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19th of August 1958

The Lockheed Orion made its first flight on this day in aviation history.

The first (aerodynamic) prototype of the (then) Lockheed P3V Orion


The origin of what we now know as the P3 Orion go back to the summer of 1957. It was then that the US Navy put out a request for proposals. The purpose of this proposal was to get a modern and more advanced replacement for the Lockheed Neptune (P-2) and Martin Marlin (P-5). Lockheed suggested modifying the Lockheed L-188 Electra (at that time still under development) to a military aircraft fulfilling the US Navy requirements.

Lockheed Electra airframe number 3 (c/n 1003) was modified to the prototype YP3V-1/YP-3A. This was an aerodynamic prototype. The main differences between the standard Electra and the prototype were:

  • 7 feet (2.1 meters) shortened fuselage forward the wing

  • Bombay in the lower fuselage

  • Magnetic detection boom protruding from the tail

  • Hardpoints under the wings

  • Several internal and external changed production procedures

The Allison T56 turboprop was the chosen powerplant, which would give the aircraft a top speed of 411 knots (473 mph / 761 kph) After a 2 1/2 year development and test program the first production, then designated as a P3V-1, was launched on the 15th of April 1961. With the first aircraft deliveries to squadrons started in August 1962. With the introduction of a standardized designation system for all military services, the aircraft was renamed to P-3 Orion. Up to 2000 the aircraft ha da crew complement of 12, after 2000 this was brought down to 11.

As a patrol aircraft, it is important for the P-3 Orion to be able to stay at its patrol area for as long as possible. To reduce the fuel burn at lower flight levels the Number 1 (LH outboard) engine is often shut down when the aircraft reaches its patrol area. This engine does not have a generator, so shutting the engine down has no effect on the electrical system of the aircraft. It also facilitates better observations by the aft obesever by eliminating the exhaust from that engine. Under certain conditions (depending on weather, a/c weight, fuel load) on occasions the number 4 (RH outboard) engine can be shut down. The record for the longest time a P-3 Orion was airborne was set in 1972 by the RNZAF (Royal New Zeeland Air Force), 21 hours and 30 minutes from lift off to touchdown.

A range of different versions of the P-3 Orion ave been developed and built over the years, Wikipedia list 25 main variants and numerous sub variants at time of writing this blog!

Lockheed P-3C of the Japanes Navy

Specifications for a P-3C Orion the third main production variant,

General characteristics

  • Crew: 11

  • Length: 116 ft 10 in (35.61 m)

  • Wingspan: 99 ft 8 in (30.38 m)

  • Height: 33 ft 8.5 in (10.274 m)

  • Wing area: 1,300.0 sq ft (120.77 m2)

  • Aspect ratio: 7.5

  • Empty weight: 61,491 lb (27,892 kg)

  • Zero-fuel weight: 77,200 lb (35,017 kg)

  • Max takeoff weight: 135,000 lb (61,235 kg) MTOW normal, 142,000 lb (64,410 kg) maximum permissible

  • Maximum landing weight: (MLW) 103,880 lb (47,119 kg)

  • Fuel capacity: 9,200 US gal (7,700 imp gal; 35,000 l) usable fuel in 5 wing and fuselage tanks ; (62,500 lb (28,350 kg) maximum fuel weight) ; 111 US gal (92 imp gal; 420 l) usable oil in 4 tanks

  • Powerplant: 4 × Allison T56-A-14 turboprop engines, 4,910 shp (3,660 kW) each (equivalent)

  • Propellers: 4-bladed Hamilton Standard 54H60-77, 13 ft 6 in (4.11 m) diameter constant-speed fully-feathering reversible propellers

Performance

  • Maximum speed: 411 kn (473 mph, 761 km/h) at 15,000 ft (4,572 m) and 105,000 lb (47,627 kg)

  • Cruise speed: 328 kn (377 mph, 607 km/h) at 25,000 ft (7,620 m) and 110,000 lb (49,895 kg)

  • Patrol speed: 206 kn (237 mph; 382 km/h) at 1,500 ft (457 m) and 110,000 lb (49,895 kg)

  • Stall speed: 133 kn (153 mph, 246 km/h) flaps up, 112 kn (129 mph; 207 km/h) flaps down

  • Combat range: 1,345 nmi (1,548 mi, 2,491 km) (3 hours on station at 1,500 ft (457 m))

  • Ferry range: 4,830 nmi (5,560 mi, 8,950 km)

  • Endurance: 17 hours 12 minutes at 15,000 ft (4,572 m) on two engines, 12 hours 20 minutes at 15,000 ft (4,572 m) on four engines

  • Service ceiling: 28,300 ft (8,600 m), 19,000 ft (5,791 m) one engine inoperative (OEI)

  • Rate of climb: 1,950 ft/min (9.9 m/s)

  • Time to altitude: 25,000 ft (7,620 m) in 30 minutes

  • Wing loading: 103.8 lb/sq ft (507 kg/m2)

  • Power/mass: 0.1455 hp/lb (0.2392 kW/kg) (equivalent)

  • Take-off run: 4,240 ft (1,292 m)

  • Take-off distance to 50 ft (15 m): 5,490 ft (1,673 m)

  • Landing distance from 50 ft (15 m): 2,770 ft (844 m)

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