Re: "Darting" to Left on Slow Speed Taxi


David J. Gall
 

Hi Jim,

 

Merry Christmas to you, and to all on the Q-List!

I retired from ATC four years ago, then successfully pursued my dream of being an airline pilot for three and a half years before the coronavirus put an end to it, which was for the best since the strain on family of such a foolish job was starting to show. (Whenever an airline job is touted on the basis of “per hour” pay, divide that by 4 to figure out what the hourly equivalent would be in any other job.) I’m still in CA, still mucking about with airplanes and such.

 

David J. Gall

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jim Patillo
Sent: Wednesday, December 23, 2020 12:01 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] "Darting" to Left on Slow Speed Taxi

 

David, you are still a funny guy! Corbin is just earning his Quickie Wings.

 

Hope all is well with you and your family. Do you still live in CA or are you domiciled somewhere else? I don’t hear you on NorCal.

 

Merry Christmas

Jim

N46JP Q200

 

 

 

Sent from Outer Space


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of David J. Gall <David@...>
Sent: Wednesday, December 23, 2020 10:40:23 AM
To: main@q-list.groups.io <main@q-list.groups.io>
Subject: Re: [Q-List] "Darting" to Left on Slow Speed Taxi

 

So you’re taxiing downwind at idle at 15 kts. with a tailwind gusting 18-26 kts. from 20 degrees to the right off your tail. Basically, your vertical stabilizer/rudder is at zero airspeed gusting to -10 kts. airspeed. Any change of wind direction to be more from the left off your tail is going to be changing the roll moment imparted by the wing dihedral as much as the yaw moment imparted by the vertical stab/rudder. I think almost any taildragger would behave similarly, but the Quickie main gear is known to be a little more responsive to roll coupling than other planes. Did it do anything similar on the taxi back to the hangar when you had a headwind? If not, I’d diagnose it as “Corbin flies his Quickie when mere mortals cower in the hangar.”

 

JMHO



On Dec 22, 2020, at 1:33 PM, Corbin via groups.io <c_geiser@...> wrote:



[Edited Message Follows]

Well, I thought today would be the first day I flew with the new Lightspeed ignition.  My plan was to do a couple high speed taxi tests and, if all was well, then depart for a test flight.  However, when simply taxiing down to the runup area it "darted" left on me twice.  I don't think it was because my feet aren't awake from not flying.  It just seemed to randomly "dart" left.  

The pedals and brakes feel normal and there is no play in the rudder cables.  Could it be the left tire/caliper is grabbing but then releasing.  I don't know where to begin troubleshooting.

I had a camera recording but not with the tailwheel in view.  Here is the video in case you want to see the "dart" and have any ideas for me to look into tomorrow.  I included the startup just for fun.  Skip to 1:15 and 2:15 for the two darts before I decided to head back to the hangar.

https://youtu.be/LpUadPr6480

Could it simply be wind gusts....they started picking up around that time.  My heading on taxi was 360 and winds were 160 18-26kts....

Thanks,

Corbin
--

Corbin 
N33QR

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