John King explains ground effect, and what it does to your flying. This video is an excerpt from our Private Pilot Ground School & Test Prep Course: kingschools.co...
So true. Now I know that "ground effect" is the effect that the ground has on your airplane when you smash into it while imagining that it would barely keep you airborne on a small cushion of air.
Thank you so much for the whole clarifications and explanations. It helps a lot while studying for my ATPL, you are such a pedagogical instructor Mister John King :)
I’ve just started ground school and your videos have been a lifesaver. The way you present the information makes everything much easier to grasp. Thank you!
But hang on John....what are the remedies? If a nose wheel is for taxiing and advice is to keep weight off it and aircraft wants to take off what is the remedy? Hold the nose down? And if floating in ground effect do we force it down, release back pressure, go around?
If you realize upon takeoff, or landing, that you’re in ground effect (and it might take an inexperienced pilot a little time, or length of available runway, to realize this) what are your best options to put into action? And, what poor technical flying skills are most likely to get you into this situation in the first place.
I'm not sure I understand your question. Being in ground effect is normal, and happens every time you take-off and land. However, the hazard comes when you don't know it's happening and don't expect it.
King Schools Accepted that it always happens on take-off and landing. I was trying to understand better the dangers associated with it going unchecked and how best to respond. The guy who hit the tree was seemingly ‘stuck’ in ground effect, through his own fault, but what actions should he have taken ? I assume he was at full power.
Andrew Wilkinson I believe what John is getting at is that he should have trusted his airspeed indicator to tell him the proper rotation speed and not his perception of speed, based on how fast he observed the ground moving beneath him. He also might have chosen not to have flown at such a high density altitude (i.e. fly in the morning or at night with cooler OAT’s), or perhaps reduced the weight of his aircraft, to increase climb performance. Also one factor might be to properly lean the mixture to provide maximum power according to the recommendations in the pilots operating handbook. You can see there are many factors than just ground effect to consider in making a safe takeoff, and those factors are influenced primarily by the pilot’s personal judgement and ability to make safe decisions when faced with that situation. So the ability to make sound decisions depends on the pilots experience and knowledge of takeoff performance factors.
@@andywilk38 ah, got it. Sorry I misunderstood your original question. The pilot that was stuck in ground effect had two options: 1 - abort the takeoff, or 2 - lower the nose (this will feel weird!) and allow the airplane to speed up, before pitching up again to climb. On a hot day in Lake Tahoe, it's very possible his airplane didn't have the performance required to takeoff in the first place, in which case option 1 was his only choice.
Well I understand why you wouldn't be able to climb out of ground effect when too slow, but shouldn't you be able to accelerate more quickly while in ground effect than while still on the ground, since there's no longer any tire friction?
THE HARRY BROWN PROJECT If an aircraft flys better in ground effect on landing that would also apply on take off too, so that explanation is negated for take off. Lifting off BEFORE 1.2x Vso means you are at a higher angle of attack with a large amount of drag and on the back side of the drag curve. Your excess power is merely keeping the aircraft level and some low powered aircraft have problems accelerating at this angle of attack through to Vx or Vy especially when hot and high.. The take off problem is not ground effect, its high drag caused by high angle of attack caused by being on the wrong side of the drag curve.! Rotate at the correct airspeed and do not use an incorrect high nose attitude especially when heavy prevents this happening. #hbmethod
You forgot to mention that even though ground effect exists with all aircraft, including helicopters, it is much more pronounced in low wing airplanes.
Ok John, what gives? When I took your course in 1986, you said ground effect occurs at half the wingspan. Now, you say it occurs at full wingspan. I certainly cannot "feel" ground effect at 36 feet high, but more like 15. What made you change from half wingspan to full? Certainly, your jet is not in ground effect at one full wingspan?
Went flying yesterday...other pilots have told me you can feel ground effect. Coming in to land...I feel nothing. So I still don't get it. Any suggestions??
4:39 “So now you know, why an airplane will fly BETTER, when it’s less than one wingspan above the ground.” No. Now we know THAT. We really have no clue WHY. It is a profoundly complex system of gas dynamics and a complex aerodynamic object.
1/2 the wingspan....his aerodynamic theory part is dubious....his practical application is ok... Wikipedia has a page on ground effect for those who care and don't want to study aerodynamics in depth.
I don't thing that's actually accurate. It isn't from "allowing the aircraft to become airborne before reaching recommended "takeoff speed." It is, more accurately, "trying to climb before recommended "takeoff speed." This is distinct. A "soft field takeoff" is allowing the aircraft to to become airborne before "normal" recommended "takeoff" speed (to avoid the drag or undesirable surface) and flying in ground effect, then climbing once the recommended takeoff speed has been achieved. Am I wrong?
The hottest day ever recorded at Tahoe was 99 degrees and 90 degree temperatures are rare! Sacramento which is almost at sea level, is in the high-90s low 100s in the summer. Tahoe's at 6000 ft. Do the math! A minor point with regard to this subject, but let's stick to the facts professor!
