A gust lock on an aircraft

Aircraft

An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

 is a mechanism that locks control surfaces in place preventing random movement and possible damage of the surface from wind while parked. Gust locks may be internal or external.

Safety

A gust lock can pose a serious safety hazard if its removal is omitted before an aircraft's takeoff because it renders the flight control inoperative.

The very first example built of the Boeing B-17 Flying Fortress, the initial Model 299 aircraft, was lost in just this way on October 30, 1935, when its self-contained gust locks were left engaged, with the resulting crash killing Boeing chief test pilot Leslie Tower, and United States Army Air Corps

United States Army Air Corps

The United States Army Air Corps was a forerunner of the United States Air Force. Renamed from the Air Service on 2 July 1926, it was part of the United States Army and the predecessor of the United States Army Air Forces , established in 1941...

 test pilot Ployer Peter Hill

Ployer Peter Hill

Ployer Peter Hill was a pilot and an officer with a varied career, but is best known for his abilities as a test pilot. In an aviation career that spanned eighteen years, Hill piloted nearly 60 of the Army Air Corps' newest aircraft, testing and evaluating their capabilities for service.Pete Hill...

. Less than a year later, Nazi German Luftwaffe Generalleutnant Walter Wever lost his life in a similar accident from gust lock neglect, when his Heinkel He 70

Heinkel He 70

The Heinkel He 70 was a German mail plane and fast passenger aircraft of the 1930s, that also saw use in auxiliary bomber and reconnaissance roles. It had a relatively brief commercial career before it was replaced by types which could carry more passengers...

 Blitz monoplane crashed on June 3, 1936 from the Blitz's aileron gust locks not being disengaged before takeoff. Prince Gustaf Adolf of Sweden

Prince Gustaf Adolf, Duke of Västerbotten

Prince Gustaf Adolf Oscar Fredrik Arthur Edmund, Duke of Västerbotten was Duke of West Bothnia and the eldest son of Gustaf VI Adolf of Sweden and his first wife Princess Margaret of Connaught...

, the American singer and actress Grace Moore

Grace Moore

Grace Moore was an American operatic soprano and actress in musical theatre and film. She was nicknamed the "Tennessee Nightingale." Her films helped to popularize opera by bringing it to a larger audience.-Early life:...

and 21 others were killed in 1947 during the crash of a KLM flight at Copenhagen Airport due to the flight crew forgetting to disengage the gust lock on the tail fin of the aircraft.

For this reason, gust lock disengagement is a very important step on the takeoff checklist for those aircraft equipped with gust locks.