The Lockheed P-3 Orion is a maritime patrol aircraft used by numerous navies and air forces around the world, primarily for maritime patrol, reconnaissance, anti-surface warfare and anti-submarine warfare.

Development

The P-3 Orion, originally designated P3V, is based on the same design philosophy as the Lockheed L-188 Electra. It is not the same aircraft structurally in that it has had 7 ft (2.1 m) of fuselage removed forward of the wings, as well as myriad internal, external, and airframe production technique enhancements. The prototype YP3V-1/YP-3A BuNo 148276 was in fact modified from the third Electra airframe c/n 1003. The P-3 Orion served as the replacement for the postwar era P-2 Neptune and P-5 Marlin. The Orion is powered by four Allison T56 turboprops which give it a speed comparable to fast propeller powered fighters, or even slow turbofan jets such as the A-10 Thunderbolt II or the S-3 Viking. Many other countries have seen the value of this platform design and have developed similar patrol aircraft based on this model, with the Soviets adapting their own counterpart to the Orion, the Ilyushin Il-38. The P-3 also competes with the British Hawker Siddeley Nimrod adaptation of the de Havilland Comet and the French Breguet Atlantique.

The first production version, designated P3V-1, first flew 15 April 1961. Initial squadron deliveries to Patrol Squadron EIGHT (VP-8) and Patrol Squadron FORTY FOUR (VP-44) at Naval Air Station Patuxent River, Maryland began in August 1962. On 18 September 1962, the U.S. military transitioned to a unified designation system for all services, redesignating the aircraft as the P-3A. Paint schemes have changed from an early 1960s blue and white scheme, to a mid-1960s white and gray, to a mid-1990s flat finish low visibility gray with subdued markings to an early 2000s gloss finish gray with full color markings.

Over the years, more than 40 combatant & noncombatant variants of the P-3 have been developed due to the rugged reliability displayed by the platform flying 12 hour plus missions 200 ft (61 m) over salt water while maintaining an excellent safety record. Versions have been developed for the National Oceanic and Atmospheric Administration (NOAA) for research and hurricane hunting/hurricane wall busting, for the U.S. Customs Service (now U.S. Customs and Border Protection) for drug interdiction and aerial surveillance mission with a rotodome adapted from the E-2 Hawkeye or an AN/APG-66 radar adapted from the F-16 Fighting Falcon, and for NASA for research and development.

There have also been claims of the CIA operating two to three P-3As, described as having been painted all black with the markings of the Taiwanese/Republic of China Air Force (RoCAF), for aerial surveillance and agent/leaflet delivery in the vicinity of the People's Republic of China in the mid-1960s. This mission supposedly ended in January 1967 and the aircraft returned to U.S. Navy control. However, this particular mission has never been confirmed in any official "open source" U.S. Government documentation and its authenticity cannot be positively confirmed.

The United States Navy remains the largest operator of the P-3, currently distributed between a single fleet replacement (i.e., "training) patrol squadron, 12 active duty patrol squadrons, two Navy Reserve patrol squadrons, and two active duty special projects patrol squadrons and an active duty test and evaluation squadron. Two additional active duty fleet reconnaissance squadrons operate the EP-3 Aries signals intelligence (SIGINT) variant. The U.S. Navy's P-3Cs are slated for replacement beginning in 2013 by the Boeing P-8 Poseidon, which is based upon the Boeing 737-800 series airliner.

Design

The P-3 has an internal bomb bay under the front fuselage which can house conventional Mark 50 torpedoes or Mark 46 torpedoes and/or special (nuclear) weapons. Additional underwing stations, or pylons, can carry other armament configurations including the AGM-84 Harpoon, AGM-84E SLAM, AGM-84H/K SLAM-ER, the AGM-65 Maverick, 5 in (127 mm) Zuni rockets, and various other sea mines, missiles, and gravity bombs. The aircraft also had the capability to carry the AGM-12 Bullpup guided missile until that weapon was withdrawn from U.S./NATO/Allied service.

Crew complement

The number of crew on board a P-3 varies depending on the role being flown, the variant being operated, and the country who is operating. In US Navy service, the normal complement for a P-3C is 11.

The senior of either the PPC or TACCO will be designated as the aircraft Mission Commander (MC).

