Old Jan 19, 15, 2:51 pm
Join Date: Aug 2008
Location: PHL
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Originally Posted by chiph View Post
The V speeds (e.g., V1, V2, Vr, Vref, etc) are calculated per-takeoff by the flight management system (FMS) and takes into consideration the runway (including direction), winds, temperature, conditions (e.g., wet/dry), weight, etc.

The crew has the #s before takeoff and they're also displayed on the airspeed tape/display.

Also see http://en.wikipedia.org/wiki/Balanced_field_takeoff
Thanks! From all the episodes of Air Disasters I've watched, I was pretty sure that it took weather, weight, etc into consideration and is not done using a computer. I'm also pretty sure it is something discussed with the crew in the pre-flight briefing. I remember some "incidents" that were a result of the crew not fully "in-sync" regarding what speed V1 is. (Although, I think modern technology has helped reduce these types of errors)

Also, if I recall, after a rejected takeoff, you might might burst a tyre or overheat the brakes, or have something catch on fire. Then you have to investigate the actual cause of the rejected takeoff. Then get back in line. Basically alot of delays, but better safe than sorry.

Originally Posted by FWAAA View Post
And for the aftermath of poor-decision making by the pilots and subsequent crash after V1, see:


They aborted the takeoff after the plane was airborne.
I'm no pilot, but if I recall, you aren't suppose to abort the takeoff after V1 unless you don't think your plane is capable of safe flight. I'm sure this sort of thing is drilled into pilots during training. Ofcourse its easy for us to come to conclusions, we weren't in their seats
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