17. That is what I had always thought, but they actually did - in the last week of the war.
The Leonidas Squadron, formally known as 5th Staffel of Kampfgeschwader 200 was a unit which was originally formed to fly the Fieseler Fi 103R (Reichenberg), a manned version of the V-1 flying bomb, in attacks in which the pilot was likely to be killed, or at best to parachute down at the attack site. The Reichenberg was never used in combat because Werner Baumbach, the commander of KG 200, and his superiors considered it an unnecessary waste of life and resources, and preferred to use the Mistel bomb, piloted from an aircraft which released it and returned, instead. However, from 17 April until 20 April 1945 (during the Battle of Berlin) thirty-five pilots of the Leonidas Squadron flew suicide sorties against Soviet bridges over the river Oder with little noticeable effect.