Astro14,
Our -400's had the 3000# horizontal stabilizer fuel tanks, could that be what you were thinking? (If the horizontal stabilizer fuel transfer pumps fail, you land immediately due to aft CG limitations during landing if you burn main tanks down too far.) I don't remember anything about an extra ADP, but I'm getting to the age where I cannot remember all the previous airplane differences anymore. Didn't you guys have 2 fixed based -400 simulators in Denver that where called Fred and SuperFred? I remember visiting your training center with our 747-400 Fleet Captain and we where told to stay away from that design - it was a disaster. A guy by the name of Chuck Ferrari was one of your Captains that was a simulator guru.
Between the DC-9-10,-30,-40,-50,-80,-88,-90, 727, 747-200, 747-400, A320, 757-200, -300 and 767-300 I'm amazed that I remember anything at all. The limitations I remember best are from the 747-400: Max Taxi 873,000 lbs., Max takeoff 870,000 lbs., and Max landing weight of 670,000 lbs. (I think!)
Throw in ops specs, tailwind limits, crosswind limits, takeoff performance requirements - second segment climb gradients, etc., and I'm glad we don't have to commit everything to memory anymore. That's why there are 2 of us flying the plane and I cannot imagine it ever going to single pilot like NASA is studying right now.
"Nose" Dickerson's name rings a bell, but you know how this business is, you fly with someone once, and you may not see them again for another 6 or 7 years and they suddenly have retired never to be heard from again. Makes me miss the old days...we sure had some good guys to fly with over our careers.
Fly safe and enjoy the schoolhouse!