Cessna Aircraft Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor
Flight Crew Last 90 Days 50; Flight Crew Total 2540; Flight Crew Type 2000
ATC Issue All Types; Ground Excursion Runway; Inflight Event / Encounter Loss Of Aircraft Control
Flight Crew Executed Go Around / Missed Approach; Flight Crew Regained Aircraft Control
Procedure; Environment - Non Weather Related; Human Factors
My primary student and I were practicing takeoffs and landings at AEG and Runway 17 was in use. There was also a helicopter doing pattern work; including stop and go's and hovering over the runway. We shared the airspace. My student and I were assigned by Tower to make a right pattern and the  helicopter was assigned doing a left pattern on Runway 17.Everything worked well. We were on final and wanted to do another touch-and-go. We kept the right wind correction inputs because there was a crosswind coming from the east; from 130 degrees. We noticed that the helicopter was waiting on taxiway Bravo; which is to the left of Runway 17. Tower had advised him to do so and wait for us before they would be able to takeoff again. We touched down on the centerline; cleaned up the aircraft and added full power for takeoff. We started our takeoff roll and right opposite of where the helicopter was sitting with his rotor blades turning; our aircraft was; in one violently push; forced to the left of the runway; off the runway pavement; into the adjacent grass area with takeoff speed. At first; we briefly reduced power. My student and I both had right rudder input but the pushing left force was too strong and we taxied over the grass. At first; we reduced power but within 2-3 seconds; we reacted; added full power and I took over the controls; and did a go-around; and was able to get back in the air without hitting anything; and no stall horn coming on; even when our airspeed at first was pretty low. The Tower advised us to make a left pattern; which I acknowledged.After this scary experience; we executed a full stop. I called Tower and asked them if they had noticed anything. NO; nothing. I explained to them briefly what had happened and hopefully made them realize; how unpredictable it is for a small single engine aircraft to do any maneuvers next to a helicopter with running rotor blades. The aircraft has no damage at all and my student and I are fine.
Cessna instructor pilot reported encountering rotor wash from a helicopter operating nearby that resulted in a loss of control and runway excursion.