Re: Sparrow strainer stall
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For a moment I thought it gave me a bit faster airspeed but the I realized that the air was pretty turbulent and I was having a hard time trimming for straight and level. I do know that someone said "if you trim the elevator up and compensate level cruise trim with the reflexor you get more airspeed. I cannot confirm that was the case. And yes the zig zag did work. Just made the airplane ride nose high for cruise.
---------- Original Message ----------
From: "David J. Gall" <David@...>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 12:10:51 -0700
I don’t think the zig-zag tape “created drag” the way you describe it. To me, your description seems like the tape was doing exactly what it was supposed to be doing: keeping the airflow energized and attached. The fact that the now-attached airflow made the elevator “ride up” is exactly what one would expect from an improvement in the air flow over the top of the airfoil; instead of matching the new elevator position with reflexor, you could have accepted the “new normal” and trimmed for it. My bet is that you’ll see similar or identical results with VGs. Was the airplane slower as a result? If so, perhaps that was caused by the nose-high attitude you created when you trimmed the reflexor TE up instead of elevator TE down, and not by “added drag” from the zig-zag tape.
The problem with the sparrow strainer being stalled is that the little beastie is too small and/or too close to the elevator hinge line. This could be fixed in any of several ways, including making it bigger or re-contouring the elevator.
I wouldn’t count the zig-zag tape as a failure — according to your description, it was eminently successful!
David J. Gall
On Mar 18, 2020, at 6:25 PM, Bruce Crain <jcrain2@...> wrote: