Lockheed EC-121 Warning Star


1st Flight 1949

Crew: typically six flight crew, 11–25 radar crew

Length: 116 ft 2 in (35.40 m)

Wingspan: 126 ft 2 in (38.45 m)

Height: 24 ft 9 in (7.54 m)

Wing area: 1,650 sq ft (153.27 m2)

Empty weight: 69,210 lb (31,387 kg)

Max takeoff weight: 143,000 lb (65,000 kg)

Powerplant: 4 × Wright R-3350-34 turbo compound 18-cylinder supercharged radial engines, 3,400 hp (2,536 kW) each


Maximum speed: 299 mph (481 km/h, 260 kn)

Cruise speed: 255 mph (410 km/h, 222 kn)

Range: 4,250 mi (6,843 km, 3,700 nmi)

Service ceiling: 25,000 ft (7,620 m)

Rate of climb: 960 ft/min (4.87 m/s)


The Lockheed EC-121 Warning Star was an American Airborne early warning and control radar surveillance aircraft operational in the 1950s in both the United States Navy and United States Air Force.

USN variants

WV-1. 2 prototypes, L-749A Constellation, designated PO-1W before 1952

EC-121K (WV-2). Main USN variant, designated PO-2W before 1952; 244 ordered, 142 produced (the rest to USAF).

JC-121K. One modified EC-121K used as a US Army avionics test bed

NC-121K. Unknown number modified as special mission aircraft

YEC-121K. One modified avionics test bed

EC-121L (WV-2E). One modified WV-2, test bed for rotating radar dome with an AN/APS-70 radar

EC-121M (WV-2Q). ELINT collection variant, 13 modified WV-2

WC-121N (WV-3. Weather reconnaissance variant, 8 modified WV-2

EC-121P. Unknown number modified from EC-121K as anti-submarine variant

JEC-121P. 3 EC-121P used by the USAF

USAF variants

RC-121C: 10 produced, initial USAF variant

JC-121C: 2 converted from C-121C and 1 TC-121C as avionics test beds

TC-121C: 9 RC-121C modified before 1962 as crew trainers

EC-121D: 73 produced 1953–55 as main USAF variant and 1 converted from C-121C, originally designated RC-121D

EC-121D Quick Look: 1 test bed for QRC-248 IFF transponder interrogator

EC-121H: 42 USAF upgrades in 1962, 35x EC-121D and 7x WV-2s transferred from the Navy

EC-121J: 2 USAF EC-121D modified with upgraded electronics

EC-121M Rivet Top: 1 EC-121D test bed for Rivet Gym crypto logic linguist electronics suite, originally designated EC-121K

EC-121Q: 4 EC-121D modified with upgraded electronics for USAF Gold Digger missions

EC-121R: 30 EC-121K / EC-121P transferred to USAF in 1966–1967 and converted to Batcat sensor signal processor

EC-121S: 5 converted for Pennsylvania Air National Guard from USAF C-121 transports

EC-121T: Final USAF variant. A total of 22 T’s were converted from 15x EC-121D and 7x EC-121H.

XW2V-1: Proposed naval development with new features such as 4 Allison T56-A8 turboprop engines, L-1649A Starliner wings and Bomarc missiles for defense.

None built; was designated L-084 due to the large differences from its predecessors.

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