This is a work in progress...
Carrier Onboard Delivery (COD) is the mission of delivering people, mail, and high-priority cargo to a carrier at sea by air. COD doesn't seem to have been a mission, certainly not a dedicated aircraft, before about 1950. For one thing, up until then there were a goodly number of airplanes in the air group with more than one seat and a bomb bay that could be used for transportation by air to and from the carrier. Tailhook-equipped utility aircraft like the Grumman J2F Duck could also be used when necessary.
The airplanes in the air group were fairly simple and reliable in any event. However, as the single-seat AD Skyraider, which did not have a bomb bay, began to replace the SB2C Helldivers and TBM Avengers and airplane electronic systems grew in number and complexity, a logistics gap appeared.
The first solution was the TBM-3R, R being the Navy designation at the time for a transport. This was one of several conversions of surplus TBMs to other purposes. In this case, the gun turret was removed and the canopy extended over the tail gunner's position. Two seats were installed in the compartment aft of the pilot and two in the former turret area. Two seats were also provided in the former radioman compartment below the turret area for a total of six passenger seats. One was usually occupied by the load master/crew chief, leaving the other five available for passengers. A basket was installed in the bomb bay for cargo.
The TBM-3R appears to have been introduced in 1950 or so. For certain, it was in widespread use during the Korean War.
The AD-5 was the next COD development. It was created as a multi-place, multi-purpose modification of the AD Skyraider. The upper fuselage was widened to provide side-by-side seating for a pilot and a crewman and create a compartment aft of them for additional crewmen.
National Archives 80-G-652832 via Jim Sullivan
Neither the TBM-3R or the AD-5 was capable of filling two of the Navy's emerging high-priority cargo requirements, jet engines and nuclear weapons. The result was a variant of the Navy's new twin-engine, antisubmarine warfare aircraft, the Grumman S2F. Designated the TF-1, it had a slightly wider and somewhat deeper fuselage with a large double door on the left side of the fuselage and windows on each side. Nine seats could be set up in the passenger compartment to accommodate eight passengers and the load master.
The TF-1 first flight was made on 19 February 1955. The use of a "T" prefix (rather than and "R" suffix) designation was that was the majority of the roles originally envisioned for the aircraft and used as the justification for its procurement were as a trainer.
In 1963, the CNO was reportedly concerned about resupply of the carriers of essential items too big for the C-1 and requested an evaluation by NATC of the C-130 for operation to and from Forrestal-class carriers. The first question was whether to train a C-130 pilot to make carrier landings or checkout a carrier-qualified pilot in the C-130. The obvious answer was that a fighter pilot, LT James H. Flatley III, would fly it along with another carrier-suitability branch pilot as copilot and a C-130 flight engineer volunteer from VR-1. The NATC pilots were checked out in the C-130 by a Lockheed test pilot. The changes to the C-130F, BuNo 148798 borrowed from the Marine Corps, were minimal and did not include the addition of a tailhook: the nose gear strut response was stiffened by the substitution of a smaller bleed orifice, higher capacity brakes were installed, and the external tanks were removed.
After shore-based trials established the feasibility of taking off from and landing on a carrier and the best technique to be used, at-sea trials were accomplished aboard Forrestal (CVA-59) in October 1963. No significant difficulties were encountered in takeoffs or landings, with a maximum takeoff weight demonstrated of 121,000 pounds. While the evaluation demonstrated the feasibility of resupply using the C-130, it was decided that the capability was not practical given the disruption of normal carrier operations when it was aboard and the risk that the C-130 might go hard down after landing, requiring it to be dumped overboard under certain circumstances due to the deck space it took up.
In any event, the Navy had already decided to buy a COD derivative of its new AEW airplane, the Grumman E-2 Hawkeye, configured for carrier onboard delivery. The E-2A had first flown in October 1961 and was first deployed in 1965. The C-2 first flew in 1964, with the wing and engines from a prototype E-2A mounted on a much wider and deeper fuselage equipped with a rear ramp. It had a four-man crew and could carry either 26 passengers or total cargo of about 10,000 pounds or a mix of passengers and cargo. Maximum range was about 1,200 nautical miles. C-2A production totaled two conversions from prototype E-2A BuNos 148147/8 and 17 new airframes, BuNos 152786-2797. The first of these entered service in 1966. The C-2s were not assigned to a carrier but operated by east and west-coast based Fleet Logistic Support (VRC) squadrons with detachments located worldwide.
