A dive brake is a type of aerodynamic device used on aircrafts to reduce their speed and altitude during a dive. There are several synonyms for the term "dive brake" including dive flap, air brake, drag flap, and spoiler. The purpose of these devices is to slow down the aircraft and prevent it from overspeeding during a steep and fast dive, which can be dangerous for the pilot and passengers. They work by increasing the drag of the aircraft, which slows it down by diverting a portion of the air flowing over the wings. These devices have proven to be essential in enhancing the safety of aviation over the years, especially in military aircrafts.