This is the most excellent explanation of ground effect I have seen. Good on you, Larry. Yes, in powerful airplanes we have to push hard against the trim set for takeoff. In the lower powered 170, notice how Larry push/pulls just a bit dynamically and proactively to bracket level in low ground effect. Lower powered airplanes will want to return to earth. We want neither to touch down again nor to stay at the high pitch attitude required to get off when still slow. The practice you mention in ground effect on long runways, what I call hover taxi, is very important. We get so little time at less than Vso in ground effect on every normal landing. Thanks Larry. We all need to learn how to use ground effect effectively. It is just good total energy management. We don't need it until we need it...and then we wish we had used it by default.
This is very similar to being towed in a glider. The second you lift off, especially in a high performance glider, you must push the stick forward so as not to rise above the tow plane (which most often is still on the ground). And until you get used to it, it surprises you how much you have to push. Very useful video. Thanks
It would be interesting to see some tests of a takeoff using ground effect purposefully vs doing a normal short field takeoff and climb at Vx. I have not seen anything that shows that using ground effect is advantageous in this scenario as the higher speed means more drag as compared to just climbing out at Vx. I would love to see an actual comparison on the same runway and same conditions to see which technique works best to clear a 50’ obstacle and which provides the most altitude say 1 mile from the start of the takeoff roll.
Larry will get the data for you. Notice, however, that crop dusters (sorry Ag now) use low ground effect on every takeoff. We clear the 50' obstacle on every swath run with what Wolfgang, in Stick and Rudder, calls zoom reserve airspeed. Why does he recommend trying to hit the tree and then zoom over? Because it is safer to zoom over with the outcome never in doubt. It comes from low altitude orientation where being able to maneuver around things is just as important and being up high. Vx will get us high enough to kill ourselves in the stall/fall very quickly should the engine quit or we get startled somehow.
@@jimmydulin928 Yes, many factors come into play. Wind is also a factor. In calm conditions, you won’t gain headwind with altitude, but with any amount of headwind you will. Since wind speed generally increases dramatically with height above the surface, climbing into a headwind can be very advantageous and I suspect staying in ground effect in that case might leave performance on the table. However, without actually testing that, it is hard to know all of the subtleties.
@@LTVoyager Yes, we fly in rivers of air. In the mountains, especially, down drainage egress can be even more important that wind management, especially with one way strips. I flew too many 65 hp airplanes in the mountains to factor climb to higher winds. Ground effect to up slope ridge lift was a critical factor, however. I instructed at Monte Vista 7200 MSL in the more powerful Cessna 140 at 85 hp. I too will appreciate the data. Scott, "gunny," on FlyWire gave us some bit larger airplane data on the impossible turn like that.
I've been flying for 30 years but hut there is no way I would ever trust an aircraft this much. This slightest drop in performance or hiccup from he engine and you're dead. Some people have different risk tolerances...
Sometimes if you REALLY wanna have fun you gotta take some chances, have some personal courage. This pilot does everything he can to mitigate risk and in my opinion is an exemplary airman.
It is hard to damage an aircraft or hurt ourselves very much at Larry's faster than Vx or Vy takeoff airspeed and slower than Vso (in ground effect) approach airspeed. We increase safety by taking off as fast as possible and landing as slow as possible. Vcc on takeoff is safer than Vx or Vy. Less than Vso after arriving in ground effect is safer than 1.3 Vso to the fence and then round out and hold off. The pilot might as well be a passenger in the hold off portion. I have survived eleven engine failures at low altitude crop dusting and patrolling pipelines using this basic level in low ground effect to Vcc takeoff and this slower than Vso after arriving in ground effect landing. Energy management is the safer way to fly. Vx or Vy is a risk where the outcome of the maneuver, given that drop in performance or hiccup, is always in doubt. I never had altitude, but always had airspeed to maneuver to a survivable landing zone in the very near hemisphere in front of the wing. Using full flaps and forward slip with rudder to the stop, I always got into the beginning of the LZ in a three point attitude all slowed up and ready to squat.
Why would you fly in ground effect with flaps instead of climbing? I could understand if you flew in ground effect with no flaps, then pulled a notch when you started to climb.
@@motoadveBackcountry182 wasting energy like that probably isn’t good advice for people flying in Idaho on a hot day, or any day for that matter. You’re really limiting your options.
