What is the worlds most deadliest Air craft?

It depends on which type of aircraft. According to the Military Channel, the most deadliest aircraft include:

The deadliest bomber planes are the B-29, the Thunderbolt A-10, and the Flying Fortress B-17.

The deadliest helicopters are the AH-1 Cobra, and the Apache.

The deadliest gunship is the AC-130 Spectre.