David you talk about commercial operations and delivering "as fast as possible". Attemting to discredit what is fact for min fuel calculations. This is wrong. My experience internationally is,almost without exception ,flight plans were based on min cost. Cost index is inputed, Location (price) of fueluplift and tankering are all considered.Optimun Levels speeding up in a head win will increase fuel consumption but is part of the algorithum of min cost. For 10 years our plans listed direct operating costs. Routing was considered and the plan that cost less was the top option.
Erhart was heavy. Military ops in, admittedly British piston AC after WW2, with a miltary load out of Cairo for south would be dodging sandhills 30 miles from Cairo