Trim down vs. stick down?

Sazzy

Sazzy

Pre-takeoff checklist
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Sazzy
My instructor likes to have me trim down two rolls immediately after flaps (in a design ctls) on base, but I've read in some articles that this is unnecessary, and to simply push stick forward.

Is this a matter of preference? Last time I went up was the first time i did a few touch and go's in a row, and we did it with trim. I didnt realize there were other opinions regarding trim vs. stick forward until I did some reading today, so I have not yet had an opportunity to try stick-forward only myself. Any opinions are greatly appreciated!
 
If you can take you hand off the stick and the airspeed doesn't change you have it trimmed about right. If you have it trimmed about right you will hold you airspeed much better than if you try just hold forward pressure on stick.

Brian
 
how many more trim adjustments do you make after the initial "2 throws"?
 
Only the initial two, but I read a couple articles saying that trim wasn't necessary at all...perhaps the articles were erroneous, or maybe they were talking about AFTER the two throws?

As I said, I am flying an LSA, which i only assume would land differently than heavier planes (i just started flying this plane about a month ago after spending almost a year in a c152)
 
do some google-ating.

You should be be trimming routinely until on the ground. The "2-Throw" guess is often close, but keeping it right all the way in is important and reduces your workload.
 
I trim to take pressure off of the controls. I always move controls first then trim. I try to anticipate what is coming next too. If I’m in the pattern, I’ll likely keep the plane trimmed based on how it feels on base & final and hold a little extra pressure on upwind->downwind. In a 172 it’s not really a lot of difference.
 
See, that's what my instructor was saying...I was just curious today and googled a few questions I came up with regarding landing...I guess i just came across a few bogus articles. Thanks for confirming.
 
Trim the damn thing until it flies the airspeed you want hands off. We don't know how many turns that is... We don't fly your airplane.
Pretty simple.
 
Ok, so consensus says "trim the heck out of it until it feels right". Got it. Glad I asked!
 
Sazzy said:
Ok, so consensus says "trim the heck out of it until it feels right". Got it. Glad I asked!
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A high-wing, conventional-tail airplane will typically require nose-down trim when flaps are extended. You can anticipate this so that it doesn't surprise you, yet at the same time, the advice written above is more general and works for any airplane.
 
pigpenracing said:
Trim the damn thing until it flies the airspeed you want hands off. We don't know how many turns that is... We don't fly your airplane.
Pretty simple.
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This. Follow what your instructor is telling you. This sounds like a case of not understanding the purpose of trim.
 
kaiser said:
I trim to take pressure off of the controls. I always move controls first then trim.
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That’s the correct way. “Flying the trim” - using trim to fly the plane - is generally a bad habit and can lead to imprecision.

Though, as always, if it works for you, go for it!
 
Ryanb said:
This. Follow what your instructor is telling you. This sounds like a case of not understanding the purpose of trim.
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You are correct...I have honestly just begun actual landing training. This instructor is very different from my first instructor. Both are very good, but my first instructor had me focus mainly on in-air maneuvers and then would land the plane himself most of the time, whereas my current instructor wants me to get more comfortable getting the plane off of and back down onto the ground.

That's why I love forums like these! Thanks, all, for your tips and advice.
 
Seems like this is being over-thought. You get a certain number of hours in an airplane and you basically know that if you put the flaps down its gonna need two throws of trim. You don’t need to wait and find out or feel the forces on the yoke then trim them out. I think that’s all your instructor is doing, just making it easier for you with something that you’re eventually going to figure out for yourself anyway.
 
I do have another question then...if I don't do those 2 initial throws quickly enough, how huge of an effect will that have on my final, and can i fix that by turning base farther out? During my last class, I had two good landings and one go-around, the go-around being because either a) I trimmed too late, b) updraft, c) both.

And yes silvaire...despite me having started flying a year ago, I only have 20 hours...I'm still trying to figure things out. It's kinda difficult switching airports and instructors, but I hope to actually get the hang of it soon.
 
Sazzy said:
My instructor likes to have me trim down two rolls immediately after flaps (in a design ctls) on base, but I've read in some articles that this is unnecessary, and to simply push stick forward.

Is this a matter of preference? Last time I went up was the first time i did a few touch and go's in a row, and we did it with trim. I didnt realize there were other opinions regarding trim vs. stick forward until I did some reading today, so I have not yet had an opportunity to try stick-forward only myself. Any opinions are greatly appreciated!
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Whats your airplane like on a go around? Some planes require a lot of forward pressure on a go around. Already having to hold forward pressure before the go around is initiated is just going to make that worse. I've read of folk who like to trim to hold a little back pressure on final to compensate for this.
 
