Boeing P-8 Poseidon
The Boeing P-8 Poseidon is an American maritime patrol and reconnaissance aircraft developed and produced by Boeing Defense, Space & Security. It was developed for the United States Navy as a derivative of the civilian Boeing 737 Next Generation airliner.
The P-8 operates in anti-submarine warfare, anti-surface warfare, and intelligence, surveillance and reconnaissance roles. It is armed with torpedoes, Harpoon anti-ship missiles, and other weapons, can drop and monitor sonobuoys, and can operate in conjunction with other assets, including the Northrop Grumman MQ-4C Triton maritime surveillance unmanned aerial vehicle.
In addition to the U.S. Navy, the P-8 is also operated by the Indian Navy, the Royal Australian Air Force, the United Kingdom's Royal Air Force, the Republic of Korea Navy, the Royal Norwegian Air Force, the Royal New Zealand Air Force and the German Navy. It also has been ordered by the Republic of Singapore Air Force and the Royal Canadian Air Force.
Development
Origins
The Lockheed P-3 Orion, a turboprop ASW aircraft, had been in service with the United States Navy since 1962. In the 1980s, the USN began studies for a P-3 replacement, the range and endurance of which were reduced due to increasing weight and airframe fatigue life limitations. The specification required a new aircraft to have reduced operating and support costs. In 1989, Lockheed was awarded a fixed-price contract to develop the P-7, but this was canceled the following year.In 2000, a second competition for a replacement began. Lockheed Martin submitted the Orion 21, an updated new-build version of the P-3. Boeing's proposal was based on its 737-800 airliner. BAE Systems offered a new-build version of the Nimrod MRA4, a British jet-powered maritime patrol aircraft. BAE withdrew from the competition in October 2002, recognizing that without a production partner based in the United States, the bid was politically unrealistic. On 14 May 2004, Boeing was selected as the winner of the Multimission Maritime Aircraft program.
In June 2004, the USN awarded a development contract to Boeing. The project was planned to be for at least 108 airframes for the USN. Project value is expected to be worth at least $15 billion. Raytheon, Northrop Grumman, Spirit AeroSystems, GE Aviation Systems, Marshall Aerospace and Defence Group, CFM International, BAE Systems, and Marotta were the major subcontractors. In July 2004, the USN placed an order for five aircraft, with the first flight-test aircraft to be completed in 2009. On 30 March 2005, it was assigned the P-8A designation.
Design phase and testing
The P-8 is to replace the P-3. Initially, it was equipped with legacy systems with later upgrades to incorporate newer technology. The Government Accountability Office credited the incremental approach with keeping the project on schedule and on budget. The Naval Air Systems Command deleted the requirement for the P-8A to be equipped with magnetic anomaly detection equipment as a weight reduction measure, improving endurance. A hydrocarbon sensor detects fuel vapors from diesel-powered submarines and ships.The P-8's first flight was on 25 April 2009. The second and third P-8s had flown and were in flight testing in early August 2010. On 11 August 2010, low-rate production of the P-8 was approved. A P-8 released sonobuoys for the first time on 15 October 2010, dropping six in three separate low-altitude passes. In 2011, the ice detection system was found to be defective due to the use of counterfeit components; allegedly these parts were poorly refurbished and sold to subcontractor BAE Systems as new by a Chinese supplier.
File:P 8 and P 3 over Pax River.jpg|thumb|A P-8A flying alongside a Lockheed P-3C Orion, close to Naval Air Station Patuxent River, Maryland, 2010
On 4 March 2012, the first production P-8A was delivered to the USN, flying to Naval Air Station Jacksonville, Florida, for training with the Fleet Replacement Squadron, Patrol Squadron 30. On 24 September 2012, Boeing announced a $1.9 billion order for 11 aircraft. On 10 June 2013, a U.S. Department of Defense Inspector General report recommended delaying full-rate production over a lack of key data to assess if the P-8 met operational requirements; additional tests were also needed to guarantee a 25-year lifespan. Boeing executives dismissed the report, saying that the test program was on track. In 2013, full-rate production was delayed until the P-8 could demonstrate it can survive its 25-year lifespan without structural fatigue, overcome deficiencies, track surface ships, and perform primary missions.
On 24 June 2013, during weapons integration testing, the P-8 achieved a milestone by firing a live AGM-84 Harpoon anti-ship missile and scored a direct hit on a low-cost modular target. On 1 July 2013, an initial operational test and evaluation report found that the P-8A was "operationally effective, operationally suitable, and ready for fleet introduction." Six test and nine low-rate initial production aircraft had been delivered at that point. On 31 July 2013, Boeing received a $2.04 billion contract to build 13 P-8As in the fourth low-rate initial production lot, for a fleet of 37 aircraft by the end of 2016, and long-lead parts for 16 P-8As of the first full-rate production lot.
