Almost the true story on single engine gear up

[jhickam]

On my 77 337G model I believe the airspeed was about 130 mph on climbout. As soon as the door came open I slowed to 100 mph and returned to the airport and landed. It appears the door seal shrinks over the years and allows the door not to latch as it should. Before we put the shims in you could tap on the door and it would open. After the shims where installed the is very positive when it is shut.