Cool. Where is the aircraft pitot/static probe? I couldn't see it in the video. Also is that an anti-servo tab on the back of the horizontal? That's cool. Thanks for sharing Elliot.
The pitot is on the left-wing. Stock position (according to the plans) is the top of the vertical tail. The owner decided thrust effects were too big at this location. Yes, the stabilator has a full span anti-servo tab, with pitch trim biasing. Thank you for the comment.
I'm a bit late to the party, but that's cool. I don't think I've ever seen a cone on a light GA airplane. I've seen Kiel probes on business jet prototypes (serving much the same purpose, but probably a lot more expensive). I only know that Boeing uses cones (and tufts!) on their prototype, even the 787, whereas Airbus uses neither.
Cool vid, yeah planes are cool. Cant say that i like the look of the canopyhandle, sorry. Much prefer bashing the head and leaving it at that then headbaging and poking an eye out for the same price. Very pretty plane tough, side of canopy has a mustang look to it. Grtz!
Eric H good question! First off the problem was indicated airspeed at stall, and it’s hard to fly a cloverleaf at or near stall speed. Second, if we were able to do that it wouldn’t tell us if the problem was the static or the pitot. Thanks for asking.
@@utopiasnow Thanks for the reply. My question was actually about the "hang check" procedure you have to ensure you don't snag the runway lights. It seems like a lot of hassle that could be avoided with a simple calculation. Thinking about it later - it may not be so simple when you factor in wake turbulence and the varying drag coefficients for cones at different attitudes. Since that is not what you are out there to test, a visual check seems like the safest way to avoid all those complexities.
Thanks for asking!! My wife is a hardcore T-18 fan so I may be biased. The T-18 is a great airplane and per dollar its probably better than the RV. HQ wise if you stay in the front of the CG envelope it handles quite well with nice control harmony/power and stability. The aft portion of the CG envelope has some big longitudinal HQ compromises (not unheard of in homebuilts), but I think the RV is much stronger here. And in order to compete with RV utility, you would need that aft portion of the envelope. Let me know if any of that was unclear, and thanks again!!
@@utopiasnow Regarding aesthetics, they were cool, didn't mean to insult. Regarding all flying stabs, I've always wondered on the stability they provide, if they are just pivoting, any change to aoa would just try to push the stick so the surface would adjust, but I saw a big trimtab, so I assume together with that the stab provides "constant force"? really, how does that remain stable? Springs?
@@Oinikis No Problem, I was trying to understand. Regarding the stabilator. I believe Thorp is credited with introducing it to light airplanes but it is common and accepted. Piper has used it quite a bit. The "trim-tab" surface on the horizontal is an anti-servo tab but the center position (vs stab position) can be adjusted by the pilot for a trim effect. Wiki link below, I hope that helps. en.wikipedia.org/wiki/Stabilator
@@utopiasnow The anti-servo tab explains everything, thanks, learned something interesting. Whole stabilator things got me confused, because I saw it on a glider once, and instead of the tab it had a spring, whose neutral position was adjusted by pilot for trimming. neat.
This test was to verify that the new pitot probe didnt change the readings. The series was about fixing a couple intermittent problems with the GPS, the autopilot, and the charging system. Since we were flying anyway I used the time to deal with a problem that was bugging me personally, the stall speed which was engraved on the panel didn't match the indicated airspeed at stall by some 30%. I was interested in what might be causing that.
Cool. Where is the aircraft pitot/static probe? I couldn't see it in the video. Also is that an anti-servo tab on the back of the horizontal? That's cool. Thanks for sharing Elliot.
The pitot is on the left-wing.
Stock position (according to the plans) is the top of the vertical tail. The owner decided thrust effects were too big at this location.
Yes, the stabilator has a full span anti-servo tab, with pitch trim biasing.
Thank you for the comment.
