PAUL LEWIS / WASHINGTON DC

Growing use of ageing reconnaissance aircraft in recent conflicts prompts speculation about an imminent replacement

The increased utilisation of the UK Royal Air Force's small and ageing fleet of BAC Canberra PR9 strategic reconnaissance aircraft during recent conflicts in the Balkans, Central Asia and the Middle East is fuelling a growing expectation within industry that the UK is poised to finally embark on a replacement search.

The RAF's five PR9s are more than 40 years old and are among a dwindling number of Canberras still operating worldwide. The UK Ministry of Defence is believed to want to replace the aircraft by the end of the decade, but so far has only financed limited studies. Airframe and sensor suppliers are now expecting the issue of a request for proposals in the near future.

It is unclear whether the RAF will opt for a manned or unmanned solution to its long-range, long-endurance requirement. A critical factor will be whether there is still a need to penetrate hostile airspace. Last year, the PR9s received a defensive aids suite upgrade, comprising an integrated radar warning system and countermeasures dispensers.

The US Air Force is increasingly relying on high-altitude long-endurance unmanned air vehicles, such as the Northrop Grumman RQ-4 Global Hawk, in place of Lockheed Martin U-2s over high-threat areas.

In recent years, the PR9s have been used for humanitarian missions where there is little or no air defence threat. Manned options for replacing the PR9s focus on adaptation of large business jets such as the Gulfstream G500/550 or Bombardier Global Express. These have operating ceilings of over 50,000ft (15,250m), comparable with the PR9's, but a longer endurance of up to 13h.

The Global Express is the platform for the UK's Raytheon ASTOR air-to-ground surveillance system, due to enter service in 2005. ASTOR is equipped with a Raytheon active-array radar derived from the U-2's ASARS-2A. Gulfstream has similarly built special mission variants of its business aircraft, including a signals intelligence aircraft for the Swedish air force and an electronic intelligence platform for Israel.

The PR9 has an electro-optical-based suite that includes the US SYERS oblique long-range optical sensor for stand-off reconnaissance, together with a datalink for real-time imagery relay, and low-, medium- and high-level cameras.

Source: Flight International