The International Cessna 170 Association

Hello Hello
I own a 52 170-B 180 hp that I flew from Anchorage to Florida last year.
It has a Sportsman STOL cuff and I want to install a SafeFlight AOA leading edge
Vane. I am looking for information from anyone that has done this and particularly
On the methodology used to find the Stagnation point. Thanks.
New member Ashley.

Ashley,
Welcome!
Check out page 10 and Appendix A of Safe Flight’s Installation Instructions. I would think the position should be close to that called for by Sportsman for the original Safe Flight stall vane as seen in the attached template.

While not making any suggestion as to personal choices of equipment for ones’ own airplane…. I point out that the 170-B model has as Required Equipment the Safe Flight Stall Warning System. (see TCDS A-799, Item 607). The Safe Flight AOA system does not replace this required system but may be installed in addition-to the original stall warning system. (see the AOA “Limitations” on pg 9.)

Doesn’t the safeflight AOA system under discussion here provide trend indicators on AOA that could have safety value beyond a simple stall warning? I remember the FAA recommended these systems a few years back and eased approval for their installation. Sounds like a good idea to me. Its also good to have the stall warning alert required by TCDS.

Hey! Thank you all for the information. It will be useful
And thank you Gary for the diagram. I couldn’t find the information that you referred to on page 10
But I will keep looking. I got more information from you all than I got from SafeFlight!!
Ha ! Ashley

Like most (if not all) of these GA-oriented AoA indicators, they are only truly useful for one flap configuration. It would be nice to have a true AoA system available that self-calibrated based on flap position. Still, calibrating for a single flap position can be useful, particularly for STOL-type work. The problem becomes negative transfer if you often fly in other configurations as the calibration for full flaps would very likely show low speed or stall conditions when flown with less than full flaps.

Alpha Systems AOA has a way for electric and mechanical flaps to be incorporated into the algorithm. Personally I'd rather just have a switch I dial to my landing flap setting I'm going to use rather than monkey with attaching a potentiometer to my flap cables. But it's doable.