Spearing b747 off the end of the runway--
As a lame licensed on early boeings but not on the b747 -- i was told the reason the qantas boeing 747 speared off the end of the runway in bangkok ,,,, was that 0n the early b747 you could reverse three engines with one engine lever forward of flight idle stop-- ---- but of the latter b747 all throttles had to be on flight idle stop , to remove the reversing interlock , thus allowing the reverse levers to be raised --- this could be the reason when he went manual ------- as for boeing changing the aircraft systems , at qantas on the first b707 , one training captain trick was to apply the parking brake lever on approach and carry out a normal landing ---- but he came a cropper when the next UPDATED boeing -338 arrived , same trick ,, but 8 main landing tyres burst , AND RIMS GROUND DOWN ----- ouch TOOK SOME TIME TO FIND NEW WHEELS, AND TO GET THEM TO THE TRAINING AIRFIELD IN THE BUSH , TO GET IT IN THE AIR AGAIN --