Floating on sunshine

I thought I would go back to the beginning and fly the c172 as many suggest getting it mastered first. I've learned to be at traffic pattern and on the glidescope, full flaps and at 65kt.

 

It isn't too hard to land in the first 3rd of the runway in the c172. But considering I want to improve I know I tend to float a little.

 

Obviously when I used the larger aircraft it becomes more noticed and I typically end up touching down half way of the runway. So maybe I can learn to fix the issue in the c172.

 

Again, I come in at 65kt. I put engine to idol at the threshold of the runway and flair about 10 ft above the runway.

 

So what is it causing the float that I am missing? Oh, and wind is 0.

You're slightly fast, flaring too early and getting ground effect. Try reducing airspeed to 60kts just before crossing the threshold and flare just before touchdown. Use as much runway as you need, as long as you can brake to a stop before the end of the runway, no-one's complaining.

You're slightly fast, flaring too early and getting ground effect. Try reducing airspeed to 60kts just before crossing the threshold and flare just before touchdown. Use as much runway as you need, as long as you can brake to a stop before the end of the runway, no-one's complaining.

 

I was reading somewhere that you should lower the speed to just above stall before getting to the threshold. Then round out and flare in ground effect.

 

Not sure if that is how it should really be done though. All I know is that I need my approach speed (54-60) and I need to flare at some point.

 

So are you suggesting that I just keep it at 60 and flare later? Or should I be setting throttle to idol at some point too?

Another way to say what Tim said is to not hold the 65 until starting the flare. Instead, when "over the fence*" be at idle and very gradually start easing the nose up, with the rate of "nose up" increasing as you get nearer the ground. You do want to be sure you don't, under normal circumstances, touch down too close to the approach end of the runway, but a bit closer than 1/3 is fine.

 

The recommended approach speed for an aircraft is generally 1.3 * V_so and is, among other things, set to give a comfortable margin on final for dealing with turbulence, downdrafts, etc. As you near the ground, ground effect (or ground cushion as some would say) has the effect of lowering your stall speed and of making the wing more efficient, causing you to float. Reducing the aircraft speed when near the ground helps reduce that floating. BTW, ground effect is sometimes the cause (IRL) of takeoff accidents, especially at higher field elevations and/or hot days, since the aircraft will lift off at a speed which will not sustain flight more than a wingspan or so above the surface.

 

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* "Over the fence" is a term that basically means about where Tim was talking about reducing your speed, that is, when over the (sometimes) hypothetical airport boundary fence, but for a small field, not for a typical airline field.

Ah, ok that makes sense. So pulling back to idle at that point and slowly raise the nose to level flight? Then when close to the ground I can expect the rate of descent to decrease and combined with the flare I should end up with a nice smooth landing in the first 3rd?

 

Let me know if I got something wrong in my thoughts here. And thanks again!

How are you practicing your landings? Do you have a flight saved for that last part where you make your approach or are you flying a Mission using the C-172? I always liked using the "Sitka Landing Mission" for practice with the C-172.

the rate of descent

I hope that, at that point, you are not paying attention to "the rate of descent" on the gauges, only from looking out the window*. But basically you have the idea -- practice it and see how it goes.

 

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* Actually, if you can get it a foot off the ground and hold it there, continuing to hold it a foot off the ground until you are back at the tiedowns. :cool::pilot::pilot:

 

Obviously, you can't literally do that, but you can keep holding back pressure that long. The point is that you don't stop flying the airplane until it is stopped.

I hope that, at that point, you are not paying attention to "the rate of descent" on the gauges, only from looking out the window*. But basically you have the idea -- practice it and see how it goes.

 

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* Actually, if you can get it a foot off the ground and hold it there, continuing to hold it a foot off the ground until you are back at the tiedowns. :cool::pilot::pilot:

 

Obviously, you can't literally do that, but you can keep holding back pressure that long. The point is that you don't stop flying the airplane until it is stopped.

 

I tried out the suggestions I have been given so far and now I have been able to keep it in the first 3rd. Actually, I may have to get used to the timing of the power change to idle since I am actually landing on the number now lol.

 

Is there a rule of thumb for it? I get the threshold thing but sometimes I don't know where it is. Maybe start at a certain altitude like 200 ft?

 

Thanks guys, I know I am asking a lot of questions but you have already helped me improve.

How are you practicing your landings? Do you have a flight saved for that last part where you make your approach or are you flying a Mission using the C-172? I always liked using the "Sitka Landing Mission" for practice with the C-172.