My Pitts has no trim... I have a fixed trim tab and it flies hands off full power straight and level.
When I land I pull the power and fly it to the ground and it really has no stick pressure.
Now the Bonanza is a different story, You throw the gear down and drop the flaps it requires lots of trim all the way to the ground.
They are all different....
 
Sazzy said:
I do have another question then...if I don't do those 2 initial throws quickly enough, how huge of an effect will that have on my final, and can i fix that by turning base farther out? During my last class, I had two good landings and one go-around, the go-around being because either a) I trimmed too late, b) updraft, c) both.

And yes silvaire...despite me having started flying a year ago, I only have 20 hours...I'm still trying to figure things out. It's kinda difficult switching airports and instructors, but I hope to actually get the hang of it soon.
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Only effects muscles. Use the stick to get the attitude you want... make the airplane do what you command. Then trim to take pressure off of the controls.
 
luvflyin said:
Whats your airplane like on a go around? Some planes require a lot of forward pressure on a go around. Already having to hold forward pressure before the go around is initiated is just going to make that worse. I've read of folk who like to trim to hold a little back pressure on final to compensate for this.
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The airplane I fly is a CTLS, and on go-around, it's a matter of full power, pull back, deal with flaps once you're back off the ground. I'm lucky that I'm flying a plane that is capable of flying itself for a small time. I've never been instructed to re-trim further than one throw during a go-around, and that was only if we weren't immediately returning to the pattern.
 
kaiser said:
I trim to take pressure off of the controls. I always move controls first then trim. I try to anticipate what is coming next too. If I’m in the pattern, I’ll likely keep the plane trimmed based on how it feels on base & final and hold a little extra pressure on upwind->downwind. In a 172 it’s not really a lot of difference.
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What this guy said.
 
I think its because he always has me trim back before re-entering a pattern, for practice-sake
 
Sazzy said:
The airplane I fly is a CTLS, and on go-around, it's a matter of full power, pull back, deal with flaps once you're back off the ground. I'm lucky that I'm flying a plane that is capable of flying itself for a small time. I've never been instructed to re-trim further than one throw during a go-around, and that was only if we weren't immediately returning to the pattern.
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I'm with your instructor. Knowing that it's going to be 'about' two rolls to get in trim when you throw the flaps out, just do it. Then fine tune it from there. I don't see any advantage to not being trimmed.
 
It is much more difficult to precisely control the aircraft for long when it is not neutrally trimmed. You should normally always trim the aircraft to maintain the current flight speed and regime (level flight climb, descent) with no pressure on the controls. That way, if you release pressure you know what the plane will do, and if you feel pressure you know you are deviating from the current flight regime. Deploying flaps will change the required elevator position to maintain the current flight regime, so you should trim out that change. For example deploying flaps on my AA5 on downwind will cause a nose down pitch which is trimmed out with a short roll of the trim wheel nose up. I don't want to have to hold nose up pressure all the way down final, and have no good feel for the landing flare pull required when that time comes. Use your trim to neutralize control forces and give you consistent feel for the landing flare.
 
As mentioned already you should trim the controls constantly so you don’t have to hold pressure. After 20 landings you should notice that it always takes about x (probably 2) clicks of trim after adding flaps. And presto, you end up right where your CFI led you.

Ps> the skycatcher is exactly the same. Add a notch of flaps while pushing forward a bit, trim it off with 2 clicks. Works every time.
 
This is a good topic. I have an electric trim in the 182. I find having electric trim I now trim a lot more so that I have to provide little control input to elevator. I like to have it trimmed on final to have more effortless control to allow for a better flare to get that stall horn chirping. Poor trimming make you slam it down.
 
Do a lap without touching the trim.

Then do one with the 2X only.

Then do one with the 2X AND adjusting all the way in.

You're trimming on landing will be forever improved.
 
From the book of CFI wisdom: “I’m never not trimming.”
 
My first instructor wouldn’t teach or let me use the trim. I was exhausted after every flight.

Flew with a different instructor and drilled trim trim trim and you don’t need more than 2 fingers to fly an airplane. Flying, maneuvers and landings got a lot better after that.
 
Op, keep it in trim, the articles are correct in that you can fly and land in an untrimmed condition, but life is a lot harder that way. It requires much more concentration and effort to maintain altitude, airspeed, glidepath in an untrimmed airplane. As a distraction occurs, you lose a little focus in keeping the airplane where you want it fighting the controls, the airplane pushes back to the attitude and airspeed it is mistrimmed to. So as a matter of how you should be flying the articles are wrong.

