landing with a porpoise!

Like everyone said, you porpoised because you came in with way too much energy. Hit the right speed over the numbers and the damn thing will land itself. Shouldn't need ever a bit of power in the flare either. And for Odin's sake keep that nose wheel up! Land flat like that and you'll break it. Some CFI time is damn good idea. You need land more better.

Still, big props for having the stones to show us that. Letting others learn from their mistakes. What Real Men do.

Steingar, two sheet to the wind on really good homemade wine.
 
FastEddieB said:
The goal, conditions permitting, should include...

1) Landing with the yoke/stick all the way back as the mains touch. If there’s a stall warning horn it should be blaring. This will ensure landing at the lowest possible speed and with the least energy to dissipate. And no “extra speed” which invites a bounce.

2) Using maximum flaps as consistent with conditions and POH recommendations. This will lower the touch down speed.

Stipulated this does not apply to all aircraft all the time. But for the GA planes most of us fly, it’s a good place to start.

What was the motivation to use just 10° flaps?
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10 degrees flaps is a bit mixed.

Pros:
Easier to get the nose up and not land flat. (Less back pressure needed to raise the nose),
Power off landings easier due to plane not slowing down as fast.(flare happens slower)
Minimal pitch change during flap retraction during go around
If doing touch and goes, failure or forgetting to retract the flaps not as critical.
Can add more flap if approaching high or fast.

Cons:
Flatter approach, but many pilots carry more power with flaps to get a flatter approach anyway.
Plane Floats farther if the approach is to fast.
Small increase in touch down speed, usually less than 5kts difference if doing full stall landings
Small increase in roll out distance probably less than 5 or 10% difference.

Probably more
Brian
 
bflynn said:
Generally yes, but you're assuming a horizontal relative wind.
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??? This is an odd description. Are you trying to say something about updrafts/downdrafts and actual wind? Relative wind is what you feel when stick your hand out the window while moving. Never heard anyone refer to "horizontal relative wind".
 
Excessive energy from the looks of it. Too fast.

Go straight to 20 degrees of flap for landing and add from there. Ten degrees is a waste of time, except for takeoff...
 
Too shallow & fast approach. Nail the proper approach speed recommendation by the POH, and keep the nose up after rounding until the mains only settle. If you are not landing on the two mains with the nose wheel in the air, you are likely carrying too much speed on final and during touchdown resulting in a too flat attitude, or are trying to force the plane on the runway before it is ready, which usually results in a PIO. With partial or no flaps, speed won't bleed off as quickly as it will with full flaps when you retard the throttle, potentially exacerbating a too fast approach. Nail and trim for the proper final approach speed, typically around 1.3 Vso with flaps (but your POH will have recommended speeds), and landings will be more consistent with less float. A good landing starts with a good approach configuration.

The correct response to a PIO is a go round, however, so you recognized that and responded well instead of trying to salvage non-optimal situation. Grummans will do epic PIOs if you carry too much speed on final and try to force them on.
 
Nose up,don't push it back down to fix a bounce, keep the back pressure when you bounce. Six inches to a foot bounce just reland any thing higher go around. Never push the stick in a landing for a tricycle gear. Speed is important but even if you are fast you should have the skill and patience to hold it off until it slows enough to land. Just make sure you have enough runway.
 
brcase said:
Small increase in touch down speed, usually less than 5kts difference if doing full stall landings
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Stipulated that landing 5 kts fast is not the end of the world, and one may get away with it for an entire flying career with no ill effect.

Still, the energy increase in landing just 5 kts fast is non-trivial.

I made an Excel spreadsheet where I can just plug in the numbers and get the % increase in energy from any speed increase.

23659991808_0230491531_w.jpg


Again, for most landings most of the time, even a 26% increase in energy won’t matter much - maybe just a tad more tire and/or brake wear. But on that one landing where a deer runs in front of you right at touchdown, or an axle breaks or a brake locks up, or whatever, one might wish one was carrying a bit less energy that will end up needing to be dissipated somehow. It might be the difference between no injury and minor injuries, or between minor and significant injuries, or between significant injuries and life-threatening ones.

