In early 2013 the U.S. Navy activated its first maritime surveillance squadron (VP-16) equipped with the new P-8A aircraft. Late in 2013 VP-16 sent two of its P-8As off to Okinawa for seven months of patrolling, intelligence gathering and getting a better idea of how the aircraft operates for extended periods in the tropics. This will also make it possible to see how well the P-8A is at hunting down Chinese submarines, which have been at sea a lot more often in the last few years.
The P-8 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 replacing, it is a more capable plane. The P-8A has 23 percent more floor space 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 10 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 distant sonar arrays or satellites. The 737 has, like the P-3, been equipped with hard points on the wings for torpedoes or missiles. The P-3 can also carry more weapons (9 tons versus 5.6). This is less of a factor as the weapons (torpedoes, missiles, mines, sonobouys) are lighter and 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 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, which was based on the Electra civilian airliner that first flew in 1954. Only 170 Electras were built, plus 600 P-3s. Some Electras are still in service. The Boeing 737 first flew in 1965, and nearly 5,000 have been built with more than 3,000 on order. 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
In May 2013 India received the first of 24 P-8Is, and that aircraft was soon being flown around to various naval air bases that it expects to operate from. This includes the naval air base in the Andaman and Nicobar Islands, where P-8Is would be able to watch the three main Chinese trade routes through the Indian Ocean.
In the last three years India has increased its P-8I order from 8 to 24 aircraft. Only 12 are actually on order, but the admirals expect the performance of the P-8I to convince the government to pay for another twelve. The Indian Navy was allowed to buy P-8Is largely in response to growing Chinese naval activity in the Indian Ocean. It was back in 2008 that India ordered its initial eight P-8s, for about $220 million each. The growing expense of maintaining their existing Russian Tu-142M reconnaissance aircraft, and the need for a more capable recon aircraft, led to that initial order. The first P-8I arrived ahead of schedule.
The U.S. was willing to provide a customized (to Indian needs) version of the P-9 at a price the Indians could justify. Other navies in the region that used the P-3 were enthusiastic about the P-8 as a worthy successor to the reliable and effective P-3. The U.S. and Indian navies both received the P-8 at about the same time. The Indians P-8Is are slightly different than the P-8A the Americans will use.