The Buzz

Why Russia and China Fear America's P-8 Poseidon Submarine Killer

There is a decent chance you have already flown on one of the U.S. Navy’s key new aircraft—or rather, the 737 airliner it is based on. The P-8A Poseidon maritime patrol plane may not be as sexy as an F-35 stealth fighter, but in some ways it is far closer to the forefront of international flashpoints in the Pacific Ocean. Maritime patrol planes are essential for tracking the movement of ships and especially submarines across vast oceanic waters—and potentially sinking them in the event of hostilities.

Hunting submarines from the air, however, is an airpower-intensive job that requires numerous airframes spending thousands of flight hours flying long-distance patrol patterns over the ocean. Since 1962, the U.S. Navy has operated the P-3 Orion patrol plane, based on the four-engine L-88 Electra airliner. The turboprop-powered aircraft could spend a dozen hours flying low over the ocean to drop sonar buoys, scan the water for metallic hulls of submarines with its Magnetic Anomaly Detector (MAD) and potentially launch torpedoes. After fifty-five years of able service, however, the P-3s have accumulated thousands of service hours and their hulls are growing fatigued.

In 2004 the U.S. Navy selected the jet-powered Boeing P-8 Poseidon to succeed the aging P-3. Development proceeded relatively smoothly, in part due to the use of a preexisting airframe and the decision to phase in the P-8’s advanced systems in a series of increments rather than delivering them all at once. This led the P-8 unit costs to actually come in under budget, at $150 million per aircraft.

The P-8 is based on the 737-800ERX short-to-medium-range airliner. It typically has a flight crew of three and boosts stronger power generators for its onboard electronics. The Poseidon reportedly offers a much smoother ride than the Orion, thanks to its broader-swept wings and flight computers. Orion crews were often nauseated by the strong turbulence their low-altitude flight operations required.

While the P-8 does have a strengthened hull to operate at low altitude—though at reduced fuel efficiency compared to the P-3—it’s designed to perform most of its operation from high altitude, where the thinner atmosphere allows for greater fuel efficiency and a better vantage for some of its sensors. A Poseidon can loiter overhead at speeds as low as two hundred miles per hour, and can stay on station for extended times due to its in-flight refueling capability. However, with a maximum speed of 564 miles per hour, it can also dash two hundred miles per hour faster than the P-3 aircraft it is replacing.

The Poseidon’s primary payload is its diverse array of sensors. These include an APY-10 multi-mode synthetic aperture radar, which not only can track the position of ships over hundreds of miles away, but possesses a high-resolution mode which can spot submarine periscopes poking above the waves and even identify different classes of ships. An MX-20 electro-optical/infrared turret provides a shorter-range search option, while an ALQ-240 Electronic Support Measure (ESM) derived from a system onboard the EA-18G Growler functions as an electromagnetic sensor, particularly useful in tracking the positions of radar emitters.

A recent addition is the Advanced Airborne Sensor, a dual-sided AESA radar that can offer 360-degree scanning on targets on land or coastal areas, and which has potential applications as a jamming or even cyberwarfare platform.

A number of key systems on the P-8 are designed to track submerged submarines. A rotary launcher system in the rear of the P-8 can dispense sonar buoys into the water. A recent upgrade allows P-8s to employ new Multistatic Active Coherent buoys that generate multiple sonar pulses over time, allowing for greater endurance and search range. The P-8 also has its own acoustic sensor, and even a new hydrocarbon sensor that can “sniff” for fuel vapor from submarines.

However, the P-8 lacks the tail-mounted MAD sensor of the P-3 Orion, useful for detecting the metallic hulls of submarines while flying at low altitude. Various reasons have been offered for its removal: the MAD weighed too much at 3,500 pounds, it did not fit with the high-altitude search profile of the P-8, or the new sensors on the P-8 rendered it unnecessary. However, the U.S. Navy is reportedly developing a variant of the an air launched drone, called the High-Altitude Unmanned Targeting Air System, which can carry a MAD sensor and transmit its findings back up to the P-8.

Five operator stations on the port side of the plane carry multifunction displays that can be configured to display whatever sensors and controls are most useful under the circumstances. The P-8’s computers are designed to fuse the data into a single coherent picture for the operators—and can then “push” that data to friendly ships and airplanes. This is a capability the U.S. Air Force has been struggling to integrate into its new E-3G radar planes. The P-3 is also designed to be especially compatible with Navy RQ-4N drones.

In the event of hostilities, the Poseidon can carry five missiles, depth charges or torpedoes in a rotary launcher in the rear hull, and six more on underwing racks. While the P-3 had to fly low to deploy its torpedoes, the P-8 can use a special High Altitude Air Launch Accessory to transform its Mark 54 324-millimeter lightweight torpedoes into GPS-guided glide bombs that can be dropped from altitudes as high as thirty thousand feet. These shed their wings upon hitting the water and hone in on targets using onboard sonar. Poseidons can also carry Harpoon AGM-184H/K antiship missiles with a range of 150 miles.

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