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Unbalanced elevator heavy on the ground

Lufthans

Well Known Member
Guys,

Picking up my new-to-me RV-3B in Germany turned out to be quite an adventurous two-hour flight. The prop had so much imbalance in it that anything over 2100 rpm felt unsafe, after 5 minutes of flight the throttle came loose from its cable due to the piece of wire that was supposed to imitate a cotter pin parting ways, leaving the pin free to fall out, and to top that off the MGL engine monitor turned to reading very improbable (yet very unnerving) values for oil temp, oil pressure and EGT.

Returning to field of origin not really being an option due to narrow runway and a stiff crosswind making my upcoming dead-stick first ever landing in an RV3 less appealing than heading home and landing on our generous 3000' x 3000' grass airfield, I continued the flight. Juggling the throttle cable by reaching over the quadrant, pulling on the 3/4" of exposed cable with my middle and ring finger against the spring in the carb that wanted to pull to a highly vibrating full-throttle the whole time, in happy anticipation of the inevitable landing.

In short: my observations regarding control feel have been overshadowed somewhat by events. And after safely (dead stick) landing at my home airfield, the first thing I have done is take the plane apart for a FULL rebuild (despite the thing only having logged 34 hours total time since new).

What I recall though is that the elevator really felt heavy on the ground. It felt nothing like the lightness of an RV4 (which of course has a balanced elevator), and also a lot heavier than my Jodel or Fly Baby (which haven't). More akin to the feel of the T6 that I fly on occasions. Like you really need to put some muscle in keeping the stick pulled while taxiing.

This alone makes me consider balancing the elevator.

Or has my memory been blurred and are RV3 stick forces on the ground really not that high? Everything was moving freely, nothing binding. Just felt like somehow I had to lift a lot of elevator.
 
:eek::eek::eek:
All I can say is "Wow!".. what a story!
can't speak for stick forces on a 3 but I would assume they are light like all RV's.
 
In-flight, all was normal. It was just on the ground, taxiing or even with the engine stopped, that the elevator felt quite heavy...

(And that dead-stick landing turned out to be quite nice actually:) )
 
Yes the elevator forces are very heavy on the ground.
Prop blast helps while taxiing and in flight they are great.
Typical for these planes.
 
Elevator feel

Like you coming from an RV4 & RV6 I thought the elevator felt heavy on the ground. In the air it is fine.
I quickly got used to it and don?t even notice the weight on the ground now.

Rob
RV3 G-BVDC
 
In this post I measured the moment arm it would take to statically balance the left elevator. I didn't include the trim cable and didn't measure the right elevator.

It would take a balance moment of about 16.6 inch-pounds. So that is the amount that the left elevator feeds back to the stick when the plane is at rest. You've also got the moment from the right elevator added to that. Presumably the right one would weigh less because it doesn't have a trim tab.

Dave
 
The elevators feel heavy on the ground and at first I thought there was something wrong but full aft stick just takes a little getting used to.
 
Youll get used to the heavy elevator on the ground. The prop wash helps a lot.

Get your prop balanced and lighten up the plane as much as possible if the original builder hasn't already. It doesn't get better than the -3...even compared to the Extra 300 I'm flying these days.
 
Youll get used to the heavy elevator on the ground. The prop wash helps a lot.

Get your prop balanced and lighten up the plane as much as possible if the original builder hasn't already. It doesn't get better than the -3...even compared to the Extra 300 I'm flying these days.

Thanks guys. I think I'll learn to live with it then. Pity for my girlfriend. She's not very muscular, and would like to fly the plane too, eventually.

Prop was way under pitched and way too heavy (massive aluminium thing), so it is hanging off the wall of the workshop now. Lightweight prop getting installed. Electric boat anchors (aka 1955 starter and generator) being replaced with lightweight automotive units. Already finished fabricating the mounting brackets for them. Engine being converted to EFI with loads of leftover components from previous projects (and which should more or less break even, weight-wise with carburettor, magnetos and mechanical fuel pump).

Even with the heavy stuff up front (prop, old style starter and generator) empty weight was only 750 lbs. So I've got a great starting point here... No paint. No lights. No Airbus avionics. Mechanical flaps. No fancy upholstery. All helps a lot. Trying to match Andy's empty weight of 733 lbs... :D

But first... put the pressure washer on the inside to get rid of that horrendous mouse smell. Yuck. (Yup, I have bought myself a PROJECT, not an aircraft)
 
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