While the scenario you described is likely, I truly doubt the engineering team will accept it, as the test items and procedures are very different between taxi and first flight - provided a cautious planned taxi test procesure does need to be contingent. So, only in "performance" you do see the plane takes off and files, but it won't really conduct the maiden flight test procedure and goals, and thus cannot be called that way on record.It is not unheard of for a new aircraft undergoing high speed taxi tests prior to the first scheduled test flight to accidentally become airborne, thus prempting the scheduled first flight.
I would think that the engine will immediately be powered down and the aircraft will come back down on the runway. Unless it runs out of runway, but I doubt so.
While the scenario you described is likely, I truly doubt the engineering team will accept it, as the test items and procedures are very different between taxi and first flight - provided a cautious planned taxi test procesure does need to be contingent. So, only in "performance" you do see the plane takes off and files, but it won't really conduct the maiden flight test procedure and goals, and thus cannot be called that way on record.
This is a amphibian, it probably has miles of sea in front of it. If the water is choppy a taxiing amphibian could easily become airborne without the pilot having exceeded any taxi parameter, and then glide at very low altitudes just over the wave crests relying on ground effects. If I were the pilot, I would enjoy that.
What's Y-20 and Y-20A?