Around 20 years ago, UA flight, ORD-HNL. Flight delayed due to captain talking to operations about possible overweight situation due to an exta engine being ferried to HNL, and attached to underside of wing. Since captain was outside the cockpit while on the phone, a number of us could hear the conversation.

Plane eventually took off, and quickly started violently shaking. Captain begins long process of fuel dump and we eventually land back at ORD, with emergency vehicles lining the runway.

Only time I thought I was a goner while on a plane. Bet that captain never gave into operations again.