Almost from the beginning of carrier aviation, various aircraft were used to fly personnel and high-priority parts to carriers at sea. Probably the first systematic effort at what became known as carrier on-board delivery (COD) was initiated when the U.S. Navy deployed nuclear strike aircraft at sea in the early 1950s.
Beginning in 1951, nuclear-strike aircraft were forward based ashore in the Mediterranean area and atomic bomb components were placed on board forward-deployed aircraft carriers. But the nuclear inserts for the atomic bombs were not stored on carriers until at least 1953. In the interim, under a program code-named Daisy Chain, an elaborate scheme was developed to fly the plutonium cores from East Coast storage sites to Port Lyautey, Morocco, where modified General Motors-built TBM-3R Avenger aircraft would be waiting to fly the components out to the carrier.1
Initially, piston-engine R5D Skymaster cargo planes (naval version of the four-engine DC-4/C-54) were used to transport the components to the Mediterranean; subsequently, six-jet B-47 bombers also were assigned to that role. The nuclear cores, which weighed less than 100 pounds each, were packaged in large containers—called “bird cages”—to prevent or at least reduce radiation hazards if the aircraft crashed. Several cores could be carried by an R5D or B-47, but their packaging restricted the TBMs to carrying one core per flight.
On board ship, the bombs were assembled and the cores inserted in special, highly restricted spaces by a team of up to 40 technicians. Several hours were required to assemble a bomb, insert the nuclear component, check the electrical circuits, and load it into an attack aircraft. And the Navy had limited numbers of trained technicians available to assemble the bombs.
It soon was determined that a more-capable, specialized aircraft was needed to bring other high-priority cargo and personnel to carriers at sea. In the late 1940s, the Navy and Grumman Aircraft Corporation were developing an antisubmarine aircraft that could combine the detection and attack roles—previously requiring separate aircraft—into a single, carrier-capable aircraft. The result was the S2F Tracker, a twin-engine plane with a gross weight of more than 25,000 pounds flown by a crew of four.2
The prototype XS2F-1 flew on 4 December 1952, and large-scale production followed. Its success led to almost immediate development of a cargo variant with a new fuselage that could accommodate nine passengers or 3,500 pounds of cargo plus the pilot and copilot. The tail surfaces were enlarged, the wings folded, and catapult points and arresting hook were fitted for carrier operation.
The first TF-1 Trader flew on 19 January 1955. (The aircraft became the C-1A in 1962.) Trader production totaled 87, including four aircraft configured for electronic countermeasures (TF-1Q, later EC-1A). In turn, the C-1A design evolved into the WF-1 Tracer airborne early warning aircraft (later E-1B). While S2F Tracker and WF-1 Tracer aircraft soon were assigned to carrier air groups, the C-1A COD squadrons—sometimes labeled the “COD fish” airlines—were mostly based ashore, with their aircraft shuttling between U.S. and overseas bases and aircraft carriers; forward deployed carriers often had a Trader assigned.
While the CODs flew important but generally routine missions to carry people and “stuff,” especially mail, to and from carriers at sea, they had a vital role in the abortive invasion of Fidel Castro’s Cuba in April 1961. The antisubmarine carrier Essex (CVS-9) departed Norfolk, Virginia, with her antisubmarine warfare air group embarked. Once at sea, the Essex’s engineers hastily converted some of her aviation gasoline tanks to store jet fuel (JP-5). On 4 April, one of her two 12-plane squadrons of S2F Trackers was flown off. As those planes departed, 12 A4D-2 Skyhawk light attack aircraft flew aboard. Simultaneously, a flock of some 15 TF-1 COD aircraft flew on and off the Essex, taking off the Tracker ground crews and bringing on those of the Skyhawks plus their support equipment. (The Essex retained her second 12-plane S2F squadron, a squadron of 16 HSS-1 Seabat helicopters, and four AD-5W Skyraider radar aircraft.)
The Trader CODs became increasingly difficult to handle on board carriers as they were the last carrier aircraft to use avgas and to require bridles for catapult launches, although in some circumstances they made unassisted, deck-run takeoffs. In 1988, the last Trader—the U.S. Navy’s last piston-powered carrier aircraft—was retired.
Meanwhile, the rapid development of airborne radars led to development of the Grumman W2F-1 Hawkeye early warning aircraft (redesignated E-2 in 1962). This was a still larger, twin-turboprop aircraft with a gross weight of some 52,000 pounds. The prototype W2F-1 flew on 21 October 1961, and almost immediately production was under way for the U.S. Navy and foreign services, as well as for the U.S. Coast Guard and Customs Service. And almost immediately there was “talk” of a derivative COD aircraft.
Again, the basic wings, tail assembly, and twin engines were retained for the COD configuration, but with a new fuselage, to create the C-2 Greyhound. Fitted with a rear-loading ramp, the C-2 could carry 28 passengers or 12 litters or 10,000 pounds of cargo.
The first of two YC-2A prototypes flew on 18 November 1964. Production followed—initially 17 aircraft and a later order for another 39 aircraft. The later aircraft had several improvements, including more powerful turboprop engines, updated avionics, anticorrosion materials, and a new auxiliary power unit that reduced the need for ground support equipment. For political reasons—i.e., “selling” it to Congress—the C-2A designation was retained for the improved aircraft, although some Navy internal documents used the designation C-2A(R), the “R” for “reprocured.” (The two YC-2A prototypes were converted to E-2A early warning aircraft.)
The first dedicated COD aircraft—the TBM-3R Avenger and C-1 Trader—have long been retired. The C-2 Greyhounds continue to provide valuable support to the fleet. In the offing is the next-generation COD: The Navy is considering a variant of the Bell Boeing V-22 Osprey tilt-rotor aircraft, now in service with the Marine Corps (MV-22) and Air Force (CV-22). At one point the Navy planned to acquire 48 HV-22 aircraft for search-and-rescue, but none was procured. Airborne early warning (EV-22) and antisubmarine (SV-22) variants also were considered for naval service.
Being a vertical-takeoff-and-landing (VTOL) aircraft, the Osprey in the COD role could greatly simplify flight-deck operations. Also, a VTOL aircraft could easily deliver passengers and cargo to amphibious ships and to combatants with large flight decks.
Meanwhile, the C-2 Greyhounds carry on, flying people and cargo around the world, afloat and ashore.3
1. Port Lyautey was renamed Kenitra in 1956. U.S. forces used the airfield from 1942 to 1977.
2. The Tracker originated as the XA2F-1. In 1962 the S2F was redesignated S-2.
3. See Gordon Swanborough and Peter M. Bowers, United States Navy Aircraft since 1911 (Annapolis, MD: Naval Institute Press, 1968), 258–67; and René J. Francillon, Grumman Aircraft since 1929 (Annapolis, MD: Naval Institute Press, 1989), 387–93, 481–85.