From an Indian news site:
The pilot, co-pilot and crew have now made statements to Trabzon prosecutors and both pilots passed breathalyzer tests, the Dogan news agency said.
"When we were going to make our usual manoeuvre towards the right from the seaside by reducing our speed, the right engine suddenly gained speed for a reason we do not know," the pilot was quoted as telling the prosecutors.
"Due to this speed, the plane got out of our control and suddenly swung to the left and got stuck into the mud in the cliff."
www.ndtv.com