An overview of the airplanes that have operated from aircraft carriers reveals a handful of outliers that were exceptionally large and/or heavy for their time. Let's take a look at a few examples and see what made them so unique.

It was just a few years after the Wright Brother's historic 1903 flight when people began flying airplanes off of ships. By the start of World War I, rudimentary aircraft carriers were already being used. In those early years, the airplanes were hardly more than spindly collections of spruce, linen, and castor oil. Likewise, their host ships had been built for other duties and then hastily modified to include add-on flight decks.

Aircraft carriers soon became purpose-built ships from the keel up. This set off a century-long evolution that would mold them into ever larger and more complex machines. The same is true of the airplanes they carried. You can begin to appreciate the scope of this change by comparing the 1,200 pound Sopwith Pup that flew from British ships in WWI to the 66,000 pound F/A-18E Super Hornet used by several modern navies.

A left front view of a U-2 reconnaissance aircraft parked on the flight deck of the aircraft carrier USS AMERICA (CV 66).

An overview of the airplanes that have operated from aircraft carriers reveals a handful of outliers that were exceptionally large and/or heavy for their time. Let's take a look at a few examples and see what made them so unique.

1942 – B-25 Mitchell

WWII was the conflict that first illustrated the immense offensive capabilities of aircraft carriers. A prime example is the 1941 attack on Pearl Harbor – a raid carried out solely by aircraft launched from six Japanese carriers. Immediately after the raid, President Roosevelt desperately wanted to deliver a retaliatory blow.

America's three Pacific-based aircraft carriers were not at Pearl Harbor during the attack and were thus still operational. Yet, short of staging a large (strategically risky) multi-carrier attack, the US had very little offensive muscle in the Far East.

US Navy Captain Francis Low concocted the idea of flying twin-engine US Army Air Corps bombers from the deck of a carrier. These aircraft had a much greater bomb load and range than the Navy's single-engine carrier-based bombers and torpedo planes of the time. The army bombers would ride aboard a single carrier to deliver a one-time jab to the Japanese mainland. The idea quickly developed into the famous Doolittle Raid.

A B-25 takes off from the USS Hornet on its way to Tokyo. After the Doolittle Raid, B-25s were never again flown from aircraft carriers. (US Navy photo)

The aircraft carrier selected for the raid was the new USS Hornet. Mission commander Lieutenant Colonel Jimmy Doolittle and his men flew in North American B-25 Mitchell bombers. Studies determined that B-25s with a 2,000 pound bomb load and sufficient fuel for a 2,000 mile trip could indeed takeoff from the Hornet's flight deck. After dropping their bombs on Tokyo, the planes would continue westward to land in China. So the B-25's inability to land aboard the carrier was not a concern.

The US Navy's standard carrier-based bomber at that time was the Douglas SBD Dauntless, which was significantly smaller than the B-25. The army bomber's wingspan was over 50% greater than that of the SBD (67.6' vs 41.5') and its maximum weight was more than triple (35,000 lb vs 10,700 lb). While the Dauntless could carry the same 2000 lb bomb load that Doolittle's B-25s did, it didn't have sufficient range for the mission and its cruising speed was nearly 50 mph slower.

Prior to boarding the Hornet, Doolittle and his men practiced quick takeoff techniques with their B-25s at Eglin Field in Florida. When the mission was launched on April 18, 1942, it was the first time that any of the bomber pilots had actually flown from an aircraft carrier. Despite their inexperience and the rough seas that day, all 16 of the B-25s safely became airborne.

B-25 medium bombers were tied to the deck of the USS Hornet for the Doolittle Raid. Navy planes of the time did not have sufficient bomb load or range for the mission. (US Navy photo)

The actual destructive effects of the Doolittle raid were small. Strategically, it helped to reign in Japan's rapid expansion as more resources were allocated to defending the island. Most of Doolittle's B-25s were destroyed during crash landings in China. Their crews met a variety of fates, including three killed and eight captured. B-25s never again flew from an aircraft carrier.

1956 - Douglas A3D Skywarrior

Early atomic bombs were big and heavy. Additionally, the bombs had to be armed in-flight. That meant that nuclear bombers not only had to be powerful enough to schlep the requisite weight, but also large enough to carry the bomb in an accessible internal bomb bay. When the US Navy issued requirements for a carrier-based nuclear bomber in 1947, it specified an enormous maximum weight of 100,000 pounds…a huge leap in size over other carrier aircraft of the day.

Despite the latitude in weight, North American Aviation declined to submit a proposal, believing that an airplane under 100,000 pounds could not do the job. The design submitted by Curtiss was near the 100,000 pound limit. Douglas Aircraft Company's proposal seemed almost out of place, with a projected maximum weight of only 68,000 pounds. The Navy gave Douglas the go-ahead to build the twin-jet bomber, designated the A3D Skywarrior.

This view of the A3D gives some impression of its large size. It was the heaviest carrier-based aircraft ever in the US Navy inventory. (photo from the R. Lawson collection of the National Naval Aviation Museum)

The Navy began receiving Skywarriors in 1956. The type was not fully retired until 1991. During that time, its intended role as a doomsday bomber was thankfully never utilized. The A3D did, however, fill many other roles during its career. The US Air Force had their own version of the A3D, the B-66 Destroyer.

