Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 91; Flight Crew Total 904
Conflict NMAC; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Human Factors; Procedure
We were holding short of Runway 21 waiting for traffic landing [Runway] 21. A Warrior pulled down to Runway 3. I asked multiple times what he was doing and no answer. He finally said he's going to takeoff [Runway] 3. I advised him that there are 3 aircraft (2 planes including us and a helicopter) for patterns for [Runway] 21. A moment later he pulled onto the runway and started to takeoff. He called that he was taking off after rolling halfway down the runway. There was an experimental on a short base to final for [Runway] 21 that had to cut his base really short to evade the aircraft taking off [Runway] 3.
GA aircraft flight instructor holding short for takeoff at JNX reported observing an aircraft take off in the opposite direction of the runway being used for landings; causing a landing aircraft to take evasive action.