I little behind on the videos, catching up, just wanted to comment, I love your approach your customers with ideas and suggestions. Instead telling hi to spend $150 on an airspeed indicator, you make suggestions until he figured it out on his own. Its a great management skill. Thank you for posting these.
Another great video! The relationship between you and Hakan is getting more and more interesting. I really love how enthusiastic you both are about his project and how you work together in the briefings. This special vibe between professionals (and professional amateurs) during flight testing is one of the best things about it in my opinion. Airplanes are cool!
@@utopiasnow it was great to observe the airflow indicators, especially at 45 degrees of flap, showing the airflow separation as the aircraft was stalling. I'm both an aircraft engineer and pilot so my brain is constantly looking for all the little 'tells' during all the maneuvers. Enjoyed this one as well. Sorry if my response was a bit geeky.
I too was fascinated by watching the tufts at all the different flap angles, as there is a marked difference in the rate of the propagation of the airflow from the wing root towards the tip dependent upon flap angle setting. Just as fascinating was the lammar flow seperation occuring just after of the widest portion of the Lancair. I would love to have seen how this separation affected the airflow over the tail services. Too bad the inaccuracy of the ASI rendered most of this data useless, as 0 degree flaps had a lower stall speeds than with all the other flap settings. What would have been most helpful in this analysis would have been an accurate VSI in evaluating the validity of the test. As in any anylisis, garbage in = garbage out. Thanks Elliott for another FANTASTIC video! Your enthusiasm and method of approach to aeronautics has relit a long latent fire of creating my own aircraft! -E-
I love seeing the area of the wing behind the vgs still producing lift with good airflow. It's cool to see the suction from the area next to the flow as the stall happens. For a newbie like me this is awesome to see, thanks.
My goal for today was to hit the ground running with work. But then I saw a notification of this video, sigh... 🤣 Thanks again for an awesome video! It's so fascinating to see and learn about the aerodynamics of 0HL 👍🏻
Thanks Elliot........ Looks like this is going much better than the TWERP thing you posted the other day..........I was a bit on the edge of my seat on that one (lol).
I really enjoyed this Hakan series! Is there a flight 10? You mentioned it but maybe I'm missing it, don't see it posted. I'm itching to know how it all turned out!.... also one trivial question that has been on my mind, why do you wear a mask when the hose looks to be connected to nothing? No doubt a good reason, but I can only come up with one theory. Perhaps a video would be interesting all about your flight gear and how you decide when to wear what?
No need to guess what the speed/temperature values are. While on the ground, plumb a manometer into the pitot system. Using pressure, calculate the actual airspeed at the various temperature indications on the ASI. You could also plumb a low-speed ASI into the system and just read what it says when the pitot system is pressurized to a particular temperature on the primary ASI. I have the same problem; I touch down somewhere around 10 degrees. I'd considered adding a second, low-speed ASI for slow flight - possibly with an isolation valve, or better yet, it's own pitot and a pressure relief valve to protect its calibration at high speeds/pressures.
Great comment. Thank you. As I am sure you saw in the video Håkan has hesitated to redo the panel before his flap system is proven. As a result the instrumentation is sub par. As far as the instrumentation Wasabi brings to the table it's important we mention the small scale of this kind of a program. Wasabi ends up being mostly supported by the big customers we can't talk about. These little programs while tremendously rewarding are also very cost sensitive. So the idea of spending many hours integrating thousands of dollars in instrumentation becomes hard to justify. Especially just for a single day of testing. Thanks again
More of a suggestion for Haken to accomplish on his own time. Just need a few feet of vinyl hose full of water to make a manometer. Don't even need to touch the panel. Just stick the end of the hose over the pitot tube.
A classy addition to the panel would be the addition of a Mach-meter. Passengers would be extremely impressed regardless of how fast the aircraft was capable of flying.
Elliot. another great Video! What is with the vacuum suction dropping off each stall on cockpit view? am guessing it is on an engine-driven vacuum pump. was it just dropping back with low engine RPM? Where are you hiding Justin?
Yes engine driven vac pump. My assumption is that is takes time for the engine/pump to spool down and the pneumatics to vent back up. But honestly I haven't spent much time on it.
Elliot, I'm curious. The lower than expected stall speed with 0 flaps, does that indicate the lancair has a better stall speed than advertised already? Or is that likely thanks to some none flap related modifications that Hakan made (or just the VG's even)? I'm just a software engineer who only just got his PPL, but I really enjoy these videos and the level of detail and professionalism, thanks for making them!
These are the questions. The VGs will improve stall behavior even flaps up. But even with that the flaps up stall speed is suspiciously slow. More to come.
Hey Elliot, you're inspiring me to build a light GA experimental flight test data acquisition kit. I envision a device the size of a deck of playing cards with accurate pitot/static and onboard GPS. I would plumb inline with ship pitot/static quickly for missions like this. The goal would be to make it as simple as possible one switch operation to enable Phase 1 testing for the experimental community at large. If that's reinventing the wheel someone please let me know. I've been looking for a fun project idea for a class later this year.
We developed a similar product with Andrew Angelotti and his company called Spin garage five or so years ago. The result is fantastic but more expensive and complicated to install than would work on these types of programs. An important reminder, our current business model (flawed) in most cases puts a test pilot at several jobs per week, spending a day configuring the airplane, getting the data, and deconfiguring the airplane. Yes there are longer more committed programs, but alot of the really fun customers can't bear the burden of many days commitment. For this kind of gig work the idea of spending many hours installing thousands of dollars in equipment can't be justified. That being said our business has consistently changed over the years. It doesn't take very many of a new type of program to radically change how we solve these problems. Thanks for the comment, I hope my response made some sense. -Elliot
@@utopiasnow thanks a bunch for the explanation Elliott. I'll look that project up. I am definitely thinking of something as simple and low cost as practicable to aim at the owner/builder community if even to remove distractions during early phases. Really digging this series with Hakan!
10:12 was the throttle and prop lever vibrating back on their own? Did they move when the gear “thumped” into the wells? Edit: you addressed it later in the video.. thanks!
I’m interested that you would do stalls with asymmetric tufts and vg’s. Gutsiest move I ever saw man, lol. And after watching more of the stalls you performed, the left wing seems to break first in each case. Do you think tufts and VG’s on the right side could be keeping the airflow attached further into the stall?
Another great video, Elliot. From what we can see it doesn't seem like there is much of a stall speed difference between zero degrees and 45 degrees of flaps, which is frigging weird. If the difference comes down to sink rate, then why not eliminate the flaps entirely and just slip to increase the sink rate? It would save effort, save weight, and make the plane both faster and slower. But of course I am being too simplistic. And yet, John Parker had a Glasair III racer built by Jeff Aukland that had no flaps at all and showed the same kind of numbers (not much change). What's the zero flap stall speed for a straight stock Lancair 320? Shouldn't it be the same as this or even a bit less since it stock is lighter?
Bob, great to hear from you. As usual I am impressed by your perspective. I wouldn't say the difference between a flaps up and flaps down stall in this is small. And slips are absolutely effective for getting down to a glideslope. The problem is, as you know some folks are more comfortable in a slip than others. If I learned anything from the last two Hakan flights (currently editing) it's that there is a big difference between a seasoned bush guy hanging off the stall to stop on a 20' gravel bar, and your typical 200 hour 172 pilot. And while the big flaps and the bush tires make the airplane look the part there is no substitute for the skill to taking the airplane to the corner (as well as the risk tolerance). Again great to hear from you.
@@utopiasnow I'm sure you are correct, Elliot, and it's way too late for Hakan to rip out those Fowlers. Still, it argues (as always) for building light. I recall 40 years ago when my 999 lb 150-hp Glasair TD (one of the lightest ever built) was humiliated by an 850 lb. 135-hp W8 Tailwind flown by a more aggressive pilot than I will ever be.
Boy those fowler flaps slow it down !! The extended tips help alot. When she lets go she really lets go! breaks right breaks left but almost all high performance rides do that.
I was wondering, why the focus is generally still on fixed stall speeds and less on AOA. Most stall accidents happen above the published Vs, as the aircraft is in a banking turn (to base or final). Personally, I would wager a bet that flying AOA only and forgetting about speed will yield safer results overall. (I do understand that speeds are legally required.)
The tufts were removed to get to a more representative drag configuration so we could check cruise speed. Yes tufts change boundary layer behavior, but they are so useful we put up with it.
Great video! The R wing camera gives a fantastic look at the longitudinal axis with respect to the horizon in each stall, very neat to see. Is fuel flow affected by MAP, or just directly by mixture setting? Would that be an indication to confirm reduced HP output?
Thanks for the comment. Great point about fuel flow. We learned alot about these issues over the weekend. I apologize but hang on there is more coming.
Wouldn't it be great to have spring-loaded VG's that folded down at any kind of cruise speed, eliminating drag, but popped up at slower speeds, to lower the stall speed? Best of both worlds.
@@utopiasnow I was actually letting my mind run the other day and thought that you can blow a laminar layer (re: NASA and their modified F16 experiment) but if you used a larger port the right way you could create a vortex with an angled stream. That's unfortunately one more thing that would have to be factored into the initial build, that's a lot of plumbing to try and add to the front of an assembled structure... and also assumes you have one hell of an air pump on board, maybe turboprops could swing it natively. If you're that early in design you could just add a bellcrank to the flap linkage internally and use it to pop up some hidden VG features, so they'd only be deployed when they're useful. Then again, just introduced more holes to seal or provide drainage for and require inspection for corrosion issues...
@Elliot - I keep meaning to ask: What do you use to secure your external camera mounts? I keep thinking that I'll need to fab up some thin fiberglass cuffs, but you appear to be using some kind of adhesive... VHB, or something like it?
VHB, I have had pretty good luck below 250 KIAS with a single VHB. With dual stickies I am comfortable into the 400 KIAS range. Beyond that I want something mechanical.
Right after work, another video! Great timing again, thanks! And at first glance less sound-effects, thanks! Quick question: you say around 3:00 you have now demonstrated that the static indication error was fixed. Did you also demonstrate that for higher speeds? If so, how? Or is higher speed generally not a problem? Can you elaborate on this a little bit?
My apologies. The point I was trying to make at 3:00 was that the bulk of the confusion from the initial stall testing could be explained with static error, and the new location is much better. That being said there is still error. The question now is the error on the high side. Which we are learning a lot about. Thanks for the question.
Airspeed indicator error seems to be a common problem with these experimentals. Would it be worth investing in the BOM pod and a variety of inspection plate mounts?
The BOM pod is super cool and solves a lot of the problems but not all of them. Spin garage makes a cool similar product. The problem typically isn't the total pressure side, its the static. Thanks for the comment!
"Oh 80 then we take the VG's off" made me laugh hard. How do the stalls feel? It does seem to roll of a bit, but that might be that it is looking more aggressive on camera. I hope that the cruise speed comes back as well, did you notice any difference in fuel flow at WOT compared to last time?
Thanks for pointing out that moment. I was worried it came off as snarky but as far as taking the audience along I think it's an important moment. More dynamic, yes. The last few VGs on the outboard portion of the wing I think are the reason. It's amazing the difference they make. Thanks for the thoughtful comment.
Quick question, I noticed that the suction gauge was low at 13:54 and that it was "ship static", what were your power settings? Also would the suction still read between 4-5 once at idle? Absolutely Love this series..
Thanks for the comment, great to hear from you! I haven't spent much time with this topic but yes the vacuum pump is engine driven and it takes some time after pulling the power back for the engine to spin down and the system to leak up to atmospheric pressure. Also on the 10" MAP points the engine didn't spin all the way down.
I have built a digital ASI, extremely accurate even at low speeds, and very inexpensive. Can be velcroed to the panel. I would gladly donate one to wasabi.
Thanks for that. Sounds very useful. I would be happy to tell people about the source of such product if we had it. Meanwhile it's worth noting that the Wasabi business model involves many short visits to customers a week. As a result we need to be able to configure and deconfigure (and fly) in the same day. So breaking into the P/S system may not be a feasible option. But I am eager to try new things.
@@utopiasnow i understand that fiddling with the P/S system might not be always possible. another option would be a wireless pitot/static to stick to the wing. i started playing with that some time ago. the electronic part is not complicated at all, but i do not have the skills to design a proper static port integrated in the pitot/transmitter. here you can see the prototype of my electronic ASI, is right on top of the Dynon D10A, it also has 6 lights of different color that indicate the correct approach speeds (1.3 Vs, settable of course) the sensor is separate, ASI can be powered by a battery and is simply attached to the panel with tape. ua-cam.com/video/Fr622hOJqL4/v-deo.html here a unit i built for a friend, will go in the rear place of a vari-eze gianmarco.dyndns.org/public/asi1.jpg the sensor in use is good to 220kts
Ok so Elliot, I just purchased myself a Glasair SII-TD O-360 180hp CSU. The aircraft doesn’t have the best flight manuals in comparison and I want to nerd it up. I want to do things like determine what my minimum radius turn is. My co-efficient of lift, drag profile. lift drag ratios, climb and glide performance. I want to make all the graphs. In other words, I’d love to learn the techniques that test pilots use to determine all of these things, both practical and theoretical. I have “Aerodynamics for Naval Aviators” Do you recommend any other good books or places I can go to learn more? Kind regards.
Aerodynamics for Naval Aviators is a great text. That being said none of this stuff is secret. there are newer methods but the old methods work too. As far as places to go, I can't say enough about the National Test Pilot School in Mojave. Well worth a visit. Let me know how we can help!!
From a lay persons point of view I find it interesting that the tufts on the wing get blown forward before any of the tufts on the flaps are moving. Is this normal?
I’m after a 4-6 seataircraft that has a 200KT cruise burning no more than 40lph, complete STOL capability with a stall of 30KTS. And all for under 200k. Is that too much to ask?😄
Awesome! I look forward to every one! Maybe a dumb question? Would a spedo app on a small tablet show anything useful? I have one on a 7" tablet I've used in my truck and golf cart (it's slightly modified LOL). The app acquires 7 satellites and determines the best 3-4 to use. Then displays, and records w/ time stamps in MPH or KPH. Pretty simple. Maybe not accurate speed, but consistent numbers? Just a thought... Thanks for sharing!!! 8) --gary Ps; Might work on an android phone also??
