AOA Indicator and Stall Speeds

[Andy A]

We got our CTLSi in March of this year and most of the 40+ hours I have in it have been solo flights.  On my most recent two flights with a passenger, I have noticed the AOA indicator chirping at a higher speeds than when solo.  Today my brother in law and I were leaving a flyin at a 7,000’ grass strip, we were at max gross weight , 90 degree air temp, 700’ field elevation, 1,500’ density altitude, 15 degrees of flaps and when I rotated at 60 knots, the AOA was steadily chirping.  Why was it chirping at 60 knots?  I tried to keep my speed up before rotating since we were at max weight, but the airplane wanted to fly at 60 knots.  I thought the stall speed in that configuration was around 45 knots.  Should I have taken off with 30 degrees of flaps?  Also, when we were landing, turning base to final at about 65 knots, I also heard chirping.  When I am flying solo, I only hear the chirping on the landing flare...probably around 50 knots or slower.  Anybody have any insight on this?

[Roger Lee]

You may need to calibrate the AoA. Look in the Dynon manual and it will tell you how to do the calibration. It isn't hard and you do it in flight.

[Ed Cesnalis]

On 9/8/2018 at 6:06 PM, Andy A said:

We got our CTLSi in March of this year and most of the 40+ hours I have in it have been solo flights.  On my most recent two flights with a passenger, I have noticed the AOA indicator chirping at a higher speeds than when solo.  Today my brother in law and I were leaving a flyin at a 7,000’ grass strip, we were at max gross weight , 90 degree air temp, 700’ field elevation, 1,500’ density altitude, 15 degrees of flaps and when I rotated at 60 knots, the AOA was steadily chirping.  Why was it chirping at 60 knots?  I tried to keep my speed up before rotating since we were at max weight, but the airplane wanted to fly at 60 knots.  I thought the stall speed in that configuration was around 45 knots.  Should I have taken off with 30 degrees of flaps?  Also, when we were landing, turning base to final at about 65 knots, I also heard chirping.  When I am flying solo, I only hear the chirping on the landing flare...probably around 50 knots or slower.  Anybody have any insight on this?

Stall speed decreases  increases as weight increases.  You are using fixed speeds, meaning same speeds when solo or heavy so the margin you have when solo is reduced when you have a passenger and you get a warning at that same speed.

If you only use the AOA for its chirping then its little more than a stall warning horn.  If you use the AOA instead of air speeds than you can keep your margin from stall, or margin from chirping the same no matter what your current weight

[FlyingMonkey]

On 9/8/2018 at 10:34 PM, Ed Cesnalis said:

Stall speed decreases as weight increases.

Um...no?

[Ed Cesnalis]

4 hours ago, FlyingMonkey said:

Um...no?

thanks, point stands though change in stall speed accounts for chirps when heavy.