@@kylewood17 Cessna recommends 20 degrees of flaps for VX, because the airplane climbs better with flaps, I am adding a safety margin by climbing with flaps ,specially at high density altitude, if I start ground effect with 20 degrees of flaps , I cannot retract flaps right away or the airplane will sink back to the ground, if I retract them at speed then will have to add them again when I leave ground effect, this does not work well with Cessnas, no one does that, maybe with an airplane that accelerates really fast this could work.
@@motoadveBackcountry182 you’re right, they recommend climbing with flaps. You’re trying to gain speed with flaps. Try this sometime, start your ground roll with no flaps. Pull two notches of flaps when you get to VX, or when you’re out of runway, which ever happens first. You’ll get to VX faster that way.
I've been asking the same question all my life and never found any logical answer from any University or any flight instructor. The ground effect theory. The answer is. It can't exceed more than half the length of your wings. Makes perfect FUC#$%^ING sense. Thanks man. That's the answer. It should be included in any tutorial, video course etc etc.
I did my commercial pilot's license 25 years ago and and they talked about the 50% wingspan ground effect then so I'm unsure where this ground effect 'ignorance' is coming from? It has been known for quite some time before I did my CPL - perhaps about 90 years.
Received my Commercial Certificate 38 years ago and it was discussed, taught, and demonstrated to me (I had to demonstrate it as well). That was in a Part 61 training environment.
Six inch ground effect is far more energy effect, acceleration effective, than is half the length of the wing. Quite a few backcountry pilots use full flaps to get off into ground effect and then reduce them, but just using elevator will get you off at much slower airspeed. The sooner off and level in low ground effect, the sooner effective acceleration occurs. See how early (like the STOL guys) you can get off but work the elevator dynamically and proactively to bracket level in low ground effect. Unfortunately they only give points for distance to mains off. The big engine guys show poor energy management by climbing out at a high pitch attitude after mains off rather than using the free energy of ground effect. Those of us who flew 65 hp trainers to those strips when they were shorter didn't operate like that. Yes, off early. No, don't maintain the pitch up. Watch all of the Backcountry 182 videos to see how to manage all energy available, both on takeoff and on landing.
@@jimmydulin928there is not one single example in the video of the guy trading altitude for airspeed. There are only examples of him trading airspeed for altitude.
@@XPLAlN Granted and my apology to Savanna. The fact that he left down drainage is important, however. The fact that this down drainage altitude, like ground effect energy, is free is also critical for most mountain takeoffs. Good energy management is recognizing and using airspeed that we don''t have to trade altitude for (ground effect) and altitude we don't have to trade airspeed for (down drainage egress). He uses both. We all should use both. I get carried away sometimes, but use of both has made the outcome of the maneuver so not in doubt so often I have made both techniques default everywhere. We often don't need the extra energy...and then we do. Needing but not having free extra energy is the definition of startle. Larry is going out to rough places and putting his airplanes and his life on the line to demonstrate some of the energy management principles in "Stick and Rudder" that are dangerously missing in Airmen Certification Standards. The average private pilot need not be a mountain and backcountry pilot, but he needs to understand the principles in "Stick and Rudder" that make flying easier and safer. Vx or Vy as appropriate, neither appropriate on long runways, has killed a lot of general aviation pilots. Too many have climbed quickly to enough altitude to kill themselves in the stall/fall using the very techniques they were taught. Yes, startle was a hole in the cheese, but why didn't they know safe extra energy was there on that long runway just for the taking?
Very instructive. Thank you.
Ground effect+excess speed=PIOs
Especially in a Piper at the Grand Canyon airport.
This is the most excellent explanation of ground effect I have seen. Good on you, Larry. Yes, in powerful airplanes we have to push hard against the trim set for takeoff. In the lower powered 170, notice how Larry push/pulls just a bit dynamically and proactively to bracket level in low ground effect. Lower powered airplanes will want to return to earth. We want neither to touch down again nor to stay at the high pitch attitude required to get off when still slow. The practice you mention in ground effect on long runways, what I call hover taxi, is very important. We get so little time at less than Vso in ground effect on every normal landing. Thanks Larry. We all need to learn how to use ground effect effectively. It is just good total energy management. We don't need it until we need it...and then we wish we had used it by default.