Thanks for the comment. GPS speed absolutely has value. The biggest problem for the stall stuff is the update rate is so slow. The GPS reports position a couple times per second. Then the change in position is used to compute speed. Then that speed is posted at whatever the instrument refresh rate is. The result is it's hard to know what's what. Meanwhile all part 23 stall stuff is designed using a pneumatic based speed indication system. Hakan and I have debated this alot so I don't mean to sound directive, but I personally question the value. Thanks again.
@@utopiasnow I guess I was thinking it could provide an independent number, taking the ships systems out of the calculation, to compare the 2 readings to. It could be 60 beans v 54 beans, then how each MPH/KPH number compared. A calibration of sorts? I used a Samsung 7" tablet, and it would use 3 of 7 satellites it acquired for readings. It seemed fast and smooth (I don't have numbers), and would record in numbers or graph format w/time. It was a 'free' app at the M$ (Microsoft) play site. Again just a thought, just wanted to explain the whole thought. Thanks Ell.! 8) --gary
Cool question. I start as high as we dare and stop high enough to stall-depart-attempt a recovery and bail out safely. On this flight I started the point at 10.5K and stopped stalling before going through 6.5K.
@@utopiasnow awesome thanks! Does the stall behaviour change much over that window? On a career question, how much flying did you have before you started flight testing? What sort of flying had you done as well as how much of it?
37:53 "I would fly approach similar to an RV... 80kts".... Ha ha yes at slow speeds an RV can sink but the stall speed of an RV-7 or RV-8 is 58 mph (50 knots). Vs x 1.3 would be 75 mph (66 kts) which is a fine approach speed no excess sink or AOA..... 80 kts (92 mph)? Ha ha, That is 15 mph faster than needed. *Sink or no sink he rags on the RV because he now realizes after all this work the RV is still a better plane with slower stall and the same or similar top speed.... with FIXED GEAR! Not to mention the RV has better control feel and does aerobatics better and TO/Lds in shorter distances... .*
Geez mate - this is so meticulous- wish Pete at Raptor would quit trying to do his own test flying and figure out a way to move out to Mojave n hire wasabi- no harm in wishful thinking!
I little behind on the videos, catching up, just wanted to comment, I love your approach your customers with ideas and suggestions. Instead telling hi to spend $150 on an airspeed indicator, you make suggestions until he figured it out on his own. Its a great management skill. Thank you for posting these.
Awesome to see that there's generally more smiling as these flights progress. a good visual indicator :)
Hahaha, thats a great indicator. thank you for the observation!!!
Another great video! The relationship between you and Hakan is getting more and more interesting. I really love how enthusiastic you both are about his project and how you work together in the briefings. This special vibe between professionals (and professional amateurs) during flight testing is one of the best things about it in my opinion. Airplanes are cool!
Thanks Robert. If we didnt find this part fun I might be worried I was in the wrong business.
i think I'm going to enjoy this before it's finished. I have a cup and tea and sitting down.
Thanks, let me know what you think.
@@utopiasnow it was great to observe the airflow indicators, especially at 45 degrees of flap, showing the airflow separation as the aircraft was stalling. I'm both an aircraft engineer and pilot so my brain is constantly looking for all the little 'tells' during all the maneuvers. Enjoyed this one as well. Sorry if my response was a bit geeky.
I too was fascinated by watching the tufts at all the different flap angles, as there is a marked difference in the rate of the propagation of the airflow from the wing root towards the tip dependent upon flap angle setting. Just as fascinating was the lammar flow seperation occuring just after of the widest portion of the Lancair. I would love to have seen how this separation affected the airflow over the tail services.
Too bad the inaccuracy of the ASI rendered most of this data useless, as 0 degree flaps had a lower stall speeds than with all the other flap settings. What would have been most helpful in this analysis would have been an accurate VSI in evaluating the validity of the test.
As in any anylisis, garbage in = garbage out. Thanks Elliott for another FANTASTIC video! Your enthusiasm and method of approach to aeronautics has relit a long latent fire of creating my own aircraft! -E-
I love seeing the area of the wing behind the vgs still producing lift with good airflow. It's cool to see the suction from the area next to the flow as the stall happens. For a newbie like me this is awesome to see, thanks.
I am glad you came along!!
So interesting to see the progress on this. Great stuff Elliot 👌
Thanks for coming along
My goal for today was to hit the ground running with work. But then I saw a notification of this video, sigh... 🤣 Thanks again for an awesome video! It's so fascinating to see and learn about the aerodynamics of 0HL 👍🏻
Thanks for saying that. I am glad you came along!
