I use Professional Flight Planner X (PFPX) to plan my flights and I'm very curious about the meaning of two parts of the OFP (Official Flight plan, the viewable, ".txt" version of the flight plan). In the fuel section towards the top of the OFP, right under the spot for "Captain's Signature", there is a spot where it says "CLB: 250/310/84   DES: 84/320/250"

 

I know that they stand for Climb and Descent but I don't understand what the numbers mean next to them. I've looked all over the internet and I can't find a single answer.

For CLB:

First value=speed below 10,000ft,

Second value=speed above 10,000ft before transition to Mach

Third number=Mach number*100 (so in your case Mach=0.84) for climb

Reverse order for DES.

Ah! Thank you. For something so simple, I can't believe it wasn't anywhere on the internet. BUT it is now Thanks again!