Keep in mind, that "two throws" of the trim wheel is the action that gives you a result. As a pilot you perform many actions that give you a result. While the action and the ability to do it when needed is important, the most important thing to understand is the result is what you want to focus on, not the action. In your trim example, "two throws" of the trim, along with a power setting, give you an attitude that results in a desired airspeed and descent rate. The completion of your task is not "two throws" of the trim wheel, but the resultant airspeed and descent rate. You set the power if needed, put in the flaps, give the trim "two throws", wait to stabilize, then look at the result. You should see something like 70 knots and 500 fpm descent. If instead you see 65 knots and 400 fpm, you may need to add another " throw of trim until you get the airspeed and descent you want. These adjustments can be affected by full tank versus almost empty tank. More load in the back of the airplane, hot day versus cold day, all change the action required. That's why it's important to always think of the result of an action as the final indicator of something being done, versus just doing the action.
 
The trim setup on my ride is total ****. So, I tend to not use it for short term corrections. Yes, you can fly down final and land with a bunch of pressure on the stick, but as someone who does that, I don't recommend it. You loose a lot of feel.
There are some aircraft that take enough trim that it would cause problems on a go-around. But unless there is some specific reason not to - trim.
 
Jamie Kirk said:
My first instructor wouldn’t teach or let me use the trim. I was exhausted after every flight.
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That’s a bad instructor that should’ve been fired. Unfortunately, you probably didn’t know any better at the time.
 
Ryanb said:
That’s a bad instructor that should’ve been fired. Unfortunately, you probably didn’t know any better at the time.
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I wanted to say something but was at a loss for words. "Bad" doesn't quite describe someone teaching the exact opposite of what you're supposed to.
 
Jamie Kirk said:
My first instructor wouldn’t teach or let me use the trim. I was exhausted after every flight.

Flew with a different instructor and drilled trim trim trim and you don’t need more than 2 fingers to fly an airplane. Flying, maneuvers and landings got a lot better after that.
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The trim was probably broken.
 
My primary instructor never said NOT to trim, but he did tell me if he ever caught me using the electric trim he would break my thumb.

He also refused to teach Auto Pilot usage until I was in Checkride prep.

His theory, with which I still agree, was that the plane knows how to fly. I need to learn how to fly it. I can play video games at home.
 
Sazzy said:
My instructor likes to have me trim down two rolls immediately after flaps (in a design ctls) on base, but I've read in some articles that this is unnecessary, and to simply push stick forward.

Is this a matter of preference? Last time I went up was the first time i did a few touch and go's in a row, and we did it with trim. I didnt realize there were other opinions regarding trim vs. stick forward until I did some reading today, so I have not yet had an opportunity to try stick-forward only myself. Any opinions are greatly appreciated!
Click to expand...
How far along in your training are you? I was taught similarly. It's a good rule of thumb for beginners. You will learn to fine-tune it more as you gain experience. Generally any time you make a power adjustment, you should be checking trim. Someone mentioned you should be able to fly hands off without the airspeed changing. Which is true. Remember, there are 3 keys to good landings:

1. Airspeed control.
2. Airspeed control.
3. Airspeed control.
 
Sazzy said:
My instructor likes to have me trim down two rolls immediately after flaps (in a design ctls) on base, but I've read in some articles that this is unnecessary, and to simply push stick forward...
Click to expand...

A lot of comments of a generic nature being made about the OP's question which is about a specific action in a specific aircraft at a specific point of approach on which he has seen two different opinions (one from his current instructor and another from articles he has read) My guess is it could probably be done either way but I'll ask my own question of the OP or anyone else who flies a Design CTLS:

When you put the flaps down on base you apparently need to either push the stick forward or dial in two rolls of nose down trim but what happens after that? Since you are probably not yet down to your final approach speed do you then eventually, as you slow further, relax the forward pressure on the stick or need to undo the two rolls of trim? Because, if that's the case then forward stick pressure probably makes a bit more sense especially in an aircraft like this with presumably very light control pressures to begin with.

Like I said earlier, you're probably over-thinking this whole thing.
 
Generally speaking, I would advise to always use trim to relieve control pressures... It takes most of the work out of maintaining a stable airspeed on approach... That said, my Mooney makes it necessary to pull the yoke while putting in flaps or it will quickly accelerate back above the white arc... but my next move is still to trim out the control pressure... To the OP: I strive to trim to a known pitch and power to achieve a desired result... especially in the pattern... IMHO I suggest you learn what works in your airplane and use it.
 
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