c172 trainer takeoff trim

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Lewis - A2A
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Re: c172 trainer takeoff trim

Post by Lewis - A2A »

iefbr14 wrote:
wbrown wrote:Thanks to all who replied so quickly. HOWEVER... I am not mistaken about this problem. I am a private pilot who flies C172s. ...
Same happens to me. I fully agree with wbrown! I've finished my 100hrs on RW this week, mostly on c172's and c152's. And I can confirm, none of them tends to turn to the left that way during t/o especially with light cross winds from the right. This happens with FSX, and P3D v1-to 4, with different yokes. I carefully monitored the forum over the years, and a lot of people reported these about (drag left) problems. But never I read a solution about. You have to leave the A2A c172 nose wheel on the ground until Vy to circumvent this problem. But this is a work around, and not a behavior of real world c172. A2A guys really make a very great jobs on their planes, I love every nut on these machines, but to tell certified pilots not to be able to take off a c172 when they report real existing drag problem's on 2 of their modelled planes, this is why I'm very disappointed about these discussions.

Sorry for some clear words.

Andreas
Andreas, if you read the thread you will see this is a tech support issue with an issue on wbrowns system that is now resolved and they are using the simulation for practice and training at the moment all OK. If you are experiencing tech issues then you might want to post a tech support thread so we can begin troubleshooting the issue with you.

thanks,
Lewis
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Oracle427
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Re: c172 trainer takeoff trim

Post by Oracle427 »

As it bears repeating. I experienced this problem when I loaded the sim directly in the A2A 172 instead of first launching with a stock simulator aircraft and then changing over to the A2A 172 while in sim.

The sim engine initializes in strange ways and the behaviors can be subtle in that they affect handling instead of altogether stopping operation.

Best to try this along with ensuring that you have all patches applied.

Active Sky is also known to cause some handling issues with the default turbulence and wake turbulence settings. I experience loss of control where the controls stop working momentarily if I leave the default settings in place.
Flight Simmer since 1983. PP ASEL IR Tailwheel
N28021 1979 Super Viking 17-30A

GeorgeF
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Re: c172 trainer takeoff trim

Post by GeorgeF »

I know this is an old subject but!! I experienced the same problem with elevator trim on takeoff. Place it at the trim arrow, and the plane would jump off the ground at 55 and pitch up to the point of stall. No amount of pushing the joystick forward could bring the nose down. By the way, P3D and all the latest updates. The loading was like this Pilot and lady friend up front, another man and lady in the back, with 35 lbs of baggage, and 24 gallons of fuel. I then placed the man up front with me and the girls in the back and reduced the baggage to zero. (Caught a lot of grief from the ladies) Then did a test flight with the trim set at the arrow and no more problem. Was able to rotate at about 60 and accelerate to 70 - 80 climb speed with a little forward pressure. Then trimmed to reduce the pressure on the stick.
Now, how do we determine the CG with various loading. I have not been able to find out where in the application how to determine the CG and therefore the proper trim for takeoff.

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AKar
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Re: c172 trainer takeoff trim

Post by AKar »

GeorgeF wrote:Now, how do we determine the CG with various loading. I have not been able to find out where in the application how to determine the CG and therefore the proper trim for takeoff.
You can google various apps, spreadsheets and so on. For instance: link.

However, trim should not be too sensitive to CoG variations, if you stay within limits, and is usually not set as a function of CoG in this kind of airplane. It is only a ballpark setting. In A2A Cessna, I've noted that the takeoff arrow makes the airplane quite light on its nose, so I usually just set the trim a bit more nose down than the arrow for my convenience. But if yours goes out of control even if it was at the arrow, then there is something wrong. It should be controllable with modest forward pressure.

-Esa

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Nick - A2A
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Re: c172 trainer takeoff trim

Post by Nick - A2A »

AKar wrote:[...] But if yours goes out of control even if it was at the arrow, then there is something wrong. It should be controllable with modest forward pressure.
Indeed - I'd start by checking the maintenance hangar (shift 7) for a problem with the trim system or the elevator itself. Perhaps a simulated broken part is preventing full control deflection? Anyway, in a quick test I just carried-out with the same loading, even with the trim set fully aft, the aircraft is still controllable with yoke inputs alone (this is no PC-6!). As Esa says, with trim set at the arrow, only modest forward control pressure should be needed to climb out at Vx or whatever.

However, as I mentioned earlier in the thread, the choice of prop makes a difference to handling too, so it's important to let us know which one you've got fitted.

Also, be sure to follow Oracle's advice above if you're seeing issues.

Thanks,
Nick

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