N64LR Took to the Sky Today

lr172 · #1 08-21-2015, 10:45 PM

I did my first flight today. It was mostly uneventful. We picked the perfect rudder trim size to start and got neutral yaw at cruise. I also have a heavy left wing, but it became neutral after we burned about 8 gallons of fuel from the left tank. I also have some gremlins to chase in the engine, as one or two cylinders were way out of of range (EGT/CHT) from the others at different times. I am confident that I will be able to chase it down eventually. It also seems that my prop is over-pitched (I bought a Catto designed for a 9 with the same HP engine as mine) as we could only get about 2550 at 3000'

Until today, I had never flown an RV. It was so exciting to feel exactly how responsive they really are and how effortlessly they bank. A very exciting experience. I am really looking forward to my training and completing my Phase I Testing.

I wanted to say a big thank you to all of you that provided guidance through my build and for being generous with your experience. Searching in VAF always provides good insight.

Larry

rvbuilder2002 · #2 08-21-2015, 11:11 PM

Quote:

Originally Posted by lr172

It also seems that my prop is over-pitched (I bought a Catto designed for a 9 with the same HP engine as mine) as we could only get about 2550 at 3000'

Congratulations Larry

Do you have the wheel pants and all fairings installed.
If not, that will have a huge effect on WOT engine RPM.

Mike S · #3 08-21-2015, 11:16 PM

Larry-------------------

lr172 · #4 08-21-2015, 11:18 PM

Thanks for the head's up. No, I don't have the pants on. I thought it would be best to get the rigging stabilized first. An hour ago I was thinking that maybe increased speed would change the max RPMs.

Larry

pierre smith · #5 08-22-2015, 06:00 AM

Quote:

Originally Posted by lr172

Thanks for the head's up. No, I don't have the pants on.
Larry

We could only get 186 MPH TAS without the pants/fairings on our 180 HP -6A.

201 true fully faired.

Best,

lr172 · #6 08-22-2015, 07:34 AM

So now that I have my rudder trim pretty close, should I put on the pants and fairings now or wait until I resolve the left wing? I have been worried about the pants introducing their own rigging issues and was hoping to isolate.

Larry

krw5927 · #7 08-24-2015, 06:10 AM

Quote:

Originally Posted by lr172

So now that I have my rudder trim pretty close, should I put on the pants and fairings now or wait until I resolve the left wing? I have been worried about the pants introducing their own rigging issues and was hoping to isolate.

Larry

Doesn't really sound like you have a heavy left wing if burning 8gal (~50 lbs) from the left tank evens things out, unless that was with full right roll trim to start.

If you can trim it to fly straight and level hands off, I would say wait to mess with roll any more. When you put a passenger in the right seat it might be just about perfect.

MikeyDale · #8 08-24-2015, 07:20 AM

Congrats! Having just gone thru my 40 hr testing, I would not touch that heavy wing until fairings is on. Doesn't sound like it is that bad anyway.

BobTurner · #9 08-24-2015, 11:43 AM

Just as others have said, as part of your phase 1 testing you'll want to fly with 180 lbs of weights in the right seat. See if you still have a heavy wing then.

If so, take a very good look at the vertical position of the ailerons relative to the wing. 1/32" can make a difference. (high aileron = heavy wing).

rvbuilder2002 · #10 08-24-2015, 01:03 PM

Quote:

Originally Posted by lr172

So now that I have my rudder trim pretty close, should I put on the pants and fairings now or wait until I resolve the left wing? I have been worried about the pants introducing their own rigging issues and was hoping to isolate.

Larry

The proper way to make final trim adjustments is with the airplane completely assembled (all fairings, wheel pants etc. installed). Don't even bother with roll trim and rudder trim until you do this.
Then correct the roll imbalance. Then the rudder trim.
The reason is that when using a fixed trim tab, you can really only adjust for one specific condition (one speed at one pressure altitude).
Because of this you need to have the airplane in its final configuration and then choose what speed/altitude you will fly at the majority of the time, and make your adjustments based on that.
Since you have a fixed pitch prop this is even more important. Because the faster the airplane goes, the more RPM's the engine will turn. The faster the engine turns the more power it produces, so it makes the airplane go faster... and on and on, until the airplane finally finds an equilibrium of power vs speed vs drag. Once you are at that point, then you can adjust trim for that specific speed.