rhubarb
Of fighter aircraft: to fire at a target opportunistically.
rhubarb: opportunistic strafing by fighter pilots
In fighter aviation, to rhubarb means to conduct an unplanned attack on a ground target during a combat flight. The pilot identifies an opportunity, targets a vehicle, installation, or personnel below, and makes a firing pass with guns or rockets without prior assignment or coordination. The term emerged in Royal Air Force use during World War II, particularly among RAF Spitfire and Hurricane pilots operating over occupied Europe.
The word carries connotations of improvisation and individual initiative. A pilot might rhubarb an enemy truck convoy spotted on a road, or strafe a railway yard if the primary bombing run was cancelled. The term's origin remains obscure, though some sources link it to a nonsense phrase; others suggest it derives from the sound of gun fire. Unlike a planned strike, rhubarbing relies on the pilot's judgment, quick decision-making, and the aircraft's current fuel and ammunition state.
Rhubarbing introduced significant tactical risks. A low-altitude strafing pass exposes the aircraft to small arms fire, anti-aircraft artillery, and barrage balloons. Pilots absorbed battle damage, lost engines, or suffered hydraulic failure during passes. Fuel consumption for unscheduled detours reduced range and time on station. In formation flying, a pilot's break to rhubarb a target threatened unit cohesion and left wingmen vulnerable.
The practice was tolerated, even encouraged, when targets presented legitimate military value and the risk remained acceptable. A crippled locomotive or a fuel truck destroyed opportunistically still damaged enemy logistics. However, commanders recognized the tension between aggressive initiative and disciplined tactics. Some units restricted rhubarbing to trained pilots or mandated wingman confirmation before opening fire.
The term persisted through the Cold War and appears in declassified combat reports and pilot memoirs. Modern rules of engagement, permissive fire coordination, and real-time intelligence sharing have largely formalized what rhubarbing once represented: the gap between assigned tasking and battlefield opportunity.