Scenario:

MISTAKE YOU ONLY MAKE ONCE
Poor Preflight
An excellent reminder that there really are good reasons to do a thorough preflight and to make sure the controls are free. This happened just north of Winnipeg, and the aircraft was the first version with PT-6-67 Turboprops.The Canadian DOT concluded that the control locks were still locked when the aircraft took off. People who have flown the Caribou wonder how that could have happened when it is physically impossible to advance the throttles with the lock on - but this aircraft was being modified (still restricted category) and the throttle quadrant was not properly rigged to accommodate the throttle levers for the turbine engines.
Three people were on board; two test pilots and an engineer.

Video at http://rds.yahoo.com/_ylt=A0geu6K9akFH7.AAM2JXNyoA;_ylu.../watch?v=KdVT4T6v7RQ

I've seen that happen a couple of times over the years, and I can only imagine what a horrible feeling the pilot must have had when the realization hit him. What a rotten shame.