I don't think I understand trim...

... I mean I understand what it does and why you would do it. What I'm having trouble with is its usefulness anywhere other than cruising. I have pitch trim set up as a thumb button on my yoke, so it's very easy to adjust. But, for instance, if I try to trim for ascent, by the time I have it set correctly I'm already at cruise altitude. Kind of the same thing during approach. If I try to trim for descent by the time I get it correct, it's time to flare. LOL.

 

Is it just that I'm new and it's one of those things that I'll learn to do automatically?

Kirk - Yes, right now it just seems like another item that you don't really need, and you are correct! But it will become your friend and it will help your flying the aircraft that much easier. It won't make decisions for you, but it will ease the controls when you need help the most! Still sounds like an un-necessary item, right? When you start taking your RW flying lessons, when you reach the session which involves "slow flight," you will understand more about that wheel and become closer to it!

 

Years ago, I flew sky divers with a Cessna 170B model. It was so underpowered for the "task at hand" that you were literally flying that plane by the "seat of your pants!" I became very close to that trim wheel in that 170 in those conditions. I allowed myself to become dependent on that wheel, not that I needed it, just made my job that much easier. Flying "on the edge," making small corrections with the trim wheel rather than trying to make small corrections with the yoke and possibly over-correcting instead.

 

Kirk, you are learning to fly the hard way, and that's not a bad thing. If you were taking RW flying lessons now, you would have an instructor sitting next to you, helping you along the way, answering any questions you might have! All the ingredients to flying will someday come together for you! Example, like the saying, "Throttle means altitude, the yoke means airspeed!" Sounds simple enough and your instructor would show you how that makes sense. Now, add the trim wheel to those ingredients and ask yourself, how can a trim wheel help me with this saying? It will help immensely when making an approach to land. Left hand on the yoke, eyes on the airspeed indicator, and your right hand on the trim wheel. Kind of like driving a stick shift, you are doing all these things automatically and not really thinking about it, until later and you realize you did do all these things many times, just to get you home safely! For now, just know that every item in that cockpit has a purpose. When you finally know what each and every item does, you can then sit back and rationalize how everything contributes to the total act of flying!

 

So this is a long way of answering your question! In the short of it all, Yes, you are new, and it is one of those things that you will learn to do automatically! Do you have children? If you do, then think about the time when you first tried to teach them to tie their shoes. I don't know about you, but, how do you put that automatic task into words for someone else who has never done it! It really takes some thought to make that explanation!

 

Anyway, Kirk, hang in there. You are learning something we all love and cherish. Someday, you will get long winded like this old %#@%! Like my wife tells me, "you sure love to hear yourself talk!"

 

Happy flying, be careful! Rick :cool:

Basically, it's letting the airplane do most of the work. If you can't get trim adjusted during the climb much before leveling, either you're not climbing very far or you're taking way too much time and effort to set the trim. If I'm in a Bonanza and climbing only 500 feet, I'll still use the trim, and while it will seem a constant trimming effort, it doesn't take long and it takes a lot of the effort out of holding the pitch attitude needed for climbing (or any other change). However note that in the Bonanza you don't really get down to "climb speed" before reaching that 500 foot change, so at 100 feet or so before your desired altitude you're already starting to lower the nose a tad, so it will feel as if you're almost constantly trimming. Doing that same 500 feet in a Cub lets you get the pitch attitude established and pressures trimmed off well before reaching altitude, so it's a tad different experience, more like 1500 feet or more in the Bonanza.

 

Perhaps you're chasing the airspeed (or rate of climb, which is worse). If so, that may be your problem. Basically, from cruise (whether fast or slow cruise), add back pressure to establish the pitch attitude needed for the climb -- practice will help you find that attitude quickly -- then trim the pressures off, but since you know you'll need nose up trim you can actually add some of that early, about the time you add the back pressure (but don't fly with the trim -- that's for the stick/yoke). Granted that for a short climb you may not have it completely trimmed before leveling, but it still reduces your workload, once it becomes an automatic habit, and comes more quickly.

