Aviation fuel contamination at Mount Pleasant Complex

In mid-2011, a major aviation safety crisis unfolded at the Mount Pleasant Complex (MPC) in the Falkland Islands. The incident began when a routine delivery of chemicals arrived at the Petroleum Storage Depot (PSD). Due to a series of misidentifications in the logistics chain starting in the UK, a 20,000-litre ISO tank (known as a "glycol") containing Icing Control Agent (ICA)—a corrosive runway de-icer—was mislabelled and treated as Fuel System Icing Inhibitor (FSII).

The investigation revealed that the mislabelled tank was connected to the main aviation fuel blending rig and decanted into the bulk fuel system. For several weeks, aircraft at MPC—including the VC10 tankers, Typhoon fighters, and the Hercules transport aircraft—uplifted fuel contaminated with the de-icer. The issue was only discovered after aircrew and engineers noticed "cloudy" fuel and unusual deposits in aircraft fuel filters. By the time the contamination was confirmed on 5 August 2011, approximately 2.5 million litres of F-34 fuel had been compromised.

The Service Inquiry (SI) highlighted a "latent weakness" in the Ministry of Defence's global supply chain. It found that the paperwork for the chemicals had been swapped or incorrectly entered into the VITAL (Visibility in Transit Asset Location) tracking system at the Bicester terminal in the UK. Furthermore, the inquiry noted that the personnel at MPC were operating under significant stress and fatigue, which led them to trust the system’s labels over physical visual checks. The grounding of the "air bridge" between the UK and the Falklands caused a significant strategic vulnerability, forcing a rapid and costly maritime resupply of clean fuel to restore operational capability.