 

Saved a flight at 2000 agl lined up about 5 miles out. Gives me time to catch the glidescope and adjust power and trim.

In addition to what others have suggested, be gentle on your flare as even at 60-65 KIAS, if you are heavy/fast in making your flare, you stand the chance of ballooning just above touchdown, and that brings on bigger problems, especially in crosswind situations!

 

When I was learning to fly RW, my instructor instilled a thought which to this day has stuck with me.

He said, think of the flare to landing as easing back on the yoke to almost a level attitude, come back on the throttle, and then, and this is his thought, "KEEP THE AIRCRAFT FLYING!" In doing so, you will be un-conscientiously (I hope I spelled that right, but you will know what I am saying) easing the yoke back bringing the aircraft into a flared attitude! When the plane decides it can't keep flying, it will gently settle down for a nice landing! This will also help you keep that nose wheel up and safe off the runway! Try this and see if it helps! And remember, Practice makes perfect, well almost perfect. Only you will know how good you are doing! No instructors in these sim aircraft!

 

Good luck! Rick :cool:

Edited October 9, 2019 by Downwind66

Saved a flight at 2000 agl lined up about 5 miles out. Gives me time to catch the glidescope and adjust power and trim.

 

If you have to catch the glideslope, then you're not yet ready to progress much. And five miles out is waaaaayy too far out for a Cessna. It shouldn't be more than a mile, and might be better at close to half a mile. If you need that five miles to stabilize the aircraft, then you should go to the practice area and do some exercises strictly in the air until you can get the aircraft slowed from cruise to approach speed, and can make level turns, climbing turns, descending turns, and straight and level flight quickly and easily (this will pay off for you later). You might go to the Real Aviation Tutorials & FAQs section of the forum, under Basic Aircraft Control, where though you already know most of this, the second half describes some very useful exercises to develop your "muscle memory" for the various maneuvers to make them second nature.

 

Back to the approach, you need to learn to judge that glideslope visually, which isn't difficult. As you descend down final, notice the spot in the windshield that is staying put, that is, it is neither moving up in the windshield nor down. That is the spot where, if you make no changes, the nose will plow into the ground. This gives you an aim point. A slight pitch change (changing the airspeed) or a slight power change (changing the rate of descent, but keep your eyes outside) will change that point of aim.

 

So as you come down final at approach speed, adjust that aim point until it is just a little short of your intended point of touchdown. Then, as you get near the ground (maybe 100 feet up or a bit less- practice will let you find the right spot), be at idle and start easing the nose up (much as Rick describes above). At this point you should be looking at the far end of the runway, which lets you more easily judge your height above the ground, so that you can level off about a foot above the ground, then as Rick describes* or, as I mentioned above, "Hold it off, don't let it touch," keep it that foot off the ground until you're back at the tiedowns, or at least until you are stopped.

 

And here, I'm going to make a suggestion that a lot of people may not agree with: Since you are still learning, don't do touch and goes. Make all your landings full stops. I've never let my students do T&G until after they've soloed, which means they know all of this.

 

The reason for full stops is two fold. One is that you then practice the complete landing to a full stop, rather than skipping the rollout, where a number of accidents happen. Two is that on the taxi back to the numbers for the next takeoff, you have a chance to think about what you did (and were you with a CFI, time to discuss this too), and to think about how to correct anything that wasn't quite right. Also, you're not in a hurry to get the airplane cleaned up for a safe takeoff, so you can experience the complete takeoff, not just a partial. Many accidents occur on takeoff, also.

 

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* Quote from Rick: "When I was learning to fly RW, my instructor instilled a thought which to this day has stuck with me."

Essentially the same thing is what my first instructor told me (which I pass on to students): Hold it six inches off the ground and keep holding it there. Taxi back to the tiedowns still holding it that six inches off the ground. When you get to the tiedowns, put the ropes through the rings and pull the airplane down that last six inches.

 

This emphasized two things: one is to fly the airplane until stopped, and the other is you don't actually land an aircraft, rather you try to hold it off, even with power at idle, until it actually lands itself. Your attempts to actually land often result in bounces or worse.

Great advice from Larry, who I think is one of the sagest contributors to these threads. I have an additional suggestion: go up a few thousand feet and practice slowing and stalling in the landing configuration (flaps down). When you get used to your airplane's slow flight characteristics, the bottom end of the speed range is a lot less scary.

hi,

go to a safe altitude above AGL and practice STALLS at various Flap settings to get the feeling for the plane as well.

 

use these numbers to fly your approach accordingly until TD.

 

sincerely g. kirschstein