Engine loiter shutdown

On many missions, an engine is shut down (usually the No. 1 engine - the port outer engine) once on station to conserve fuel and extend the time aloft and/or range when at low level. On occasion, both outboard engines can be shut down, aircraft weight, weather, and remaining fuel permitting. Long deep-water, coastal or border patrol missions can last over ten hours and may include extra crew. The record time aloft for a P-3 is a 21.5 hour flight undertaken by the Royal New Zealand Air Force's No. 5 Squadron in 1972.

Engine 1 is the primary candidate for loiter shutdown because it is the only one without a generator, and is not needed for electrical power. Eliminating the exhaust from engine 1 also improves visibility from the aft observer station on the port side of the aircraft.

Operational history

Developed during the Cold War, the P-3's primary mission was to track and eliminate ballistic missile and fast attack submarines in the event of war. Reconnaissance missions in international waters led to occasions where Soviet fighters would "bump" a U.S. Navy P-3 or other P-3 operators such as the Royal Norwegian Air Force. On one occasion in the 1980s the MiG and pilot did not survive the "bump" while trying to ward off a P-3 photographing a Soviet fleet exercise. The P-3 lost more than 10 feet (3.0 m) of its wing in the collision.The P-3 completed its mission and returned to base.

Civilian uses

Several P-3s have been N-registered and are operated by civilian agencies. The United States Customs Service has a number of P-3A and P-3Bs used for maritime patrol. NOAA operates two WP-3D variants specially modified for hurricane research. One P-3B, N426NA, is used by NASA as an Earth science research platform, primarily for the NASA Science Mission Directorate's Airborne Science Program. It is based at Goddard Space Flight Center's Wallops Flight Facility, Virginia.

Aero Union, Inc. operates eight ex-USN P-3As configured as air tankers, which are leased to the U.S. Forest Service, the California Department of Forestry and Fire Protection and other agencies for firefighting use. A unique capability of the P-3 is that on so-called "downhill runs," i.e. when the plane is commencing a low pass to drop fire retardant, it is possible to put the propellers into "Beta" range, which is reverse-thrust mode, in order to slow the plane for the drop of water-based retardant. Several of these aircraft were involved in the U.S. Forest Service airtanker scandal but have not been involved in any catastrophic aircraft mishaps.