In January 2014, Naval Air Systems Command proceeded with full-rate production of the P-8A. Increment 1 systems include persistent anti-submarine warfare capabilities and an integrated sensor suite; in 2016, Increment 2 upgrades will add multi-static active coherent acoustics, an automated identification system, and high-altitude anti-submarine weapons. Increment 3 in 2020 shall enable "net-enabled anti-surface warfare".
In July 2014, Fred Smith, business development director for the P-8, noted that the program had: "saved $2.1 billion on 2004 estimates of the cost of production... the aircraft is now selling for $150 million, down from the forecasted $216 million". The halving of USN orders from 16 aircraft per year down to eight in 2015 due to the expiration of the Bipartisan Budget Act of 2013 was expected to be partially offset by commercial 737 sales and P-8 export sales. The DoD wanted to follow a program template for the P-8 similar to the Joint Strike Fighter program, with international cooperation from prospective users.
Derivatives
In 2010, Boeing proposed to replace the United States Air Force's E-8 Joint STARS fleet with a modified P-8 at the same cost Northrop Grumman proposed for re-engining and upgrading the E-8s. The proposed P-8 Airborne Ground Surveillance would integrate an active electronically scanned array radar, and have ground moving target indicator and synthetic aperture radar capabilities. A key feature was a pod-mounted radar on the fuselage's lower centerline, positioned so the engine nacelles do not obstruct its line of sight. It reuses the P-8A's Raytheon AN/APY-10 multi-mission surface search radar. Two aft ventral fins increase stability.In 2013, Boeing proposed repackaging some of the P-8's systems in the smaller and less expensive Bombardier Challenger 600 series business jet, as the Boeing Maritime Surveillance Aircraft. In 2014, Boeing also offered a JSTARS replacement based on the 737-700, rather than the P-8's 737-800.
Design
The P-8 is a 737-800ERX, roughly similar to the 737-800 commercial passenger aircraft and the USN's 737-700-based C-40 Clipper transport aircraft, but with several modifications to make it suitable for its military service role. Many of the changes reflect the need for the aircraft to operate at lower altitudes and be capable of more aggressive maneuvering than a commercial aircraft. However, the changes were kept in line with the existing assembly process. Boeing 737 fuselage builder Spirit AeroSystems added structural strength to the airframe, while adding a short bomb bay for torpedoes and other stores behind the wing.The aircraft is assembled at the Boeing Renton Factory with the stronger wings from the 737-900. The aircraft uses raked wingtips similar to those fitted to the Boeing 767-400ER, instead of the blended winglets available on 737NG variants. To combat icing on the raked wingtips, horizontal stabilizers and vertical stabilizers, the aircraft is outfitted with electro-mechanical expulsion deicing systems. In the cockpit, changes were made to the flight control and alerting systems, allowing for an increased bank angle, a more responsive autothrottle, and the elimination of audible warnings during low-altitude operations. In order to power additional onboard electronics, the P-8 has a 180 kVA electric generator on each CFM International CFM56 engine, replacing the 90 kVA generator of civilian 737s; this required the redesigning of the nacelles and their wing mountings. The Navy says that compared to the P-3, the P-8 has a smoother flight experience, subjecting crews to less turbulence and fumes, allowing them to concentrate better on missions.
After the aircraft roll off the assembly line, five operator stations are mounted in a sideways row, along the port side of the cabin. Other than one large window on each side of the forward cabin for two observers, none of the other crew stations have windows. A short bomb bay for torpedoes and other stores opens behind the wing. The P-8 is to be equipped with the High-Altitude Anti-Submarine Warfare Weapon Capability Air Launch Accessory, turning a Mark 54 torpedo into a glide bomb for deploying from up to.
The P-8 features the Raytheon APY-10 multi-mission surface search radar. Unlike the preceding P-3, most versions of the P-8 lack a MAD, but the P-8I is equipped with a MAD at India's request. Various sensor data are combined via data fusion software to track targets. Following the cancellation of Lockheed Martin's Aerial Common Sensor project, Boeing proposed a signals intelligence variant of the P-8 for the USN's requirement. During the P-8A Increment 2 upgrade in 2016, the Littoral Surveillance Radar System will be replaced by the Advanced Airborne Sensor radar.
In U.S. service, the P-8A is complemented by the MQ-4C Triton unmanned aerial vehicle which provides continuous surveillance. In January 2015, BAE Systems was awarded a contract for the USN's High Altitude ASW Unmanned Targeting Air System program to develop a sub-hunting UAV equipped with a MAD for launching from the P-8.
The P-8 cannot use the Navy's typical probe and drogue in-flight refueling method, instead using a flying boom receptacle on the upper-forward fuselage, making it, like the USN's E-6 Mercury aircraft, reliant on US Air Force KC-135 Stratotanker, KC-10 Extender and KC-46 Pegasus aircraft for in-flight refueling. In April 2017, the USAF 459th Air Refueling Wing worked with the Naval Air Systems Command to certify operationally the P-8 for in-flight refueling. For extended endurance, the P-8 is equipped with six auxiliary fuel tanks.