This is a general aircraft question, but being that I am testing an FS-designed aircraft in a similar manner, thought to post here for a response. If wrong, please feel free to move it.

I was taking in an article on the F-15A Streak Eagle (that makes for some interesting reading BTW!). Time-to-climb was discussed among other things, including the fact that the aircraft had no paint or radar to reduce weight, ran on fumes, and had to fly on a very cold day while adhering to a precise flight profile, in order to obtain the results that it did. Still impressive, nonetheless. Anyway, my question is regarding the definition of climb rate. Time-to-climb was discussed both in this article and another relating to the EE Lightining, with the latter claiming the highest climb rate until the advent of the Su-27 & MiG-29. The Lightning's time-to-climb was reported to be 2.5 minutes from brakes off to 36,000 feet, at full afterburner, and was described as being nearly similar to the Eagle in this aspect of performance. It's initial rate of climb was described as being 50,000 ft/min, which of course is not anywhere the same as the previous figure. I cannot find any proper definition of how an aircraft's initial rate of climb is calculated. If anyone can clue me in to how these figures are determined, I would appreciate the info.

...For the flightsim part of this, the design I tested made it to 36,000 ft in 70 seconds from brakes off, in standard (59 degree F) temps. Don't think it did too badly!

Thanks for the info. It would seem to be a that things are not necessarily as straightforward (or uncomplicated!) as they might at first appear. As far as Streak Eagle flights go, it might make for an interesting addon mission in FSX.