I had an interesting experience with the 350-B4 which has a "suicide door" like the ones on the A-Star ( but with a less positive latching mechanism) .
I had flown the same tail number all week, and the first flight of the day, post load walkaround, I neglected to check the latches of the suicide door on the right side.
120ish knots when it opened, interestingly without opening the right forward door. Made quite a bang as it hit the airframe ( denting it ).
After landing back at the field, the pax wanted to know if this meant they weren't going to get their tour. I said "I don't know, but I know that
I'm not getting one!"
Luckily found out that our Asst. Chief had had the same mishap not that much earlier, and that another op. had their suicide doors screwed shut.
Door back to EC, airframe repaired, about $18k USD in parts.
A few days later, a competitor's pilot walked up to me and said that he had been in trail, and watched me rain shattered plastic window bits all over a busy blvd. He commented that I sounded very cool and professional explaining to ATC.
I explained to him that i may have
sounded calm, but it was definitely a shorts-changing experience!
HB