dougweil
Well Known Member
My RV-7 has now been flying for just over two years. The Hobbs meter has clicked past 300 essentially trouble free hours. My wife and I have flown it from Maine to California and it has proven to be everything we wanted in a fast and efficient cross-country machine.
But.. since its first flight it has had ?twitchy? ailerons. So what does that mean? Well I truly think it could rival an Extra 300 in roll rate. It handled too nice. The lateral control seemed really fast? way fast. It was uncomfortable to fly in turbulence and if I hand flew it under IMC, I was ?this close? to declaring an emergency. My old RV-4 never flew like this. It was smooth and responsive but not overly so. I?ve got almost 2000 hours in RVs; made 12 initial test flights in all models and never did I find one that handled quite like my -7. Frankly I flew it on autopilot 95% of the time so I wouldn?t have to hand fly this hyper-active RV with a bad case of ADHD.
A few weeks ago I was flying another RV-7 and marveled at how it flew. Nice smooth ailerons, no snapback like I had in mine. That was enough. Time to look into this deeper. My -7 is a quick build and the ailerons came all finished and ready to install. I just assumed that they were built correctly. Hmm? maybe not. I really got to looking carefully at how the trailing edge was formed and discovered that they had the dreaded ?round? shape that Van warned about years and years ago when rolling your own ailerons. I closely looked at my hangar partner?s RV-7A and saw a nice ?sharp? trailing edge (his was a quickbuild also). A call to Van?s confirmed that not all quick-build ailerons are created equal. They suggested trying the ?squeeze-the-trailing-edge? technique to see if I could get back that nice RV feel.
So today I spent about an hour laying out two oak 1x3?s and a half dozen clamps and squeezing down the trailing edge on both ailerons (careful not to mar by multi-thousand dollar paint job). Mission accomplished, I headed out for a test flight. WOW?. I couldn?t believe this? a totally new airplane!!! Smooth ailerons... certainly not a competition acro machine anymore but no snap-back, no ultra-lightness, and no twitchiness. It handled WAY better in turbulence and even the autopilot now was 100% better in making turns, intercepting a course to a waypoint and tracking an LNAV path.
Moral of the story folks? check your trailing edges on even those pristine quickbuild ailerons. Lay a straight edge along the top and bottom and be sure they are flat right up about a quarter inch from the trailing edge (mine started curving about an inch from the TE). And remember to make the squeeze the same to both ailerons (if your effort results in a heavy wing, squeeze the radius a little more on the light side). Now that I have a ?new? RV-7, I might even be brave enough to try a little hand flown IFR!!
Here's the "before" photo. Note the rounded trailing edge compared to the ruler.
Here's the "after" shot. The aileron is flat (in my case a little concave) right up to the trailing edge.
But.. since its first flight it has had ?twitchy? ailerons. So what does that mean? Well I truly think it could rival an Extra 300 in roll rate. It handled too nice. The lateral control seemed really fast? way fast. It was uncomfortable to fly in turbulence and if I hand flew it under IMC, I was ?this close? to declaring an emergency. My old RV-4 never flew like this. It was smooth and responsive but not overly so. I?ve got almost 2000 hours in RVs; made 12 initial test flights in all models and never did I find one that handled quite like my -7. Frankly I flew it on autopilot 95% of the time so I wouldn?t have to hand fly this hyper-active RV with a bad case of ADHD.
A few weeks ago I was flying another RV-7 and marveled at how it flew. Nice smooth ailerons, no snapback like I had in mine. That was enough. Time to look into this deeper. My -7 is a quick build and the ailerons came all finished and ready to install. I just assumed that they were built correctly. Hmm? maybe not. I really got to looking carefully at how the trailing edge was formed and discovered that they had the dreaded ?round? shape that Van warned about years and years ago when rolling your own ailerons. I closely looked at my hangar partner?s RV-7A and saw a nice ?sharp? trailing edge (his was a quickbuild also). A call to Van?s confirmed that not all quick-build ailerons are created equal. They suggested trying the ?squeeze-the-trailing-edge? technique to see if I could get back that nice RV feel.
So today I spent about an hour laying out two oak 1x3?s and a half dozen clamps and squeezing down the trailing edge on both ailerons (careful not to mar by multi-thousand dollar paint job). Mission accomplished, I headed out for a test flight. WOW?. I couldn?t believe this? a totally new airplane!!! Smooth ailerons... certainly not a competition acro machine anymore but no snap-back, no ultra-lightness, and no twitchiness. It handled WAY better in turbulence and even the autopilot now was 100% better in making turns, intercepting a course to a waypoint and tracking an LNAV path.
Moral of the story folks? check your trailing edges on even those pristine quickbuild ailerons. Lay a straight edge along the top and bottom and be sure they are flat right up about a quarter inch from the trailing edge (mine started curving about an inch from the TE). And remember to make the squeeze the same to both ailerons (if your effort results in a heavy wing, squeeze the radius a little more on the light side). Now that I have a ?new? RV-7, I might even be brave enough to try a little hand flown IFR!!
Here's the "before" photo. Note the rounded trailing edge compared to the ruler.
Here's the "after" shot. The aileron is flat (in my case a little concave) right up to the trailing edge.