JAR25.107(a)(1)VEF.This is the CASatwhich the critical engine is assumed to fail.It is never less than VMCG and is always less than V1..
not enough Swatton readers about\'Aircraft performance theory\',covers all the JAR stuff..
Cheers
Ergo as VEF is at least one second prior to V1(average,could be as high as 3 seconds on a triple engine aircraft)the V1 is at least 4knots higher than VEF/VMCG
