On Monday, March 27, 2017 at 1:45:44 PM UTC-7, Matt Herron Jr. wrote:
This weekend I did a high speed run to test some new seals I had installed on the rudder for vibration. VNE is 147 Kts in the Ventus, and so I only took it up to 130 kts IAS (yes I was only at 2000 ft MSL, so altitude was not a factor). At that speed the air scoop on the sliding canopy window suddenly popped open and scared the hell out of me with the sudden noise and rush of air.

Anyone have this happen, and is there a way to fix it?

Thanks for any suggestions.

Yes, both vent windows at the same time giving a ride in a DG1000.
Install a cockpit extractor vent.
Jim