Folks,
Aaaaah!!!! for the Good Old Days.
In the early days of the B747, transcontinental cruise speeds for a B747-238 ( Qantas) M0.88. Climb was 360 IAS above 10,000, descent was 0.88/360.
Where there was no speed limit below 10,000, descent was 0.88/360 to 3,000 agl.
As "luck" would have it, doing an Olympic charter for GE in 2000,( in a GE engined B744) I was very late out of KJFK for KLAX, Ops. Control said: "Get to LA as fast as you can". What an open invitation, so back to 360 and 0.88+ at FL260/280 ---- what a wonderful TAS, not often seen since the first "oil price shock" -- !!! From the controller comments, they hadn't seen an airline aircraft proceeding at that rate of knots for a long while, and in several cases never.
Even the CV990 would have had trouble keeping up.
Descent planning was a no-brainer --- 100, period ---- from 260/270, at those rates of descent wind components hardly make any difference for the very brief period from cruise to 10,000.
Old Qantas hands will recall the first "descent slide rule", developed by a QF management pilot, we will call him Neal.
It gave rise to the following limerick:
There was a young lad called Neal,
They said he was some kind of a wheel,
He invented a computer, to make descents cuter,
Hundred miles, power off,
Big F-----ing deal.
Tootle pip!!