Bruce ---------- Original Message ---------- From: Sam Hoskins
To: Quickie List
Subject: [Q-LIST] Need a Sparrow Strainer alternative Date: Wed, 18 Sep 2013
The Sparrow Strainers are draggy and slow our planes down. �There
must be an alternative. �Every time a speed specialist looks at the the
sparrow strainers they go "WTF"?
So, let's start at the beginning. �Why are there in the first
As I understand it, they are an aerodynamic trim designed to counteract
the high pressure on the bottom of the canard elevator. �Air wants to push the
TE of the elevator up, causing the plane to dive, so the sparrow strainers
help by pushing it back down.
Is this logic correct?
So, what would be a drag-free alternative? �Well, I suppose one could
increase the spring tension already used for the control stick. �Why didn't
QAC do something like that? �Maybe it would increase the stick
forces. �Just guessing but when they first flew flew the new �LS-1 airfoil,
they probably found they needed an extraordinary amount of nose up trim.
�Followed by going with the cheapest fix - add sparrow strainers.
Another issue with using internal trim, is you are applying a constant
torque to the joint there the elevator bellcrank slips into the elevator
torque tube. �Maybe it's not a big deal, bit it's there.
This is all supposition. �Is anyone privy to the real story?
So, all of you aerodynamic tinkerers, what could be a viable
way to eliminate the sparrow strainers?
Thanks for reading.