When to pull throttle idle on landing.

Checkout_my_Six said:
Carb’d 0-540…..260HP. Surprised me. I’d seen it in my C-150 with an 0-200. That was a real ice maker.

after that experience I went back to using regular carb heat below 1,800 RPM.
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My worst carb Ice event occurred at about 400 feet after take off, engine started running rough and lost about 200 rpm. Was a 1st test flight on a new engine in a C-150. I pulled the carb heat and lost another 200 rpm. Had just enough power (2100rpm) and had already started a turn back to runway as soon as the engine started running rough.
At the 180 point of the turn I had the runway made so decided to continue downwind and make a normal if not low pattern for the runway. About mid-field, about 30 seconds after pulling on the carb heat, the RPM increased about 200 Rpm to a normal RPM with Carb heat on. After landing I performed another run up and all was good completed the test flight with no further issues. Determined the likely cause was the extended run up I did one the new engine after checking the carb heat and near ideal conditions for Carb ice. For the rest of the takeoffs I left the Carb heat on until I was advancing the throttle for takeoff.

Brian
CFIIG/ASEL
 
Jayboard said:
But in crosswinds, strong headwinds, or tailwind (gulp!) keep some power in for control authority.
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I’ve never flown anything that lacked adequate control authority for headwinds, crosswinds, or tailwinds at idle.
 
Jayboard said:
But in crosswinds, strong headwinds, or tailwind (gulp!) keep some power in for control authority. Watch your airspeed. Another trick is power to idle over the fence and then ease a little power back momentarily in the flare and continue to touchdown back to idle. Because you’re on the backside of the power curve, a little bit of throttle will serve to grease wheels on runway.
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Don’t know what you fly, but if I did this with my Mooney it would result in a overrun.
A better idea is just to not use flaps with strong crosswinds.

And add power for a tailwind?!! You’re insane.
 
Crashnburn said:
I'm learning to fly in a SportStar….As soon as we cross the fence, pull the throttle to idle, and go to full flaps. After that, keep descending until you feel like you're about to hit the runway.
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If that’s how you’re being taught and it’s working for you, have at it.

But just know that, in general, configuration changes on final - especially short “crossing the fence” final - are generally frowned upon. Because they kind of violate the “stabilized approach” concept. I may have flown that way in the past, and even taught it*, but I’ve found being squared away in your landing configuration on base, or at least right after turning final, make the whole process easier by eliminating one more variable in the process.


*I’m recalling that in Cessnas with 40° of flaps, we’d put in the last 10° “with the runway made”. Doable, but I now believe it was making things unnecessary difficult for the student.
 
Jayboard said:
But in crosswinds, strong headwinds, or tailwind (gulp!) keep some power in for control authority.
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Like MooneyDriver78 and MauleSkinner, I think this is bad advice. 1.3 or even 1.2 Vso should give you plenty of control authority at idle.

None of the conditions mentioned - crosswinds, strong headwinds, or tailwind - require any additional power. What might need an adjustment in gusty conditions is speed, increasing approach speed by 1/2 the gust velocity as a rule of thumb. But even that does not necessarily require power. I think, overall, far too many pilots get used to carrying power to gloss over their lack of skill in other areas.
 
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FastEddieB said:
*I’m recalling that in Cessnas with 40° of flaps, we’d put in the last 10° “with the runway made”. Doable, but I now believe it was making things unnecessary difficult for the student.
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I agree, my SOP as an instructor in such cases was 30° flaps for normal landings and 40° for short field.
 
While power might give you a small amount of extra flow over the tail, airspeed is the prime control factor. I've not seen many planes that don't lack control authority until you get well below Vs.
 
Jayboard said:
But in crosswinds, strong headwinds, or tailwind (gulp!) keep some power in for control authority.
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I'm a low-time pilot. Could you please explain to me the difference in control authority at idle between a headwind and a tailwind? And how does the plane know aerodynamically which it is in?
 
FastEddieB said:
Like MooneyDriver78 and MauleSkinner, I think this is bad advice. 1.3 or even 1.2 Vso should give you plenty of control authority at idle.

None of the conditions mentioned - crosswinds, strong headwinds, or tailwind - require any additional power. What might need an adjustment in gusty conditions is speed, increasing approach speed by 1/2 the gust velocity as a rule of thumb. But even that does not necessarily require power. I think, overall, far too many pilots get used to carrying power to gloss over their lack of skill in other areas.
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For real. Flying is like any other activity. Some people have weird ideas about technique. Some people fly like Charles Barkley's old golf swing LOL.

https://tenor.com/oYxi.gif
 
Half Fast said:
I'm a low-time pilot. Could you please explain to me the difference in control authority at idle between a headwind and a tailwind? And how does the plane know aerodynamically which it is in?
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Quartering tailwind, bad ju ju baby.
 
