Poseidon looks set for a big adventure

Boeing is pushing ahead with development of its P-8 Poseidon anti-submarine aircraft. A major redevelopment of the Boeing 737 airliner, it is due to achieve initial operational capability in 2013.

The P-8I (for ‘international’) scored its first export success with an order for eight from India (plus four options) to replace its elderly Russian-built anti-submarine aircraft and Boeing anticipates further international sales.

Gulf air forces have few maritime patrol assets and Boeing Defence Space and Security (BDS) president and CEO Dennis Muilenburg admitted there had been interest in the P-8I from the region. He declined to name specific nations but added: “Our customers in the Middle East face a number of very important security threats that continue to grow in significance. There are certainly very relevant submarine threats in the region.”

This is an obvious reference to Iran, which has a force of three Russian-built diesel-electric boats, known by their NATO Kilo-class classification. Kilos are generally regarded as effective vessels, although the type’s banks of batteries are known to have suffered in the high ambient temperatures of the Gulf and the shallowness of the waterway poses some problems in their deployment. Iran also has four midget submarines.

The fact remains that it would take very few submarines to close the strategic Straits of Hormuz to merchant vessels simply by threatening hostile action. How long any hostile submarines or surface vessels would survive what would surely be a decisive response by the US Navy and its allies is an interesting debating point.

Boeing sees “around 100” potential international sales of the P-8I, with the company hoping to replace fleets of the aircraft’s predecessor, the Lockheed Martin P-3 Orion, around the world. “We think the next customer will be Australia,” said Chuck Dubando, vice-president on the P-8 programme.

Canberra signed an MoU with the US Navy about a year ago and is collaborating on the increment 2 version of the aircraft, which is due to enter service around 2015 and will have additional capabilities, such as the ability to launch anti-submarine weapons from high altitude and an automatic identification system – basically a transponder for merchant vessels.

Boeing submitted a proposal for the P-8I to Saudi Arabia earlier this year but declines to give further details.

The aircraft is designed to fly 1,200nm (2,220km) from its base, loiter at low or medium altitudes for four hours then return without the need for air-to-air refuelling. If airborne tanking does take place, the crew of the P-8 could be in for a 20-hour stint aloft, although the fuselage is large enough to accommodate resting or replacement crew members, especially as it contains only five workstations.

When the idea of using a 737 variant as an ASW aircraft was originally mooted, doubts were raised as to whether an aircraft based on an airliner that spent most of its life cruising at high altitude would be able to cope with manoeuvring in the denser air just above sea level.

Boeing is at pains to stress that the aircraft is not so much a modification as a substantial re-design, with many structural components twice as thick as those on the 737 to take account of the more turbulent conditions the aircraft will encounter at low levels. However, it believes that it will spend less of its service life close to the waves than its predecessor.

“You don’t need to fly it like a P-3,” said Dubando. “You don’t need to be at 2-300 feet, although it will happily do that.”

More of its work will be carried out at altitude, particularly as it will have much more of an intelligence, surveillance and reconnaissance role than the P-3 – something that can be guessed at from the 100-plus aerials scattered over its structure.

“We’re talking to several international customers for the intelligence version with a variety of sensors,” said Dubando.

On the Renton production line in late September were the last of six test aircraft together with the first production aircraft, with the latter due for delivery in the first quarter of 2012. Outside on the flight line, the first Indian aircraft was being prepared for its first flight.

The aircraft’s aft ventral weapons bay will be able to carry up to five Mark 54 anti-submarine torpedoes, while four under-wing hardpoints will be able to carry either Boeing’s Harpoon anti-ship missiles or SLAM ER precision land attack weapons. The aircraft will also be able to carry chaff and flares.