 

A lot of the problem for short climbs is that as you raise the nose, the airspeed bleeds off, requiring trim change, but it doesn't happen all at once so the trim can't be set all at once. The same is true, of course, for descents, but INcreasing airspeed, though a power reduction can compensate for most of that trim change.

 

As Rick indicates, in real life, it's a major time and effort saver, and it can be the same in the sim.

 

So let me suggest an exercise that I have always put my students through:

 

In a C-172, Cub, or aircraft of similar performance, level off a couple of thousand feet up (from sea level maybe 2000 MSL, from Denver maybe 7000 MSL) and get the aircraft trimmed up for level flight with 2100-2200 RPM. This gives you additional power available for maneuvers, should you wish.

 

Once level, without changing power, raise the nose a few degrees (the attitude that in a sustained climb will give you 70 knots -- 70 mph in the Cub -- in the climb) and hold that attitude (looking outside, NOT at the gauges except for a quick glance at the airspeed), trimming to take off the pressures. Hold that attitude and make minor adjustments once the aircraft has slowed to maintain the above airspeed. You are aiming for a 1000 foot climb, so 50-100 feet before reaching the altitude, start adding forward pressure, easing the nose down and trimming as needed to take the pressures off. Now do the same thing for a 1000 foot descent, noting the airspeed increase as you get about 500 FPM descent rate, so 100 feet above your altitude add back pressure to stop the descent, adjust trim as needed until you are back at the same original speed at that 2100 to 2200 RPM and established in level flight.

 

Do the above several times, noting what the pitch attitude is (looking outside -- get that sight picture). Once you're comfortable with that, starting doing the same thing, but in a 25º banked turn -- be sure you practice both directions -- for the climb and descent.

 

Once that's comfortable, make the altitude change 500 feet instead of 1000 and repeat all the above. You are trying to develop habits that will stick with you in all your flying, so practice this well. Once those are all comfortable, start changing power during the exercise to maintain a constant airspeed during climb and descent.

 

There are many other things I could suggest, but try this for now and see if it helps you.

Larry - Well put and a very good exercise! I really think trying to learn on a sim would be much more difficult than the real instruction, but he will get if if he can stick with it and keep asking the right questions!

 

Rick :cool:

You always trim the plane for takeoff, and that is what I do. If you fly say the PMDG 737 you have a set trim prior to takeoff. I use trim all the time when I land. I manually follow the ILS and depending on the fuel and load, aircraft, etc, you want to maintain a certain VS while on glideslope. So trim becomes necessary to try and maintain that VS without having to push down and pull up on the yoke so much. You literally trim to that VS. For me in the F-22 it's around 600/800 feet per minute on the ILS.

Thank you, guys, for the replies. And the encouragement. Larry, your suggested exercise(s) sound to me like a real challenge. Which I'm up for!

 

I want to learn and understand everything. And you all here are so generous with your experience and knowledge. Thank you.

 

Now, me and the trim wheel are going to spend some time together.

... I mean I understand what it does and why you would do it. What I'm having trouble with is its usefulness anywhere other than cruising. I have pitch trim set up as a thumb button on my yoke, so it's very easy to adjust. But, for instance, if I try to trim for ascent, by the time I have it set correctly I'm already at cruise altitude. Kind of the same thing during approach. If I try to trim for descent by the time I get it correct, it's time to flare. LOL.

 

Is it just that I'm new and it's one of those things that I'll learn to do automatically?

 

Change power, change weight, change trim.

It's as necessary as night following day - but it's usefulness really becomes apparent when you let go of the controls, or take your eyes off of the prize for more than an instant...

One of the things you need to fully understand is power versus trim. Lesson 4- Slow Flight in the learning section gave me the understanding that was needed to properly use the trim. After reading this section over then follow up with Larry's tips you should be well on your way to understanding trim.

