Hi Folks,
Nothing you guys didn’t already know - but - here’s the response from the F-15 pilot when I asked him about vertical acceleration and time to climb….
Yep, I'm an Eagle driver. Been flying that beautiful beast since 2001\. Lots of people ask about the thrust to weight and vertical acceleration. The thrust to weight of a "demo clean" Eagle is greater than 1:1\. That jet doesn't have pylons or external tanks on it. It is a configuration that we could get into in combat, but it's never happened. The short story is that you are not going to accelerate in the vertical because you'd need 1:1 PLUS 9.8m/s/s to overcome gravity so if you had a 56k# airplane and you had 56,500# of thrust, you have greater than 1:1, but you aren't going to go straight up like a Saturn 5 rocket. You have induced drag from creating lift, you have induced drag because you are going through a fluid (wind resistance) and you might have engines that have been slightly tuned back to get better life out of them.
Climbing to the flight levels all depends on how high you are going and how fast you need to be there. We normally take off in our training configuration using afterburner till around 300KIAS, then accelerate to 350KIAS and climb at 350 until around 31k' when we switch to .90M and climb at that airspeed. Typical loads and temps you'll probably see just upward of 6k'/min climb below 10k' and then between 4-5k'/min until the low 20's. If on the other hand you leave the afterburners cooking, you are about 50-60 degrees nose high at 350KIAS and you are climbing somewhere in the neighborhood of 15k'/min. But, as with anything in aviation, it all depends.
Hope that answers your questions.
Regards,
Scott