Cessna 170B Sportsman STOL: PIREP

[robw56]

As most of you know I got a Sportsman STOL kit for my 170. I picked up my plane from Q-Aeromotive in California City yesterday and flew it home. First I went up for a little bit with glidergeek in the right seat and we did some slow flight and a few stalls and only one landing back at Cal City before flying back to Rio Vista. Today I went out by myself to see what it could do and I was even more impressed with the kit, I think having less weight and not as mush of a forward CG changed the feel a little from the first flight test. First I did some slow flight with 20 degrees of flaps and power, I could keep it level at about 35mph and start to get a slight buffet. Next I tried 40 degrees with power... this time I was flying with the ASI below 30mph. At this point you could take the yoke all the way back put in full power the ASI is fluttering back and forth between 0 and 20 and it still doesn't really want to stall. Power off stalls with 40 degrees of flaps are impossible, it would just decend at about 600fpm at 40mph indicated. You can make turns back and forth at this speed with no problem. Next I went and shot a few landings at Rio Vista on the grass next to the taxi way. Yesterday when I flew I just approached at 60mph and it felt like it used to at 70mph. Today I was flying approaches at 45mph indicated and carrying power. WOW before there was no way I could do this. Before if I got a little below 60 you could feel the plane want to drop out from under you. Not anymore, 45mph carrying power into the flair and I would plop down on the grass nice and soft and stop in about 100 feet or less... I also had about a 15mph head wind. I felt like I was flying a helicopter on approach. Taking off with 20 degrees of flaps I'm airborne at 35 mph and climbing out nicely at 45mph. Stene's site lists VX at 48mph and VY at 75mph at gross. Also on the flight back from Cal City I noticed no loss in cruise speed. Overall I'm very happy with the kit and glad I got it. I'm looking forward to seeing what it can do in the backcountry this year. I hope this review can help anyone that's interested in installing the kit on their Cessna.

[akflyer2001]

Nice plane, what is the HP.?

Ken in Alaska

[robw56]

145!!!

[kevbert]

Outstanding, Rob! Thanks for sharing the data, that is most helpful. However, the airspeed indicator isn't very accurate in high angles of attack, so if you ever have the chance to measure ground speeds with a gps on a calm day, I'd be interested in hearing the results.

The voices keep telling me to put an STOL kit on my 1959 172. I think it has exactly the same wing as yours, so I would expect almost identical results. I'd better start buying lottery tickets.

[mountainmatt]

Awesome Rob!

[260Driver]

Nice Rob! She looks real pertty now. With the STOL kit and the bushwheels you've been pretty busy.

[Tadpole]

That's awesome!

[Glidergeek]

Rob
Thanks for the ride yesterday, quite impressed with the performance. And what's up with the "I think having less weight and not as mush of a forward CG changed the feel a little from the first flight test" I used to be as skinny as you 40 yrs ago, you just wait

[richw56]

Sometimes when Rob gets home he gets to borrow a 1959 STOL 172 that lives on our strip. Rob’s 170 with the seaplane prop has a better feel at the flare then the STOL 172 before Rob put on the STOL kit, so bring the 170 home some your old Dad can check it out.
This 172 also has some flap gap seals on it, I think that is a bad combo, it just has a hard time keeping that dam training wheel off the ground on flare. On take off pull the yoke all the way back and it fly’s off at 35 mph indicated at near gross.

[lesuther]

Very cool.

The Stene Sportman site says the modification "Nearly doubles lift coefficient". Their numbers hint at a 31% increase at Vy: Old Vy=80, new Vy=70; Cl(new)/Cl(old) = V(old)^2/V(new)^2=1.31=31% more. It seems neat regardless. It sounds like you might get more AOA, which would also increase the Cl max a lot more than a comparison at Vy.

Is there any mention of a maneuvering speed reduction in the flight supplements, or were they able to certify it without a change?

Did you find the pitch was less nose-heavy, or more nose-heavy?

[robw56]

With the seaplane prop I already cruise well below Va anyways and I haven't heard of it changing because of the Sportsman STOL. There aren't any flight supplements. I haven't noticed it being more or less nose heavy either.

[robw56]

Here is a short cell phone video of the first takeoff at Cal City

[hotrod150]

I think the sportsman kits are about $2K, what was the installed price? I tried to cheap out so bought a VG kit for my C150XP, but was underimpressed with the results-- there is some improvement but it is subtle.

[robw56]

Install cost me 1k.

[oldtech]

Attaboy! That's what that plane needed. Check out the improvement in glide ratio too. it's a good thing they have the big flaps

[EZFlap]

Alan Quackenbush at Q aeromotive is good people. A good mechanic, airplane lover, and a lifetime airport rat of the highest order.

[Zzz]

Are you going to keep the cuffs unpainted aluminum? Looks kinda cool. Maybe a clearcoat or something?

[c170pete]

I'm sold. I just need permission from the wife...

[robw56]

Are you going to keep the cuffs unpainted aluminum? Looks kinda cool. Maybe a clearcoat or something?

It will stay unpainted for now. Eventually I'd like to do an entire strip and repaint.

[buzzlatka]

How much weight did it add?