Take-Off Trim Settings

First I would like to thank all of the ATR pilots for helping all of us newbies out, your continued input is what really makes the ATR a great  aircraft!

So now for my trim question, how do you calculate the take-off trim in the sim.

I always leave it at the default setting, I never know were the correct position really is.

Also on take-off when I try to maintain V2+5 speed. I must hit the up trim quite a few times (number 1 on the keyboard) which sounds out an alarm, is this normal or am I trimming up to fast.

So how do you ATR pilots trim the aircraft on the ground and after take-off??

Thanks
-Paul Cartier
KBDL

The way my company figures CG could be done by my grandmother.  We use a "calculator" by a company called SeeGee.  It's hard to explain it to you because you need to see it to see how it works.  Let me suffice it to say that we don't refer to any charts or figure anything according to %MAC.  Once we get our load (pax, bags and cargo) we take out this calculator and "spin the wheel."  Its a plastic unit with two lighter plastic units attached to it.  These plastic units are used in conjuction with each other to graphically show where your CG is within the CG envelope!  With all your load data in hand, you can literally figure out your CG and trim setting in about 10 seconds.  We don't refer to any charts for either CG or trim setting.

I know this isn't a very technical answer and probably doesn't help you much.  This SeeGee calculator makes it too easy!

Terry

Thanks,

Guys, well I guess in the sim we just except the default settings and then adjust it on take-off

BTW,
do you guys re-trim on take-off? and do you get the funny trim sound warning?

-Paul Cartier
KBDL

Paul,

I trim on the ground 2 degrees up which seems okay for most situations.  After rotate, trim to relieve stick pressure for desired climb angle.  The noise you hear is the trim indicator noise just letting you know you are trimming.  This activates if you hold the trim lever more than 1 second at a time.

I second Todd's method.  I usually trim the FS ATR to the top of the green arc and then adjust after rotation.  In the real ATR, the trim setting is generally in the 1/2 to 2 range, depending on the load.  The SeeGee calculator will give you the exact setting.

As Todd told you, the trimming sound is normal.  It's called a Whooler, and indicates that the pitch trim is in motion for more than 1 second, and that's EXACTLY how it sounds in the real ATR!  The names for the some of the other sounds are as follows:

Overspeed - "Clacker"

AP Disconnect - "Cavalry Charge"

Stall Warning - "Cricket"

FA Call - "Door Bell"

Cheers!

Terry

Terry has explained everything!
In addition: trimming depends a lot how the payload will be redistributed by ground service. You would be surprised, how far that can be from the top edge of envelope to make rotation possible at Vr

Old thread I know, but just in case anyone wants to know...

We don't pitch to V2+5 on a normal 2-engine take off. We rotate to 9 degrees (in about 3 seconds, and let the aircraft fly whatever speed that gives you, usually around 120-130kts, depending on weight. The V2+5 is there ONLY in the event of an engine flame out or engine fire. It's preset, so if either of those events happen, you don't have to muck around changing the speed before engaging the autopilot.

Try pitching to 9deg on take-off rather than V2+5,and see if your trim setting works better.