P-3 Orion

A land-based aircraft originally developed for the U.S. Navy for anti-submarine warfare (ASW), the P-3 Orion soon took on the broader role of a maritime patrol aircraft. With the decreasing emphasis on "blue-water", open-ocean, ASW with the end of the Cold War, the Orion has been modified so it is useful for surveillance over land, as well as ASW, ASuW, and surveillance and reconnaissance in littoral warfare.

The Navy has shifted the P-3C’s operational emphasis to the littoral regions and is improving the anti-surface warfare (ASUW) capabilities of the P-3C. While it is to be replaced by the P-8 Poseidon, it will be in service through the early 21st century.

History and versions

The original version was based on the L-188 Electra commercial airliner, followed by continuing improvements:

• Update I (1975): new data processing avionics software.
• Update II ((1977) included an infrared detection system, a sonobuoy reference system, the Harpoon anti-ship missile and 28-channel magnetic tape recorder/reproducer.
• Update III (1981): Doubled the number of sonobuoy channels that could be processed.

Avionics

Flight and navigation

• Protected Instrument Landing System
• IFF Mode S and Required Navigation Performance Area Navigation,
• GPS
• AN/ASQ-60 Autopilot

Mission-related

All analog acoustic data recorders are being replaced with digital data recorders.

Anti-surface warfare

Updated Orions can engage surface targets both on water and inland. The basic AGM-84 Harpoon is a long-range anti-shipping missile, but the AGM-84 SLAM is a long-range land attack missile with a high degree of commonality.

For shorter range engagements, the aircraft uses the AGM-65 Maverick, which has a wide range of sensor and warhead combinations, as well as extreme precision. Most often, the passive infrared seeker is used.

Avionics supporting ASuW include:

• AN/AAS-36A Infrared Detecting Set [IRDS] operating both in thermal imaging and visual light modes.
• AN/AVX-1 Electro-Optical Sensor System [EOSS] stabilized day to night vision devie.
• AN/APS-137B(V)5 radar with navigation, weather, and SAR and ISAR imaging. is capable of multimode operation to provide periscope and small target detection, navigation, weather avoidance, long range surface search and Synthetic Aperture Radar (SAR) and ISAR imaging modes. SAR is best against fixed targets and ISAR against moving targets including surfaced submarines. All output can be recorded.
• EP-2060 Pulse Analyzer with AN/ALR-66C(V)3 ELINT/electronic support receiver.

Antisubmarine warfare

The principal sensors are passive and active sonobuoy dropped by the P-3 or cooperating aircraft. Magnetic Anomaly Detection is a supplementary system, as well as radar detection of periscopes or surfaced submarines. Never to be forgotten is the human eye; submarines at shallow depth can be seen in clear water.

A wide range of equipment receives, processes, and displays information from them:

• AN/USQ-78(V) Single Advanced Signal Processor system Display Control Unit
• AN/ALQ-158(V) Adaptive Controlled Phased Array System [ACPA] VHF sonobuoy receiving antenna system amplifies reception of sonobuoy signals
• AN/ARR-78(V)1 Advanced Sonobuoy Communications Link [ASCL] Receiver contains 20 receiver modules, each capable of accepting RF operating channels 1-99 (those sonobuoy channels now in use and those being developed for future use)
• AN/UYS-1(V) Single Advanced Signal Processor System (SASP) of two basic subsystems, both controlled by :

• TS-4271/UYS-1(V)10 Analyzer Detecting Set, also called the AU, is installed with a primary function of processing acoustic signals through the use of a Spectrum Analyzer TS-4271/UYS-1(V).
• CP-1808/USQ-78(V) SASP Display Control Unit (DCU)'

• AN/ARS-5 Receiver-Converter Sonobuoy Reference System not only allows monitoring of sonoboys at a distance, but, when one of the remote buoys detects a signal, the display unit considers the aircraft's current course, the bearing to the target, and the display appears with the "fly to" bearing.

Communications

• AN/ARC-230 High Frequency (HF) radio, built around Rockwell-Collins HF-121C voice and data operation at 400W transmit power
• USQ-130/AN/USQ-130 Data Link

• AN/ASX-6 Multi-Mode Imaging System (MMIS)
• Telephonics Secure Digital Intercommunications System (SDI)
• over-the-horizon C4I international marine/maritime satellite (INMARSAT).

Weapons

Carries 20,000 pounds:

• AGM-65 Maverick
• AGM-84 Harpoon
• AGM-84 SLAM
• Mark 46 torpedo
• Mark 50 torpedo
• Mark 54 torpedo

Variants and operators

• EP-3 Aries II electronic intelligence]
• VP-3 executive transport,
• NP-3C research and development, testing and evaluation and oceanographic survey aircraft

Primary user: U.S. Navy; many foreign operators

General characteristics

• Primary Function: Antisubmarine warfare(ASW)/Antisurface warfare (ASUW).
• Contractor: Lockheed Martin Aeronautical Systems Company.
• Date Deployed: First flight, November 1959; Operational, P-3A August 1962 and P-3C August 1969.
• Unit Cost: $36 million.
• Propulsion: Four Allison T-56-A-14 turboprop engines (4,600 hp each)
• Length: 116.7 feet.
• Height: 33.7 feet.
• Wingspan: 99.6 feet.
• Weight: Maximum takeoff, 139,760 pounds
• Airspeed: Maximum, 411 knots; cruise, 328 knots
• Ceiling: 28,300 feet.
• Range: Mission radius, 2,380 nautical miles; for three hours on-station at 1,500 feet, 1,346 nautical miles.
• Crew: (P-3C) three pilots, two naval flight officers, two flight engineers, three sensor operators, one in-flight technician.