1992–1995 Bosnian War. It launched raids on Serb forces and provided air-support for the international taskforce units conducting Operations Deny Flight and Deliberate Force against the Army of Republika Srpska. On 16 April 1994, a Sea Harrier of the 801 Naval Air Squadron, operating from the aircraft carrier HMS Ark Royal, was brought down by an Igla-1 surface-to-air missile fired by the Army of Republika Srpska while attempting to bomb two Bosnian Serb tanks. The pilot, Lieutenant Nick Richardson, ejected and landed in territory controlled by friendly Bosnian Muslims. It was used again in the 1999 NATO campaign against the Federal Republic of Yugoslavia in Operation Allied Force, where Sea Harriers operating from Invincible frequently patrolled the airspace to keep Yugoslavian MiGs on the ground. They were also deployed on board Illustrious in 2000 as part of Operation Palliser, the British intervention in Sierra Leone. Retirement The UK is procuring the STOVL F-35B to be operated from the Royal Navy's s. The Sea Harrier was withdrawn from service in 2006 and the last remaining aircraft from 801 Naval Air Squadron were decommissioned on 29 March 2006. The MoD argued that significant expenditure would be required to upgrade the fleet for only six years of service to meet the F-35s then planned in-service date. Both versions of Harrier experienced reduced engine performance (Pegasus Mk 106 in FA2 – Mk 105 in GR7) in the higher ambient temperatures of the Middle East, which restricted the weight of payload that the Harrier could return to the carrier in 'vertical' recoveries. This was due to the safety factors associated with aircraft landing weights. The option to install higher-rated Pegasus engines would not have been as straightforward as on the Harrier GR7 upgrade and would have likely been an expensive and slow process. Furthermore, the Sea Harriers were subject to a generally more hostile environment than land-based Harriers, with corrosive salt spray a particular problem. A number of aircraft were retained by the School of Flight Deck Operations at RNAS Culdrose. The Royal Navy's Fleet Air Arm would continue to share the other component of Joint Force Harrier. Harrier GR7 and the upgraded Harrier GR9 were transferred to Royal Navy squadrons in 2006, but were retired prematurely in 2010 due to budget cuts. Although withdrawn from active Royal Navy service, Sea Harriers are used to train naval aircraft handlers at the Royal Navy School of