The “Do Not Pull” sign must have been missing.

French Air Force officials are investigating what caused the sudden ejection of a civilian passenger on a ride-along from a fighter jet as the aircraft was taking off last month.

The 64-year-old man shot from the back seat through the plane’s glass canopy and into the sky, after which he parachuted to the runway, according to Aerotime News, an aviation and aerospace industry website.

An ejection normally requires air crew to pull the ejection seat trigger, which is either between the pilot’s legs or above their head. It is possible the unidentified man triggered the ejection himself, either accidentally or as some kind of thrill.

The pilot was able to safely land the twin-seat Dassault Rafale B fighter jet at Saint-Dizier air base in northern France after the March 20 incident, despite minor cuts from the broken canopy. The plane was reportedly operating normally.

The man was hospitalized with a back injury after he parachuted to the runway. The injury was apparently serious but not life-threatening. His identity was not released, but journalists and elected officials are often invited on “observation” flights approved by the nation’s Armed Forces Ministry.

The French Air Force temporarily grounded its fleet of Rafale fighter jets out of caution pending investigation. They returned to the air on March 28.