Hey, guys.
When I am flying the Cessna 172 Skyhawk, and I try to “cruise”, I can’t seem to get the trim right. I will make SUPER fine adjustments to try and get the aircraft to level, but it always does this up and down issue. How do I properly trim the aircraft to keep it flying level?
Here’s a visual of what the aircraft does. It never equalizes itself.
I find that using trim to get it close and then fine tuning it with small throttle adjustments does the trick
If the plane is trimmed for a given attitude & airspeed, but the attitude is not the same as what it is trimmed for, it WILL Oscillates with decreasing amplitude, until it settles to a stable state.
The C172 will typically HALF its oscillation amplitude on each cycle. This is its Pitch Dynamic stability.
The AP is very good at dampening this oscillation QUICKLY !!! … the Pilot, typically no so, especially without Force Feedback, and having a spring centered yoke / joystick.
IMPULSE RESPONSES
AUTOPILOT OFF
Other possibilìty is to reach the desired flight level,then adjust speed of your choice,then slowly release the pull pressure on the stick and trim + and - many times .If you reach +500ft and you are going down …once you reach +200ft (don’t waith to reach -500ft) trim a bit to raise up (counteract).The nose will reach maybe -100 or -200 anyway because of the inertia then it will raise up.Again,while going up,before you reach the target give a little trim to descend. If you are fast on trimming you may level in about 3-4 times.
Unfortunately, this is a classic case of the Sim, teaching Pilots BAD, Incorrect habits for trimming the aircraft, that will come back to bite them, when they fly in real life.
If we all had Force Feedback Yokes/Controllers, this would not occur, but we all know the sad story about Force Feedback devices, and their rarity, in consumer Flight Simulators !!
So what I am hearing is there is really no way to stop this oscillation without auto pilot?
It absolutely is possible, small changes have great effects. Here is a tutorial I made on how to trim in the 152 but works just as well in the 172.
You want to set your power and speed first and then trim. This is the same IRL. Even in something tricky like the Beechcraft D18 where some people think the trim has a bug because of its sensitivity, check out the VFR Beechcraft video I have as well for more examples on how to trim for level flight.
NO, the oscillation will reduce naturally, if the pilot does nothing, or the pilot can add input to gently fight the oscillations, and damp it quicker (like the smart (?) Autopilot does)
In fact, and experienced pilot can damp those oscillation quicker than the AP, and also never let then initially start at such a high amplitude, by more precise trimming at the start.
I have 2200 hours flying my own real C172L. I have not seen this extended pitch oscillation in my airplane. After control input causing a pitch change (power change, elevator trim adjustment, quick push on the yoke) my airplane overshoots the final state a bit, then settles down within 30 seconds at most, without any further oscillations.
Any experienced pilots - what’re you seeing flying a real C172?
EXACTLY – “Settles down within 30 seconds”
In this simulator it is not easy to trim planes like C-172 like in others. In other simulators you can trim “for speed”, the plane will keep the airspeed she was trimmed for. In this simulator a trimmed for horizontal and straight flight aircraft may start diving accelerating and will dive almost “endlessly” loosing hundreds of feet like there are no trims at all. I do not remember such a behavior from RL (yes, I remember we trim to reduce forces but we do not have here in this sim any kind of FFB realized ).
I do not have this experience; when trimmed for level flight, planes generally keep on going pretty stably in my experience in the sim.
Correction - I mean, that when I reduce/add RPMs, the plane (C-172 Classic) is not diving/climbing on the airspeed she is trimmed for. When I trim the plane at, for example, 80 knots and reduce RPM she starts to dive and accelerates almost to 90 knots, and stabilize finally at 85 knots. And she is loosing to much altitude to stabilize to my taste. I am not going to say that this is not “real”, my RL Cessna experience is not grate, however this is not as it is on FSX, for example.
Its also not how it was on Microsoft FS1 either.
This is what I said before - “In this simulator it is not easy to trim planes like C-172 like in others”. Yes, currently, after all those updates planes in MSFS are more stable on trim - I rechecked the C-172s behavior after your postings and I see that you are correct. I was basing on my initial impressions and now I see that I was wrong. I was not able to notice this, may be because I was flying with FFB (via simFFB application and G940 joystick) and simply was not allowing the plane to fly herself:))) So, I am glad to join this topick:))) However, I still think about why in my test the C-172 does not keep the speed she was trimmed for at least when she dives - when she climbs she keeps that speed better. May be because she (C-172) does not fly straight when I switch off the autopilot and reduce RPM - she starts to turn (and this is what she does IRL, if I remember properly) - is this a result of adverse yaw?
In general I like the flight model in MSFS and their atmospheric effects, especially with their new SU10 turbulence. I hope MSFS will continue to improve their flight model. As for the WB-SIM mode, unfortunately for me, I am not able to purchase this mode.
I got the impression SU10 is way more sensitive to trim inputs than before.
Also have troubles getting GA aircraft flying straight and level.
Previously you could make fine adjustments with the trim wheel on the Honeycomb Bravo to get it straight and level. So you had to turn it quiet a lot.
Now even small changes have huge effects.
So does anybody feel the same?
