glueball & Junkflyer (man, you gotta change that screen name!),
Isn't there a field in Lima Peru or someplace in Peru that has a Takeoff above 10,000 ft field elevation? Maybe that's where a "bleeds off" t/o is required in the performance charts in ground school. The supplemental procedure would be part of the individual airline's AOM as approved by the POI. The data it is derived from would come from Boeing performance data/charts in Seattle. I don't think its a case of a binary question of: are bleeds off required or not required by certification data. At certain high gross weights if an operator wishes to avail himself of that higher weight capability he must find a way in the already certified master 747-200 performance data at boeing to allow that heavy-high operation. The gain might be another 8,000 lbs of permited TOGW for example if all four bleeds are selected off until after cleanup.
I could have sworn there was a (packs off & three bleeds off then?) procedure and charts for this but maybe you guys don't do this anymore. If I can find it I'll have to post it up here in about three months when I get back to the states. In the meantime, I'll just have to take your word for it guys.
Cheers & thanks for the insight.