Good positioning for Airspee sensor for an X8

Hi guys, I am currently rebuilding my X8 for much more range than previous ( 10km out and back )

This time I am fitting the APM 2.5 with 2.75 firmware.

With the X8, I was planning on fitting the airspeed sensor to the lid of the X8 so it sits high above the plane by a good 6" to avoid air bouncing off the body onto the sensor.

Before I take a knife to the new prepped body, does this sound like a good idea or any better suggestions for very accurate airspeed values ?

Thanks in advance


Hi Coyote,

If you look at where pitot tubes are mounted in manned aviation, you’ll find them generally around the front of the aircraft. As your X8 travels through the air, the nose will send wave of turbulence. To picture this, think of the bow waves a boat creates as it’s propelled through water.

The further back you mount the sensor, the further away it will need to be from the body. Even at the front of the hatch, it’s going to need to be mounted a significant distance from the body based on my experiences. In addition, this position could causes issues when opening and closing the lid by either getting in the way, or becoming unknowingly disconnected.

My advice would be to mount it in the nose, with the front of the pitot tube projecting beyond the edge of the aircraft, with ~4" between the centre line of the pitot tube and the body.

If you decide to mount it in the lid, it will still function, but you may get inaccurate readings - particularly when your X8 is pitched up and the nose casts a turbulence ‘shadow’ over it.

Hi Guy, that`s some very good info, thanks for that, I had not considered it that way.

My only concern is not damaging it, but as you say, that will probably be the only position to get as truer reading as possible

If you have access to a 3D printer, I designed a pitot tube mount that pops apart if the tube gets caught during landing:

There’s a bit more info on a blog entry I posted a while back: … blet-mount