Skyhawk 172/Cutlass 172
Flight Crew Commercial; Flight Crew Flight Instructor
Flight Crew Last 90 Days 90; Flight Crew Total 475; Flight Crew Type 300
Situational Awareness
Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Took Evasive Action
Human Factors
My student and I were about to depart from Runway 2 at MGY. We observed a Mooney land and clear the runway. Once the Mooney was clear [of] the runway on a taxiway my student and I checked the traffic pattern for traffic. Observing no traffic we called on the Unicom that we were departing Runway 2.  As we lined up on the runway I observed a Citation 10 moving toward the runway at the far end of the runway on a perpendicular taxiway. I told my student to stop as the jet turned on the runway and faced toward us. I immediately instructed my student to turn around and clear the runway. Not long after I had turned around the jet departed on the opposite Runway 20. There is no reason that jet could not have taken off with the flow of traffic; I have noticed a recent increase of private jets departing and landing on runways at uncontrolled airports based not on the flow of traffic and/or the prevailing winds but on which runway will expedite their arrivals and departures.
C172 Instructor Pilot reported observing a Citation taking off against the flow of traffic at MGY; a non-Tower airport. Reporter stated he has noticed an increase in this kind of activity from private jets.