Boeing has started assembly of the first P-8A Poseidon production aircraft ahead of first delivery in 2012, with the US Navy accelerating the programme despite concerns over a published list of performance shortfalls.
The first production version of the 737-800-based maritime patrol aircraft will join seven P-8As inducted for flight and ground testing since 2009.
The P-8A is being assembled in Renton, Washington on a separate production line that incorporates changes required for the military version of the 737 in normal production flow.
In addition to an internal weapons bay, the P-8A also modifies the 737 to carry sensors, wing-mounted stores and raked wingtips to allow the aircraft to patrol at low altitudes for long periods without the threat of ice building on the wings.
The navy plans to buy 117 P-8As during the next nine years to replace most of the Lockheed P-3C Orion fleet, which has struggled to remain airworthy as the airframe has aged.
In last month's fiscal year 2012 budget request, the navy announced it would speed-up its P-8A purchases.
The Naval Air Systems Command (NAVAIR) confirmed that the "accelerated buy rate is based on the navy's commitment to replacing the inventory of ageing P-3Cs in as timely a manner as possible [given fiscal constraints]".
So far, Boeing has kept the programme on schedule and on budget, but the 2010 annual report by the director of the office of test evaluation notes some concerns.
The report describes 33 system performance shortfalls that could delay the programme. At the time the report was published, late last year, no solutions had been identified to correct the shortfalls, test evaluation staff said.
NAVAIR says 18 of the 33 shortfalls have been fixed after flight testing. The other 15 shortfalls will be addressed in time for the initial operational test and evaluation phase next year.
"The number and severity of issues identified to date have been in line with programme expectations and the programme is progressing towards [initial operational capability in 2013] as planned," NAVAIR says.