Lol 9:30 I was thinking to myself “was that a Merlin / Mustang?” Nah, what are the odds of that.
....end of video, shows mustang taxiing 🤣
Really enjoyed this video! It is really cool watching you two figure the performance numbers out. Great “nerdy” engineer stuff. Airplanes are cool!
Glad you enjoyed it! Thanks for the comment.
I’m at work when this vlog hit my notifications. Looks like I gotta go find myself someplace to hide and watch! 😈
Let me know what you think!
This is fantastic to watch the testing process. Fascinating to see how the sausage is made so to speak
Thanks for saying that. This engineer struggles with the story telling side.
Thanks Elliot........ Looks like this is going much better than the TWERP thing you posted the other day..........I was a bit on the edge of my seat on that one (lol).
Yeah, very different programs.
Great stuff Elliot, really look forward to your updates as you work through this program 👍👍👍
Thanks Elliot.
Rich.
:)
A great one! @Elliot was wondering if the tufts close to the static port could add to position error ?
Great point, and absolutely yes.
I really enjoyed this Hakan series! Is there a flight 10? You mentioned it but maybe I'm missing it, don't see it posted. I'm itching to know how it all turned out!....
also one trivial question that has been on my mind, why do you wear a mask when the hose looks to be connected to nothing? No doubt a good reason, but I can only come up with one theory. Perhaps a video would be interesting all about your flight gear and how you decide when to wear what?
Unreal video. Thanks Elliot!
Thanks Greg. I appreciate you coming along.
Great stuff!
Thanks man
No need to guess what the speed/temperature values are. While on the ground, plumb a manometer into the pitot system. Using pressure, calculate the actual airspeed at the various temperature indications on the ASI. You could also plumb a low-speed ASI into the system and just read what it says when the pitot system is pressurized to a particular temperature on the primary ASI. I have the same problem; I touch down somewhere around 10 degrees. I'd considered adding a second, low-speed ASI for slow flight - possibly with an isolation valve, or better yet, it's own pitot and a pressure relief valve to protect its calibration at high speeds/pressures.
Great comment. Thank you.
As I am sure you saw in the video Håkan has hesitated to redo the panel before his flap system is proven. As a result the instrumentation is sub par.
As far as the instrumentation Wasabi brings to the table it's important we mention the small scale of this kind of a program. Wasabi ends up being mostly supported by the big customers we can't talk about. These little programs while tremendously rewarding are also very cost sensitive. So the idea of spending many hours integrating thousands of dollars in instrumentation becomes hard to justify. Especially just for a single day of testing.
Thanks again
More of a suggestion for Haken to accomplish on his own time. Just need a few feet of vinyl hose full of water to make a manometer. Don't even need to touch the panel. Just stick the end of the hose over the pitot tube.
Another English tea head here. This is definitly a 2 cup video ( that's a big compliment ) .
Thanks for saying that. I am glad it was worth your time.
Excellent. Very enjoyable.
Thanks man.
What was going on with the vac/suction gauge that it should sit so low.!
A classy addition to the panel would be the addition of a Mach-meter. Passengers would be extremely impressed regardless of how fast the aircraft was capable of flying.
Cool plane, ran great and didn't break. =)
Truth
Elliot. another great Video!
What is with the vacuum suction dropping off each stall on cockpit view? am guessing it is on an engine-driven vacuum pump. was it just dropping back with low engine RPM?
Where are you hiding Justin?
Yes engine driven vac pump. My assumption is that is takes time for the engine/pump to spool down and the pneumatics to vent back up. But honestly I haven't spent much time on it.
And Justin has been deployed on a test program. Excited to have him back in the mix soon.
Elliot, I'm curious. The lower than expected stall speed with 0 flaps, does that indicate the lancair has a better stall speed than advertised already? Or is that likely thanks to some none flap related modifications that Hakan made (or just the VG's even)? I'm just a software engineer who only just got his PPL, but I really enjoy these videos and the level of detail and professionalism, thanks for making them!
These are the questions. The VGs will improve stall behavior even flaps up. But even with that the flaps up stall speed is suspiciously slow. More to come.
Who makes those cool sunglasses with the skeletonized temples?
Method Seven!!
Hey Elliot, you're inspiring me to build a light GA experimental flight test data acquisition kit. I envision a device the size of a deck of playing cards with accurate pitot/static and onboard GPS. I would plumb inline with ship pitot/static quickly for missions like this. The goal would be to make it as simple as possible one switch operation to enable Phase 1 testing for the experimental community at large. If that's reinventing the wheel someone please let me know. I've been looking for a fun project idea for a class later this year.
