The Grumman E-1 Tracer was the first purpose-built
airborne early warning
Airborne or Airborn may refer to:
Arts, entertainment, and media
Films
* ''Airborne'' (1962 film), a 1962 American film directed by James Landis
* ''Airborne'' (1993 film), a comedy–drama film
* ''Airborne'' (1998 film), an action film sta ...
aircraft used by the
United States Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...
. It was a derivative of the
Grumman C-1 Trader
The Grumman C-1 Trader is a carrier onboard delivery (COD) variant of the Grumman S-2 Tracker. It was replaced by a similar version of the Northrop Grumman E-2 Hawkeye, the Grumman C-2 Greyhound.
Design and development
The C-1 Trader grew out o ...
and entered service in 1958. It was replaced by the more modern
Grumman E-2 Hawkeye
The Northrop Grumman E-2 Hawkeye is an American all-weather, carrier-capable tactical airborne early warning (AEW) aircraft. This twin-turboprop aircraft was designed and developed during the late 1950s and early 1960s by the Grumman Aircraft ...
by the 1970s.
Design and development
The E-1 was designated WF under the
1922 United States Navy aircraft designation system
From 1922 until 1962, the United States Navy, the United States Marine Corps and the United States Coast Guard used a system to designate their aircraft that included information about a craft's role and its manufacturer. For a listing of all such ...
; the designation earned it the nickname "Willy Fudd". The Tracer was derived from the
C-1 Trader, itself a derivative of the
S-2 Tracker
The Grumman S-2 Tracker (S2F prior to 1962) was the first purpose-built, single airframe anti-submarine warfare (ASW) aircraft to enter service with the United States Navy. Designed and initially built by Grumman, the Tracker was of convent ...
carrier-based antisubmarine aircraft, known as S2F under the old system, nicknamed "Stoof", leading to the WF/E-1, with its distinctive
radome
A radome (a portmanteau of radar and dome) is a structural, weatherproof enclosure that protects a radar antenna. The radome is constructed of material transparent to radio waves. Radomes protect the antenna from weather and conceal antenn ...
, being known as "Stoof with a Roof."
[O'Rourke, G.G., CAPT USN. "Of Hosenoses, Stoofs, and Lefthanded Spads". ''United States Naval Institute Proceedings'', July 1968.] The E-1 featured folding wings of a very particular design for compact storage aboard aircraft carriers; unlike the S-2 and C-1 in which the wings folded upwards, the radome atop the fuselage required the E-1's designers to re-adopt an updated version of the Grumman-patented ''Sto-Wing''
folding wing
A folding wing is a wing configuration design feature of aircraft to save space and is typical of carrier-based aircraft that operate from the limited deck space of aircraft carriers. The folding allows the aircraft to occupy less space in a co ...
system, pioneered on their earlier
Grumman F4F-4 Wildcat piston-engined fighter of the early-WW II period, to fold its wings aftwards along the sides of the fuselage.
Radar
The Tracer was fitted with the
Hazeltine AN/APS-82 in its radome and fuselage. The radar featured an Airborne Moving Target Indicator, which compares the video of one pulse time to the next in
reflected Reflection or reflexion may refer to:
Science and technology
* Reflection (physics), a common wave phenomenon
** Specular reflection, reflection from a smooth surface
*** Mirror image, a reflection in a mirror or in water
** Signal reflection, in ...
radar
Radar is a detection system that uses radio waves to determine the distance ('' ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, w ...
energy to distinguish a flying aircraft from the clutter produced by wave action at the ocean's surface. The energy reflected from an aircraft changes position rapidly compared to the energy reflected from the surrounding sea. Separating a moving object from stationary background is accomplished by suitable hardware.
Operational history

As one of the first carrier based early warning aircraft, the E-1 Tracer served from 1958 to 1977, although considered only an interim type, being replaced by the
Grumman E-2 Hawkeye
The Northrop Grumman E-2 Hawkeye is an American all-weather, carrier-capable tactical airborne early warning (AEW) aircraft. This twin-turboprop aircraft was designed and developed during the late 1950s and early 1960s by the Grumman Aircraft ...
in the mid-1960s. During the early years of the Vietnam War, E-1s saw extensive service, providing combat air patrol (CAP) fighters with target vectors, and controlling Alpha strikes over North Vietnam. With a radius of 250–300 miles, the E-1B served as an early warning to strike aircraft, of enemy MiG's activity.
By May 1973, most E-1Bs were retired, with only four VAW-121 Tracers based at
NAS Norfolk
Naval Station Norfolk is a United States Navy base in Norfolk, Virginia, that is the headquarters and home port of the U.S. Navy's Fleet Forces Command. The installation occupies about of waterfront space and of pier and wharf space of the Hampt ...
, Virginia, still in service. These aircraft were soon retired during mid-summer 1977 following a final cruise on board and were ferried to the
Davis-Monthan storage facility. The E-1B Tracer was struck from the inventory by 1977.
