Well, I may have to take issue with Chris’ graph in reply #9. As presented it seems to show an uncanny correlation between the speed and density altitude. However, when you look at the numbers and make a more valid graphical comparison, the correlation seems much less emphatic (see worksheet below). Plus, there were apparently jet changes involved, morning/afternoon changes in the salt surface, wind, etc. etc. And, does anybody know just how the density altitude printed on the time slips is arrived at? Does SCTA calculate that on their own as a site specific value, and if so how do they do it. Or do they just repeat a value obtained on-line, like Wendover airport or Weather bureau numbers. Some of the simpler calculation methods (incorrectly) do not include the effect of humidity e.g. Weather Bureau.
So, with only about a 3% variation in velocity for a 20% variation in an ill-defined DA, and a number of other unsubstantiated variables, concluding that there is a speed/DA correlation of some sort would seem to be unjustified on the basis of this data set or any other such loosely supported numbers.