What effect does a reduction in V1 due to a wet runway have on one engine out obstacle clearance/climb performance?

A reduction in V1 due to a wet runway impacts the takeoff performance of an aircraft, particularly in the context of engine-out scenarios. V1 is the decision speed, and lowering it typically results from increased stopping distances required on a less-than-ideal runway surface.

In an engine-out scenario, the aircraft must clear obstacles after losing an engine. While V1 is lower, which effectively decreases the speed at which the pilot would commit to taking off or aborting, the climb performance remains constant. This is because the climb performance in such scenarios is primarily dictated by the aircraft’s weight, configuration, and the power available from the operating engine, rather than the V1 speed itself.

Therefore, while the reduction in V1 may lead to a decrease in the speed during the takeoff roll prior to the point of no return, it does not necessarily impact the climb performance after takeoff. The obstacle clearance requirements remain consistent with the aircraft's performance capabilities, which do not inherently change just because V1 has been lowered.

This understanding clarifies why the effect on engine-out climb performance remains constant, while the need for more distance might imply a decrease in operational safety margins in terms of obstacle clearance during the critical phases of flight immediately post-take