PaulS said:
You're welcome, don't believe me? Go try it out.
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No, I don't want to land in a quartering tailwind. But that wasn't my question. My question was

Half Fast said:
Could you please explain to me the difference in control authority at idle between a headwind and a tailwind? And how does the plane know aerodynamically which it is in?
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The correct answers would be (1) there isn't any and (2) it doesn't.

The plane is moving in a mass of air, and regardless of the direction that mass is going, control authority is determined by the movement of the plane relative to that air mass.

If the air mass is moving in an awkward direction relative to the runway (such as a quartering tailwind), that will make landing a challenge. But that's not because the wind causes less control authority. Rather, it might be that an inordinate amount of control authority is required to align the plane with the runway in that situation.
 
Half Fast said:
No, I don't want to land in a quartering tailwind. But that wasn't my question. My question was



The correct answers would be (1) there isn't any and (2) it doesn't.

The plane is moving in a mass of air, and regardless of the direction that mass is going, control authority is determined by the movement of the plane relative to that air mass.

If the air mass is moving in an awkward direction relative to the runway (such as a quartering tailwind), that will make landing a challenge. But that's not because the wind causes less control authority. Rather, it might be that an inordinate amount of control authority is required to align the plane with the runway in that situation.
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If you knew the answer why did you ask the question?
 
Jayboard said:
If winds calm then yes, power to idle over the numbers and glide in. You should hear the stall horn just at touchdown if done right. But in crosswinds, strong headwinds, or tailwind (gulp!) keep some power in for control authority. Watch your airspeed. Another trick is power to idle over the fence and then ease a little power back momentarily in the flare and continue to touchdown back to idle. Because you’re on the backside of the power curve, a little bit of throttle will serve to grease wheels on runway.
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Ah, yes. The stall horn. If it's set right, as per the service manual, it should sound at 5 to 10 MPH/Kt above the stall. If it isn't sounding at touchdown, you're definitely too fast. If it's set right.

And that gives the lie to the "full-stall" landing baloney. Most pilots never hear that horn in the landing. They're so far above the stall it's not funny.
 
Half Fast said:
No, I don't want to land in a quartering tailwind. But that wasn't my question. My question was



The correct answers would be (1) there isn't any and (2) it doesn't.

The plane is moving in a mass of air, and regardless of the direction that mass is going, control authority is determined by the movement of the plane relative to that air mass.

If the air mass is moving in an awkward direction relative to the runway (such as a quartering tailwind), that will make landing a challenge. But that's not because the wind causes less control authority. Rather, it might be that an inordinate amount of control authority is required to align the plane with the runway in that situation.
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Ok, a more serious answer to this. For your original answer to Jayboard, I mostly agree, especially in landing, adding power to increase control authority is not something I would do . But even so, there may be some taildraggers where that is warranted, so who knows, but not any of the planes I fly.

For your response I quoted here, keep in mind, that what you say is applicable when your airplane gets into what I call a steady state condition. Nothing accelerates instantaneously, the best example of this I can think of in wind shear, where you are tooling along on approach, got your airspeed nailed, you hit some shear and your airspeed indicator drops 10 knots. All of a sudden you are part of a different airmass, things have not had time to achieve a steady condition. and your control authority is definitely changed. It's a subtle thing, but it happens. In the case of wind shear on the approach, in the aircraft we fly, the correct answer is usually more power and maybe lower the nose. A better answer of course is that you know about it ahead of time because you checked the weather and adjusted your approach accordingly, but nothing is perfect.

I think where this can become more of an issue is landing, sudden shifts, changes of direction and/or velocity can cause decreased control authority, lower lift, direction changes. Maybe momentarily, but close to the ground it can scare the crap out of you. Does it happen often, it depends on where you are at flying. I was going to fly today, but the winds were forecast to be over 20 knots, turns out they are gusting to 33. Too much for me.

So is it a huge problem? It shouldn't be, but I found out a long time ago, looking for a recipe, like x power, x degrees nose down/up or whatever, expecting control inputs to be consistent on each approach is a fool's errand. You do what you need to do to keep an approach stable, on the proper speed for the conditions, the proper glide slope, proper aim spot, whatever. This means control input as appropriate for the deviation you are experiencing.
 
PaulS said:
Ok, a more serious answer to this. For your original answer to Jayboard, I mostly agree, especially in landing, adding power to increase control authority is not something I would do . But even so, there may be some taildraggers where that is warranted, so who knows, but not any of the planes I fly.