We developed a similar product with Andrew Angelotti and his company called Spin garage five or so years ago. The result is fantastic but more expensive and complicated to install than would work on these types of programs.
An important reminder, our current business model (flawed) in most cases puts a test pilot at several jobs per week, spending a day configuring the airplane, getting the data, and deconfiguring the airplane. Yes there are longer more committed programs, but alot of the really fun customers can't bear the burden of many days commitment. For this kind of gig work the idea of spending many hours installing thousands of dollars in equipment can't be justified.
That being said our business has consistently changed over the years. It doesn't take very many of a new type of program to radically change how we solve these problems.
Thanks for the comment, I hope my response made some sense. -Elliot
@@utopiasnow thanks a bunch for the explanation Elliott. I'll look that project up. I am definitely thinking of something as simple and low cost as practicable to aim at the owner/builder community if even to remove distractions during early phases. Really digging this series with Hakan!
Elliot I thought those tufts were bugs when I first saw them!
Hahaha
Why throttle and mix moves with gear retraction? 😅
10:12 was the throttle and prop lever vibrating back on their own? Did they move when the gear “thumped” into the wells?
Edit: you addressed it later in the video.. thanks!
Thanks for the thoughtful question. I like knowing you are watching.
Could someone explain the “reversal” observed in the power off stalls? Tia
I’m interested that you would do stalls with asymmetric tufts and vg’s. Gutsiest move I ever saw man, lol. And after watching more of the stalls you performed, the left wing seems to break first in each case. Do you think tufts and VG’s on the right side could be keeping the airflow attached further into the stall?
Great stuff, thank you!! Short answer is yes, tufts change the flow around the wing.
Another great video, Elliot. From what we can see it doesn't seem like there is much of a stall speed difference between zero degrees and 45 degrees of flaps, which is frigging weird. If the difference comes down to sink rate, then why not eliminate the flaps entirely and just slip to increase the sink rate? It would save effort, save weight, and make the plane both faster and slower. But of course I am being too simplistic. And yet, John Parker had a Glasair III racer built by Jeff Aukland that had no flaps at all and showed the same kind of numbers (not much change).
What's the zero flap stall speed for a straight stock Lancair 320? Shouldn't it be the same as this or even a bit less since it stock is lighter?
Bob, great to hear from you. As usual I am impressed by your perspective. I wouldn't say the difference between a flaps up and flaps down stall in this is small. And slips are absolutely effective for getting down to a glideslope. The problem is, as you know some folks are more comfortable in a slip than others.
If I learned anything from the last two Hakan flights (currently editing) it's that there is a big difference between a seasoned bush guy hanging off the stall to stop on a 20' gravel bar, and your typical 200 hour 172 pilot. And while the big flaps and the bush tires make the airplane look the part there is no substitute for the skill to taking the airplane to the corner (as well as the risk tolerance).
Again great to hear from you.
@@utopiasnow I'm sure you are correct, Elliot, and it's way too late for Hakan to rip out those Fowlers. Still, it argues (as always) for building light. I recall 40 years ago when my 999 lb 150-hp Glasair TD (one of the lightest ever built) was humiliated by an 850 lb. 135-hp W8 Tailwind flown by a more aggressive pilot than I will ever be.
@@robertcringely7348 Boy doesn't that just sum it all up. Cool stuff.
Boy those fowler flaps slow it down !! The extended tips help alot. When she lets go she really lets go! breaks right breaks left but almost all high performance rides do that.
Awesome
Cool. The camera probably distorts what we see, but is the AoA @ stall with these big flaps pretty standard compared to the stock Lanceair? Cheers.
The nose is actually really low. Wait until you see what we did over the weekend.
I was wondering, why the focus is generally still on fixed stall speeds and less on AOA. Most stall accidents happen above the published Vs, as the aircraft is in a banking turn (to base or final).
Personally, I would wager a bet that flying AOA only and forgetting about speed will yield safer results overall.
(I do understand that speeds are legally required.)
What happened to you? Haven't seen a new video in a long time from you !
Let me get in my head....So the tufts were causing an error at what point or ?...Thanks Elliot
The tufts were removed to get to a more representative drag configuration so we could check cruise speed. Yes tufts change boundary layer behavior, but they are so useful we put up with it.
Great video! The R wing camera gives a fantastic look at the longitudinal axis with respect to the horizon in each stall, very neat to see. Is fuel flow affected by MAP, or just directly by mixture setting? Would that be an indication to confirm reduced HP output?
Thanks for the comment. Great point about fuel flow. We learned alot about these issues over the weekend. I apologize but hang on there is more coming.
Wouldn't it be great to have spring-loaded VG's that folded down at any kind of cruise speed, eliminating drag, but popped up at slower speeds, to lower the stall speed? Best of both worlds.
Yes, that would be super cool.