In the Vietnam War, A3Ds operated as conventional bombers, dropping bombs and mines. They also served vital roles as VIP transports, electronic reconnaissance/countermeasures platforms, and aerial tankers.

The A3D was originally designed as a nuclear bomber, but the airplane's large size made it suited for many other duties during its career. (photo from the R. Lawson collection of the National Naval Aviation Museum)

A3Ds operated at weights up to 84,000 pounds, which remains the record as the heaviest carrier-based airplane to have served in the US Navy. Depending on how you define "biggest" the North American A5 Vigilante is also a contender. This Mach 2-capable plane was longer than the E3D by just 2 inches. It actually served alongside the A3D for many years. Like the Skywarrior, the Vigilante was designed as a nuclear bomber but served alternate roles during its service life.

1963 – U-2 Dragon Lady

When the long-winged Lockheed U-2 was introduced in 1956, it was touted as a high-altitude weather research airplane. The 1960 downing of CIA U-2 pilot, Francis Gary Powers, while overflying the Soviet Union revealed the true spy plane intent of the U-2 Dragon Lady. Some nations that had previously allowed U-2 operations to originate from and/or overfly their territory suddenly turned a cold shoulder to the airplane. To recapture the global reach of the U-2 the CIA embarked on Project Whale Tale, which explored the idea of operating them from aircraft carriers.

One of the keys to the U-2's exceptional high-altitude performance was its lightweight structure. There was some concern whether the airframe would prove stout enough to handle the hard-knock life of a carrier-based aircraft. The father of the U-2, Lockheed Chief Engineer Kelly Johnson, was confident that it wouldn't take much to get his welterweight bird ready for carrier operations.

The U-2 is tough to land on any surface. A few modifications were made to help pilots bring the Dragon Lady aboard aircraft carriers.

Initial tests showed that a fully-loaded U-2 had no trouble launching from an aircraft carrier – even without the shove of the ship's steam catapult. As expected, the real challenge was landing. With its large wing and bicycle-style landing gear, the U-2 was notoriously tough to land, even on normal runways. Dragon Ladies landing at air force bases were typically shadowed by a chase car with someone coaching the pilot all the way down to the ground via radio. Carrier-bound U-2s had no such luxury. They received stronger landing gear as well as spoilers on the wings that would help the pilots pinpoint their landings. The Dragon Ladies also received tailhooks to grab the ship's arresting cables when they landed.

The CIA pilots who operated the U-2 received training for carrier landing techniques and they eventually became proficient at bringing the Dragon Lady aboard.

Interestingly, the only operational use of carrier-based U-2s was the observation of French nuclear tests in Polynesia.

1963 – Lockheed C-130 Hercules

This photo shows the C-130 on the deck of the USS Forrestal. Note how close the right wingtip is to the ship's island. The dashed line on the flight deck from bow to stern was added just for the C-130 tests. (US Navy photo)

Aircraft carriers are hungry ships and require frequent resupply. Urgent and particularly important items (like mail) are often flown aboard with COD (Carrier On-board Delivery) aircraft. In the early 1960s, the Navy was looking for ways to improve upon the 3,500 pound payload limit of their current COD aircraft, the Grumman C-1 Trader.

The much larger, land-based Lockheed C-130 had already proven itself to be a capable cargo plane. The question was whether the Herc's 133 foot wingspan would allow it to even fit on an aircraft carrier. As it rolled down the flight deck, there would be less than 15 feet of clearance between the C-130's right wingtip and the carrier's island structure.

A Marine C-130 was selected for trials aboard the USS Forrestal. The only alteration made to the ship was the addition of an orientation stripe down the full length of the flight deck. Marginal changes were applied to the C-130. The damping of the front landing gear was altered, better anti-skid brakes were installed and external fuel tanks were removed.

The tests took place on October 30, 1963. During the course of the day, Lieutenant James H Flatley III piloted the C-130 through 29 touch-and-go landings, and 21 full-stop landings with subsequent takeoffs. The Hercules was flown at weights ranging from 85,000 pounds all the way to 121,000 pounds.

The C-130 did not require either the ship's steam catapult or arresting wires for operation. There was actually room to spare for takeoff and landing, even at the highest weights. When landing, Flatley would begin moving the C-130s propellers to reverse pitch while still 4 feet above the flight deck! His superb airmanship earned him the Distinguished Flying Cross. The C-130 used for the tests now resides at the Naval Aviation Museum in Pensacola, Florida.

Despite the success of the C-130 carrier trials, the Navy decided to procure a different replacement for the C-1, the Grumman C-2 Greyhound. While considerably smaller and lighter than the C-130, the C-2 did provide a significant payload increase over the C-1. The Greyhound still serves as a COD aircraft for the Navy today.

These are just a few examples of large airplanes that have flown from aircraft carriers. If you know of other large carrier-planes, please share them in the comments below – especially non-US aircraft.

Terry spent 15 years as an engineer at the Johnson Space Center. He is now a freelance writer living in Lubbock, Texas. Visit his website at TerryDunn.org and follow Terry on Twitter: @weirdflight