E-8C JSTARS, tail number 93-0597, assigned to the 379th Air Expeditionary Wing, experienced a near catastrophic fuel tank over-pressurisation during aerial refueling.

The aircraft terminated its mission and returned to Al Udeid Air Base, Qatar. The crew and mission personnel evacuated the aircraft safely with no injuries. The mishap resulted in damage to the aircraft in the amount of $25 million dollars. There was no damage to private property. The mishap occurred during operations in the Area of Responsibility (AOR). The crew had begun aerial refueling (AR) with a KC-135, when a loud bang was heard and felt throughout the midsection of the aircraft. The crew suspended AR to evaluate the aircraft to checkout their systems and evaluate the aircraft for any damage. Finding nothing apparently wrong, the crew re-latched to the tanker and attempted to continue the AR when another series of loud noises and vibrations were heard and felt throughout the aircraft. Personnel aboard the KC-135 observed a stream of vapour and fuel streaming from the aircraft and alerted the crew. The crew checked for damage through a rear window and observed fuel streaming from at least two holes in the left wing, just inboard of the number two engine. The crew opted to terminate the mission and return to Al Udeid. Maintenance personnel then examined the aircraft and found that the number two main fuel tank had ruptured, causing extensive damage to the wing. The Accident Investigation Board (AIB) President found, by clear and convincing evidence, that the mishap was caused when a civilian subcontractor employee inadvertently left a test plug in the fuel vent system of the aircraft during recently completed Programmed Depot Maintenance (PDM) performed on the aircraft. Additionally, the AIB President found by substantial evidence three factors which contributed to the mishap. First, the PDM subcontractor employed ineffective tool control measures. Second, the PDM subcontractor failed to follow Technical Order (TO) mandated procedures when employing the fuel vent test plug during PDM. Third, due to the relatively short period of time between takeoff and AR, the crew did not have the opportunity to burn a substantial amount of fuel from the number two fuel tank which could have allowed the dive flapper valve to open. This explains why this mishap did not occur during ARs conducted between the time the aircraft left the PDM facility and the time of the mishap. [via http://www.adastron.com/707/qantas/VH-EBU.htm]