Without scales, most pilots are willing to take the passengers' word on their weight - and the passengers LIEEEEEEEE! Aircraft manufacturers, in their efforts to compete in the marketplace, don't help when they come up with GWT increases without increasing available power. Two cases in point: The Bell Long Ranger (the original): Bell lengthened the fuselage enough for two more passengers; kept the same Allison C-20b engine; and added glycol injection for takeoffs and landings. If you were careful, the 2-gal tank would last 40-50 landings (I think you were limited to 20 seconds per use - maybe less). The BO-105 CBS was a 5-place aircraft trying to compete with the LongRanger and the A-Star. They developed another seat modification which required the front-seat passenger to move his seat all the way forward (making it difficult to get out in an emergency) and the increase in GWT made it chancy to successfully accomplish a single-engine recovery if an engine failed on takeoff. Essentially, the pilot would have to dump the collective, reach down and activate 2 fuel-dump switches, and then - if enough fuel was dumped in the 75 feet between the platform and the water and the aircraft reached single-engine flyaway speed - remember to turn OFF the fuel dump switches. Pilots weren't optomistic about that.
I'm surprised any pilot would fail to dump off an external load (that wasn't carrying passengers on it - e.g. a rescue or cargo basket) upon experiencing an engine failure. An external load can do bad things to CG, and, until it's sitting on the ground, contributes to the aircraft GWT. It's almost a trained instinct to jettison external loads in an emergency.