This is very similar to being towed in a glider. The second you lift off, especially in a high performance glider, you must push the stick forward so as not to rise above the tow plane (which most often is still on the ground). And until you get used to it, it surprises you how much you have to push. Very useful video. Thanks
It would be interesting to see some tests of a takeoff using ground effect purposefully vs doing a normal short field takeoff and climb at Vx. I have not seen anything that shows that using ground effect is advantageous in this scenario as the higher speed means more drag as compared to just climbing out at Vx. I would love to see an actual comparison on the same runway and same conditions to see which technique works best to clear a 50’ obstacle and which provides the most altitude say 1 mile from the start of the takeoff roll.
@@LTVoyager Good idea, I can do this test next time I fly and share the results.
@@motoadveBackcountry182 That would be super interesting. And a fun excuse to fly more!
Larry will get the data for you. Notice, however, that crop dusters (sorry Ag now) use low ground effect on every takeoff. We clear the 50' obstacle on every swath run with what Wolfgang, in Stick and Rudder, calls zoom reserve airspeed. Why does he recommend trying to hit the tree and then zoom over? Because it is safer to zoom over with the outcome never in doubt. It comes from low altitude orientation where being able to maneuver around things is just as important and being up high. Vx will get us high enough to kill ourselves in the stall/fall very quickly should the engine quit or we get startled somehow.
@@jimmydulin928 Yes, many factors come into play. Wind is also a factor. In calm conditions, you won’t gain headwind with altitude, but with any amount of headwind you will. Since wind speed generally increases dramatically with height above the surface, climbing into a headwind can be very advantageous and I suspect staying in ground effect in that case might leave performance on the table. However, without actually testing that, it is hard to know all of the subtleties.
@@LTVoyager Yes, we fly in rivers of air. In the mountains, especially, down drainage egress can be even more important that wind management, especially with one way strips. I flew too many 65 hp airplanes in the mountains to factor climb to higher winds. Ground effect to up slope ridge lift was a critical factor, however. I instructed at Monte Vista 7200 MSL in the more powerful Cessna 140 at 85 hp. I too will appreciate the data. Scott, "gunny," on FlyWire gave us some bit larger airplane data on the impossible turn like that.
another piece of art video ! super educational, great content for PPL like us, gracias !
Absolutely amazing video! Thank you
Love the videos and thank you
8:23 “C-FCKD” 😂🤣😂🤣😂
Wonderful!
Great content
Hell yeah I enjoy your videos!
Awesome video man! I'd like to link up and do some flying with you. I'm down at VUO.
Great content as always!
Only a motocrosser has the huevos to fly in & outa strips like this. Super vid!
I've been flying for 30 years but hut there is no way I would ever trust an aircraft this much. This slightest drop in performance or hiccup from he engine and you're dead. Some people have different risk tolerances...
@gawebm
Especially since our civilization is collapsing and maintenance is becoming more and more random.
Sometimes if you REALLY wanna have fun you gotta take some chances, have some personal courage. This pilot does everything he can to mitigate risk and in my opinion is an exemplary airman.
It is hard to damage an aircraft or hurt ourselves very much at Larry's faster than Vx or Vy takeoff airspeed and slower than Vso (in ground effect) approach airspeed. We increase safety by taking off as fast as possible and landing as slow as possible. Vcc on takeoff is safer than Vx or Vy. Less than Vso after arriving in ground effect is safer than 1.3 Vso to the fence and then round out and hold off. The pilot might as well be a passenger in the hold off portion. I have survived eleven engine failures at low altitude crop dusting and patrolling pipelines using this basic level in low ground effect to Vcc takeoff and this slower than Vso after arriving in ground effect landing. Energy management is the safer way to fly. Vx or Vy is a risk where the outcome of the maneuver, given that drop in performance or hiccup, is always in doubt. I never had altitude, but always had airspeed to maneuver to a survivable landing zone in the very near hemisphere in front of the wing. Using full flaps and forward slip with rudder to the stop, I always got into the beginning of the LZ in a three point attitude all slowed up and ready to squat.
@@jimmydulin928 Thank you for your input Jimmy, I put into practice what you wrote in Contact Flying and worked.
@@jimmydulin928great input Jim I’ve read your book twice since I got my pilots license two years ago.
