[Blw2]

I'm just curious at this point, which most builders choose.

 

[Snowflake]

Why not both?

 

[warmi]

Knots for airspeed, mph and knots for ground speed.

 

[wcalvert]

Didn't know there was a choice ... ?! GO NAVY!

 

[RVDan]

For aeronautical use, knots is pretty standard. MPH is typically old school snall airplanes to make it sound like you airplane goes faster. If you have a round dial, you can have a dual scale.

 

[Pilot135pd]

My "new" plane is a 1969 model and it's in MPH plus the transition training I got was in another old plane like mine and also in MPH, so that's what I fly with.

 

[rocketman1988]

And

If you are flying in the IFR world, there is no choice. It is always knots.

 

[RV7A Flyer]

Furlongs/fortnight.

 

[VANDawg]

Mach number

 

[9GT]

Never heard ATC direct anyone using miles per hour, only Knots.

 

[rocketman1988]

Yep

Never heard ATC direct anyone using miles per hour, only Knots.

Knots only

 

[Steve Barnes]

Both

Tailwind = knots
Headwind = MPH

 

[Steve]

Airspeed - mph
Groundspeed - knots
I have a G3X system in my 9A. All of Vans performance numbers are in mph, so I configured my system likewise. My old airspeed indicator had mph on the outer scale, too.