Variants

• P-3A: The original production version; 157 built.
• P-3A (CS): Four with ex-USN P-3As reequipped with AN/APG-66 radars for use by the United States Customs Service.
• EP-3A: Seven modified for electronic reconnaissance testing.
• NP-3A: Three modified for the U.S. Naval Research Laboratory.
• RP-3A: Two modified for scientific uses for the former Oceanographic Development Squadron EIGHT (VXN-8) at NAS Patuxent River.
• TP-3A: 12 modified for training duties in Fleet Replacement Squadrons with all ASW gear removed.
• UP-3A: 38 reconfigured as utility transports with all the ASW gear removed.
• VP-3A: Three WP-3As and two P-3As converted into VIP/staff transports.
• WP-3A: Four converted for weather reconnaissance.
• P-3B: Second main production version/series T56-A14 engines in lieu of T56-A10W engines on P-3A.
• EP-3B: Two P-3As converted into ELINT aircraft during the Vietnam War.
• NP-3B: One P-3B converted into a testbed, for the U.S. Naval Research Laboratory.
• P-3BR: Modification to P-3A model for Brazilian Air Force. Eight aircraft with EADS avionics.
• P-3C: Third main production version/series. T56-A14 engines. P-3C had A-NEW ASW suite and mission computer. Revised internal layout. Externally P-3C featured electrically operated entry ladder, small fin-top antenna, externally loaded belly sonobuoy chutes, 3 small windows on the aft right side (one window forward of the overwing emergency exit and two well aft). Initial production aircraft had camera nose located on lower part of radome. Later production aircraft had retractable IRDS turret in lieu of nose camera. Beginning in the early 1980s existing camera noses were retrofitted with IRDS turrets.
  • P-3C Update I: New and improved avionics, 31 built.
  • P-3C Update II: With infra-red detection system (IRDS), sonobuoy reference system (SRS), and ability to carry the AGM-84 Harpoon anti-ship missile; 44 built.
  • P-3C Update II.5: 24 aircraft with more reliable LTN-72 inertial navigation system and enhanced communications equipment.
  • P-3C Update III: 50 aircraft with new acoustic processor, sonobuoy receiver, plasma displays, and improved auxiliary power unit (APU).
  • P-3C Update IV: P-3C with Boeing Update 4 avionics suite. Update 4 was going to be common avionics interior for P-3Cs and its planned replacement aircraft, the Lockheed P-7A, which never made it to production. One one P-3C was converted to UD4 interior and that aircraft was later stripped and turned into a Special Mission aircraft.
  • P-3C AIP {Anti-Surface Warfare Improvement Program} (US) P-3C Update III with interior modification to add ASQ-222 mission computer, ASQ-78A/B acoustics system, APS-137 ISAR radar
  • P-3C UIP {Upgrade Improvement Program} (RNoAF) P-3C with interior modification to add ASQ-222 mission computer, ASQ-78A/B acoustics system, APS-137 ISAR radar
  • P-3C BMUP {Update III Block Modification Upgrade Program} (US) 25 aircraft with interior modification to convert UD2 and UD2.5 to carry ASQ-227 mission computer and ASQ-78B acoustics suite
  • P-3C CUP {Capability Upkeep Program} CUP (RNLN) P-3C with interior modification to convert UD2.5 to carry ASQ-227 mission computer and ASQ-78B acoustics suite; all aircraft relinquished by Royal Netherlands Navy in 2005 due to budget cuts and subsequnetly sold to/operated by the German Navy (eight aircraft) and the Portuguese Air Force (five aircraft)
• EP-3: ELINT aircraft for the Japanese Maritime Self-Defence Force.
• NP-3C: One P-3C converted into a testbed for the U.S. Naval Research Laboratory.
• RP-3C: One P-3C modified to replace the RP-3A.
• OP-3C: 10 P-3C converted to reconnaissance aircraft for the Japanese Maritime Self-Defence Force.
• UP-3C: Equipment test aircraft for the Japanese Maritime Self-Defence Force.
• UP-3D: ELINT training aircraft for the Japanese Maritime Self-Defence Force.p
• RP-3D: One P-3C modified on production line to optimize MAD capabilities. Aircraft did extensive MAD surveys and was painted "Project Magnet". In 1973, an RP-3D was instrumental in pinpointing the wreckage of Civil War ironclad USS Monitor.
• WP-3D: Two P-3Cs modified on production line for NOAA weather research, including hurricane hunting.
• EP-3E Aries: 10 P-3As and 2 EP-3Bs converted into ELINT aircraft.
• EP-3E Aries II: 12 P-3Cs converted into ELINT aircraft.
• EP-3E SIGINT: Eight US Navy EP-3Es are to be converted by L-3 Communications Integrated Systems into "surge configuration" Signals Intelligence aircraft. This will expand their multi-source intelligence capacity to meet the increased intelligence demands of the "surge" in counter-terrorism operations.
• NP-3E: Various aircraft used for tests.
• P-3F: Six Orions delivered to the former Imperial Iranian Air Force in the late 1970s. The airframe of the P-3F was based on the P-3C was which the then current production variant for the U.S.Navy. The P-3F and P-3C featured electrically operated entry ladder, small fin-top antenna, externally loaded belly sonobuoy chutes, 3 small windows on the aft right side (one window forward of the overwing emergency exit and two well aft), camera nose located on lower part of radome. The P-3F did not have ASW suite or mission computer of the P-3C. Most of the displays and processors were adapted from the P-3A/P-3B (although the P-3F had the APS-115 radar of the P-3C) The P-3F came from the factory with the then-standard gray and white U.S Navy paint scheme, but while crews were undergoing training in the U.S., the aircraft were repainted in a unique 3-tone blue paint scheme; three aircraft still operational with the Islamic Republic of Iran Air Force.
• P-3G: Original designation of the Lockheed P-7A.
• P-3H: Proposed P-3C upgrade.
• EP-3J: Two modified from P-3As for FEWSG use as a simulated adversary EW platform in exercises; later transferred to the former Tactical Electronic Warfare Squadron Thirty-Three (VAQ-33), then transferred to the former Fleet Air Reconnaissance Squadron Eleven (VQ-11) of the Navy Reserve.
• P-3K: five aircraft originally of P-3B standard but subsequently updated, delivered to New Zealand in 1965-67, replacing Short Sunderlands. The original P-3Bs were operated by No. 5 Squadron RNZAF from Whenuapai, Auckland. These received part of the P-3C Update II package and some local innovations, then being designated P-3K (for Kiwi), together with a P-3B purchased second hand from the Royal Australian Air Force and brought up to P-3K standard. Aircraft were re-winged and underwent a further round of avionics and sensor updates in 2005 (P-3KII).
• P-3M: Five former RNoAF P-3B modernized by EADS-CASA for the Spanish AF. They have a new sensor suite integrated by a six console EADS-CASA Fully Integrated Tactical System (FITS)data system. New sensors include an Elta-2022 radar, SPAS-16 acoustic processor, new 99-channel sonobuoy receiver and AMES-C ESM system. Only the original MAD system was kept.
• P-3N: Two P-3B modified for coast guard missions for the RNoAF.
• P-3P: Six ex-RAAF originally of P-3B standard but subsequently updated for the Portuguese Air Force. Being replaced by newer P-3C Update II.5s (P-3C CUP) formerly operated by the Royal Netherlands Navy.
• P-3T: Two P-3A modified for Royal Thai Navy.
  • VP-3T: One P-3A modified for Royal Thai Navy VIP use and some surveillance operations.
• P-3W: Designation used internally by the Royal Australian Air Force (RAAF) to distinguish the first 10 P-3C aircraft procured in the P-3C Update 2 configuration (1978-79) from the second 10 aircraft which were procured in the Update 2.5 configuration (1982-83). The older aircraft were designated as P-3Cs and the newer aircraft P-3Ws. All were equipped with the British AQS-901 Acoustics Processor. Eventually with various system upgrades to the mission systems the two types mergerd into one and they are now all known as AP-3Cs.
• AP-3C: All Royal Australian Air Force P-3C/W aircraft which have been fully upgraded with totally new mission systems by L-3 Communications to include an Elta SAR/ISAR RADAR and a GD-Canada Acoustic Processor system.
  • TAP-3: 3 modified B-models for training duties with the Royal Australian Air Force, with all the ASW gear removed and passenger seating installed. Removed from service with the full introduction into service of the AP-3C Simulator. Designator reflected them as being 'Training Australian P-3'
• P-3CK: Designation of the eight former P-3B aircraft that the Republic of Korea Navy procured from the USN and which are in the process of being rebuilt with P-3C configuration wings and fitted with updated Mission System Equipment by Korea Aerospace Industries and L-3 Communications.
• P-3AEW&C (originally nicknamed "Sentinel"): Eight P-3B aircraft were converted into Airborne Early Warning and Control aircraft. The P-3AEW&Cs are used by U.S. Customs and Border Protection for drug interdiction and homeland security missions. "Slicks" are P-3s with an optical sensor turret in the nose which often work with the AEW ships.
• CP-140 Aurora: Longe-range maritime reconnaissance, anti-submarine warfare aircraft for the Canadian Armed Forces. Based on the P-3C Orion airframe, but mounts the more advanced electronics suite of the S-3 Viking.
• CP-140A Arcturus: Three CP-140s without ASW equipment installed for Aurora crew training and various coastal patrol missions.
• P-7 proposed new-build and improved variant as a P-3 Orion replacement later cancelled.
• Orion 21 proposed new-build and improved variant as a P-3 Orion replacement; lost to Boeing P-8 Poseidon.

