Trouble explaining landings

Have you looked at the Jacobson Flare? I ran across it in the mid 2000s. At that time Mr. Jacobson had it available as a PDF download of about 16 or so pages that explained the theory, the math, and the practical applications. I learned it and applied the principles to my Cherokee and it helped me.

After I sold my Cherokee and bought my Mooney in 2019, I had lost my first copy and looked for it again to refresh my understanding. What I found was nothing like the original pamphlet and it was right expensive. I think Mr. Jacobson had passed and his family wanted more money for his idea. I would have been happy if I could have purchased the original pamphlet for a reasonable fee, but that was not an option.

I just checked and they now have a pdf version that is free. It doesn't have any math and I have not had time to read but it all might be worth a look. The general principle is that if you are on the glide path at the proper glide angle, then the horizontal distance from the aim point is proportional to the vertical distance above the ground, and using that that distance as a guide helps you begin the flare in a more precise manner. The math helps you tune your sight picture to any aircraft from a small trainer to a 747.

The Jacobson Flare helped me become more consistent with my landings at a time when I needed it. Maybe it will help you in you quest to be a better instructor. Hope this helps.
 
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One more thing about Jacobson Flare. If you are on a 4° glide path, then for every 1 foot vertical drop, the airplane moves forward 14.3 feet, or about 14:1 ratio. On a 3° glide that becomes 19.1 feet, or about 19:1. Using this principle makes it easier to fine-tune when to flare with more precision.
 
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MauleSkinner said:
I’m not sure I agree…if the only published approach speed is at max weight, and you’re 20% under that weight, you’re 10% fast. That usually translates into float, and braking action kinda sucks until you’re on the ground. It could very easily result in landing longer than you would at max weight.
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. . . and other variables include power setting and ground effect, neither of which really "calculate" well but both of those will extend the float.
 
FastEddieB said:
I’d argue it’s not arbitrary. And it’s what the FAA recommends. And it works.

”When the airplane, in a normal descent, approaches within what appears to be 10 to 20 feet above the ground, the round out or flare is started.”

I’m not saying an instructor needs to be a blind slave to every FAA recommendation. But if you‘re teaching something different from what the Airplane Flying Handbook recommends or what the ACS requires, you risk putting the student into a confused “who do I believe now” mentality. If you do so, be prepared to explain exactly why you think your way is better than the FAA recommendation. And make sure that in the end it will result in meeting ACS standards. If not, I’d argue that is what might “set a student up to fail”.
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It seemed very arbitrary to me as a student in the 'unconsciously incompetent' phase of learning.

Yes I am above the runway, but how many feet? Way beyond my experience level.

In my current 'consciously incompetent' phase what appears to be way too low is about perfect.
 
Revtach said:
When do you all normally start reducing speed from final approach to the roundout and how would you explain that procedure? ... Thanks.
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"When" IS the operative word, not "how high". So, here's how it should go: "Power off, one thousand one, one thousand two, one thousand three, one thousand four, one thousand five, one thousand six, one thousand seven, chirp, chirp."
 
First, make sure your student can perform all of the building blocks necessary to fly a traffic pattern and landing. i.e. speed control, descents, turns, wind correction, etc. If they can't, they'll be lost in the pattern chasing goals that they don't know how to achieve. When a student is struggling, look for the building block(s) that is lacking and work on that before continuing with the pattern work.

Reference Chapter 9 of the Airplane Flying Handbook and base your explanations on what is written there. That is the source FAA document. Insert the details of your airplane and airport environment into the AFH descriptions.

Don't insist on unnecessary precision in the beginning. i.e. holding pattern altitude as the airplane slows to 85kts. Does it really matter if the pre-solo student descends 100' while slowing? They will be focusing too much on maintaining pattern altitude and neglecting the bigger picture of the upcoming base turn and traffic situation. Added precision can come later.

Once you have your explanations worked out, watch how the student responds to them and adjust how you explain it to match how they learn. Every student will need to hear it a bit differently.

CFIs don't have to fly maneuvers perfectly. In fact, it's better if you don't. As you demonstrate, point out the deviations and demonstrate the corrective action.

It is not necessary for the CFI to be talking continuously. The student needs time to think about what they are doing.
 
Revtach said:
My question is if pilots are holding final approach speed until round out. I find that going 65 knots into the round out is too much and the plane floats too far, so I have developed the habit of slowing down as I’m approaching the round out phase. I am having trouble putting into words my methodology as it is very much instinctual.
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Teaching / learning landings is a multi skill process. You didn’t develop a habit of doing anything until you are able to round out at the proper height of above the runway, establish a landing attitude for the aircraft and putting the plane on the surface. You have to teach each element at the speed the student can learn it.
 