@@utopiasnow I was actually letting my mind run the other day and thought that you can blow a laminar layer (re: NASA and their modified F16 experiment) but if you used a larger port the right way you could create a vortex with an angled stream. That's unfortunately one more thing that would have to be factored into the initial build, that's a lot of plumbing to try and add to the front of an assembled structure... and also assumes you have one hell of an air pump on board, maybe turboprops could swing it natively.
If you're that early in design you could just add a bellcrank to the flap linkage internally and use it to pop up some hidden VG features, so they'd only be deployed when they're useful. Then again, just introduced more holes to seal or provide drainage for and require inspection for corrosion issues...
When do we get see flight 9?
Have him stick a G5 standby for now! He can always repurpose it later in the upgraded panel.
Loud and clear. thanks for the comment
@Elliot - I keep meaning to ask: What do you use to secure your external camera mounts? I keep thinking that I'll need to fab up some thin fiberglass cuffs, but you appear to be using some kind of adhesive... VHB, or something like it?
VHB, I have had pretty good luck below 250 KIAS with a single VHB. With dual stickies I am comfortable into the 400 KIAS range. Beyond that I want something mechanical.
Right after work, another video! Great timing again, thanks! And at first glance less sound-effects, thanks!
Quick question: you say around 3:00 you have now demonstrated that the static indication error was fixed. Did you also demonstrate that for higher speeds? If so, how? Or is higher speed generally not a problem? Can you elaborate on this a little bit?
My apologies. The point I was trying to make at 3:00 was that the bulk of the confusion from the initial stall testing could be explained with static error, and the new location is much better. That being said there is still error. The question now is the error on the high side. Which we are learning a lot about. Thanks for the question.
@@utopiasnow No worries! Thanks for the answer! Curious to see what the future conclusions about the static locations will be.
@@RoelBaardman This last weekend was very interesting. Editing now.
Airspeed indicator error seems to be a common problem with these experimentals. Would it be worth investing in the BOM pod and a variety of inspection plate mounts?
The BOM pod is super cool and solves a lot of the problems but not all of them. Spin garage makes a cool similar product. The problem typically isn't the total pressure side, its the static.
Thanks for the comment!
Lancair bush plane!
Would be cool
Six Shooter cameo.
Good eye!! Thanks for the comment.
Cool Elliot, I am curious about the size of the VG's. Those seem really big. Thanks for the schooling!
They are big, Hakan made them himself. Super rad.
@@utopiasnow Cool engineer stuff right there.
"Oh 80 then we take the VG's off" made me laugh hard.
How do the stalls feel? It does seem to roll of a bit, but that might be that it is looking more aggressive on camera.
I hope that the cruise speed comes back as well, did you notice any difference in fuel flow at WOT compared to last time?
Thanks for pointing out that moment. I was worried it came off as snarky but as far as taking the audience along I think it's an important moment.
More dynamic, yes. The last few VGs on the outboard portion of the wing I think are the reason. It's amazing the difference they make.
Thanks for the thoughtful comment.
Quick question, I noticed that the suction gauge was low at 13:54 and that it was "ship static", what were your power settings? Also would the suction still read between 4-5 once at idle? Absolutely Love this series..
Thanks for the comment, great to hear from you! I haven't spent much time with this topic but yes the vacuum pump is engine driven and it takes some time after pulling the power back for the engine to spin down and the system to leak up to atmospheric pressure. Also on the 10" MAP points the engine didn't spin all the way down.
@@utopiasnow Appreciate you responding, hoping all is well and looking for the day where I can see you again. Clearest of skies my friend.
I have built a digital ASI, extremely accurate even at low speeds, and very inexpensive. Can be velcroed to the panel. I would gladly donate one to wasabi.
Thanks for that. Sounds very useful. I would be happy to tell people about the source of such product if we had it. Meanwhile it's worth noting that the Wasabi business model involves many short visits to customers a week. As a result we need to be able to configure and deconfigure (and fly) in the same day. So breaking into the P/S system may not be a feasible option. But I am eager to try new things.
@@utopiasnow i understand that fiddling with the P/S system might not be always possible. another option would be a wireless pitot/static to stick to the wing. i started playing with that some time ago. the electronic part is not complicated at all, but i do not have the skills to design a proper static port integrated in the pitot/transmitter.
here you can see the prototype of my electronic ASI, is right on top of the Dynon D10A, it also has 6 lights of different color that indicate the correct approach speeds (1.3 Vs, settable of course)
the sensor is separate, ASI can be powered by a battery and is simply attached to the panel with tape.
ua-cam.com/video/Fr622hOJqL4/v-deo.html
here a unit i built for a friend, will go in the rear place of a vari-eze
gianmarco.dyndns.org/public/asi1.jpg
the sensor in use is good to 220kts
Ok so Elliot, I just purchased myself a
Glasair SII-TD O-360 180hp CSU.
