GFC500 Yaw Damper Speed Mod

[Bob - S50]

I had an occasion to fly at 9500' yesterday to compare speed pre-yaw damper vs post-yaw damper.

Pre-yaw damper, cruising just barely LOP at 9500' I would see 157 KTAS.  If I remember right, fuel flow was about 9.0 to 9.3 GPH.  That speed was calculated using our TAS indicator by aligning the OAT with altitude and reading the value.

Yesterday I did the same thing.  Fuel flow yesterday was 9.1 GPH.  Using the airspeed indicator I got 160 KTAS.  Using the TAS calculator utility on the GTN650 I got 161 KTAS.

So it appears that the yaw damper is about a 3 - 4 knot speed mod.

[ArtVandelay]

Were you coordinated with out the YD?

[Bob - S50]

Just now, ArtVandelay said:

Were you coordinated with out the YD?

Apparently not.

[DAVIDWH]

 

Four knots is significant, will check mine later this week. Never thought of going to Garmin, instead of Lo Presti, for a speed mod.

Every day I am glad I never sent my GFC-150  in for repairs. That little GFC500 box is worth every penny.

Best,

 

 

[carusoam]

Since most Mooneys have their rudder trim set in one place...

It will be a slight drag depending on where the airplane’s WnB is actually at...

Of course, electric rudder trim allows a perfect centering of the coordination ball... a standard for LBs...

Where the YD is going to shine... is in bumpy weather...

Good luck trying to capture before and after data in the bumps...   

A movable rudder trim is worth the money...

Best regards,

-a-

[bradp]

I got about 1 kt improvement with YD engaged. My TAS is read directly from the G5’s. May have more to do with feet off rigging than anything.  
 

Haven’t nearly gotten to exercise the GFC 500 because of the pandemic, but the system is excellent so far. Really worth it.