November 11, 2011: The U.S. Navy is upgrading 55 of its 157 P-3C maritime reconnaissance aircraft with new computers, communications and integrated flat-screen displays. More importantly, structural components that are weakened because of old age will be replaced or reinforced. The upgrades will enable the P-3Cs to quickly share data with other aircraft, ships and ground stations. This is considered an upgrade that will prepare crews for the transition, starting in two years, to the new P-8A.

Even as the P-8A is about to arrive, the P-3C remains in great demand. For example, during the last decade, over 60 P-3Cs have also been upgraded to turn them into land reconnaissance aircraft. The P-3Cs are particularly useful for patrolling over Iraq and Afghanistan, looking, and listening, for enemy activity.

Despite all this popularity, the elderly P-3Cs are falling apart. This year, the navy spent nearly $10 million per aircraft to refurbish the wings of 14 P-3Cs. This was part of an effort to keep enough P-3Cs flying until the new P-8A enters service. The wing fatigue is a symptom of age. The P-3 was originally designed to spend 7,500 hours in the air before retirement. But the average of the navy P-3s is 30 years, and, because of lots of refurbishment and diligent maintenance, the average air time is 16,000 hours.

Keeping the elderly P-3Cs flying has not been easy. Four years ago, the navy grounded a quarter of its P-3Cst because of age related metal fatigue in the wings. This sort of thing is common with older aircraft, especially those that spend most of their time flying over salt water. The navy believes that it would have all, or most, of the grounded aircraft back in service by now. But not all the work was done, and about a third of P-3Cs still in service are unavailable because of these age-related repairs. The aircraft have to be partially disassembled for replacement parts or reinforcing elements to be installed, and the process can take nearly a year per aircraft.

The P-3 entered service in 1962. The current version (the P-3C) has a cruise speed of 610 kilometers per hour, endurance of up to 13 hours and a crew of eleven. The 37.4 meter (116 foot) long, propeller driven aircraft has a wingspan of nearly 33 meters (100 feet). The P-3C can carry about ten tons of weapons (torpedoes, mines, or missiles like Harpoon and Maverick).

The 63 ton aircraft is based on the 1950s era Lockheed Electra airliner (which first flew in 1954). Only 170 Electras were built, plus 600 P-3s. About 40 Electras are still in service. The last P-3 was built in 1990. Likely replacements for these elderly search planes, are UAVs (Unmanned Aerial Vehicles), like Global Hawk or smaller aircraft like Predator. These UAVs typically stay in the air for 24 hours, or more, at a time. What maritime reconnaissance aircraft need, more than anything else, is endurance or, as the professionals like to put it, "persistence."

But before the UAVs take over, there is the new P-8A Poseidon. About a hundred of these aircraft will replace the P-3C. The P-8A 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 (118 foot wingspan, versus 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 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.