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mry110

Altitude Maintainence and Trim Advice

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Anyone have good advice on how to maintain altitude (minus pressing the autopilot button)? The problem I am having is while I am attempting to trim the aircraft, as I try to release the pressure I am applying on the yoke (Saitek), my altitude maintainence gets a little jerky. Next thing I know I am 400 feet from my desired altitude. I purchased a trim wheel from GoFlight which has improved this process dramatically for me, but I am still not satisfied.

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That is a common problem with flight sims, and to some extent it is a limitation of them. In most of the gliders I fly in real life, trimming is simply a case of holding the stick in the right position to maintain the right speed/atitude, and moving the trim lever until you feel the friction of it locking the stick in that position. Would that it was so simple in a sim. But it is worth noting that you can trim to a reasonably stable state in most sims and then make minor throttle adjustments to hold the altitude, which is often a bit more effective than trying to use the limited trim capabilities of most flight sims, and that's one thing you can't do in a glider, for obvious reasons. In short, use the trim as best you can, and then try using minor throttle adjustments to further fine tune things. You'll find that the minor variations in lift from the minor speed changes can have a nice controlling effect on your altitude hold.Al

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Get your aircraft relatively stable. Then trim for speed, rather than altitude. Figure out what you cruising speed ought to be, and then apply trim to achieve that speed. If you are properly trimmed, you might get some oscillation when you let go of the stick, but eventually the aircraft should settle on its cruising speed in level flight without you touching the controls. If you are not properly trimmed, well, that doesn't happen so much. Once you have trimmed for airspeed, use your throttle to adjust altitude. You should be able to make slow adjustments to your climb rate with small changes to the throttle. Once you are level at your proper altitude, trim again for airspeed, and then you should be set until your aircraft loses fuel weight, there's some turbulence, or your passenger drops a can of Red Bull that rolls under your rudder pedal. Jeff ShylukSenior Staff ReviewerAVSIM

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Proper technique is to climb to your desired altitude, then level off and adjust throttles for cruise speed. As the speed increases, it will require more 'stick forces' forward. Adjust the trim slowly to relieve the pressure on the stick. Once you have your cruise speed set and your trim correct, you should be able to fly 'hands off' without gaining or losing altitude. One note, I have yet to find a plane in FS that trims correctly, pay, free, or default. They all are too sensitive so its a matter of VERY small adjustments to the trim.

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I've had best success in FS by establishing my speed steady, then using trim/ easing elevator pressure making sure I don't speed up/down. Once elevator is neutral fine tune with throttle.scott s..

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Anyone have good advice on how to maintain altitude (minus pressing the autopilot button)? The problem I am having is while I am attempting to trim the aircraft, as I try to release the pressure I am applying on the yoke (Saitek), my altitude maintainence gets a little jerky. Next thing I know I am 400 feet from my desired altitude. I purchased a trim wheel from GoFlight which has improved this process dramatically for me, but I am still not satisfied.
Trimming on the sim is much harder than in reality. Getting the trim wheel from Goflight is a great help.What I do is keep the vsi in my peripheral vision without really looking at it and keep the altimeter in the constant scan. Any movement on the vsi and I am ready to respond with the altimeter which reacts slower.If you can hold your altimeter in fs you will have no trouble in the reality. Much harder in fs-but good practice.

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Trimming on the sim is much harder than in reality. Getting the trim wheel from Goflight is a great help.What I do is keep the vsi in my peripheral vision without really looking at it and keep the altimeter in the constant scan. Any movement on the vsi and I am ready to respond with the altimeter which reacts slower.If you can hold your altimeter in fs you will have no trouble in the reality. Much harder in fs-but good practice.
Interesting that you made that comment about FSX versus reality. I just finished an online ground school course, and my difficulty in FSX is spooking me a little bit as far as moving on to flight training (that or I am just using it as an excuse because I am scared, lol). Thanks for the advice everyone. I would be awsome if someone were able to make a yoke that actually simulated that pressure relief that the trim provides.

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Interesting that you made that comment about FSX versus reality. I just finished an online ground school course, and my difficulty in FSX is spooking me a little bit as far as moving on to flight training (that or I am just using it as an excuse because I am scared, lol). Thanks for the advice everyone. I would be awsome if someone were able to make a yoke that actually simulated that pressure relief that the trim provides.
In many ways the sim is much harder-so I would not let that scare you away.Go for it-it is amazing how many people who were scared of flying end up being great pilots. I just had lunch with a renowned cfi in my area who told me he was so scared of flying he carried two pairs of shoes when he took a flight (he was in the military at the time). He said his feet sweat so much because of fear that his shoes would be soaked on landing and he would have to change shoes. No fear from him now-and learning to fly cured it. I think Chuck Yeager even admitted some fear. Probably makes a safer pilot...

