Speeds for the Katmai

[nworth]

Over the past few weeks, there's been a lot of discussion regarding the Katmai. I have contributed to some of these and it's piqued my interest regarding precise airspeeds given the canard / XSTOL wing combo.

This is probably a question for Todd as he has the most experience both in flying the Katmai and in performance flying in general. Anyway, here's the detail I would be most interested in.

Vy (clean): Does it change? How about with altitude?

Vg: I was expecting to see 75 or so as the best glide speed but my experiments to date suggest that slower, possibly even into the high 60's will be best. I plan to go up and do a scientific test across the compass points at various altitudes soon. Also, on planes Vg and Vy are usually very close together (if not identical() but it seems like this is no so on the Katmai. Why would this be?

Does Todd change his base, final and flare speeds with the Katmai setup? (Not that I'm brave enough to do it like Todd yet!)

What setting (flaps or no) gets the best climb rate? It seems on my plane that 70 kts and 10 degrees gets me going up fast, but I have not done a lot of experimentation.

Does max loiter speed change?

Any comments?

[Todd Peterson]

To be honest the speeds I have been using with the Katmai are pretty much the same as the 260SE with a few exceptions. The biggest change are the slower speeds on short final, touchdown and lift off. I have not done a detailed analysis of climb speeds or glide speed/ratio. Currently I haven't taken time to do this and my only excuse is I'm just having way tooooooooooooo damn much fun flying in and out of just about every small dirt hole I can find. Kevin can attest to the fact I've found a lot of them and it really is a bunch of fun. One also needs to take an airplane like this into the really tough places to demonstrate its capabilities (as hard as it is to believe there are some that may think I am exaggerating the Katmai's capability) and continue the process of fine tuning the airplane. I'm also getting ready for all those great spots in AZ, UT and Idaho that I plan to visit this spring.

The speed on short final depends on temp, wind, etc. but with that said during my short field work I am generally holding around 40 to 45 knots on short final. This is with twenty degrees of flaps and a rate of descent that averages 400 fpm. I leave a little bit of power on in the flare and I'm normally down and stopped in under 250 feet under no wind conditions. To demonstrate the effectiveness of the canard I have also flown approaches as slow as 48 knots with the airplane in a clean configuration, flaps up. The aerodynamics of the canard are truly amazing.

[nworth]

Todd,

What numbers (and flap settings and altitudes, if relevant) do you typically recommend for:

Vy
Vx
Vr
Vg

I have been playing with a 10 degree, 70 kt regime that sure seems to get the VSI moving up fast. I have seen a consistent 1500 fpm during the first 1500 feet or so during some of the cooler days (and about 400 under gross) here in Florida with this regime.

This plane definitely doesn't behave like any other. It's really interesting exploring some of the differences!

[Todd Peterson]

It's just an educated guess but I think most of the climb speeds are going to be reduced by about 5 knots or so. Likewise on the engine out glide speed. I will try to take some time in the next week or two and do some flight testing.