This Caudron, on display at the Udvar-Hazy Center, is among the oldest surviving bomber aircraft and one of the very few remaining multi-engine aircraft extant from WWI. The term 'Blindage 16K' is marked on the rudders, probably indicating that the aircraft was an innovative G.4IB armoured Caudron. The armour consisted of a heavy metal plate (now missing) inserted behind the seat of the rear cockpit, protruding upward so as to cover the back and head of the pilot.