So much of flying is to maintain and manage lots of kinetic energy (airspeed) and potential energy (gravity/altitude) that we may forget the danger both forms of energy present on landing. To touchdown slowly and softly on the beginning of the landing zone, we must manage airspeed and altitude effectively. Here we are concerned with elemination of altitude and out of ground effect flying speed.

One way to eleminate the altitude problem is to not climb. This technique is common with crop dusters and patrol pilots. This low approach does not help us get in near the beginning of the landing zone over obstacles, however.

Generally we simply reduce power to descend. The problem with closing the throttle, however, is that we lose a very effective glide angle control. Better management is to actively maintain glide angle with whatever throttle movement necessary. This becomes critical in rough air. Simply increasing airspeed to manage gust spread is robbing Peter (airspeed management) to pay Paul (altitude/gravity) management. Using less flap is the same.

Landing slowly and softly requires the in ground effect stall speed rather than the out of ground effect stall speed. With the stabilized approach speed to the fence, round out over the numbers, and hold off until the airplane deceletates to the in ground effect stall speed, we are waiting on the airplane to somewhat control itself. This works on long runway to a less than satisfactory extent considering the run off and go around accident rates. The drag it in behind the power curve takes boldness and skill but the apparent rate of closure approach requires moderate skill and doesn't go behind the power curve until in ground effect, if then.

Whatever management technique we use, we need practice to be consistent.

Since brakes create their own set of problems and Navy quality arrest systems are expensive, we look for ways to pull air. We can use flaps, slats, slip (present side to relative wind), and inefficient climb pitch attitude to control airspeed. Power, in conjunction with any or all of these, will control descent angle and descent rate.

We can approach at a stabilized fast airspeed and slow down when we get to the landing zone but this allows little control of touchdown point and landing distance. We can approach at a stabilized slow airspeed, even behind the power curve. This gives good speed control, touchdown point control, and distance control but much skill is required prior to touchdown and with the decision to cut power for touchdown. Finally, we can approach at a closure rate that appears to be a brisk walk all the way to touchdown. Maintaining this apparent brisk walk rate of closure with the numbers will slow the airspeed from short final to touchdown. It will not cause any slowing until short final when height and distance to the numbers cause an apparent speed up of closure rate. The effect is a sort of round out earlier than the spreading base of the runway mentioned by Wolfgang and Cary. Actually no change is required except to use elevator to keep the apparent rate from speeding up and power to control descent angle and descent rate.

Thanks Professor.....

Pretty simple stuff. I'm pretty sure Wolfgang didn't extensively cover what he called the stall down approach because it was in common use by experienced pilots at the time.

If you have a adjustable horizontal stabilizer I like to use a lot of nose up trim. This will require forward stick/yoke pressure on final. This increases drag and you will need more prop rpm, this means more airflow over wing and tail (better control). If done properly (test at altitude) you will be at proper AOA for landing, maybe tail low depending on plane. You don't have to look at airspeed if you have to pull back on stick you are too slow. The advantage of nose up trim is it helps keep the tail down with hard braking. The hardest part for me is allowing the plane to settle into ground effect as Contact points out. When I do it right I can land 3-4 mph slower. As Contact points out ground effect is your friend learn to use it!!
DENNY

Flaps have a dual purpose. At shallow angle to cord, they increase camber smoothly and induce more lift/drag. Those that go on down to very steep angle to cord provide parasite drag, very effective drag, down there.

With airplanes that don't have effective parasite drag flaps, we have to use more elevator to fly at an inefficient angle of attack with the relative wind to maintain longitudinal alignment while slowing in a way that requires more, not less, power to maintain glide angle.

We practice slow flight at altitude but too many pilots forget the purpose of that drill. We can get down slowly and softly on the numbers if we are comfortable with slow flight on short final.

Airspeed is altitude. Fast flight on short final will always result in landing well into the landing zone.

DENNY wrote:If you have a adjustable horizontal stabilizer I like to use a lot of nose up trim. This will require forward stick/yoke pressure on final. This increases drag and you will need more prop rpm, this means more airflow over wing and tail (better control). If done properly (test at altitude) you will be at proper AOA for landing, maybe tail low depending on plane. You don't have to look at airspeed if you have to pull back on stick you are too slow. The advantage of nose up trim is it helps keep the tail down with hard braking. The hardest part for me is allowing the plane to settle into ground effect as Contact points out. When I do it right I can land 3-4 mph slower. As Contact points out ground effect is your friend learn to use it!!
DENNY

I was following you up until you said "if you have to pull back on the stick you are going to slow". I can't wrap my head around that. Pulling back would nose up further, slowing you down more wouldn't it??
Sorry if I'm a bit slow on figuring it out, I'm always looking for new tricks!
David

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A1SKINNER,

I think Denny is talking about the advantage of already having the go slower trim in for short final. I think he meant too slow response not too slow airspeed. I assume he is flying a heavier airplane where the pre-set trim up could help getting the extra pitch up for short final slowing. He is having to push on the stick way back on final when he wanted to go faster.

