Trim issue (Resolved. My fault, not the plane's.)

[RedNorth 0]

Is anyone else experiencing uncontrolled pitch-up movement on takeoff where even pushing the yoke in all the ways and trimming the nose down as far as the trim wheel will allow won't reduce the ascent angle to anything less than 10 degrees up? All my other aircraft behave properly - it's just the B1900D that's affected. I'm stumped. 

 

Beautiful plane but with this issue it's currently unflyable for me.

 

I'd appreciate any suggestions you might have on getting around this difficulty.

[Bert Pieke 7,585]

How do you have the airplane loaded?

 

The default (2 pilots, no pax, no baggage) takes off like a rocket,

but the pitch is perfectly controllable with the yoke..

 

I take off with 1 notch of flaps and rotate around 110 knots.

[RedNorth 0]

I've only tried the one configuration so far: fully loaded with passengers (each weighing a remarkably consistent 180 lbs), 100lbs of baggage in the 1st baggage area and 1000 lbs in the second. That puts the plane over its maximum weight, of course, so I reduce fuel load to 50% and it's just a shade under the MTOW. 

 

I take off with 1 notch of flaps and rotate anywhere between 110 and 120. The plane then pitches upwards like it wants to be vertical, and naturally the speed drops through the floor, into stall territory. The nose just doesn't want to go down no matter how much encouragement I give it...

 

I'll load 'er up again and try it with your 2 pilots, no pax, no bags loading and see if that helps. 

Well, this is awkward. With just pilots, no pax or bags and full fuel, the trim issue is gone. I guess it was just too heavy, despite being under max takeoff weight?

 

The good news is the plane is perfectly flyable in that configuration, and a lot of fun, too. I'll experiment with adding in more pax/bags and see how much I can get away with. 

 

Thanks for your comment, Bert. Without it I don't know how long it would've taken me to get to "maybe it's just loaded badly"! 

[Bert Pieke 7,585]

Real airplanes have had fatal accidents that way... we really need better documentation

on the loadout parameters.  I know that on small airplanes the pax are sometimes moved forward in the plane

to keep the center of gravity as far forward as possible..

[briansommers 74]

I think there was one that crashed like that at KCLT IIRC... it just pitched up and stalled.. 

[tttocs 301]

 

 

I guess it was just too heavy, despite being under max takeoff weight?

 

Likely not too heavy, but with CG aft of the allowable envelope.  IRL, you don't just do weight, you do weight and balance.  Many planes can be loaded under gross, but out of the CG envelope.

 

Scott