The pilot can decide very quickly after learning that the airport and the engine turns off, which could lead to aircraft at the airport. At that time, the pilot saw the river fit decision, landing at the river.
Pilots can decide very quickly after learning that the airport is a long way off and the engine, which could lead to a plane at the airport. At that time, the pilot decided to land in the river just a river.
The pilot can decide very quickly after that the airport is far and the engine off, which can not bring the aircraft into the airport. While the pilot saw the river just decided to land at the river.