I used 15 to 30 feet. 15 feet is already into ground effect, where stall speed begins to get lower, and if you arrive near the surface still carrying close to approach speed, you will float a long time, and floating raises the risks of ballooning, bouncing, porpoising, wheelbarrowing and so on. Those events wreck more airplanes than stalling on short final. One needs to go up high, extend approach flaps, and start slowing down until the airplane stalls. Note the indicated stall speed. That's what you need to avoid. That speed, adjusted for altitude and temperature, which any pilot with a whiz wheel should be able to do. Do it again, noting the sink rate near the stall. Some airplanes can get wrecked just by pancaking into the ground at lower speeds above the stall. Short-winged airplanes are famous for that.

How many pilots stall on short final? Most are way too fast, and the long, flat-attitude landings are proof of that.

Here's the diagram from the Canadian Flight Training Manual, published by Transport Canada:

1697910386579.png
 
Dan Thomas said:
I used 15 to 30 feet. 15 feet is already into ground effect, where stall speed begins to get lower, and if you arrive near the surface still carrying close to approach speed, you will float a long time, and floating raises the risks of ballooning, bouncing, porpoising, wheelbarrowing and so on. Those events wreck more airplanes than stalling on short final. One needs to go up high, extend approach flaps, and start slowing down until the airplane stalls. Note the indicated stall speed. That's what you need to avoid. That speed, adjusted for altitude and temperature, which any pilot with a whiz wheel should be able to do. Do it again, noting the sink rate near the stall. Some airplanes can get wrecked just by pancaking into the ground at lower speeds above the stall. Short-winged airplanes are famous for that.

How many pilots stall on short final? Most are way too fast, and the long, flat-attitude landings are proof of that.

Here's the diagram from the Canadian Flight Training Manual, published by Transport Canada:

View attachment 121646
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Floating is a result of kinetic energy, not round out height.
 
Revtach said:
My question is if pilots are holding final approach speed until round out. I find that going 65 knots into the round out is too much and the plane floats too far, so I have developed the habit of slowing down as I’m approaching the round out phase. I am having trouble putting into words my methodology as it is very much instinctual.
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I'd tell them target 55 - 60 kts over the numbers on (very) short final, depending on your weight and available landing distance. Yet after some practice they'll do this without looking at the airspeed indicator, but by sight and feel. Looking out the window at pitch attitude. Normally, if you don't hear the stall horn in the flare just before the wheels touch, you were too fast.
 
Dan Thomas said:
One needs to go up high, extend approach flaps, and start slowing down until the airplane stalls. Note the indicated stall speed. That's what you need to avoid. That speed, adjusted for altitude and temperature, which any pilot with a whiz wheel should be able to do.
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Nice explanation, Dan. In agreement with almost all of it.

One quibble: the indicated airspeed of the stall should not change with altitude and temperature. It will change with weight and cg location, however.
 
Clip4 said:
Floating is a result of kinetic energy, not round out height.
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Yes, and carrying approach speed into the flare near the surface means you have a lot more kinetic energy to dissipate somehow.

The fact remains that it is easier and safer to get rid of the speed while still out of ground effect than within it, and that's why the round-out needs to happen well above the surface, not at three feet. The round-out and flare are two different things: the round-out is to start slowing the descent rate while also lowering the airspeed, and the flare is the final bit of the round-out, to get the descent rate down to near zero and the speed low enough that float cannot happen.

Too many pilots learn to fly on long runways, and so are not motivated to get the landing distances down. They just arrive at the runway at whatever speed and plunk it on in whatever attitude, and try to fix it with brakes, which eats tires and causes nosewheel shimmy and all the rest.

It's the same old problem of not understanding angle of attack and its relationship to airspeed. At high airspeed the angle of attack is low, to generate the lift needed to support the airplane. At lower airspeed the AoA needs to be higher to support the same weight. Trying to land fast means a nose-low attitude that causes all sorts of difficulties, as I noted earlier. There's one more difficulty: running off the end of the runway. I saw it several times at our rural airport's 3000-foot paved runway. Too fast, touching down too far down the runway (because at higher speed the glide angle is flatter), and so we'd see smoking tires and runway excursions. Pilots spoiled by long runways. On shorter grass strips they're really in trouble, trying to brake on grass. Little traction there.
 
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FastEddieB said:
One quibble: the indicated airspeed of the stall should not change with altitude and temperature. It will change with weight and cg location, however.
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You are right. Not enough coffee this morning, and the memory was a little slow.
 