I'm a bit late to the party, but that's cool. I don't think I've ever seen a cone on a light GA airplane. I've seen Kiel probes on business jet prototypes (serving much the same purpose, but probably a lot more expensive). I only know that Boeing uses cones (and tufts!) on their prototype, even the 787, whereas Airbus uses neither.
It was super cool to get to use a trailing cone and publish the results on TH-cam. Thanks for the comment.
Cool vid, yeah planes are cool.
Cant say that i like the look of the canopyhandle, sorry.
Much prefer bashing the head and leaving it at that then headbaging and poking an eye out for the same price.
Very pretty plane tough, side of canopy has a mustang look to it.
Grtz!
Thanks for the comment.
Interesting point about the canopy handle. It ends up pretty far back but that is certainly a valid observation. Thank you.
@@utopiasnow your welcome Elliot, thanks.
Till the next vid, grtz
Why not just calculate the resultant vector of the airspeed and windspeed to get an idea of the worst case offset?
Eric H good question!
First off the problem was indicated airspeed at stall, and it’s hard to fly a cloverleaf at or near stall speed.
Second, if we were able to do that it wouldn’t tell us if the problem was the static or the pitot.
Thanks for asking.
@@utopiasnow Thanks for the reply. My question was actually about the "hang check" procedure you have to ensure you don't snag the runway lights. It seems like a lot of hassle that could be avoided with a simple calculation. Thinking about it later - it may not be so simple when you factor in wake turbulence and the varying drag coefficients for cones at different attitudes. Since that is not what you are out there to test, a visual check seems like the safest way to avoid all those complexities.
Hi Elliot, what are your thoughts on the thorp? Compared to say an RV?
Thanks for asking!! My wife is a hardcore T-18 fan so I may be biased.
The T-18 is a great airplane and per dollar its probably better than the RV.
HQ wise if you stay in the front of the CG envelope it handles quite well with nice control harmony/power and stability.
The aft portion of the CG envelope has some big longitudinal HQ compromises (not unheard of in homebuilts), but I think the RV is much stronger here. And in order to compete with RV utility, you would need that aft portion of the envelope.
Let me know if any of that was unclear, and thanks again!!
Elliot Seguin thanks very much for the reply. It’s certainly a long standing design.
Well this was very A E S T H E T I C, maybe more neon colours would help. BTW, is that horizontal stabilizer an all moving surface?
Thanks, I think?
The Hstab is all flying like most T-18s.
@@utopiasnow Regarding aesthetics, they were cool, didn't mean to insult.
Regarding all flying stabs, I've always wondered on the stability they provide, if they are just pivoting, any change to aoa would just try to push the stick so the surface would adjust, but I saw a big trimtab, so I assume together with that the stab provides "constant force"? really, how does that remain stable? Springs?
@@Oinikis No Problem, I was trying to understand.
Regarding the stabilator. I believe Thorp is credited with introducing it to light airplanes but it is common and accepted. Piper has used it quite a bit.
The "trim-tab" surface on the horizontal is an anti-servo tab but the center position (vs stab position) can be adjusted by the pilot for a trim effect.
Wiki link below, I hope that helps.
en.wikipedia.org/wiki/Stabilator
@@utopiasnow The anti-servo tab explains everything, thanks, learned something interesting. Whole stabilator things got me confused, because I saw it on a glider once, and instead of the tab it had a spring, whose neutral position was adjusted by pilot for trimming. neat.
That cut... :D
Base to final?
Yeah closer than I'd have liked, I think I was getting pretty comfortable. Nice to see how far from the fence I was....terrifying.
What was the purpose of the test?
This test was to verify that the new pitot probe didnt change the readings.
The series was about fixing a couple intermittent problems with the GPS, the autopilot, and the charging system.
Since we were flying anyway I used the time to deal with a problem that was bugging me personally, the stall speed which was engraved on the panel didn't match the indicated airspeed at stall by some 30%. I was interested in what might be causing that.
@@utopiasnow Thanks for that. Thats why Airplanes Are Cool