I flew with a psychopath once. This guy was, however utterly charmless. This owner/cp used to bleat on about 'safety' and the GA industry. He often surrounds himself with young GA kids and tells them about how QF should operate their B747s. Once, this psycho tried to taxi without a clearance(I was flying ICUS). When I placed my feet on the brakes and told him we didn't have a clearance, he screamed "GET YOUR FEET OFF THE F$%^&G BRAKES". I told him I would check with the controller. Again, screamed: "DONT YOU DARE TOUCH THE F$%^&G RADIO". Same nutcase belives that it is ok to decent below LSALT at night in "Moonlit visual conditions" and do GPS arrivals without a current data base(no ops manual approval to do so notwithstanding). Became very abusive (with profanities, in front of pax) when I explained that this was not legal. Went off his dial when I refused to depart immediately behind a Medium category aircraft due to my concerns regarding wake turbulence("KUHNS LIKE YOU, RALPH , ARE F$%^&G THE WHOLE INDUSTRY!!"). Punched his fist into his hand yelling "F...F...F.." because I got one word wrong whilst I was making my 'Welcome abord' PA (All the pax could hear and see this). One day on departure with 2 pax, I was climbing at blue line +10 and 10deg. nose up, he suddenly shoved the yoke forward(at about 30'AGL!) and yelled "10 DEGREES YA KUHNT!!" Aside from pinning 2 pax to the ceiling, we nearly impacted the runway. Ther last straw for me was when he raised his fist as if to punch out a refueller(little old bloke of about 70 years age),( whilst yelling "YOU STUPID F$%^&G OLD C%^T!!" )who had forgotten to re-zero the meter on the fuel truck. When I told him that I was quitting and the reasons(see above) he began to blubber and agreed that he had a problem and that his wife had encouranged him to get help. Also sent another pilot around to my place one day to check and see what was in my fridge..