Why would you fly in ground effect with flaps instead of climbing? I could understand if you flew in ground effect with no flaps, then pulled a notch when you started to climb.
Great question, I just do it to avoid distraction and work load that close to the ground.
@@motoadveBackcountry182 wasting energy like that probably isn’t good advice for people flying in Idaho on a hot day, or any day for that matter. You’re really limiting your options.
@@kylewood17 Cessna recommends 20 degrees of flaps for VX, because the airplane climbs better with flaps, I am adding a safety margin by climbing with flaps ,specially at high density altitude, if I start ground effect with 20 degrees of flaps , I cannot retract flaps right away or the airplane will sink back to the ground, if I retract them at speed then will have to add them again when I leave ground effect, this does not work well with Cessnas, no one does that, maybe with an airplane that accelerates really fast this could work.
@@motoadveBackcountry182 you’re right, they recommend climbing with flaps. You’re trying to gain speed with flaps. Try this sometime, start your ground roll with no flaps. Pull two notches of flaps when you get to VX, or when you’re out of runway, which ever happens first. You’ll get to VX faster that way.
@@kylewood17 I can give it a try
I've been asking the same question all my life and never found any logical answer from any University or any flight instructor. The ground effect theory. The answer is. It can't exceed more than half the length of your wings. Makes perfect FUC#$%^ING sense. Thanks man. That's the answer. It should be included in any tutorial, video course etc etc.
I did my commercial pilot's license 25 years ago and and they talked about the 50% wingspan ground effect then so I'm unsure where this ground effect 'ignorance' is coming from? It has been known for quite some time before I did my CPL - perhaps about 90 years.
Received my Commercial Certificate 38 years ago and it was discussed, taught, and demonstrated to me (I had to demonstrate it as well).
That was in a Part 61 training environment.
must have picked a crap school if none of the CFIs knew this. it's literally in the books you should have read.
Six inch ground effect is far more energy effect, acceleration effective, than is half the length of the wing. Quite a few backcountry pilots use full flaps to get off into ground effect and then reduce them, but just using elevator will get you off at much slower airspeed. The sooner off and level in low ground effect, the sooner effective acceleration occurs. See how early (like the STOL guys) you can get off but work the elevator dynamically and proactively to bracket level in low ground effect. Unfortunately they only give points for distance to mains off. The big engine guys show poor energy management by climbing out at a high pitch attitude after mains off rather than using the free energy of ground effect. Those of us who flew 65 hp trainers to those strips when they were shorter didn't operate like that. Yes, off early. No, don't maintain the pitch up. Watch all of the Backcountry 182 videos to see how to manage all energy available, both on takeoff and on landing.
Great !
He's WAAAAY above ground effect for climbout....someone please show him the facts....
He is on a down drainage egress using the potential energy of altitude traded for airspeed. Total energy management.
@@jimmydulin928there is not one single example in the video of the guy trading altitude for airspeed. There are only examples of him trading airspeed for altitude.
@@XPLAlN The law of the roller coaster works both ways. Read Stick and Rudder.
@@jimmydulin928 …the fact remains that at no point in this video does he trade altitude for airspeed, which is what you say he was doing.
@@XPLAlN Granted and my apology to Savanna. The fact that he left down drainage is important, however. The fact that this down drainage altitude, like ground effect energy, is free is also critical for most mountain takeoffs. Good energy management is recognizing and using airspeed that we don''t have to trade altitude for (ground effect) and altitude we don't have to trade airspeed for (down drainage egress). He uses both. We all should use both. I get carried away sometimes, but use of both has made the outcome of the maneuver so not in doubt so often I have made both techniques default everywhere. We often don't need the extra energy...and then we do. Needing but not having free extra energy is the definition of startle.
Larry is going out to rough places and putting his airplanes and his life on the line to demonstrate some of the energy management principles in "Stick and Rudder" that are dangerously missing in Airmen Certification Standards. The average private pilot need not be a mountain and backcountry pilot, but he needs to understand the principles in "Stick and Rudder" that make flying easier and safer. Vx or Vy as appropriate, neither appropriate on long runways, has killed a lot of general aviation pilots. Too many have climbed quickly to enough altitude to kill themselves in the stall/fall using the very techniques they were taught. Yes, startle was a hole in the cheese, but why didn't they know safe extra energy was there on that long runway just for the taking?