Trim Tab rigging

[cpirrmann]

Does anyone know of or if there is a travel span specified for the trim tab on a 1946 BC-12D either in degrees or turns of the crank or pulley? It seems to allow much more nose up trim (down tab) than down. I believe this makes sense but I wanted to know if there are some numbers to go by.

[VictorBravo]

Re: Trim Tab rigging

If you can trim it to 45 mph power off on the low side and maybe 105-110 mph in a slight descent at cruise power, IMHO you're a winner. As to the actual degrees of travel, you will have to contact Forrest or someone else who has the original drawings/specs.

[N96337]

Re: Trim Tab rigging

My manual says elevator tab movement is 25 degrees up, and 30 degrees down.
JH

[cpirrmann]

Re: Trim Tab rigging

Thanks V.B. but your first suggestion never seems to want to communicate with me in any form so I have to find alternate sources.

JH Thanks . that's the info I was looking for.

[Forrest Barber]

Re: Trim Tab rigging

Always use the ATC degrees posted and then the test in the air is
" minimum trim speed" at a mid range C.G., throttle at idle, full nose up trim, hands off controls, ship should ahve an indicated air speed of 60-65 mph.... That is for certification....be careful with the full nose up, sometimes the old system wants to stick and not come back to neutral.... this is for new stuff after rebuild.

[cpirrmann]

Re: Trim Tab rigging

Always use the ATC degrees posted and then the test in the air is
" minimum trim speed" at a mid range C.G., throttle at idle, full nose up trim, hands off controls, ship should ahve an indicated air speed of 60-65 mph.... That is for certification....be careful with the full nose up, sometimes the old system wants to stick and not come back to neutral.... this is for new stuff after rebuild.

I know, that happened one time and I learned from that to count my turns carefully. Have you received any of my other communique's?