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Permalink Reply by Samuel McNair on August 2, 2018 at 10:49pm

I am on my second 801. In both cases I removed the slats and installed VGs on the wing. I also installed them on the elevator to help get and keep the nose up.  I did pretty thorough testing before and after. Here is what I found:

1) VGs on the elevator:

a) Get the nose wheel off the ground and can keep it off not quite 5 knots lower airspeed compared to no VGs (wide tail). b) But be careful! That last bit of elevator travel when the VGs get exposed is like turning on a switch.  It makes easy to over control if care is not taken. 

2) VGS on the wing with no slats did the following: (virtually identical results both ACs)

a) Increased stall speed by 1.5 to 2 Knots ( I used carefully calibrate airspeed backed up by GPS in a box pattern to verify)

b) Increased ground roll by about 50 feet (still ridiculously short)

c) Added 8mph cruise on one AC and 10mph cruise on the other at same %power, DA, etc.

I cruise at 101 KTAS (not miles, Knots) at about 60-65% power at 3000 feet and up. (with some other minor clean ups) but with a lot of draggy junk like square landing lights, a bunch of antennas, air scoops, and boarding stairs hanging in the breeze.  I have gotten 105 KTAS at 9000 feet or so at 60%

d) Added 100 to 150 fpm climb (from drag reduction). 

Also If you don't have good strut covers and fairings, get some.  They are good for another 100-150 fpm climb and +5 to +8 cruise compared to bare struts due to the parasitic drag reduction. But don't use the draggy, hard to remove for inspection factory design. You can make a nice set of low drag ones for around $100 to $150 depending on how fancy you want to get. 

e) Raised my Vy to about 72 Knots which cools better and gives you a better look over the nose. 

f) Made the stall when it does come a more gentler mush rather that dropping like a rock all of a sudden.. 

g)Firmed up stability in pitch. With the slats on both AC tended towards very light, vague stick forces at cruise. Like a plane loaded at aft CG.  Taking the slats off firmed things up. Still light on the stick but nowhere as bad as prior.  

h) Made it harder to slow down. When you chop power it no longer pushes you against the should harness from sudden deceleration. So you have to manage power better or overshoot.

I) Likewise the approach although only a bit faster, is much flatter with slats off. So to drop in over the trees without slats, be prepared to use that big rudder and really slip when you need too. But slips are fun. 

That said, I plan to reinstall my slats in a retractable configuration. Reason?  This fixed slats are set too high compared to the bottom chord line of the wing to be really effective like the slats are on a Helio or a Just Aircraft, or other retractable slats. Conventional slat design call for them when extended to have their lower tip edge well below the bottom chord line. As they are in the factory design, they basically flush and aren't nearly as effective as they could be. Fixed slats compromise both ends of the speed envelope.

But if you set the slats lower than the plans call for the AC gets decidedly squirrely in pitch and at higher speed the stick suddenly acts sort of "disconnected" and there is a strong pitch down moment and nose bob that you can only arrest by pulling power and bleeding speed.  Flying an unstable AC is not my bag. And the drag is horrific with the slats set low.  I think that with the right geometry in both extended and retracted I can reduce the stall speed more significantly  than a measly 1-2 knots and as Troy at JustAircraft found, you can get a bit more cruise speed out of a less blunt leading edge. 

Before I took the slats off, did the minor clean ups, and added the strut covers,  I had to run 70%-75% power to get ~85 KTAS, and my ceiling was a good 3000 feet lower.  There is a lot of drag to be eliminated. 

I hope that this info helps. 

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Permalink Reply by Jerry on August 4, 2018 at 1:52pm

Thanku very much for the reply would like to talk to u if you don’t mind have quite a few questions to ask u. Seems you have lots experience with 801 my phone nu is 250 9440028. Can call me anytime and we can arrange a talk time look forward to that thanku Jerry

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Permalink Reply by Samuel McNair on August 6, 2018 at 11:30am

Jerry;

I tried the number that you posted. It repeatedly went to a voice mail with a name of: Richard (unintelligible). I left messages No response. Is it possible that the number you posted is incorrect.  I will be in my office and can take a call today anytime until 4:30 PM Eastern Daylight lime. tomorrow I expect to be near the phone all day. Please contact me at 864-617-3192.  I will try to answer your questions. I don't know a lot, but have learned some things and willing to share what little I have learned.

Sam

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