The aircraft doesn’t have the best flight manuals in comparison and I want to nerd it up.
I want to do things like determine what my minimum radius turn is. My co-efficient of lift, drag profile. lift drag ratios, climb and glide performance. I want to make all the graphs.
In other words, I’d love to learn the techniques that test pilots use to determine all of these things, both practical and theoretical.
I have “Aerodynamics for Naval Aviators”
Do you recommend any other good books or places I can go to learn more?
Kind regards.
Aerodynamics for Naval Aviators is a great text. That being said none of this stuff is secret. there are newer methods but the old methods work too. As far as places to go, I can't say enough about the National Test Pilot School in Mojave. Well worth a visit. Let me know how we can help!!
From a lay persons point of view I find it interesting that the tufts on the wing get blown forward before any of the tufts on the flaps are moving. Is this normal?
Normal might be a tough question, but it's not surprising. Thanks for the comment.
I may have missed it, but what was the density altitude at 7k ft for these tests?
I didn't include it in the video. But you bring up a great point that came up on this past weekends flight.
I’m after a 4-6 seataircraft that has a 200KT cruise burning no more than 40lph, complete STOL capability with a stall of 30KTS.
And all for under 200k. Is that too much to ask?😄
hahaha, awesome.
Awesome! I look forward to every one! Maybe a dumb question? Would a spedo app on a small tablet show anything useful? I have one on a 7" tablet I've used in my truck and golf cart (it's slightly modified LOL). The app acquires 7 satellites and determines the best 3-4 to use. Then displays, and records w/ time stamps in MPH or KPH. Pretty simple. Maybe not accurate speed, but consistent numbers? Just a thought... Thanks for sharing!!! 8) --gary Ps; Might work on an android phone also??
Thanks for the comment. GPS speed absolutely has value. The biggest problem for the stall stuff is the update rate is so slow. The GPS reports position a couple times per second. Then the change in position is used to compute speed. Then that speed is posted at whatever the instrument refresh rate is. The result is it's hard to know what's what. Meanwhile all part 23 stall stuff is designed using a pneumatic based speed indication system. Hakan and I have debated this alot so I don't mean to sound directive, but I personally question the value.
Thanks again.
@@utopiasnow I guess I was thinking it could provide an independent number, taking the ships systems out of the calculation, to compare the 2 readings to. It could be 60 beans v 54 beans, then how each MPH/KPH number compared. A calibration of sorts? I used a Samsung 7" tablet, and it would use 3 of 7 satellites it acquired for readings. It seemed fast and smooth (I don't have numbers), and would record in numbers or graph format w/time. It was a 'free' app at the M$ (Microsoft) play site. Again just a thought, just wanted to explain the whole thought. Thanks Ell.! 8) --gary
Do you climb back to a test altitude after each stall?
Cool question. I start as high as we dare and stop high enough to stall-depart-attempt a recovery and bail out safely. On this flight I started the point at 10.5K and stopped stalling before going through 6.5K.
@@utopiasnow awesome thanks! Does the stall behaviour change much over that window?
On a career question, how much flying did you have before you started flight testing? What sort of flying had you done as well as how much of it?
Fwiw, my kanardia horis reliably indicates down to 18mph. My G5 down to about 30mph.
Fantastic, thank you
Is anyone going to start making Lancair RG kits again?
I don't know of anyone building them.
37:53 "I would fly approach similar to an RV... 80kts".... Ha ha yes at slow speeds an RV can sink but the stall speed of an RV-7 or RV-8 is 58 mph (50 knots). Vs x 1.3 would be 75 mph (66 kts) which is a fine approach speed no excess sink or AOA..... 80 kts (92 mph)? Ha ha, That is 15 mph faster than needed. *Sink or no sink he rags on the RV because he now realizes after all this work the RV is still a better plane with slower stall and the same or similar top speed.... with FIXED GEAR! Not to mention the RV has better control feel and does aerobatics better and TO/Lds in shorter distances... .*
Thanks for the comment, always great to have your comments on the channel. What is your design/build experience?
@@utopiasnow I know you are fibbing, but thank you.
Not fibbing, you seem to have a background in design and build of airplanes. I am curious to know more.
That airplane needs a modern EFIS
It does for sure.
3 disliked haters must be Raptor fans lol just kidding! The Raptor seems to be working the bugs out.
Hahaha, I hadn't considered that. Thanks for the note.
🛩🛩🛩
Thanks man
What are these comments
Yeah it's super weird, I try to catch them and delete them when they show up.
Geez mate - this is so meticulous- wish Pete at Raptor would quit trying to do his own test flying and figure out a way to move out to Mojave n hire wasabi- no harm in wishful thinking!