What is the appropriate action at V2+10 knots after takeoff?

At V2+10 knots after takeoff, the appropriate action is to call for speed mode. This is a critical moment during the climb phase of flight, as the aircraft has just taken off and is transitioning into the climb segment. V2 is the safety speed that allows the aircraft to safely clear obstacles, and reaching V2+10 knots indicates that the aircraft is well on its way to achieving a normal climb profile.

Calling for speed mode is essential because it ensures that the aircraft's flight management systems are set to handle the climb phase efficiently. By engaging speed mode, the autothrottle system can maintain the desired airspeed, allowing the pilot to focus on other tasks such as monitoring the climb and systems in the aircraft without having to manually adjust throttle settings during this critical phase.

In this context, reducing throttle, beginning descent, or preparing for landing do not apply as they would compromise the safe climb and transition to the cruise phase of flight. These actions would not be suitable at this stage and could lead to a loss of lift or altitude control.