Operators

Military operators

 Argentina

• Argentine Navy - 6 P-3B; based at Base Aeronaval Alte. Zar, Trelew

 Australia

• Royal Australian Air Force - 18 AP-3C, 1 P-3C (No. 92 Wing – 10 Sqn, 11 Sqn) and (No. 292 Sqn; based at RAAF Base Edinburgh

 Brazil

• Brazilian Air Force - 8 P-3AM(Upgraded) in 2008; forming at Base Aerea de Salvador and Base Aerea de Santa Cruz.

 Canada

• Canadian Forces Air Command - 24 CP-140 Aurora (P-3 Orion airframe with S-3 Viking electronics suite)

 Chile

• Chilean Navy - 4 P-3A; based at Base Aeronaval Torquemada, Con-Con

 Germany

• German Navy - 8 P-3C (ex Dutch Navy); based at NAS Nordholz, Marinefliegergeschwader 3 Graf Zeppelin

 Greece

• Hellenic Navy - 6 P-3B; based at Eleusina Air Base

 Iran

• Islamic Republic of Iran Air Force - 5 P-3F (71ASW SQN); based at Shiraz International Airport (Shahid Douran Air Base)

 Japan

• Japan Maritime Self-Defense Force - 101 P-3C, 5 EP-3, 1 UP-3C, 3 UP-3D

 New Zealand

• Royal New Zealand Air Force - 6 P-3K (5 Sqn); based in RNZAF Base Auckland

 Norway

• Royal Norwegian Air Force - 4 P-3C, 2 P-3N (333 Sqn); based in Andøya Air Station

 Pakistan

• Pakistan Navy - ~10 P-3C; based in Naval aviation base Faisal, Karachi. Upgraded P-3C MPA and P-3B AEW models (equipped with Hawkeye 2000 AEW system) ordered in 2006, first upgraded P-3C delivered in early 2007.

