July 15, 2012: Boeing, the manufacturer of the large and expensive P-8 maritime patrol aircraft, is feeling the heat from the growing number of countries turning to twin-engine turboprop transports for use as maritime patrol aircraft. These aircraft weigh a third or less than the larger P-3s/P-8s and cost a lot less. Boeing said it is seeking a suitable twin-turboprop aircraft to be its new medium-sized maritime patrol aircraft.
One candidate for this is the Spanish C295. This 23 ton twin engine turboprop aircraft can carry six tons for up to 2,200 kilometers. Top speed is 570 kilometers an hour and max payload is nine tons or 71 troops. The C295 entered service twelve years ago and are mainly used as transports but some do maritime patrol. There are several similar aircraft on the market and by the end of the year Boeing will select one to be its cheaper "P-8 Lite." It's all because so many potential customers, when faced with the price of new maritime patrol aircraft (like the new P-8 or even second-hand patrol aircraft like the P-3), find that a twin-turboprop equipped with a surface search radar is much cheaper and as effective as required.
Twin engine turboprop transports are increasingly popular with military organizations. They are cheaper to buy and operate and are adequate for most countries. Four engine turboprop transports like the C-130 are still popular but increasingly expensive.
For maritime patrol the larger twin-turboprops like the C295 have enough weight capacity to carry the new generation of lightweight radars and other sensors required. For example, even the high end APY-10 radar on the P-8A weighs less than 200 kg (440 pounds). For most countries, a radar and some long range night vision or thermal (heat sensing) cameras are all they need. In effect, the Cold War era P-3, or its replacement P-8, has more carrying capacity than most nations require. The Cold War maritime patrol aircraft needed lots of carrying capacity for weapons (depth charges, anti-submarine torpedoes) and expendable sonobuoys for finding submarines. Boeing has picked up on the new demand and pitches its new medium patrol aircraft as one that can carry the P-8 sensors, at least the key ones that will attract your average bargain hunting customer.
The 83 ton P-8A Poseidon is based on the widely used Boeing 737 airliner. Although the Boeing 737 based P-8A is a two engine jet, compared to the four engine turboprop P-3, it is a more capable plane, at least compared to what was demanded of Cold War era maritime patrol aircraft. The P-8A has 23 percent more floor space than the P-3 and is larger (38 meter/118 foot wingspan, versus 32.25 meter/100 foot) and heavier (83 tons versus 61). Most other characteristics are the same. Both can stay in the air about ten hours per sortie. Speed is different. Cruise speed for the 737 is 910 kilometers an hour versus 590 for the P-3. This makes it possible for the P-8A to get to a patrol area faster, which is a major advantage when chasing down subs first spotted by sonar arrays or satellites. However, the P-3 can carry more weapons (9 tons versus 5.6). This is less of a factor as the weapons (torpedoes, missiles, mines, sonobouys) are pound for pound more effective today and that trend continues. Both carry the same size crew of 10-11 pilots and equipment operators. Both aircraft carry search radar and various other sensors.
The 737 has, like the P-3, been equipped with hard points on the wings for torpedoes or missiles. The B-737 is a more modern design and has been used successfully since the 1960s by commercial aviation. Navy aviators are confident that it will be as reliable as the P-3. (The P-3 was based on the Electra civilian airliner that first flew in 1954, although only 170 were built plus 600 P-3s. Some Electras are still in service.) The Boeing 737 first flew in 1965, and over 5,000 have been built. The P-8A will be the first 737 designed with a bomb bay and four wing racks for weapons. The P-8 costs about $275 million each.
The P-8 lite doesn't have to carry many, or any, weapons and some of the equipment operators can be on the ground, communicating via a satellite link.