Originally Posted by
Ondraayyy
I was flying on an ordinary day and calculated the TO Data, using LPC Software provided by my company.
The stop margin calculated was 29 meters with the flex temp of 60.
I advised my captain if he wanted to take off with a lower flex temp of 59, as to achieve higher stop margin.
He refused, and without me knowing his reason I inserted the TO Data with the Flex temp of 60 in the FMGC.
I disagree with him completely.
As when using FLEX the thrust reduction is made to take advantage of thrust reduction possible using the additional runway length available. The thrust reduction amount is determined by calculating the temperature at which the ASD can be achieved using full length available. The output from LPC shows the distance remaining by reducing thrust and taking longer to reach V1, then to decelerate at same rate to stop. The LPC distance does not differentiate between reaching the point on the runway from which to stop.
OAT does have an impact on stopping performance, this is where the 3% as referred to in above posts comes in.