You guys did read when JT wrote that it’s half the headwind and all of the tailwind, not twice, what’s accounted for on the calculations, right?
I giggle a bit when I see these extreme “conservatism” for no good reason. Some even do it as a regular basis...
Perf margins are per se playing to our favor. Moreover, as some have pointed out, the performance margin is actually larger than calculated as the airplane (engines and wing) is operating in higher density than what the EFB spit out. I’ve seen some people reduce flex by one or two degrees but leaving the speeds for the original flex (since they shouldn’t differ too much) for a slight increase in margin.
I always recheck my numbers before takeoff to see if what I did on the gate is still valid. Airplane has OAT readings and an altimeter to check for temp and press and I should be on tower freq a couple of mins before takeoff to check for wind. They would give me wind info with my takeoff clarance so even at the latest, I could still check if my previous wind is still valid. Mentally, it doesn’t take longer than 5 secs to check this. Re run numbers if too different from initial calculations, just for peace of mind. I’ve already catched a couple of gotchas by doing this...