Has anyone modified a 701 to include an increased aileron deflection , I am not very happy with my roll authority and was thinking of increasing the leverage on the bell crank arms ... might make the yoke a little stiffer , just wondering if anyone has ever experimented with an increased aileron deflection

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With my 80 hp. Rotax, an stock 701, the authority of the ailerons is quite snappy, any improvement on the ailerons on my stock plane would be dangerous or twitchy there so effective. Can be in a 60 degree bank in mere second. Not even sure what to advise you. Are you engine heavy, or stock? Perhaps others will know more. This raises alarm to me because they are so effective and correct, in flight, and all cross wind landings & take offs, at least on my craft. 

I agree you must have something not set up right, the aileron set up on my plane is very responsive? That being said you should check your deflection with the specifications Zenith Recommend.

My 701 has the 912ul , (80hp) the deflection is stock , the cross winds here can come up very quick 30kts+ then back to calm again (lots of mountains) ,on a number of occations I have had little to no authority left at 60mph and had to push the nose down to regain adécuate control ... would be nice to have some increased deflection specially at lower approach speeds..

Thanks for the comments

Or, you could stay on the ground when the weather forecast includes the chance of a 30 knot crosswind gust! 

When 20kts are forecasted I stay on the ground , however in this country 30kts and heavy turbulence can occurre at any time during Dec to Feb ...

I can’t find anything posted by Zenith regarding any demonstrated crosswind component for the 701. There is a post here http://www.zenith.aero/m/blogpost?id=2606393%3ABlogPost%3A243192 perhaps you can contact  him and find out exactly what he did and if it made an improvement. As a point of reference a 12,500 pound King Air crossing the numbers at 120 Knots has a max demonstrated crosswind component of 25 MPH. I suppose we’re all test pilots with regard to crosswind controllability in all the Zenith kit planes. Perhaps give Roger at Zenith a call about the risks of adjusting the ailerons beyond the maximum deflections in the drawing. Those deflections had to have been based on something and I’d guess it’s related to both the max structural speed at the high end, and the very low speeds that we can use to land a 701. If exceeding the factory kit deflections I’d be concerned about inducing a wing stall on the down aileron wing during landing speed or exceeding a structural design limit at higher speeds. 

As I recall, the demonstrated crosswind capability of the 701 is an astonishing 30 knots, presumably with a rather large crab angle.  

im and Amelia
Yes it would be nice to see some formal numbers on maximum cross wind performance .. I find as long as you keep the airspeed up it’s not a big issue , but on short final under 50 mph she starts sinking pretty fast , this is where I feel vulnerable with very poor aileron authority... buy the way thanks for your comments very usefull Input I will ask the gentlemen who made that post
just now

If you have 2 notches of flaps (which most know ZAC took outa the plans) and you actually use the second notch; and your elevator control bellcrank isn't divorced from the torque tube then you may very well have restricted aileron travel when the second notch is selected. That's the way mine was and I gradually figured out what was going on. I agree that ZAC disapproved the 2nd notch.

I have the 4 position flap upgrade , the elevator is not “divorced” never though much about it but I will need to compare full flap and no flap aileron effectiveness at slow speeds ...

Put a digital level on the aileron top surface and check the travel at the different flap settings. Believe you will find that the more flaps the less aileron. Really shouldn't do much right xwind landings til divorce the ailerons from the elevator bellcrank. On my airplane anyway. Let us know what you find.

For clarification, the four position control has the fourth position identical to the first notch (15 degrees) - the second notch is thirty degrees in the two notch system, double what you get in the four position system.

Without a divorce, flaps 30 restricts aileron travel and has much greater adverse yaw.  If you are going to fiddle with the geometry of the bell cranks, think long and hard, make careful measurements of the up/down deflections and how they change with flap, so you can compare what you get afterwards.  Also consider changing the geometry for differential ailerons at the same time, to reduce adverse yaw.


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