Good morning Kirk. Came across this, this morning, thought you might need some extra reading material :rolleyes:!

 

http://www.pilotfriend.com/training/flight_training/fxd_wing/trim.htm

 

Enjoy! Rick :cool:

Larry - Well put and a very good exercise! I really think trying to learn on a sim would be much more difficult than the real instruction, but he will get if if he can stick with it and keep asking the right questions!

 

Rick :cool:

 

Thanks, Rick. These are exercises that I also had instrument students do while under the hood, to help them identify pitch attitudes, power settings, etc. that they'd need for precision instrument work.

 

And you're right, it is likely more difficult in the sim, partly because an airplane is easier to fly and partly because in the sim you don't really have an instructor at your side to guide you (Machado is good, but he's not there in person).

I did a lot of reading, lessons, and practicing today. And thanks to you all I had a kind of lightbulb moment! It came when I gave myself the task to descend from 3,000' to 1,000' and remain at 1,000' for a bit, all while maintaining an airspeed of 80 knots. Setting trim for the descent then again for level flight, all while adjusting power, was so much easier than trying to do it without trimming! It's not quite "set it and forget it" but once having the trim set, it was just a matter of glancing at airspeed, altimeter, and VSI, and making minor adjustments.

 

I was feeling so confident that I decided to tackle a turn into my base leg and final approach... at which time all hell broke loose. I threw trimming out the window and just fought to calm the hell down and land on the runway in one piece. LOL. But that's OK. Crawl first, walk later.

 

Seriously, thanks again for all the help. It was a good day!

 

(BTW, I'm not flying anything right now but the FSX default C172.)

I'm glad things are working out for you, Kirk.

 

Traffic patterns are a different animal. You might peruse the Real Aviation Tutorials & FAQs section of the forum, under Takeoff and Landing for some hints. But to walk before you run, do a few ground reference maneuvers, that is, maneuvers in which what you try to accomplish is dictated by a path over the ground, unlike the previous stuff you've done.

 

Do these at about 500 feet over the ground (AGL). To get maximum benefit from them, I'd suggest putting in a 8-10 kt wind that goes straight along some road you can see in the sim. So if you have a road running east west, with a wind from the west, do an S-turn crossing the road, that is fly (say) north and as you're over the top of the road, start a right turn, trying to make the path over the ground make a sine wave, thus continuing the turn until you are again over the road but headed south, at which point you roll into a turn to the left and do the same thing, rolling out on a north heading again.

 

You are trying to make your ground path over each side of the road a constant arc. To accomplish this with a wind you'll need a constantly changing bank angle as your GROUND speed changes (maintain as near a constant AIRspeed as you can).

 

Do this again going the opposite way, that is, from the initial north heading do a left turn, instead of right, and so your trend is into the wind instead of away from it. Do these maneuvers smoothly, rather than jerking or manhandling the controls. It WILL take practice, and even more so because you don't have a CFI (Certificated Flight Instructor) there to guide you and to make corrections.

 

These S-turns are one of the ground reference maneuvers that all students must learn (yes, there are others), and is invaluable for learning to maintain your path over the ground, not only in the traffic pattern, but in many other situations too.

 

I'll suggest that, for seeing what the ground path should look like, that you first do these with no wind.

 

For further reading, this page on the FAA's website has links to various FAA manuals. In the Airplane Flying Handbook linked there, chapter 6 is Ground Reference Maneuvers, and it describes AND pictures not only the S-turns, but the other ground reference maneuvers such as turns about a point, eights across a road, and so on, with more and better descriptions than I've given here.

 

If you just look at the chapter list, you'll see everything from Introduction To Flight Training to Airport Traffic Patterns to Transition To Jet-Powered Airplanes.

 

It's good reading.

Thank you, Larry! The entire Airplane Flying Handbook looks like good.