
Would there be any utility in making the stall vane a controllable surface? Especially when at high AOA, would it be advantageous to be able to drive the vane with a sliding potentiometer mounted to the stick, for instance? Could you delay the onset of stall in a controllable manner?
I mention mounting it to the stick primarily so if the pilot is flying on the edge of a stall he doesn't need to move his hand off of the control to adjust the tab and ride the last bit of air he can find with the vortex generator. Definitely not envisioning this for a guy with 150 hours in a Cessna, rather I'm wondering if this might be useful for airshow guys or other precision flying.
Clearly a fixed surface to potentially save the butts of inexperienced pilots who have gotten too close to the limit of their skill either by accident or mental infarction would be superior for most applications.
What with vacuum gauge?
Isn't your vane concept running contrary to conventional ideas about stall recognition and prevention? I thought it was generally accepted that it is best for a stall to start at the wing root and progress outboard so that pilots can feel the initial buffet while they still have laminar flow and aileron control at the wing tips before a full stall develops?: en.wikipedia.org/wiki/Stall_strips
That being said, in your video, the tufts seem to show that the stall does appear to initiate at the root with the vanes installed.
Could articulate the FVG.... chines? strakes? Roto-rooters? Anyhow, articulate them and gang them with the gear doors. Gear out is de facto "dirty mode", why not save the rest of the 'dirt' for a single configuration?
Also, the stick-on VGs... something Hakan may want to plug into the model is finding the true leading edge at cruising AOA and sticking the VGs at that point. There would be a neutral angle of incidence for the vane itself at that AOA, but as AOA increases the vane angle increases with regards to flow just by geometry. Basically if you can hit them top-on they're much more straight, but turn the wing and the angle comes back for the vortex.
explanation of vortex generator👉🏻 8:10
I am glad you liked it
If there is a small hole in the hydraulic line and the pressure is high enough it may puncture the skin and lead to a nasty type of blood poisoning. Perhaps best to put a small aluminium plate below you if you need to remove the seat and basically sit on the hydraulics?
Thanks, I hadn't considered that.
1:00:19 looks like a shot from a Tarantino movie
Thanks
but if the aoa crosses the cfd you could get an inverted vortex in the aoacfd and come out the result of a que in a vortistic vane that gives off a turbulence in drag well we all no what drag is and no one wants a drag hanging around so in conclusion sort out the vortex and you will see aoa and cfd clearly no need to thank me all good :)
Interesting video, definitely enginery (is that a word). Just curious, I get wearing a helmet, for egress when it’s not so casual, but what about the oxy mask, you have bottled oxygen on your person?
Thanks for the kind words and the question.
I wear the mask for three reasons:
1. Smoke in the cockpit
2. Better comms
3. Crash protection
I can also acknowledge that after the accident it became a bit of a security blanket for me.
More information here: ua-cam.com/video/a-lceaOL2E8/v-deo.html
Nope nope nope... fluid in the cockpit = emergency end of session. Too much risk elliot.
That’s what I was thinking too!
140kts seems slow for a lancair.
Did I forget something?
Thanks for the comment. Yes, cruise speeds are down. This is a puzzle that will take some time to sort out.
Baseline. That's 140 KIAS at 8k pressure altitude. Which is about 180 MPH True.
Then you add the two instrumentation errors we talked about (1k altitude and 1" MAP) and there is more to the whole thing.
Anyway we'll see.
@@utopiasnow I can’t wait to see how it unfolds.
Many thanks for your reply and keep up the great work!
Elliot, this is absolutely fascinating! Awesome work! I could go do stalls all day!
-@right_seat_captain