In yesterday’s post I asked about your most recent flight. Specifically, how did you, without checking your AFM first-segment climb gradient chart, know beyond the shadow of a doubt you were going to cross the departure end of the runway at a minimum of 35 feet.

The answer I was looking for is:

You did this when you determined your takeoff distance on the day, and checked to make sure you had at least that much runway. The number your AFM, QRH or perhaps your FMS gives you, guarantees you – as much as that is possible – that you will, in that distance, be able to either:

  • accelerate and reject the takeoff if an engine failure occurs before V1,
  • accelerate and continue the takeoff if an engine failure occurs at V1 – AND CROSS THE DEPARTURE END AT 35 feet, or,
  • accelerate and continue the takeoff if no engine failure occurs – AND CROSS THE DEPARTURE END AT 35 feet.

In the last case, you’ll actually need less than the stated distance, because that gets “padded” by 15%.

You can read up on that in the FARs here.

Note that’s for a dry runway.

Next, I’ll talk more about the hurdles the departure procedure designers usually put in place to let us know what we have to do to be safe. Look for another post shortly but not immediately – I’m still working on the illustrations I’m gonna need.

Email b l o g @ e 6 b j e t . c o m if you have comments. I read them all, just can’t promise a reply. Please explicitly state if it’s okay for me to use your reply in future posts.

Cheers