Variants

; XTF-1W: Aerodynamic prototype (BuNo 136792) without electronics, later rebuilt as a standard C-1A, retaining the twin tail.
; XWF-1: The XTF-1W re-designated in the W-Warning category.
; WF-2: Production Airborne Early Warning version of the
TF-1 Trader, redesignated E-1B in 1962, 88 built.
; E-1B: WF-2 redesignated in 1962.
Operators
;
*
United States Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...
Aircraft on display
There are five E-1 Tracers preserved at museums throughout the United States:
*E-1B, BuNo 147212:
Intrepid Sea, Air & Space Museum
The ''Intrepid'' Sea, Air & Space Museum is an American military and maritime history museum in New York City with a collection of museum ships. It is located at Pier 86 at 46th Street, along the Hudson River, in the Hell's Kitchen neighbor ...
,
New York City
New York, often called New York City or NYC, is the most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the most densely populated major city in the U ...
*E-1B, BuNo 147217:
New England Air Museum
The New England Air Museum (NEAM) is an American aerospace museum located adjacent to Bradley International Airport in Windsor Locks, Connecticut. The museum consists of three display hangars with additional storage and restoration hangars. Its ...
,
Windsor Locks, Connecticut
Windsor Locks is a town in Hartford County, Connecticut, United States. As of the 2020 census, its population was 12,613. It is the site of Bradley International Airport, which serves the Greater Hartford-Springfield region and occupies approx ...
*E-1B, BuNo 147225: On board the
USS Yorktown (CV-10)
USS ''Yorktown'' (CV/CVA/CVS-10) is one of 24 s built during World War II for the United States Navy. Initially to have been named ''Bonhomme Richard'', she was renamed ''Yorktown'' while still under construction, after the , which was sunk ...
,
Patriots Point,
Mount Pleasant, South Carolina
Mount Pleasant is a large suburban town in Charleston County, South Carolina, United States. In the Low Country, it is the fourth largest municipality and largest town in South Carolina, and for several years was one of the state's fastest-growin ...
*E-1B, BuNo 147227:
Pima Air & Space Museum
The Pima Air & Space Museum, located in Tucson, Arizona, is one of the world's largest non-government funded aerospace museums. The museum features a display of nearly 300 aircraft spread out over 80 acres (320,000 m²) on a campus occ ...
, adjacent to
Davis-Monthan AFB in
Tucson, Arizona
, "(at the) base of the black ill ILL may refer to:
* ''I Love Lucy'', a landmark American television sitcom
* Illorsuit Heliport (location identifier: ILL), a heliport in Illorsuit, Greenland
* Institut Laue–Langevin, an internationally financed scientific facility
* Interlibrar ...
, nicknames = "The Old Pueblo", "Optics Valley", "America's biggest small town"
, image_map =
, mapsize = 260px
, map_caption = Interactive ...
*E-1B, BuNo 148146:
National Naval Aviation Museum
The National Naval Aviation Museum, formerly known as the National Museum of Naval Aviation and the Naval Aviation Museum, is a military and aerospace museum located at Naval Air Station Pensacola, Florida.
Founded in 1962 and moved to its curr ...
,
Naval Air Station Pensacola
Naval Air Station Pensacola or NAS Pensacola (formerly NAS/KNAS until changed circa 1970 to allow Nassau International Airport, now Lynden Pindling International Airport, to have IATA code NAS), "The Cradle of Naval Aviation", is a United State ...
Another 11 E-1 Tracers are in storage at United Aeronautical, an aircraft surplus yard located just outside
Davis–Monthan Air Force Base
Davis–Monthan Air Force Base (DM AFB) is a United States Air Force base southeast of downtown Tucson, Arizona. It was established in 1925 as Davis–Monthan Landing Field. The host unit for Davis–Monthan AFB is the 355th Wing (355 WG) ass ...
in Tucson, Arizona.
At least one of those aircraft (E-1B, BuNo 148922) was sold to a private collector in 2011 with the intent to restore to fly, although no updates on the project have been posted since 2012.
Specifications
See also
References
Notes
Bibliography
* Sullivan, Jim. ''S2F Tracker in Action (Aircraft in Action No. 100).'' Carrollton: Texas: Squadron/Signal Publications, 1990. .
* Winchester, Jim, ed. "Grumman S-2E/F/G/UP Tracker." ''Modern Military Aircraft'' (Aviation Factfile). Rochester, Kent, UK: Grange Books plc, 2004. .
External links
Global Security.org page on WF-2/E-1 TracerAirborne Moving Target Indicator (AMTI) explanation provided by Mercury Computer
{{US EW aircraft
E-001 Tracer
1950s United States special-purpose aircraft
High-wing aircraft
Carrier-based aircraft
AEW aircraft
Aircraft first flown in 1956
Twin piston-engined tractor aircraft