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-   -   How to make an RV fly really bad!!!! (https://vansairforce.net/community/showthread.php?t=201471)

lr172 11-29-2021 07:07 AM

Quote:

Originally Posted by NYTOM (Post 1571717)
Iím sure this post will have a bunch of us wondering where our planes fall in this trailing edge spectrum. In my quest to get the optimum qualities out of Vans design, does anyone out there have before and after photos of a corrected poor trailing edge. If anything, just to compare our edges to a property formed edge.
Thereís most likely a lot of RVís out there that could be greatly improved and much safer. :)

Section 5 has descriptions and pictures. It will guide you through the process. My 6 was somewhat sensitive in pitch but not a problem. When I started IFR training, It was hard to hold 100' when doing other things. I addressed the under squeezed TE's on the elevators and it made a noticeable difference when under the hood. Didn't take away any of the fun factor, just the over sensitivity.

Larry

rv8ch 11-29-2021 07:31 AM

This looks like it's ripe for a nice video showing a trailing edge that is too rounded, and a trailing edge that is correctly rounded, and how to make it right. Also, any hints for those with painted surfaces would be welcome!

Mike, next time you're in Switzerland I'd love to have you fly my 8 to determine where on the --twitchy----------stable-- spectrum it sits. I'm happy with it, but I've only flown 5 RVs, and they all seemed about the same.

Mel 11-29-2021 08:10 AM

Pillowing trailing edges are also the major cause of skin cracking around the most aft rivets.

rvbuilder2002 11-29-2021 08:44 AM

Quote:

Originally Posted by lr172 (Post 1571729)
Section 5 has descriptions and pictures. It will guide you through the process.

Larry

Quote:

Originally Posted by rv8ch (Post 1571734)
This looks like it's ripe for a nice video showing a trailing edge that is too rounded, and a trailing edge that is correctly rounded, and how to make it right. Also, any hints for those with painted surfaces would be welcome!

As Larry wrote, there is fairly detailed instructions in SECTION 5 on how to evaluate the shape of control surfaces with bent (vs riveted) trailing edges, and how to adjust them if the shape is not correct.

The shape / profile is far more important than the actual bend radius of the trailing edge.

This is equally important for the ailerons, elevators, and rudder.

Next on the list of things that can make an RV fly bad is control system friction. This is particularly bad in the pitch circuit.
For the best flight qualities (and static and dynamic stability), the control system should be very low in friction.
I.E., if you flick a control surface, it should move and bounce around without quickly stopping.
Sometimes solving this just requires doing some good lubricating but it is usually caused by excess friction being induced by improper assembly.

SantosDumont 11-29-2021 09:27 AM

I hope someone takes pictures or makes a video the next time they encounter this.

I actually went around at OSH and took pictures of the rudder and aileron trailing edges to compare to mine because as a first time builder I have no idea what I am doing.

RV7A Flyer 11-29-2021 09:36 AM

Quote:

Originally Posted by Sam_B (Post 1571704)
Iím not flying yet, but this thread has grabbed my interest. I realize that this is probably a progressive adjustment, but is there a ballpark number for a radius that we should be aiming for?

From the Construction Manual, in the section on building the ailerons:

Quote:

The bent skins must be straight up to the radius and the radius must be between 3/32Ē to 1/8Ē. Match the degree of bend to the full size end view drawings. The upper and lower skin should just touch the spar when placed in position.

Mconner7 11-29-2021 10:04 AM

This makes a lot of sense now.
 
I have owned of a -10 for several years. I had the chance to fly my first two seat RV last week, it was a -6. I have a lot of time in many high performance aircraft including many aerobatic biplanes. This -6 had the most sensitive elevator control I have felt. I called the owner who is new to Vans and he is checking the skins now.

Thanks for the tip!

PhatRV 11-29-2021 10:09 AM

1 Attachment(s)
Quote:

Originally Posted by Michael Seager (Post 1571681)
...
1 Do not cut 6 inches off your control stick. It was designed to be the length that it was shipped in the kit. If you want to cut it down to put on a stick grip make sure you put back to the original length.
Michael Seager
rv6cfi@hotmail.com

From the plan, it says the maximum length from the bushing is 15 inches but it does NOT mention the minimum length to keep it from being twitchy.

What is the preferred length from the pivot point to the hand position? Like many builders, I cut mine so it will just clear of the lower instrument panel.

rvbuilder2002 11-29-2021 10:19 AM

Quote:

Originally Posted by PhatRV (Post 1571781)
From the plan, it says the maximum length from the bushing is 15 inches but it does NOT mention the minimum length to keep it from being twitchy.

What is the preferred length from the pivot point to the hand position? Like many builders, I cut mine so it will just clear of the lower instrument panel.

Short enough to clear the standard kit supplied instrument panel is appropriate.
Shortening to clear a custom, deeper, panel would be staring to deviate towards unacceptable.

rvbuilder2002 11-29-2021 10:20 AM

Quote:

Originally Posted by SantosDumont (Post 1571769)
I hope someone takes pictures or makes a video the next time they encounter this.

I actually went around at OSH and took pictures of the rudder and aileron trailing edges to compare to mine because as a first time builder I have no idea what I am doing.

As already mentioned, detailed photos already exist in Section 5 of the manual.


https://www.vansaircraft.com/service...d-revisions/5/


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