The way I remember, cuffs were a temporary fix to address low speed stability. Retaining the cuffs is an owner's prerogative. One person at the Kerrville flyin years ago said he kept them to keep from disturbing the paint. Functionally, from the shade tree mechanic/aerodynamicist's position, it seems to me that the cuffs simply provided the effect of two vortelons at their ends.
But technically, per the CPs, vortelons are required.
When my plane was painted a couple of years ago I flew it once on a 6000 ft runway without the vortelons, observing their significant benefit. Both the vortelons and TE Fences are of benefit in my current flying, shortening the ground roll for takeoff and landing.
Per the comment, “The POH puts aft CG limitations with planes that do not have them”. It is very comforting that comments from the POH and CPs would appear here for clarification. I commend and applaud you for doing your homework. This is a positive indication in an area where many have concerns about adequate Eze knowledge.
I would offer that the phrase is an incomplete reading, which benefits from being brought up in this particular thread. My response, obviously all VariEzes have an aft CG limit. To continue, the vortelons should be installed. I don't see them making a difference to the way we determine CG. The plane is set up for first flight per the plans, CPs and POH. During the restricted period, actual flight will indicate the preferred CG within the CG range. This would also be prudent (required) after purchasing an Eze. After the proper CG determination, nose wheel liftoff speed provides an indication on each flight that the CG is correct. Minimum speed tests at altitude provide for setting the approach speed. It has been stated, I believe correctly, that Ezes need a 22 mph buffer over minimum speed for adequate energy to reduce rate of descent. I don’t use the term stall speed because at full aft stick my plane just sits at a very high angle. I’ll just let that irritating stall rabbit chase end there.
At my first Jackpot, after the race one of the other racers noticed that I had two quarts of oil stored in the nose. He was astounded that I would leave them there during the race. That is what I think of when being told that an aft CG reduces wt on the canard, allowing a faster speed. That aft CG attraction must be balanced with the other operational concerns, and not carried to an extreme.
The details are in the CPs. Many current flyers benefitted from growing up through the VariEze birthing pains, reading the CPs multiple times and understanding the growth process. Actually it wasn’t any easier to be knowledgeable then than it is today. Congrats on doing it right.