I’m happiest with the stick/yoke just about hitting the rear stop as the mains touch, stall horn blaring if there is one. Doesn’t work out that way on every landing, but it remains my goal, conditions permitting. And, barring a sudden gust, it pretty much precludes a “porpoise”.
 
FastEddieB said:
I’m happiest with the stick/yoke just about hitting the rear stop as the mains touch, stall horn blaring if there is one. Doesn’t work out that way on every landing, but it remains my goal, conditions permitting. And, barring a sudden gust, it pretty much precludes a “porpoise”.
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This^^^, @Peter Ha, is the "airmanship" to which I referred.
 
One other thing, speed is an issue, and the ultimate reason for the porpoise. But if wager your patten habits contribute. Tighten up, get in the habit of going to idle on downwind, and manage your energy to touchdown without having to stretch, and your landings may improve. If you weren't taught this way, maybe find a comfortable CFI and spend an hour practicing.
 
bflynn said:
Generally yes, but you're assuming a horizontal relative wind.
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So, then, what is the direction of the relative wind when you're floating above the runway waiting for the speed to bleed off?

Edit: Besides that, the direction of relative wind is irrelevant when we talk about angle of attack and lift. It takes a specific angle of attack--the difference between the relative wind and the wing's chordline--to generate lift equal to the weight at a specific airspeed, and that's whether the airplane is flying level or in a steady climb or steady descent. In a banked turn, where the loading is higher, the angle of attack must be higher to overcome the extra load if the speed is to stay the same.
 
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brcase said:
Cons:
Flatter approach, but many pilots carry more power with flaps to get a flatter approach anyway.
Plane Floats farther if the approach is to fast.
Small increase in touch down speed, usually less than 5kts difference if doing full stall landings
Small increase in roll out distance probably less than 5 or 10% difference.
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Momentum increases by the square of the increase in speed. 10% over proper touchdown speed means 21% more momentum and that much more runway. Actually, it's worse than that; in ground effect, drag decreases and stall speed drops a little, so the airplane uses up far more runway. And braking is almost useless with so much speed, so the airplane rolls a lot farther. At 20% too much speed, the runway used up is at least half again what it should be, and probably more considering that the traction is poor until the speed gets down and the lift disappears. The lift does not automatically disappear when the wheels touch the runway.

Stuff like this really limits the places a pilot can take his airplane. He (or she) is stuck with nice long runways with no obstacles for his fast, flat approaches. And stuff like this costs him more for tires, brakes, nosegear parts and sometimes it costs him the whole airplane.

Landing accidents are, I believe, the largest fraction of the entire accident portfolio.
 
Here's a situation where I was landing with a tailwind, with people just off the runway as an added factor. I held a bit of power in to stay high until I got past them. So I had about 20 knots too much speed when I hit ground effect. You can see how long it took to dissipate that energy. I just kept holding it off until it all ran out. No dolphins, no bounces (well, not on the ground anyway, it was gusty, so I bounced around a bit in the air).

 
Salty said:
Here's a situation where I was landing with a tailwind, with people just off the runway as an added factor. I held a bit of power in to stay high until I got past them. So I had about 20 knots too much speed when I hit ground effect. You can see how long it took to dissipate that energy. I just kept holding it off until it all ran out. No dolphins, no bounces (well, not on the ground anyway, it was gusty, so I bounced around a bit in the air).

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You kept that nose off the runway, nice job. Why do people need to be so close to the action? I like watching airplanes land too, but not from that close.
 
PaulS said:
You kept that nose off the runway, nice job. Why do people need to be so close to the action? I like watching airplanes land too, but not from that close.
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They are prepping to repave the runway next week. So we were in radio contact. Although I thought they were on the other end of the runway until I was on final. LOL
 
Slow down!
Doesn’t matter how much flaps you have you adjust pitch and power to maintain the proper approach speed. You pitch will be a bit higher but not close to stall.
 
Grum.Man said:
Make life easy, pull the power to idle abeam the numbers and use flaps and turns to hit your touch down point. Trim for 60 at idle on final and you will never have a problem.
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I want to see that in the egg... :)
 
Dan Thomas said:
Landing accidents are, I believe, the largest fraction of the entire accident portfolio.
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Loss of control on the ground is the highest growing number of accidents and incidents right now.