That’s a lot of information and I wouldn’t want a student pilot doing 30deg bank turns at slow airspeeds low to the ground, and many (but not all) of my instructors would be picky on this too. Except my multi instructor told me to do a real turn, that’s 30 degrees (first time I heard that), and now I usually do 30degrees bank as a normal turn unless in IMC then 10degrees it is.

Set up slow flight at pattern altitude, follow the pattern nice and easy (10-20deg bank turns), power controls altitude. Choose an airspeed that gives you extra room for error. My instructor will call out GUMPFS check even in a C172 and I think that has helped me with the Arrow.

Once those get mastered, work on the other components, crosswinds and crab angles, short/soft field, slips, rudder usage and coordination. Try to treat all landings as spot landings to get those skills in place.
 
aterry1067 said:
From a student that struggled with this a few years ago, a newer student has no idea what 100, 50, 20, 300, 75, feet agl looks like. They see asphalt flying to their face, and it’s scary. Teach looking/glancing out the side window to reference agl. I had to learn this from a new instructor.

Remember, this isn’t about how YOU see it, itivabout how your student sees it. He has several hundred hours less experience than you.
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This is the first mention of experience. As times accrue your references will change, as will conditions, weights, etc. There is much to be said about seat of the pants flying and individual technique. A student needs to experience book numbers AND alternative methods.
 
I’ve posted this article of mine before, but I think it applies to the discussion about determining height…

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MRC01 said:
I'd tell them target 55 - 60 kts over the numbers on (very) short final, depending on your weight and available landing distance. Yet after some practice they'll do this without looking at the airspeed indicator, but by sight and feel. Looking out the window at pitch attitude. Normally, if you don't hear the stall horn in the flare just before the wheels touch, you were too fast.
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The Attitude is the secret. I recently had a pilot remind me of this on a flight review. He was flying a Light Sport cub off of his private 900 foot strip. He me had do his flight review with him.
The flight review went well, with the only concern was he admitted that he is a bit tone deaf and could not hear the Stall warning. I recommended he do something to change his Stall warning so he could hear it.
We did the take-off and landings at a nearby Municipal airport and before heading back to his private strip topped the plane off with fuel. On approach I heard him call out 50mph and I could just hear the stall warning squeaking. This is slower than I would have done the approach, evidenced by how high the nose was on approach , but it is his airplane and his airstrip and I know some pilots do short field approaches slow and with power like this, so I just watched and was extra careful to make sure his didn't stall it and I was ready to recover if he did. Otherwise the approach pretty normal to me. At about 10 feet above the runway, he went full power and announced it didn't look right and was going around, I thought it looked just fine, just slower than I would have done it.
On the 2nd approach he did exactly the same thing and went around, and then asked me to coach him as to why he seemed to be having trouble. I advised him I would add 10mph to the approach speed, as he turned final he said this looks a lot better and he landed just fine.

In debriefing we figured out he was flying airspeed instead of attitude on the approach. He never flies with passengers so his 50mph approach speed works just fine for him, with me in the back and full fuel, he could tell it didn't look right (to nose high) but wasn't figuring out why. The lesson is that the attitude on landing is our poor mans Angle of attack indicator. Fly same attitude and the airspeed will adjust itself for the conditions.

I only fly small airplanes, but my understanding that this is SOP for bigger airplanes and why they fly their approaches using angle of attack or possibly even attitude instead of Airspeed.

Brian
CFIIG/ASEL
 
brcase said:
In debriefing we figured out he was flying airspeed instead of attitude on the approach. He never flies with passengers so his 50mph approach speed works just fine for him, with me in the back and full fuel, he could tell it didn't look right (to nose high) but wasn't figuring out why. The lesson is that the attitude on landing is our poor mans Angle of attack indicator. Fly same attitude and the airspeed will adjust itself for the conditions.
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as long as you only fly one airplane and fly it often enough to maintain the sight picture, that works. But it’s rote level flying, IMO. I’d rather have a pilot understand why the attitude works, and how to establish that attitude, which can’t be done without understanding how the working speeds of the airplane change with weight.
 
FastEddieB said:
I’ve posted this article of mine before, but I think it applies to the discussion about determining height…
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Some call that the "Lindberg Reference" - the lower left corner of the windshield. Especially useful with airplanes (especially taildraggers but many others) having a nose-up attitude that blocks forward visibility.
 
I have had very much success by telling my students to look at the paint at the far end of the runway. When that paint begins to disappear, level off, you are close to the surface and in ground effect. Now (in Cessna trainers, which love to float if you are slightly fast), when you sense from your peripheral vision, the airplane is sinking, start to gradually raise the nose to keep the nosewheel off the ground.

The level off is the round out, the flare occurs when the airplane bleeds off excess speed and starts to sink.
 
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