Landing a C172 - power off at threshold or flare?

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blackbird7
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Landing a C172 - power off at threshold or flare?

Post by blackbird7 »

Hi all,

I'm looking for some advice on landing the C172 and most GA aircraft in general. The checklists for the C172 recommend to land with throttle power off. However, it's not clear to me when the power off phase should actually occur.

My current method is to pull the throttle from 1500 rpm down to 1000 rpm when crossing the runway threshold and then to coast the C172 in for a smooth landing at the 1000 rpm power setting. I seem to get the smoother landings and flares this way. I do realize that I am likely eating up more runway by not moving the throttle to idle, and I think that that is why the checklists recommend idle power.

I've tried idle power at the threshold, but I can't seem to get very smooth landings this way. Is it better to idle the power during the flare right before touchdown? Or is the idle power at threshold a recommended technique that I just need to master? :)

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Re: Landing a C172 - power off at threshold or flare?

Post by MarcE »

High power approaches in single engine props are actually a bad habit by Flightsim pilots as many or actually almost all default and "simple" addons use the physic engine of the sim. Too much drag.

The 172 normally needs VERY little power on a standard final decent. The flaps at 20 or even 30 don't create as much drag as one would think. The A2A Cessnas are very close to what I was used to when I flew it in reality. I used to approach the runway with just a little more power than needed to prevent the prop from stopping (carburator engine) as this was enough to fly a proper approach at around 60 kts and cut the power over the numbers/threshold, then flare the airplane and hold it close above the runway until it sits down.

If you had to fly with a relatively high power setting you would risk not to make the runway in case you lost your engine. A private Archer was almost destroyed at our aerodrome due to a too low approach well above idle (I hope it's the correct translation, in german airman's language you say "Schleppgasanflug") when the engine suddenly lost power and he had to take the colza field just 150m from the runway.

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dvm
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Re: Landing a C172 - power off at threshold or flare?

Post by dvm »

A wise old sage taught me (several thousand hours in a 172) to chop the power when abeam the end of the runway on downwind and adjust your turn to final and decent to put it on the numbers. Practice practice practice. As MarcE says if you have a engine problem you will be able to always make the runway.

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DHenriques_
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Re: Landing a C172 - power off at threshold or flare?

Post by DHenriques_ »

blackbird7 wrote:Hi all,

I'm looking for some advice on landing the C172 and most GA aircraft in general. The checklists for the C172 recommend to land with throttle power off. However, it's not clear to me when the power off phase should actually occur.

My current method is to pull the throttle from 1500 rpm down to 1000 rpm when crossing the runway threshold and then to coast the C172 in for a smooth landing at the 1000 rpm power setting. I seem to get the smoother landings and flares this way. I do realize that I am likely eating up more runway by not moving the throttle to idle, and I think that that is why the checklists recommend idle power.

I've tried idle power at the threshold, but I can't seem to get very smooth landings this way. Is it better to idle the power during the flare right before touchdown? Or is the idle power at threshold a recommended technique that I just need to master? :)
Try not to think of a specific power setting for a VFR approach. Just stabilize the airplane at your approach air speeds and use power as needed. Your key and ONLY key on the approach is to arrive over the numbers at the right altitude and right airspeed to enter the flare.
Dudley Henriques

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bladerunner900
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Re: Landing a C172 - power off at threshold or flare?

Post by bladerunner900 »

What Mr. Henriques said. I go by feel mostly for landing. As much as one can get feel in a sim anyway. Although, when landing a tricycle, I have to consciously remember NOT to put the tail down at the same time as the other pair of wheels.

Steve.

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thunderstreak
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Re: Landing a C172 - power off at threshold or flare?

Post by thunderstreak »

I think the key to a good landing is a nice stable approach, especially on final.
Make sure flaps, gear, prop are all set long before turning final.
Don’t worry so much about specific power settings.
Using the yoke or stick maintain your approach speed.
Too fast pull slightly, too slow push slightly.
If you start to sink, add a little power, if you are too high reduce power, but keep that speed right.
Perhaps practice landing first with a little power still on and cut the throttle at touch down.
Eventually, with practice you will master landing power off.
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Re: Landing a C172 - power off at threshold or flare?

Post by Caldemeyn »

Also with the ch yoke during gliding just above the surface, in the last moments before touchdown i pump the yoke a little bit with tiny movements up down as i feel is needed and it helps me to keep the plane in a correct attitude and not overcontrol just as the plane stalls, put it down gently, it is quite sensitive there. Maybe its becouse of the smaller throws available. Before that i just increase the yoke aft.

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CAPFlyer
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Re: Landing a C172 - power off at threshold or flare?

Post by CAPFlyer »

I will echo everyone else here. I usually pull power back (in a 172) to around 1700 RPM about abeam the numbers on downwind. The next time I touch the power if I did everything right should be to pull it all the way off once I have the runway made and everything else set. That way I'm focusing on flying the airplane. Typically for me, this ends up being when I'm about crossing the fence as I tend to fly a bit of a high approach to give plenty of time and altitude should I have an engine failure. The "perfect" approach would be one where you could pull the power all the way off abeam the numbers and fly it to land, but that usually results in a very short final approach which can make passengers (and other pilots) a bit uneasy, so I only practice that procedure occasionally and try to be a bit more courteous of others in the pattern by keeping a more "normal" pattern where I turn base when the threshold is about 45* behind me and carrying a little power.
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blackbird7
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Re: Landing a C172 - power off at threshold or flare?

Post by blackbird7 »

Thanks everyone for the great advice. It's greatly appreciated, and I look forward to using these tips to improve my landings. :)

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MaxZ
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Re: Landing a C172 - power off at threshold or flare?

Post by MaxZ »

thunderstreak wrote: Using the yoke or stick maintain your approach speed.
Too fast pull slightly, too slow push slightly.
If you start to sink, add a little power, if you are too high reduce power, but keep that speed.
Hi everybody, hi thunderstreak!
I treat every VFR approach like a precision app. elevator to maintain aiming point and power/thrust to maintain speed. that way you have overall smaller corrections which in turn makes for a more stabilized approach. Just my two cents!

Greetings from LFEX,
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Simicro
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Re: Landing a C172 - power off at threshold or flare?

Post by Simicro »

DHenriquesA2A wrote:Your key and ONLY key on the approach is to arrive over the numbers at the right altitude and right airspeed to enter the flare.
Dudley Henriques
By "numbers", do you mean the markings of the runway numbers?
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scottb613
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Landing a C172 - power off at threshold or flare?

Post by scottb613 »

Hi Folks,

Right or wrong - I was taught the “chop and drop” approach in a c172 - as soon as the field is made on final - I’m a glider at idle power... It stuck - if I move to bigger heavier aircraft I may have to change my method... YMMV...

Regards,
Scott


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speedy70
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Re: Landing a C172 - power off at threshold or flare?

Post by speedy70 »

Simicro.
Yes he does.The numbers on the runway.

Cheers chris

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Simicro
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Re: Landing a C172 - power off at threshold or flare?

Post by Simicro »

Thank you speedy70.
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AKar
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Re: Landing a C172 - power off at threshold or flare?

Post by AKar »

scottb613 wrote:Right or wrong - I was taught the “chop and drop” approach in a c172 - as soon as the field is made on final - I’m a glider at idle power... It stuck - if I move to bigger heavier aircraft I may have to change my method... YMMV...
What few lessons I've had in powered airplanes, that's exactly what I was told to do as well. IMO, it gives much better control of the airplane's energy and much better feel into the flare in the simulator as well than chopping the throttle only late over the runway, usually ending up in late and low, but high energy flare-like maneuver.

-Esa

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