Contact

A1Skinner wrote:

DENNY wrote:If you have a adjustable horizontal stabilizer I like to use a lot of nose up trim. This will require forward stick/yoke pressure on final. This increases drag and you will need more prop rpm, this means more airflow over wing and tail (better control). If done properly (test at altitude) you will be at proper AOA for landing, maybe tail low depending on plane. You don't have to look at airspeed if you have to pull back on stick you are too slow. The advantage of nose up trim is it helps keep the tail down with hard braking. The hardest part for me is allowing the plane to settle into ground effect as Contact points out. When I do it right I can land 3-4 mph slower. As Contact points out ground effect is your friend learn to use it!!
DENNY

I was following you up until you said "if you have to pull back on the stick you are going to slow". I can't wrap my head around that. Pulling back would nose up further, slowing you down more wouldn't it??
Sorry if I'm a bit slow on figuring it out, I'm always looking for new tricks!
David

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I think he's describing a regime where you are approaching the behind the power curve danger zone. It's a great place to be provided you don't cross over. If it feels like you need to yank before you are in ground effect you've crossed over. More power, not more yank is required. Early Mooneys have infinitely adjustable hydraulically actuated minuscule conventional flaps. They will provide nose down pitch while hanging a little drag out there in the wind while you maintain power to establish what Contact describes as the apparent walking speed rate of closure. With a stable airspeed on a long flat final the rollout can be reduced to about 450' in very little wind. It takes practice but I think it's something like what A1Skinner is describing. Maybe. A little wind shear close to the ground can make it more exciting than you had hoped.

Mister 701,

That is a good consideration as well. With considerable tailwind we will go behind the power curve on short final if we increase pitch to prevent the speed up of the apparent closure rate. This will require considerable extra power to prevent landing hard. The throttle should not be closed until after touchdown.

I like guys who can land a Mooney reasonably short.

Contact

I should clarify I am flying a cub with an adjustable stabilizer not a trim tab. If I am flying grandma and have a lot of space I can trim for airspeed and never touch the stick except for a slight flair at the end. The method I describe is for short work with hard braking at touchdown. I fight against the stabilizer with the elevator on final this will increase the drag and allow for more rpm and more airflow over the wing and tail. At the flair I just release the forward pressure (add power as needed) and let the stick come back the plane is trimmed so it will flair by itself. That is the why I don't have to pull back the stabilizer (nose up trim) is doing the job. As contact advised I spent a lot of time at altitude practicing slow flight in the landing configuration so I know how my trim should be set. The main reason for so much nose up trim is when braking hard the stabilizer will help hold the tail down and you can even blow it down if needed with the prop. Having neutral or nose down trim will make it easier to roll on the mains but hard braking can be dangerous because now the tail stabilizer is lifting the tail. We have so many types of aircraft on the forum it is sometimes hard to remember that what works for the cub won't work for all. I hope this makes more sense to everyone.
DENNY

I can see you are making the Cub a little dirtier with the horizontal stabilizer trimmed for nose up and pushing the stick forward against it. We need to get you bigger flaps.

For short fields, I would just try to land a bit slower and not need so much brake. It would be a fine balancing act to blast the tail down with prop, on touchdown, without increasing ground roll. Get with some of the old guys up there who flew Cubs with cable operated mechanical brakes.

I have a extra set of wings in the hanger that I am going to square off, big flaps would be great!! I just need to get off my butt and get them built. I can get real slow in ground effect (I don't drag it in) but then my tailwheel is a foot or so below the mains, the transition to a good wheel landing is the hard part for me. Once down if I don't lift the tail as I brake I tend to skip. With no wind I can usually get down and stoped with 200 ft of runway consistently. Just to be clear I don't try to blow the tail down as I brake just like to have stabilizer set right in case I need to. I did fly a friends cub with ASOS gear that is set up just like mine and it was very easy to plant with no bounce!! I think that will be my next upgrade.
DENNY

Oh ya, that makes sense Denny. I did similar style landings with my 180.

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Sounds good guys. If the tail touches down, keep it there. If not, level to wheel land. All should be three point attitude just before touchdown. Slow is the ticket. Less stuff gets damaged that way.

Or you could get one of Aktahoe's ships and just land on the tailwheel with power. Back it in in just a little headwind.

Don't get carried away Denny. A big engine makes yours land just a little less sweet.

I like slow but there is such a thing as too slow. We don't want to go backwards in a strong headwind component. Also, the airplane will be more level because the airspeed will be greater to produce what appears to be a brisk walk. A three point attitude will not be possible but we want to wheel land in the wind anyway. With nose gear we have to be careful not to touch down nose gear first.