Can FLEX thrust be used on a wet runway?

Can FLEX thrust be used on a wet runway?

• A. Yes, provided the flight crew selects WET runway performance data in ACARS
• B. Yes, with no additional data
• C. No
• D. Only on dry runways

Answer: (A)

FLEX thrust relies on an assumed temperature to determine reduced takeoff thrust, saving engine wear while still using validated performance data. On a wet runway, takeoff performance changes because the surface is less grip and can require longer distances. To use FLEX under wet conditions, the crew must select the wet runway performance data in ACARS so the takeoff calculations reflect the actual surface and rain penalties. With the wet data loaded, FLEX can be applied safely; without selecting that data, the system would use dry data and could produce unsafe results. This is why the correct choice is that FLEX can be used on a wet runway provided the wet runway performance data are chosen in ACARS.

FLEX thrust relies on an assumed temperature to determine reduced takeoff thrust, saving engine wear while still using validated performance data. On a wet runway, takeoff performance changes because the surface is less grip and can require longer distances. To use FLEX under wet conditions, the crew must select the wet runway performance data in ACARS so the takeoff calculations reflect the actual surface and rain penalties. With the wet data loaded, FLEX can be applied safely; without selecting that data, the system would use dry data and could produce unsafe results. This is why the correct choice is that FLEX can be used on a wet runway provided the wet runway performance data are chosen in ACARS.