The C-2 had the capability to carry outsized and heavy cargo but did not have as much range as desired for carrier onboard delivery in the Pacific and Indian Oceans. In the 1970s, the Navy had a competition for a much larger airplane. Boeing, Douglas, and Fokker proposed derivatives of their twin jet transports, the 737, DC-9, and F-28 respectively. Although the Navy thought that they were feasible, none were taken up at the time.
However, a Lockheed Full Scale Development S-3 Viking, BuNo 157998, was converted to a COD configuration, US-3A, in 1976. In this case, the existing fuselage was retained but the aft pair of ejection seats were removed and replaced with six passenger seats, three abreast, for five passengers and a load master. The bomb bay and electronic compartments were configured to carry cargo and a large cargo pod was created that was carried on the stores pylon. The prototype first flew in July 1976 and it was assigned to Kitty Hawk in 1977. It not only had a range of 2,400 miles with external fuel tanks in lieu of the cargo pods, it retained an inflight refueling capability so unlike the C-2, it was not restricted to a peacetime radius of action that allowed it to return to a shore base in the event that a carrier landing was not accomplished. It could not, however, transport large items.
Lockheed proposed a US-3A with a wider and longer fuselage that utilized the S-3 cockpit, wings, stabilizer, and engines. It would have provided seating for as many as 30 passengers or cargo space/access for two large jet engines. The Navy elected not to buy it. However, in 1981 five more US-3As were converted from FSD aircraft, BuNos 157994-997, and another test aircraft, BuNo 158868, for high-priority logistics transportation in the Pacific. These were operated by VRC-50.
In the early 1980s, the Navy evaluated the addition of inflight refueling to the C-2 in order to remove the range restriction of requiring an airport alternate.
Photo courtesy Rick Morgan
In 1983, Naval Air Systems Command revisited the Fokker F-28 to the extent of accomplishing a flight evaluation of the Fellowship at Fokker's factory in Amsterdam and at NAS Sigonella. It would have had the payload of the C-2 and the range of the S-3. While the conclusion of the evaluation was that the "airplane has potential for the carrier-based carrier-on-board delivery, tanker, or AEW mission," no contract resulted.
The Navy elected instead to maintain the existing mix of the C-1 and C-2 for intermediate-range missions; the US-3 for high-speed, long-range missions with high-priority, small cargo; and a huge helicopter, the Sikorsky CH-53E, for short-range transport of large, heavy items from shore bases.
A service life extension program had been accomplished on the surviving C-2As from the original purchase of 19, with deliveries of the refurbished aircraft between 1978 and 1982. However, only 12 remained, not enough to meet the demand for COD support since the C-1s were being retired and only a handful of the volume-limited US-3As were available. After considering other options, the Navy elected the unusual step of putting the C-2 back into production although the degree of difficulty was somewhat reduced by the fact that the E-2 was still in production. The Navy bought 39, BuNos 162140-2178.
The major external difference between the original C-2s and the "reprocured" C-2s was a larger APU. Less obvious was a redesigned nose landing gear. The housing for the crash recorder/locator was not carried over to the new C-2s. The first one flew in February 1985, just in time to begin replacement of the original Greyhounds, the last of which was retired by the end of 1987.
The last C-1 in service, BuNo 146048, was retired on 30 September 1988. The last of the new C-2s had been delivered in 1990. The US-3As were retired in 1994.
In the late 1990s, the Navy considered the development of the Common Support Aircraft (CSA). It was to replace the E-2C for AEW, the S-3 for ASW, the ES-3A for signal intelligence gathering (Sigint), and the C-2 for COD beginning in 2013. (The EA-6B would be replaced by a derivative of the F/A-18F.) The concept was a victim of budget priorities and mission revaluation. The S-3s and ES-3As were retired, with ASW to be accomplished by a combination of carrier and destroyer-based helicopters and shore-based airplanes. Sigint would primarily be accomplished as before by shore-based airplanes although the F/A-18F has some capability in that regard. The E-2C continued in low-rate production and is being replaced by an upgrade, the E-2D.
As a result, there has been no replacement of the C-2s, which began going through a service life extension program including avionics upgrades in 2005. They are currently expected to serve through 2027.
The announced replacement for the C-2 is a variant of the Bell-Boeing V-22 tilt-rotor aircraft. While lacking the speed and range of an S-3 specifically reconfigured for COD and the payload-range of an improved C-2 that were also evaluated, the HV-22 will have the ability to make vertical takeoffs and landings from any ship with a suitable landing area. The range can be extended by inflight refueling and it can land on an aircraft carrier even in the unlikely event that arrested landings are not possible.