Negative trim

When do I use negative trim in flight?

I guess when ascending?

Yes, extend negative trim on takeoff to help assend.

Generally forward trim is used at higher airspeeds to keep the plane level. Without trim, you’d have to be pushing wayyy forward on the controls to keep from climbing as you accelerate.

I’ve also seen forward trim recommended in light aircraft when flying in the pattern. You’re low to the ground and there’s lots of stuff to distract you — by trimming forward, you ensure that if you get distracted and relax on the controls, the nose will drop. This is far better than the nose rising which could lead to an unrecoverable low-altitude stall / spin.

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As far as tendency to raise the nose, I think you mean the opposite?: positive rather than negative trim tends to cause pitch up.

As mentioned:

“Forward” of course being more descriptive than “negative”.

But there’s nothing special about the negative vs positive value of trim, other than it might describe the direction of the trim control surface (whether deflected one way or the other, or zero for neither).
Picture3

But the goal is “dialing” in a neutralizing force around the aircraft’s center of pitch rotation, which may just as well be this as opposed to that side of zero:


The forces around the pivot point change with power, speed, flaps, gear, and load distribution from the pivot point. The significance of + and - is mostly as a direction of adjustment.

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I do! Whoops!

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Trim the aircraft until the magenta line disappears without control input, the A320 family in Infinite Flight often needs a little bit of negative trim once the aircraft accelerates past 200kts.

Where I’m getting this is from a reverse perspective, when you descend, you use + trim to stabilize, so I figured the reverse must be true

Trim in descent is particularly used on flap extension. Flaps increase lift and drag so as you extend flaps you trim the aircraft out to counter this. Backtrim can also be used to increase rate of descent at slow airspeeds.

I don’t understand the following:

@FreightExpert please correct me if i’m wrong, but @adit, I believe backtrim is the trim on the back ailerons of the plane

Backtrim is “positive” trim in this game and moves the trim tab upwards. The trim tab is on the elevators at the back of the plane and moves in the opposite direction of the elevator.

I wouldn’t worry about it for in game use at this stage as what I mentioned is used for real life physics more than the game physics.

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