Bill and his fins

[av-mech]

Bill,

Do you have any pictures of the trailing MLG wheel fins that I have read about?  I came across one of the many excellent articles you have written where you mentioned these as being not much worse than a set of pants.

[Bill James]

I'll look Arnold.
The MLG trailing fins were worth about 8 mph over having nothing but the tires. They were't worth the harassment from the fast guys. I put on a regular set of wheelpants that were worth about 12 mph. Now i have Hertzler's small wheelpants that show about 15 mph benefit. Sam James has those molds now.
The nice thing about the trailing pants was that you could stand on the tire.
While using his small wheelpants, I think I use slightly larger tires than Hertzler right now. His and Klaus's are the ones to look at.

I once heard of someone putting plastic broom thistle-like filler in the space between the wheelpant  hole and tire. Whew. Wonder what percentage of a mph that helped.
I still have a few things like that on the list but am glad that i got the simple basic plane in the air 15 years ago. Lots of good flying, earlier. There is plenty of time for those extra things on cold or rainy days once the plane is flying. I started fabricating the trailing pants during the 40 hour restricted period. Like most everyone, i expected to fly that off in 4 days. But on some days, after an hour of flying i was ready to RTB and work on some of the 3rd List things. And maybe catch a sunset run later.

[av-mech]

Bill,

Thanks for the reply.  I was planning on buying a set of pants from Sam James, you say those are the early Hertzler design?  I know what your talking about concerning the list of things to do, I have a big one going now.  I actually had to put my Vari in another hangar after our return from Osh as it was to distracting to have around and was keeping me from getting customer work done.  Once I get caught up though......I have spent a lot of late nights researching and I find it amazing how much aerodynamic efficency is still left to get out of a stock Varieze, pants, cooling, boundry layer stuff etc......  For me this is where the fun is, I really like solving problems and improving perfomance maybe more than simply flying around.  I like flying but I think I like problem solving more.

[easyrider]

If you believe all the stories of speed improvements most Long's and Variz's must be approaching 500kts by now.
easyrider

[av-mech]

easyrider,

I have to laugh.......I was just talking with a friend of mine and I commented that if I were to believe the numbers associated with each common improvement, I would be going 300 mph!!  Every common improvement seems to yield between 8 and 12 knots.  So with wheel pants and inner fairings, MLG fairings, downdraft cooling, hertzler prop and hershey kiss spinner I have an speed improvement of about 40 to 60 kts!!  Not to mention that going faster will unload the prop and allow it to turn faster making more horse power....Look out Klaus I'm coming for ya!!

[Bill James]

A friend is always after me to know how fast the plane really is. I answer with the latest "on paper" speed. Funny, he is always 30 kts faster than me -  on paper 

[Bill James]

What i really want to see sometime is how my plane does next to a stock LongEZ at minimum speed. I think that's part of the reasoning behind the LongEZ, to fix the slow flight and landing characteristics of the VariEze.
At 4500 feet altitude or so, calm day, cool  , both planes already checked out for safe, good slow flight characteristics, and just see how a VariEze with vortelons and TE fins compares at minimum speed to a Stock LongEZ at minimum speed. Not maneuvering, just slow flight.
Not that it matters, i think we are all pretty happy with our birds, but i wonder if and how much the VariEze improvements over the years have helped it compared to the first flights. Surely lots of you already know how this stacks up.
Just one of those things it would be fun to do.

[Bill James]

Just to be specific, Gary Hertzler mentioned that Sam James now also had his smallest size wheel pant mold, so i am guessing that Sam has at least three sizes of Hertzler-designed EZ heritage pants. Wonder when the next craze in wheel pant design will appear.

[go ez]

I agree with your thinking Bill

The landing brake and wing improvements have made a significant difference to the Eze at reasonable weights compared to the early fast landing speeds, poor visibility on approach and Dutch roll wing rock that plagued the early days.

Clearly the Long is ultimately capable of carrying significantly more weight than the Eze but a well built clean Eze with more fuel capacity seems to be very capable now. I believe the Eze's higher wing loading makes riding in turbulence more comfortable than the Long. It is smaller and hence (as we get older) more manageable on the ground too.

