Stephen Trimble / Washington DC

Fatigue problems mean aircraft cannot be sustained until replacement arrives in 2013

A US Navy official has revealed that a third of the US Navy Lockheed Martin P-3 Orion maritime patrol aircraft fleet will be retired within the next 18-24 months.

The P-3 fleet is already being reduced from 227 aircraft to 150 by 2005, but severe fatigue problems suddenly discovered earlier this year mean that even the reduced fleet cannot be sustained before a replacement arrives in 2013, says Capt Steve Eastburg, Naval Air (NAVAIR) Systems Command programme manager for maritime patrol aircraft.

NAVAIR ordered a fatigue life evaluation on the P-3 fleet last year, and was surprised to find "significant" wear-and-tear that came close to crippling the majority of the active inventory, Eastburg told the ISR Integration 2003 conference on 18 November.

Those findings pre-dated the navy's decision in June to strongly back the P-3 and EP-3 Aries replacement concept - the Multi-mission Maritime Aircraft (MMA), says Eastburg. A request for proposals was issued last month, and bids are due by 29 December and will be based around Boeing's 737 derivative and Lockheed Martin's P-3-derived Orion 21 concept.

The $3 billion MMA system development and demonstration programme is set to begin early next year.

The acquisition could lead to an order for 108-150 aircraft, says Eastburg. The final number, he says, will be tied to the number of companion unmanned air vehicles ordered under the navy's Broad Area Maritime Surveillance programme. A related effort to replace the navy's fleet of 16 EP-3 signals intelligence platforms has been divided into a shared effort with the US Army's Aerial Common Sensor programme.

Meanwhile, the P-3s that remain in active service are being rushed into a two-tier refurbishment process to address systemic fatigue problems, says Eastburg. The improvements are expected to "buy back thousands of hours of life" for the airframe, he says. Some of the 150 aircraft will be set aside for enhanced special structural inspections.

Eastburg says the refurbishment will address fatigue "hot spots" on the aircraft, which first entered service in 1962, having been derived from Lockheed's L188 Electra airliner.

The navy had considered meeting the MMA requirement with a hybrid approach (Flight International, 1-7 April), retaining some of the Orion's airframe, combined with new-build structural assemblies and modern avionics, which would have reduced costs and yielded an earlier service entry. This option now seems unlikely.

Source: Flight International