Configuring or setting the aircraft (e.g., trim, flaps, autobrakes, etc.).

Bottom line

A sudden and complete retraction of the flaps could cause a loss of lift resulting in the airplane settling into the ground. After attaining the appropriate airspeed and adjusting pitch attitude for a climb, the pilot should “rough trim” the airplane to relieve any adverse control pressures. Unless otherwise specified in the AFM/POH, it is generally recommended that the flaps be retracted (at least partially) before retracting the landing gear for two reasons.