Ref speed mods - the speed benefit of each mod may well be true but you cannot just linearly add each speed benefit. As the aircraft speed builds up, the actual benefit of a drag reducing mod diminishes  such that a mod that (say) on its own gains 5 kts from (say) an original cruise of 140kts  to 145kt, whereas if that mod were applied to a cruise speed of 145 kts (due to other mods)  may gain only 3 kts to 148 kts

[Bill James]

     3 kts?
     I'll take it! 

[cloudman]

What i really want to see sometime is how my plane does next to a stock LongEZ at minimum speed. I think that's part of the reasoning behind the LongEZ, to fix the slow flight and landing characteristics of the VariEze.
At 4500 feet altitude or so, calm day, cool  , both planes already checked out for safe, good slow flight characteristics, and just see how a VariEze with vortelons and TE fins compares at minimum speed to a Stock LongEZ at minimum speed. Not maneuvering, just slow flight.
Not that it matters, i think we are all pretty happy with our birds, but i wonder if and how much the VariEze improvements over the years have helped it compared to the first flights. Surely lots of you already know how this stacks up.
Just one of those things it would be fun to do.

Bill,
In past years with my Varieze I have been interested in lowering my touchdown speed and improving forward visibilty. Originally with wing cuffs, I would experience wing rock around 80 mph indicate on final approach. During this process my forward visibility was gone when getting down to 70 mph at touchdown....so I recall looking to the side to view the runway !
When vortilons replaced the wing cuffs, I noticed better forward visibility along with less wing rock on final.
When I replaced the Varieze's lower winglets with LongEz style ones there was considerable improvement with both wing rock and forward visibility.
Since I thought I was really on a roll (improvement wise) I added trailing edge fences. Since I could only estimate their sizes,
I made them extra large and cut them down in stages. Without the LongEz lower winglets the fences probably would have been effective, but did not seem to make any improvement in what I was after. In fact on takeoff in a good crosswind, without correction the plane would weathevane into the wind and actually head into the wind vs normally climbing straight down the runway. After several years the trailing edge fences are just about gone except for the ones just outboard of the ailerons. I expect that they may provide some extra aileron response. Also, the total combo made my plane really bounce around in rough air....much more than previously.
Also, quite a few years ago I made a couple of dozen vortex generators that were temporarily attached to the wings. They have spent more than a dozen years in a jar on my workbench. Just seemed to dirty up the wing too much so I did not really give them a good test.
As far as being able to touchdown slowly, I expect that the idle thrust of an engine/propeller combination limits that quite a bit.
My effort over the years to lower the touchdown speed has been two-fold. To minimize the energy in case I have to make an off-airport landing and survive....... and to make the first turn-off so I do not have to taxi so far !
Happy flying........
Wayne Johnson Varieze 725EZ.......first flown Corona, CA in 1981

[Bill James]

Wayne-
At Oshkosh this year Klaus told me in no uncertain terms to do the lower winglets, similar to his. He feels it is a safety item. For years I have had the carved foam shapes sitting on the shelf … you know how that is   
I do benefit from the TE Fences, regularly flying approaches ten mph slower, and I believe a similar takeoff benefit. Per your experience with both, starting with the fences already, I may not benefit as much from the lower winglets. We’ll see.

An interesting note, to me anyway, is that with the TE Fences, while the plane is comfortable at ten mph slower approach speed, the nose is actually higher. I watched this with a string attitude indicator on the side windows, without and with the TE Fences. So for my part, the TE fences allow higher attitude on approach, and more comfortable.
A side note, immediately after doing the final paint on the plane I flew it once without the six vortelons just to see what the difference was. Never again.

They told me that after years of flying with white primer,  going to the new slick paint might have been a slight factor in changing the VariEze’s slow speed characteristics. Unrelated, some said that the plane was faster in the primer and would probably lose some speed with final paint. I think that was during the golf ball dimple craze. Ha. Don’t they know that every mod is worth 2 Kts? Anyway, love those vortelons.

So like you, am always in the hunt for lower touchdown speeds. Moving through similar cycles as you describe, I have designed three flap systems, fun but not worth the effort.
One of them is pretty enticing. However, the flap mod would probably ground the plane for a long time, with unknown potential. Looking at it from my perspective, maybe understanding things a little more, the goal moved from slower landing speed, to a lower touchdown nose attitude. I think, but wonder, if the TE Fences would be even better at a slightly lower nose attitude. So much more in the noggin but I will go easy on you and take a break here.

