I've got a 2008 Cessna T206h equipped with a G1000. I had some bugs in the pitot tube and had no readings on airspeed at all, I had the FBO blow out the line from the instrument panel back but now I show 13 to 18 knots slower on true airspeed... I took it to the avionics shop he certified it but I still show the same slow TAS on both the G1000 and the backup steam gauge..., I've ordered a new hose and pitot tube from Cessna that will be installed next week... Has anyone had experienced a similar situation?

Work with a shop with a modern RVSM digital air data test set. They can set any airspeed and altitude very accurately, via the pitot and static ports.

Simply sounds like a leak on the pilot line somewhere. The shop likely blew something out by putting too much pressure in the tubing. 150 knots you can generate by blowing with your mouth. With an air compressor that's likely close to supersonic airspeed.... . not good !

-Pascal

You can check for leaks by taping a balloon to the port and letting it sit. If its leaking the balloon will lose pressure.

Is your OAT accurate?

I took the Aerostar to Carpenter Avionics in Nashville yesterday for TXP and pitot/static certification. Both Aspen units were showing slow airspeed. They found a leak and calibrated both units to within one knot at all speeds.

I think you need to be sure that your shop really knows what they are doing with the G1000 installation. After all, it's not your father's old Buick anymore.

Jgreen