Flapsid

Flapsid is a term used in aviation to describe the downward deflection of an aircraft's trailing edge control surfaces, specifically the flaps and sometimes the ailerons, beyond their normal operating range. This typically occurs during an emergency or a specific flight maneuver where maximum lift or drag is required. The primary purpose of flaps is to increase the wing's camber and surface area, thereby increasing lift at lower speeds and allowing for shorter takeoffs and landings. When flaps are extended to their maximum setting, they are considered to be "flapsid."

In some contexts, "flapsid" can also refer to an unintended or excessive deployment of flaps, potentially leading to aerodynamic instability or structural stress. Pilots are trained to manage flap extension carefully, adhering to specific speed limitations for each setting to avoid such issues. The term is not as formally defined as other aviation terms and is more commonly used in informal pilot discussions or accident reports to describe a specific configuration of the aircraft's control surfaces. The consequences of flapsid depend heavily on the specific aircraft, the altitude, and airspeed at the time of occurrence.