Newb acro question

grantcarruthers · #1 10-11-2007, 11:32 AM

Finally got my RV-4 in my hot little hands and am starting to expand the envelope. So question is, how much should I worry about the gyros in the panel for simple rolls and beginner beginner acro. Is there a simple way to vent the vacuum temporarily to deactivate the gyros and will this improve their survival during light acro or would it be worse if they were not spinning and 'rigid'?? Sorry if this is a completely stupid question. The HI doesn't precess at all like the crud I've rented and I'd like to keep it that way.

Mel · #2 10-11-2007, 01:11 PM

Most modern gyros will do fine in roll. They do not like pitch greater than about 80 degrees, so loops will tumble them.
Disconnecting them from vacuum will not help much. Unless they are cageable, they will still bang against the stops.
If your airplane has not been tested for acro, you will have to put it back into phase I for a minimum of 5 hours. Your operating limitations will give you guidance on this.

JonJay · #3 10-11-2007, 02:41 PM

Quote:

Originally Posted by Mel

Most modern gyros will do fine in roll. They do not like pitch greater than about 80 degrees, so loops will tumble them.
Disconnecting them from vacuum will not help much. Unless they are cageable, they will still bang against the stops.
If your airplane has not been tested for acro, you will have to put it back into phase I for a minimum of 5 hours. Your operating limitations will give you guidance on this.

Hey Mel, not meaning to hijack this thread, but noticed your response on testing for Acro. I was doing Acro almost from day one, but what constitutes testing? I show in my logs what manuevers where performed, but is there more to be done?

Mel · #4 10-11-2007, 05:54 PM

Quote:

Originally Posted by JonJay

Hey Mel, not meaning to hijack this thread, but noticed your response on testing for Acro. I was doing Acro almost from day one, but what constitutes testing? I show in my logs what manuevers where performed, but is there more to be done?

Testing is doing any maneuver not already listed.

grantcarruthers · #5 10-11-2007, 07:59 PM

How much damage is done by tumbling though I guess is my question? As far as testing vs. operating limitations goes I suppose thats a legal answer but is it realistic? I bought the -4 to keep entertained as I take my time building the -8. I don't even know if I have a copy of the operating limitations to tell you the truth!! I just assumed that if Van designed a plane to +6/-3 thats what you get?

gasman · #6 10-11-2007, 08:17 PM

Quote:

Originally Posted by grantcarruthers

I don't even know if I have a copy of the operating limitations to tell you the truth!! I just assumed that if Van designed a plane to +6/-3 thats what you get?

That is part of the paperwork that is required to be in the aircraft. And it might just say..... "THIS AIRCRAFT PROHIBITED FROM ACROBATIC FLIGHT" plus a few other things that you should know.

Mel · #7 10-11-2007, 08:27 PM

It states that "Operating Limitations dated xx/xx/xxxx are a part of this certificate." The aircraft cannot be operated legally without the operating limitations. And like Gasman says, there's a very good chance that they might say "This aircraft is prohibited from aerobatic flight." Some people do not request aerobatic privileges.
Also, Van did indeed design the RV-4 to meet aerobatic standards, BUT, Van probably didn't build that particular aircraft!
Gyro tumbling puts a lot of uneven wear on the bearings greatly reducing the life of the gyro.

boomer · #8 10-12-2007, 10:02 AM

Quote:

Originally Posted by grantcarruthers

Finally got my RV-4 in my hot little hands and am starting to expand the envelope. So question is, how much should I worry about the gyros in the panel for simple rolls and beginner beginner acro.

What about the digital EFIS's like the Dynon, etc.?

-John

dan · #9 10-12-2007, 10:18 AM

Quote:

Originally Posted by boomer

What about the digital EFIS's like the Dynon, etc.?

-John

If I only had a nickel for every time my Dynon EFIS-D10 was tossed through a roll or loop...

Ironflight · #10 10-12-2007, 10:46 AM

Quote:

Originally Posted by boomer

What about the digital EFIS's like the Dynon, etc.?

-John

That is probably one of the strongest argument for solid-state "gyros" in RV's - they stay happy as clams through whatever you want to do with the airplane! Take it on an IFR cross-country one day, and turn it upside the next - and never worry about messing up the gyro bearings. I doubt I'll ever own a mechanical gyro again....

Paul