The International Cessna 170 Association

Does anyone have experience with the Avcon STOL kit on their C170B? What kind of a performance improvement did you get with this kit? I only have experience with the Sportsman.

Any insight would be appreciated. Thanks!

Most conversion STCs only state that the performance will “meet or exceed” the unmodified airplane.

This subject comes up from time to time…but the test-flights and instrumentation necessary to document aircraft performance is an expensive process and STC developers simply don’t have the wherewith-all to document it.

GAHorn wrote:Most conversion STCs only state that the performance will “meet or exceed” the unmodified airplane.

This subject comes up from time to time…but the test-flights and instrumentation necessary to document aircraft performance is an expensive process and STC developers simply don’t have the wherewith-all to document it.

Thanks. I am hoping to hear from someone who has or had the kit on their plane to get first hand feedback on how it increased performance for them.

I have the Horton stall kit/wing fences/droop tips/flap gap seals. Went up today to 4000’asl did stalls to the break, clean 40 mph ias then full flaps was indicating 20 mph till I got the wing to stall, When it did stall it was very benign buffet slight pitch down, unload the elevator and airflow reattached quickly.

This is what my aircraft does indicated, there will be airspeed errors with the high angles of attack but I know for my plane it will break at that indicated airspeed at 1G.

Slow flight down to 50 mph ias clean and have full aileron authority. At full flap I slowed down to 40 ias and using full aileron with no issues of control. I could of probably flown a little slower with full flap but that was the extent of the envelope I tried today.

With my background in flying competition aerobatics I realize you can stall an aircraft at any given ias and any attitude. I have stalled an aircraft pointed straight down/inverted and many other attitudes.

I now have 6.2 hours on FIDO.

Just checking maybe you are aware of our club warning on Full flap approaches? If not please research, thanks

Actually the problem is full flap slips in B models. And it is not just our club that warns against this, Cessna does as well. Flaps, and fuselage can block enough air from passing over the stabilizer and elevator in a full flap slip. The effect is that the stabilizer/elevator stalls and that can lead to an immediate nose down, as in straight down, attitude. Not where you want to be with less than 1500 ft and caught off guard.

c170b53 wrote:Just checking maybe you are aware of our club warning on Full flap approaches? If not please research, thanks

Thanks I know of the warning of not to side slip the 170 with full 40* flap, other than that restriction I know of no other reason limitation wise not to be able to use full flap for landing. Obviously good judgement must be used with regards to wind and turbulence in regards to flap selection for landing.
Cheers!

Thanks Kelly, just wanted to throw it out there, for any new owner and also so Bruce can correct me again (Love that guy)

Thanks for the info Kelly! We have a 170B outside of Vancouver. I saw FIDO when it came up for sale a few months back. Nice plane!

Kelly wrote:I have the Horton stall kit/wing fences/droop tips/flap gap seals. Went up today to 4000’asl did stalls to the break, clean 40 mph ias then full flaps was indicating 20 mph till I got the wing to stall, When it did stall it was very benign buffet slight pitch down, unload the elevator and airflow reattached quickly.

This is what my aircraft does indicated, there will be airspeed errors with the high angles of attack but I know for my plane it will break at that indicated airspeed at 1G.

Slow flight down to 50 mph ias clean and have full aileron authority. At full flap I slowed down to 40 ias and using full aileron with no issues of control. I could of probably flown a little slower with full flap but that was the extent of the envelope I tried today.

With my background in flying competition aerobatics I realize you can stall an aircraft at any given ias and any attitude. I have stalled an aircraft pointed straight down/inverted and many other attitudes.

I now have 6.2 hours on FIDO.

Come up to Texada and I’ll show you. I have about 50 hrs on mine now. It is a different airplane.

Sorry I did not read the post correctly, I thought you meant Avcon 0-360 conversion - duh!! I have a Sportsman cuff.

Kelly wrote:.

With my background in flying competition aerobatics I realize you can stall an aircraft at any given ias and any attitude. I have stalled an aircraft pointed straight down/inverted and many other attitudes.

.

yep:

https://www.youtube.com/watch?v=my5P6um_pCk

daedaluscan wrote:Come up to Texada and I’ll show you. I have about 50 hrs on mine now. It is a different airplane.

Sorry I did not read the post correctly, I thought you meant Avcon 0-360 conversion - duh!! I have a Sportsman cuff.

Ha! O-360 on the brain! I don't blame you. My Dad and I need to fly over before the end of the summer. We would love to check out your 'new' plane!

I have the Stene sportsman STOL kit on mine and it’s amazing. My landings got much better when I realized how slow I could go (way below the bottom of airspeed indicator arc). Just messing around at altitude doing stalls it was a docile break at approximately 25 knots!

That would be 25 …Indicated.