Boeing is due to fly the first P-8A maritime patrol aircraft equipped with a mission system early next year as the program to replace the U.S. Navy’s aging fleet of P-3 maritime patrol aircraft moves into the flight-test phase. The Navy plans to buy 117 P-8As, derived from the 737-800 airliner, with an initial operating capability in 2013. Meanwhile, India is the first export customer, with eight aircraft on order.

The first of five development aircraft flew for the first time on April 25. This aircraft, T1, is proving the performance and loads of the airframe, which has been significantly adapted. T2 followed a few weeks later from the Renton, Washington production line to nearby Boeing Field in Seattle. It is being fitted with the following systems: Raytheon’s APY-10 maritime radar; early warning self-protection, electronic support measures, datalinks and embedded GPS inertial capability, all supplied by Northrop Grumman; and Boeing’s own mission management and display system.

Boeing’s other key partners on the P-8A program are General Electric, which is supplying the CFM56 engines, and former Boeing-subsidiary Spirit Aerosystems in Wichita, Kansas, which is building the fuselages. Spirit Aerosystems also builds all the 737 fuselages and is shipping them to Renton with all the changes already incorporated, including windows blanked and antenna positions added.

“The wing skins are thicker, for longer life, and there are winglets plus two hardpoints on each wing,” said Boeing P-8 program manager Bob Feldman, describing the changes made to the 737-800 airliner. “The generator is doubled in capacity, to 180 Kv. There is a 13-foot-long weapons bay in the rear fuselage containing five stations, with another two on the center fuselage.”

U.S. Navy program managers are paying close attention to structural integrity, following experience with the P-3. Many Orions have been grounded with fatigue problems, and Lockheed Martin is now producing all-new wings for some airplanes.

A P-8 static test article (S1) now at Renton “will twist and bend for a year, before being sent to the China Lake weapons range where it will be tested for resistance to incoming weapons,” explained Feldman. Fatigue testing on a second dedicated airframe (S2) will begin in mid-2010. “For many years, the P-3 program did not even have a fatigue test airplane,” Feldman noted.

According to Boeing, early problems with excessive weight on the P-8 have been solved. “We can now fly 1,200 nautical miles, then do four hours on station before flying back,” he said.

The maximum takeoff weight of the P-8A is 187,700 pounds, and the maximum speed is 490 knots. It carries a crew of nine, and weapons include the Mk54 torpedo, the SLAM-ER missile and even 1,000-pound bombs on the centerline stations. Sonobuoys are stored in racks and launched through pressurized chutes, with an alternative free-fall chute also provided.

Boeing’s mission system has already been sold into a number of applications, including the UK’s Nimrod MRA.4 upgrade. On the P-8A, dual ultra-high-resolution 24-inch screens provide all the operators with a common tactical situation display. All onboard and offboard track data can be displayed in one view. The acoustic system can concurrently process data from up to 64 passive sonobuoys and 32 multi-static sonobuoys.

Raytheon’s AN/APY-10 radar has been developed specifically for the P-8A. It can track-while-scan and has six operating modes (inverse SAR, navigation, SAR, periscope detection, surface search and color weather). According to Boeing, Northrop Grumman’s electronic support measures system provides “a high probability of detection in high threat environments” and precision 360-degree direction finding. The early warning self-protection system provides 360-degree protection against heat-seeking surface-to-air missiles.

The third flying P-8A (T3) is planned to have the full mission system and do weapons tests. But Boeing’s Weapons Systems Integration Laboratory is also a major risk reduction tool, according to Feldman.

The U.S. Navy deleted the requirement for the P-8A to carry a magnetic anomaly detector (MAD) for submarine hunting, presumably because of the sophistication of the other sensors. But the P-8s for India will have a MAD boom. The P-8Is will also have an aft-facing radar, to meet an Indian requirement for 360-degree radar coverage. “We’re still working with the U.S. government to release some other technologies to them,” Feldman noted.

Given the problems with the U.S. Navy P-3 fleet, it’s not surprising that Boeing has suggested speeding up the P-8A production rate. It is currently set at 13 per year, preceded by low-rate initial production of six in the current fiscal year, rising to eight in 2011 and 10 in 2012.

Boeing envisions adding new technology in two “spirals” in 2015 and 2017. It is also eyeing as potential export customers a list of 17 countries that operate large maritime patrol aircraft.