Flight spoilers must not be extended in flight below which approach speed?

In aviation, flight spoilers play a crucial role in controlling the aircraft's lift and drag during various phases of flight, particularly during descent and landing. The correct answer indicates that flight spoilers must not be extended in flight below a specific speed, which is defined as the approach speed plus a certain margin.

The reason approach speed +8 is the right answer is grounded in safety protocols and aerodynamic principles. Extending spoilers slows down the aircraft by reducing lift, which could lead to undesirable handling characteristics or even a stall if deployed at too low a speed. By setting the limit at approach speed +8, pilots maintain a buffer that ensures sufficient lift is still being generated, allowing for safe maneuvers without risking a stall during critical phases of flight such as the approach.

Using other thresholds, like approach speed +5 or +10, could either be too limiting or compromise safety margins. Consequently, the approach speed +8 offers a prudent balance between maintaining control and ensuring aircraft stability while preparing for landing.