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Flying an airplane is safer than driving an automobile.--------------------------------Press 'Z' then 'Ctrl+Z'. --------------------------------Wait 10 seconds and your trim should be set (for altitude / speed). Press 'Ctrl+Z' then 'Z' to go back to hand fly.Chuck BNapamule

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I use the Ch products USB Flight Sim Yoke and Pro Pedals. In the controls setup, I have assigned the vertical rocker switch on the left handle of the yoke for elevator trim (read by the sim as buttons 11 and 12) and set the repeat slider to the far left so that when the rocker is pushed up or down a very small elevator trim adjustment is made in the sim.Since the Ch yoke is spring loaded, it does require more pressure to hold it in position the farther it is moved from center (for the in and out function of elevator/pitch attitude adjustments). I find that with it properly calibrated and with null zone and sensitivity on the axis set even reasonably well, that I can trim almost any aircraft in the sim to hold an altitude +/- 25 feet quite easily. Much the same as in reasonably non-turbulent air in realworld flying.I sim-fly the way I was taught to hand fly GA aircraft. I trim for every phase of flight. When transitioning from my initial climb to straight and level cruise, I first push the nose down to level off and once cruise speed is reached adjust the props, throttle, and mixture for cruise. When I first push the yoke in, I take most of the pressure off the yoke by making an initial "rough" adjustment with the trim wheel. After I am stable with my engine controls and at my intended cruise speed, I then focus on getting the aircraft into good trim to hold my desired altitude. Often I need to make further small adjustments to both trim and power, to make the aircraft stable on all counts. I have absolutely no trouble whatsoever getting the aircraft into very stable trim in less than 2 or 3 minutes. Most often, it only takes that long because it takes a little time for the aircraft to stablilize with the last adjustment of the engine, prop, and trim controls.This process only gets easier and easier as a pilot's familiarity with an aircraft increases, and with enough practice, can become quite second nature and almost I would dare say automatic. It's much the same as internalizing what a good "picture" out of the windscreen looks like on a visual approach all the way down to short final and touchdown. Once you know what "right" looks like and it really has become internalized for you, AND you learn to look and get your visual cues in the right place, you just get in the habit of looking in the right place, at the right time, and adjusting your controls accordingly to keep things "looking good" (that certainly includes your airspeed indicator too). Yes, this is an oversimplification to make a point, but I think it works and certainly all the other realworld pilots out there will know exactly what I am talking about.Back to the point, although the Ch yoke doesn't return to a perfect center position (equilibrium between the forward and aft spring loads) when released, it certainly returns to a center position where much the same as in a properly trimmed C172, only a thumb and forefinger are required to make very small adjustments to maintain straight and level flight in decent/reasonably smooth air. This may not be a precise simulation of the controls of a realworld aircraft, but the principle works quite the same (at least in front of my pc with my Ch Flight Sim Yoke).Note: I don't think the way to go is to adjust your trim to maintain cruise speed then adjusting your throttle to maintain altitude. The remarks in that reply are being confused with how to use the flight surfaces controls and throttle, to control your rate of descent and airpspeed on an approach - where you most certainly use throttle to control your altitude - or change in altitude, while at the same time controlling your airspeed with your pitch attitude. Again, that's how I learned to do it in normally aspirated or fuel injected, GA aircraft.Best regards all.

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Almost got through that post without a typo, hehe. Nope, "airpspeed" is not some new, cutting edge, aviation term. :( :( :( It's pretty close to "erpspeed" though, which is the airspeed at which those prone to motion sickness sometimes start "erping". B) B) Best regards.

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Just to update everyone on my progress (if you care). One thing I failed to mention in my original post was that I did not know at the time I purchased my GoFlight trim wheel that I needed to purchase a housing for the panel. So I have been having to physically hold the panel up to turn the trim wheel (otherwise the trim wheel would scrape my desk, and the wife would not be pleased). The housing showed up yesterday. WOW, what a difference. If you don't have a trim wheel, I HIGHLY recommend the one from GoFlight (the one with the landing gear and flaps switch).I was able to consistantly stay within +/-100 ft of my desired altitude, and change speeds on my aircraft at the same time (this was with a freeware Cessna 206H). Also, it makes the Flight1 Mustang one of the easiest jets in the sim to fly. You will be amazed at how easy the trim wheel makes configuring your landings.

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Hi mry110 and everyone.The basics of Trim. You trim to release pressure of your Yoke / hands, and for Airspeed. Notice that Altitude is not part of the intended Trim elements. You can achieve a release of effort / pressure at any time, but if the airspeed changes this is only a temporary condition, you must keep doing it until the Airspeed stabilizes. It can be extended to help you to maintain Altitude and Heading, as additional benefits, if you understand the dynamics going on.In All the PC sims, that I know of, there are many things that are more difficult to achieve than real flying. Looking / viewing a wide area to help you in the Pattern / land, turn radius, instrument update and, especially in the MS sims, the Trim etc. In MS sims, especially, it may take up to 3 min. to get an aircraft model trimmed. In most real airplanes, basic piston, you can be fully trimmed in under 10 sec., depending where you start. I recommend not trimming, for level flight, until you reach the expected airspeed.That said there are many real pilots that have flown for years that do not understand the trimming process, because of lack of understanding of basic Aerodynamics.You need to understand that if you are not in a Stable condition, your pitch, drag and or airspeed changes, your altitude will change. The fix, Know your numbers, and consider the Altimeter and VSI as ONE instrument. Your Altimeter tells you where you are, and the VSI tells you where you will be, assuming that your expected Performance (Attitude and Power) are set correctly. What that means is that you cannot expect to have a stable trim condition if the power is set to where the speed may increase, or decrease, given the basic attitude or power. If speed increases the Lift increase and the Altitude will change. If the power is set to give you max performance, i.e. C172 120 KIAS, full throttle, and you are at 90 KIAS, you can expect to keep trimming until you get to 120, and if you do not understand that you may never achieve a proper trim. TV

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I seem to recall an addon released not too long ago that addressed the trim issue in FS. I believe it's called real trim, or something along those lines. I never tried it, but it got some praise here in the forums somewhere. You might want to look it up and see what it's all about.

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