And anyway, in the meantime, adequate landing roll improvement has been made by just getting better at some of that pilot stuff like being set up right for the approach early. Specifically – it helps now to use a little nudge of power just before touchdown to slow the rate of descent. Logic keeps hollering at me that adding power has to increase my touchdown speed, but the experts say that power = altitude and pitch = speed. And that has been my experience. Doing this, with the goal of not raising the nose, the approach speed is slowed. 
And - when you land and get to the hangar and the brakes are normal, why mess with success?
Time for some ginger snaps-

[cloudman]

Bill,
I expect that I would have left the trailing edge fences on ( at least longer for more evaluation ) except for the violent bouncing around I had coming back from Spokane one summer afternoon. I suspect that with the LongEz lower winglets and the fences I had increased the side wind loads on the plane too much. Not being a professional aeronautical engineer type...that is just my
guess. Anyhow, I spent an hour trying to climb up high enough to get above the turbulance while keeping the plane upright.
Usually, I have tried to fly earlier in the day (or later ) when expecting those conditions and have avoided the really rough air.
Happy flying !
Wayne Johnson

[Bill James]

Wayne,
In the same vein as your impression, I do feel that the TE fences are an overall advantage, helping the wing to physically work better at higher AOAs. I appreciate your thoughts and experience. It will be interesting to see what adding the lower winglets does.

We do have to laugh about the performance claims on these planes. But.
Two weekend observations come to mind:
Arnold, your mentioned averaging about 165 mph, probably representative of many ezes at altitude and at peak or lean of peak. It got my attention at airport breakfast conversations this weekend listening to pilots of other types mention how many fuel stops they had to make on their way home from Osh, and their speeds.  Made me feel pretty …blessed?
And on the way home from that breakfast, sailing around the south side of Dallas/Fort Worth, hearing Spinks Tower call me out as traffic for a Cessna inbound on the ILS, crossing his path at his one o’clock. The Cessna said something like, “I’ve got him in sight, he’s a fast mover, no problem.” No bragging here. It just is what it is.  
At cruise I often breathe a sigh of perturbation because the ASI says 165 instead of 250. It helps to figure the TAS    It would also probably be leveling to make the same flight in my previous Cessna-120  
If you’re building, like they say, hang in there, do something every day  

So to my original thought. On landing, I got to work on the landing sequence again. It’s kinda like back when studying leaning, initially being told to just pull the mixture back until it starts to run rough and richen it a little. Then to be thorough, I gathered and read a two-foot stack of material on leaning. After digesting the documented data, now I just pull the mixture back until it starts to run rough. Same with the landings, a lot of preparation and then a simple result.
In several conversations over last winter I had mentioned how much I enjoyed the easier landings in the cool temps and dense air, and how that with the coming of summer temps I would have to re-learn how to land in the hot dissipated air. In fact, saddling up for a hot day flight, there are several hot weather “there I was” stories, along with my own experiences, that rise up to remind me to take heed. In particular, I am cautious of and work to avoid low-speed high-bank angles. However, even with record breaking temps here, for some reason this year the landings have been OK.
Maybe it is productive to again work through the intricacies of how the plane lands, to separate the event into several layers... Maybe like reviewing the fuel system operation.   I guess maybe all that falls into the “Being ahead of the airplane” category.

[easyrider]

Bill
What did Klaus say about the lower winglets, does he mean the plans version?
I remember reading a Burt Rutan article on why they are important but I can't remember where it was.
I have a standard plans built LongEZ which is slightly heavy, the builder lined the cabin with sound deading material.
I have trailing edge fences just outboard od the ailerons, they definately improve low speed handling.
I flew for about 3 years without a speed brake and it definately improved my landing technique and a conversion to Grove Wheels and brakes handles the stopping distance.
I fitted the electric speed brake after I nearly ran off the end of the runway at Friday Harbor.
There is a line of trees on approach which if you are landing flat you have to pull up to miss, the extra height is difficult to loose without a brake.
Enjoy your postings
Don Denhard
LongEZ 93EZ