Australia has increased its 2104 order for American P-8A Poseidon maritime reconnaissance aircraft from eight to twelve. Australia expects to eventually buy fifteen P-8As as well as seven MQ-4C Triton UAVs. All 22 aircraft are to be in service by the late 2020s with the first P-8As arriving by 2022. This new force will replace the 18 P-3Cs Australia has been using since 1999 and be better able to deal with the growth in the Chinese submarine fleet.
The P-8 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. 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 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. 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 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 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.
The P-8 entered service in 2013 and thirty are now operational. Crews have so far found that it is 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. A dozen or so 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.