For your response I quoted here, keep in mind, that what you say is applicable when your airplane gets into what I call a steady state condition. Nothing accelerates instantaneously, the best example of this I can think of in wind shear, where you are tooling along on approach, got your airspeed nailed, you hit some shear and your airspeed indicator drops 10 knots. All of a sudden you are part of a different airmass, things have not had time to achieve a steady condition. and your control authority is definitely changed. It's a subtle thing, but it happens. In the case of wind shear on the approach, in the aircraft we fly, the correct answer is usually more power and maybe lower the nose. A better answer of course is that you know about it ahead of time because you checked the weather and adjusted your approach accordingly, but nothing is perfect.

I think where this can become more of an issue is landing, sudden shifts, changes of direction and/or velocity can cause decreased control authority, lower lift, direction changes. Maybe momentarily, but close to the ground it can scare the crap out of you. Does it happen often, it depends on where you are at flying. I was going to fly today, but the winds were forecast to be over 20 knots, turns out they are gusting to 33. Too much for me.

So is it a huge problem? It shouldn't be, but I found out a long time ago, looking for a recipe, like x power, x degrees nose down/up or whatever, expecting control inputs to be consistent on each approach is a fool's errand. You do what you need to do to keep an approach stable, on the proper speed for the conditions, the proper glide slope, proper aim spot, whatever. This means control input as appropriate for the deviation you are experiencing.
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Agreed. I was referring to a steady-state condition, like a constant tailwind. Transient conditions are different and can be scary close to the ground. You're right, there's no complete recipe. A pilot just has to adjust in real time to what comes at him.

I trained at X04 (Apopka, FL) and the only constants were transients. The proximity of hangars to the runway tends to funnel winds, and at the south end the runway is on top of a berm. Consequently the winds swirl and have funny up and down movements. The runway also has a downward slope at the south end. There's often a wind shear on final, too.

I learned to come in a bit high on final in anticipation of the shear. If it didn't happen I'd do a brief slip to lose altitude.

More than once I've seen the windsocks at each end of the runway pointing at each other. Fun landings. Especially in the LSA I trained in.
 
brcase said:
My worst carb Ice event occurred at about 400 feet after take off, engine started running rough and lost about 200 rpm. Was a 1st test flight on a new engine in a C-150. I pulled the carb heat and lost another 200 rpm. Had just enough power (2100rpm) and had already started a turn back to runway as soon as the engine started running rough.
At the 180 point of the turn I had the runway made so decided to continue downwind and make a normal if not low pattern for the runway. About mid-field, about 30 seconds after pulling on the carb heat, the RPM increased about 200 Rpm to a normal RPM with Carb heat on. After landing I performed another run up and all was good completed the test flight with no further issues. Determined the likely cause was the extended run up I did one the new engine after checking the carb heat and near ideal conditions for Carb ice. For the rest of the takeoffs I left the Carb heat on until I was advancing the throttle for takeoff.

Brian
CFIIG/ASEL
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There are documented accidents right after takeoff due to carb ice that accumulated during taxi and hold short and so on. Even in Lycomings. Taking off with ice in the carb limits the power so that any further icing chokes the engine.

I taught my students to pay attention to the METARS even on really nice days. When the temp and dewpoint are close, watch out for carb ice. I used to hear the engine try to die when they closed the throttle after the runup on beautiful summer mornings, first start of the day, even in Lycomings. They would push the throttle in to save it. I'd walk out, rap on the window, and tell them to pull the carb heat. They'd do that and see the RPM rise two or three hundred RPM. Their eyes would get big. Nothing like the real thing to move the mind from the academic to the concrete.
 
MauleSkinner said:
I’ve never flown anything that lacked adequate control authority for headwinds, crosswinds, or tailwinds at idle.
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Exactly. The relative wind is all that matters. The airplane has no sense of groundspeed. Gravity only works in the vertical.
 
PaulS said:
Quartering tailwind, bad ju ju baby.
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Doesn't mean a thing in the air. Having a tailwind on the ground in a taildragger can make some rollout/taxi issues challenging but holding power on final doesn't do anything to help that.
 
flyingron said:
Doesn't mean a thing in the air. Having a tailwind on the ground in a taildragger can make some rollout/taxi issues challenging but holding power on final doesn't do anything to help that.
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Thread is about landing.
 
Half Fast said:
No, I don't want to land in a quartering tailwind. But that wasn't my question. My question was



The correct answers would be (1) there isn't any and (2) it doesn't.

The plane is moving in a mass of air, and regardless of the direction that mass is going, control authority is determined by the movement of the plane relative to that air mass.

If the air mass is moving in an awkward direction relative to the runway (such as a quartering tailwind), that will make landing a challenge. But that's not because the wind causes less control authority. Rather, it might be that an inordinate amount of control authority is required to align the plane with the runway in that situation.
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Learn well you have, Grasshopper.
 
PaulS said:
Thread is about landing.
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Yes, but the supposition this was referring to was that you needed to keep "power on DURING THE APPROACH to maintain control authority" it is ludicrous.
 
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