VAF Forums

VAF Forums (https://vansairforce.net/community/index.php)
-   RV-9/9A (https://vansairforce.net/community/forumdisplay.php?f=5)
-   -   Electric elevator trim tab setup (https://vansairforce.net/community/showthread.php?t=134986)

rightrudder 02-24-2016 07:16 PM

Electric elevator trim tab setup
 
Just thought I'd throw this out there. Originally, I had about 2/3 up trim, 1/3 down trim, but I'm finding that 3/4 up and 1/4 down works much better...far easier to stabilize at 65 knots in the pattern. Check those clevis pins and keep them lubricated; they're not the hardest material and I suspect they'll wear out sooner than you might think.

Everything looks good under the cowling at 11.3 hours into Phase 1. Oil consumption was maybe a quart total, and that's running it pretty hard, 65 to 75 percent power most of the time. I'm gonna continue this regimen for the next 10 hours or so and carefully track it. So far, not too much is puking onto the exhaust through the breather tube, but maybe that's because I'm keeping it at just over 6 quarts.

I cut down the baffle air dams to about 1/3 of their original size, and initial climb temps are coming down. CHTs in "performance cruise" are in the 360-370 range with a 65-degree OAT, with only about a 15-degree variance, and yes, No. 3 is the hottest. Will try the washer trick.

Today, the OAT at 6500' was about 48 degrees, and I used the heater for the first time. Veeerrrry effective, with the heat muff that surrounds both crossover tubes.

I'm still landing a bit long...this thing is a kite on approach compared to what I'm used to! :):)

Soarandtow 02-24-2016 07:48 PM

Glad to hear your flying and all is well thus far.
Keep us all posted

rockwoodrv9 02-24-2016 08:05 PM

Very cool Doug. I cant wait to get to phase 1. Are you posting pictures and experiences anywhere?

I worked on my trim today. I am ready to mount and have the D-Sub pins all done. Now I just need to figure out what wire coming from my garmin and VP to hook to it!!

airguy 02-25-2016 08:07 AM

Only 8.1 hours on my Phase I so far, but I have found that I am only using about 10% of my trim tab travel, if that.

rvbuilder2002 02-25-2016 01:30 PM

Quote:

Originally Posted by airguy (Post 1056891)
Only 8.1 hours on my Phase I so far, but I have found that I am only using about 10% of my trim tab travel, if that.

Then you either haven't begun to learn to slow down on approach like you should, you are not using flaps, you don't trim to anywhere neutral while flying a landing approach, or you have a very aft C.G. (or a combination of all of these).

The OP's post about pitch trim tab travel is right on.

rightrudder 02-25-2016 02:23 PM

Quote:

Originally Posted by rockwoodrv9 (Post 1056779)
Very cool Doug. I cant wait to get to phase 1. Are you posting pictures and experiences anywhere?

I worked on my trim today. I am ready to mount and have the D-Sub pins all done. Now I just need to figure out what wire coming from my garmin and VP to hook to it!!


It will be sooooo worth it! Hang in there!

I'll do a 20 hour update. I just haven't had the chance to take any pictures, what with dialing in the EFIS, listening for funny engine sounds, etc. Some very pretty rock formations, etc. in the high desert. I'll try to get some video with the V-stab camera at some point too.

I'll say, it's a lot more comfortable at 10 hours than 5, as I'm building a lot of trust with the engine.

airguy 02-25-2016 03:26 PM

Quote:

Originally Posted by rvbuilder2002 (Post 1057006)
Then you either haven't begun to learn to slow down on approach like you should, you are not using flaps, you don't trim to anywhere neutral while flying a landing approach, or you have a very aft C.G. (or a combination of all of these).

The OP's post about pitch trim tab travel is right on.

Part of that is true - I'm still flying fast approaches (learning to slow it down) and I'm only using 2 notches of flaps for landing (so far), and I'm not trimming to neutral for slow flight because that's only the flare portion of the landing for me. I'm still breaking in the engine and fighting oil temps, I haven't gotten to the slow flying part yet.

I don't mind holding the stick forces for landing, it's 30 seconds and the forces are light. I'm not going to be running the trim around much until I've got more time in the seat, aside from cruise conditions.

rightrudder 02-25-2016 04:46 PM

Quote:

Originally Posted by airguy (Post 1057039)
Part of that is true - I'm still flying fast approaches (learning to slow it down) and I'm only using 2 notches of flaps for landing (so far), and I'm not trimming to neutral for slow flight because that's only the flare portion of the landing for me. I'm still breaking in the engine and fighting oil temps, I haven't gotten to the slow flying part yet.

I don't mind holding the stick forces for landing, it's 30 seconds and the forces are light. I'm not going to be running the trim around much until I've got more time in the seat, aside from cruise conditions.

That explains a lot. I like to trim for that 65 knot airspeed to relieve stick pressure. It takes a lot of tab deflection, but it reduces workload in the pattern and while landing.

With my Vso speed at 39 KIAS, I may try 60 KIAS over the fence (with just me and fuel aboard). I'm putting in full flaps even before getting into the pattern, to stay ahead of the plane. Lots of Aeroncas and Cubs going that slow (or slower) at the home field, so I don't mind being a slow poke here.

Have you done any stalls yet? When you find those speeds, it really gives you the confidence to slow it down in the pattern, even though the controls start to feel a little mushy.

airguy 02-26-2016 07:50 AM

Quote:

Originally Posted by rightrudder (Post 1057061)
That explains a lot. I like to trim for that 65 knot airspeed to relieve stick pressure. It takes a lot of tab deflection, but it reduces workload in the pattern and while landing.

With my Vso speed at 39 KIAS, I may try 60 KIAS over the fence (with just me and fuel aboard). I'm putting in full flaps even before getting into the pattern, to stay ahead of the plane. Lots of Aeroncas and Cubs going that slow (or slower) at the home field, so I don't mind being a slow poke here.

Have you done any stalls yet? When you find those speeds, it really gives you the confidence to slow it down in the pattern, even though the controls start to feel a little mushy.

Yes, I did a single clean stall and a single 10-flaps stall on my first flight just before bringing it in for landing, my speeds are indicating high due to a static position error that I still need to correct so I don't know the actual TAS for stall but I got a relative number. Second and third flights I did a good stall series clean and at 10 and 20 degrees, have not yet for full flaps. I got my AOA calibrated to give me a good warning on stall approach, rather than relying on the airspeed indicator since I know that is off a bit. From what I can tell my airspeed is indicating about 5 knots fast at approach speeds and 9 knots fast at cruise, almost certainly due to static source position error.

My approaches have been with 20 flaps and 75 knots to short final, dump full flaps and pull the power completely off dropping through 50 feet into the flare, works great for me for now but I'll polish that technique later. The pressure to keep airspeed up for cooling right now is driving everything else, I should have the problem solved in the next few hours.

rvbuilder2002 02-26-2016 08:44 AM

Quote:

Originally Posted by airguy (Post 1057194)
so I don't know the actual TAS for stall but I got a relative number.

You never need to know TAS for stall.
Stall speed is always referenced to IAS.
This provides for automatic compensation regardless of what (pressure) altitude you are at.


All times are GMT -6. The time now is 06:08 PM.