B737NG AFM 1 second assumption for Eng fail

[Pin Head]

HI

Just going through my notes.

Please can someone put some clarity on the installed 1 sec time factor for engine failure just before V1.

Is it saying that all the figures are based on VEF 1 second before, hence why you have that 1 second to get on the brakes which is the gate for stop/go at V1?

Thanks

Pin

[MarkerInbound]

V1 has two parts. It is the highest speed from which you can reject the TO and stay on the pavement and also the lowest speed you lose an engine, continue the TO, and meet the 35 foot (on a dry runway) screen height. It was redefined several years ago from being the "TO decision speed" to being the speed at which the first action of the rejection takes place. Which means the decision occurred earlier. Which means the event which triggered the decision occurred even earlier. Depending on the aircraft there is at least one second between Vef and V1 for this decision to take place.

Interesting reading-

https://www.faa.gov/other_visit/aviation_industry/airline_operators/training/media/takeoff_safety.pdf