 Portugal

• Portuguese Air Force - 6 P-3P, 5 P-3C (Squadron 601); based in Beja Air Base (BA11)

 Republic of China (Taiwan)

• Republic of China Navy - 12 P-3C (Ordered, with delieveries starting in 2012); based in Taoyuan Air Base

 South Korea

• Republic of Korea Navy - 8 P-3C, 8 P-3CK; based in Pohang Airport and Jeju international airport

 Spain

• Spanish Air Force - 10 P-3M, modernized, based at Morón Air Base

 Thailand

• Royal Thai Navy - 2 P-3T, 1 VP-3T; based at RTNAB U-Tapao (102 Sqn)

 United States

• United States Navy - 154 P-3C and EP-3E; additional P-3A, P-3B, P-3C and EP-3J aircraft in long-term storage at AMARC
• National Oceanographic and Atmospheric Administration (NOAA) - 2 WP-3D flown by NOAA Commissioned Corps officers, based at MacDill AFB, Florida

Civilian operators

 United States

• National Aeronautics and Space Administration - 1 ex-USN P-3B; based at NASA's Wallops Flight Facility, Virginia used for low altitude heavy lift airborne science missions, modified to support passive microwave instruments, such as NOAA’s Polarimetric Scanning Radiometer (PSR), NASA’s 2-DSTAR, and the Jet Propulsion Laboratory (JPL) polarimetric scatterometer (POLSCAT) instruments.
• United States Department of Homeland Security / Customs and Border Protection / Office of CBP Air - 8 P-3 AEW; based at NAS Corpus Christi, Texas and NAS Jacksonville, Florida. Used for border patrol and anti-drug duties. Former USN aircraft, modified and equipped with the same Airborne Early Warning radar as fitted to the E-2 Hawkeye.
• United States Department of Homeland Security / Customs and Border Protection / Office of CBP Air - 8 P-3 LRT (Long Range Tracker). Former USN aircraft also based at NAS Corpus Christi, Texas and NAS Jacksonville, Florida. Normally operate in tandem with P-3 AEW aircraft.
• Aero Union - 8 ex-USN P-3A; aircraft based at Chico Municipal Airport in Chico, California and converted into aerial firefighting platforms

Specifications (P-3C Orion)

General characteristics

• Crew: 11
• Length: 116 ft 10 in (35.6 m)
• Wingspan: 99 ft 8 in (30.4 m)
• Height: 33 ft 8.5 in (10.3 m)
• Wing area: 1300 ft² (120.8 m²)
• Airfoil: NACA 0014-1.10 (Root) - NACA 0012-1.10 (Tip)
• Empty weight: 77,200 lb (35,000 kg)
• Loaded weight: 135,000 lb (61,400 kg)
• Useful load: 57,800 lb (26,400 kg)
• Max takeoff weight: 142,000 lb (64,400 kg)
• Powerplant: 4× Allison T56-A-14 turboprop, 4,600 shp (3,700 kW) each
• Propellers: Four-bladed Hamilton Standard propeller, 1 per engine
  • Propeller diameter: 13 ft 6 in (4.11 m)

Performance

• Maximum speed: 405 kn (750 km/h)
• Cruise speed: 330 kn (610 km/h)
• Range: 5,600 mi ferry (9,000 km)
• Service ceiling: 34,000 ft (10,400 m)
• Rate of climb: 3,140 ft/min (16 m/s)
• Wing loading: 107 lb/ft² (530 kg/m²)
• Power/mass: 0.03 hp/lb (0.06 kW/kg)

Armament

• Bombs: 20,000 lb (9,000 kg)
• Missiles: AGM-84 Harpoon, the Standoff Land Attack Missile, AGM-65 Maverick
• Sonobuoys: 48 Pre-loaded, 50+ Deployable from inside
• Other: Mk 46, Mk 50 and MU90 Impact torpedoes, mines, depth charges