Landing too fast and flat, guess what happens when a small gust comes along and most of the aircraft weight is still being removed by a mostly flying wing, Peter?

If you can’t get comfortable slow, or your instructor won’t demand it, you’re headed for being the next number in that statistic as you go bouncing off into the grass or break the nose gear.

Get that bad habit nipped Peter. It’ll become your first accident.

When training was hot and heavy at the home ‘drome by young CFIs and students recently, a weekly off roading excursion or more was becoming an epidemic. Numerous aircraft damaged because neither would slow down to land properly.

Also take a hard look at your POH and the data on stall speed change by W&B as well as the calibrated airspeed table. Then tell me exactly how many knots you have to lose indicated from the book approach speed until touchdown.

If you were touching down too fast I would tell you to keep it flying... don’t land yet... and on centerline until it slowed and then say “see how much better that landing was? I want you landing that slow right there.”

Then practice a few more so you can feel the controls becoming less effective as you slow (use more control deflection), the sink rate change in your butt (judge the altitude and flare height better, add a tiny burst of power to arrest if needed in gusts), see the nose start to try to not stay in line with the runway as the rudder authority fades (push it to the floor if you need it. If that isn’t enough, go around.), and the airplane start to drift off centerline as groundspeed slows (change that bank angle, touch down on the upwind main if needed and hold it there with aileron tracking straight with even more rudder).

And then keep coming with all controls except rudder all the way to the stops as the landing rollout continues. Fully deflected for wind for taxi unless something dictates otherwise. Always follow through.
 
denverpilot said:
Loss of control on the ground is the highest growing number of accidents and incidents right now.

Landing too fast and flat, guess what happens when a small gust comes along and most of the aircraft weight is still being removed by a mostly flying wing, Peter?

If you can’t get comfortable slow, or your instructor won’t demand it, you’re headed for being the next number in that statistic as you go bouncing off into the grass or break the nose gear.

Get that bad habit nipped Peter. It’ll become your first accident.

When training was hot and heavy at the home ‘drome by young CFIs and students recently, a weekly off roading excursion or more was becoming an epidemic. Numerous aircraft damaged because neither would slow down to land properly.

Also take a hard look at your POH and the data on stall speed change by W&B as well as the calibrated airspeed table. Then tell me exactly how many knots you have to lose indicated from the book approach speed until touchdown.

If you were touching down too fast I would tell you to keep it flying... don’t land yet... and on centerline until it slowed and then say “see how much better that landing was? I want you landing that slow right there.”

Then practice a few more so you can feel the controls becoming less effective as you slow (use more control deflection), the sink rate change in your butt (judge the altitude and flare height better, add a tiny burst of power to arrest if needed in gusts), see the nose start to try to not stay in line with the runway as the rudder authority fades (push it to the floor if you need it. If that isn’t enough, go around.), and the airplane start to drift off centerline as groundspeed slows (change that bank angle, touch down on the upwind main if needed and hold it there with aileron tracking straight with even more rudder).

And then keep coming with all controls except rudder all the way to the stops as the landing rollout continues. Fully deflected for wind for taxi unless something dictates otherwise. Always follow through.
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Yup. Students who don't see it demonstrated right the first time, or who are allowed to perform it the wrong way, are instantly handicapped, and it can be difficult to retrain to the correct standard. Of the Seven Learning factors, I think Primacy is the most important:

PRIMACY - Present new knowledge or skills correctly the first time. (Teach it right the first time.)

(a) When students are presented with new knowledge or skills, the first impression received is almost unshakeable. This means that what you teach must be correct the first time. Students may forget the details of lessons, but will retain an overall image of the skill or knowledge for a long time. Frequently you will be required to perform manoeuvres in the aircraft before a student has had the necessary background training. You must perform those manoeuvres correctly or the student may imitate any errors you make. For example, before the exercise on cross-wind landings, you and your student are required to land in a cross-wind. Any poor example shown at this time would have to be "unlearned" when the exercise came up in a subsequent lesson.

From https://www.tc.gc.ca/eng/civilaviat...5494.htm#part-i-learning-and-learning-factors

Scroll down to Learning and Learning Factors, under Contents.
 
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