A noisy, leaky propeller plane and an old but reliable weapon joined forces in 1951 to carry out an attack on a vital hydroelectric dam complex in North Korea. The plane was the Douglas AD-4 Skyraider.

The weapon was the aerial torpedo.

In a world of pointy-nosed jets, the AD Skyraider wheezed, coughed, and dripped oil. With a paddle-like, four-bladed propeller out front and a tail wheel in back, it was obsolescent half a decade after its first flight on March 18, 1945, but it was going to be around for a lot longer.

The Skyraider, also dubbed the “Able Dog” or the “flying dump truck,” was powered by a Wright R-3350 two-row, 18-cylinder radial engine. Douglas Aircraft’s brilliant Ed Heinemann designed it on the back of an envelope in the Shoreham Hotel one night in 1944 after arriving in Washington to learn that the U.S. Navy had made last-minute changes in its requirement for a replacement for the SBD Dauntless dive-bomber. Briefly named the Dauntless II, the Skyraider was too late for World War II – but not for Korea.

In a world of pointy-nosed jets, the AD Skyraider wheezed, coughed, and dripped oil. With a paddle-like, four-bladed propeller out front and a tail wheel in back, it was obsolescent half a decade after its first flight on March 18, 1945, but it was going to be around for a lot longer.

Vaulting from carrier decks, churning through foul weather and hugging Korea’s steep mountain passes, the AD Skyraider became a treetop-level warrior, providing close support to friendly troops. Naval aviators of the era were well trained – many had been recalled involuntarily after serving in World War II – and they could bomb or strafe a foe within 300 yards of friendly troops. The Skyraider gave them superb visibility, an excellent chance of survival if hit, and a muscular array of air-to-ground weapons.

The Skyraider carried so many kinds of bombs, rockets, and weaponry that sailors boasted it could carry everything but the kitchen sink. Lt. (j.g.) Carl B. Austin proved this wrong when he flew into North Korea, found a target, and dropped a box-finned, 1,000-pound bomb with a porcelain sink from his carrier’s galley strapped to it.

 

Carrier Attack

The Skyraider carried so many kinds of bombs, rockets, and weaponry that sailors boasted it could carry everything but the kitchen sink. Lt. (j.g.) Carl B. Austin proved this wrong when he flew into North Korea, found a target, and dropped a box-finned, 1,000-pound bomb with a porcelain sink from his carrier’s galley strapped to it.

The Essex-class USS Princeton (CV 37) was one of the aircraft carriers that fought as part of Rear Adm. Ralph A. Oftstie’s Task Force 77 in the Sea of Japan. On April 30, 1951, Oftstie learned that Chinese forces had launched a spring offensive. Among the flying units in Air Group Nineteen aboard the Princeton was medium attack squadron VA-195. The squadron was told to prepare for an unusual mission.

The target: North Korea’s Hwachon Dam, the great hydroelectric plant on the Pukhan River that was fueling the enemy’s war effort. The mighty dam had defied efforts of B-29 Superfortress heavy bombers to put it out of commission. The dam was 240 feet thick at its base, with both faces fortified by rocks. An immovable object in the path of an irresistible force, it refused to go down even when Skyraiders attacked it with 2,000-pound bombs and 11.5-inch Tiny Tim rockets (which had been developed years earlier with the destruction of German submarine pens in mind).

The squadron would be charged with attacking the dam complex, aiming for a goal that may seem counter-intuitive: U.S. officials worried that the Chinese might release all the water behind the dam at once, inundating the valley beneath the dam and bringing operations to a standstill, or cut off the flow of water entirely, thereby making it easier for Chinese forces to ford the river and infiltrate behind UN lines. By blasting open at least two of the floodgates stretching between the dam’s east and west abutments, an air attack would be preventing either option by creating holes in the dam that would guarantee a steady flow of water. The mission would inspire the squadron’s latter-day nickname, the “Dambusters.”

On April 30, the same day the Chinese offensive became known, Skyraiders attacked the dam with bombs. It didn’t work.

Aboard Princeton, a roll call in VA-195 and composite squadron VC-35 yielded only three pilots who had ever dropped a “tin fish” before. Ensign Robert E. Bennett, one of the pilots chosen for the mission, had never even seen an aerial torpedo and could not remember whether he had even heard of one.

That night, it was decided that there was only one way to accomplish the mission: have Skyraiders torpedo the Hwachon Dam.

Aboard Princeton, a roll call in VA-195 and composite squadron VC-35 yielded only three pilots who had ever dropped a “tin fish” before. Ensign Robert E. Bennett, one of the pilots chosen for the mission, had never even seen an aerial torpedo and could not remember whether he had even heard of one. Princeton had taken aboard a dozen Mark 13 torpedoes before her combat cruise, but when ships’ officers began to talk about using them, initially no one could remember where they were. Worse, the carrier’s ordnancemen had no experience with the weapons. They had to consult manuals to learn how to hang the weapons from Skyraider fuselages.

Undaunted, on the following morning of May 1, 1951, five Skyraiders from VA-195 and three (piloted by the aviators who had previously dropped torpedoes) from VC-35 launched from Princeton, escorted by eight F4U Corsairs from VF-192 and four from VF-193. Leading the strike was the CAG (carrier air group commander), Cmdr. Richard C. Merrick, later to be described in The Hook magazine, the journal of the Tailhook Association as “a colorful aviator who went into battle carrying a K-20 camera, a pair of 7×50 binoculars, and a Luger pistol.” Merrick led his Skyraiders on the dam strike  “operating everything but the Luger continuously, all the while puffing on his trusty pipe.” With a naval strike force boring in on a target not far south of China, there was no need for radio silence. Merrick gave instructions in clipped, verbal shorthand.

The torpedo-carrying Skyraiders were led by VA-195 skipper Lt. Cmdr. Harold Gustav “Swede” Carlson.

It was time for many hours of reading about aerial torpedoes to pay off. By burning the midnight oil over every kind of instruction they could locate, Merrick and the others had learned that the torpedoes had a narrow tolerance for error. Dropped too high, they would plunge into the water and sink. Too low and they would skip off the water. The Skyraider had to be at exactly the right speed, a relatively slow 160 miles per hour, with needle and ball centered at a height of about one hundred feet, or the torpedoes wouldn’t work.

Arriving above the river, the Skyraiders broke into two-plane sections, dodged antiaircraft fire, and maneuvered around 4,000-foot peaks to approach the reservoir behind the dam. It was time for many hours of reading about aerial torpedoes to pay off. By burning the midnight oil over every kind of instruction they could locate, Merrick and the others had learned that the torpedoes had a narrow tolerance for error. Dropped too high, they would plunge into the water and sink. Too low and they would skip off the water. The Skyraider had to be at exactly the right speed, a relatively slow 160 miles per hour, with needle and ball centered at a height of about one hundred feet, or the torpedoes wouldn’t work.

 

Skyraiders Torpedo the Hwachon Dam

The Skyraiders launched their attack. The effects were dramatic. Six of the eight Mark 13s struck on or near the floodgates. One floodgate was blown away. The dam was breached and holed on both sides.

The heavy damage wiped out electrical power over a vast area. More importantly, the destruction of the dam broke up a planned enemy offensive. In every way, the damage inflicted by Skyraiders and aerial torpedoes exceeded expectations.

In every way, the damage inflicted by Skyraiders and aerial torpedoes exceeded expectations.

Two weeks later, on a less-publicized mission on May 18, 1951 (and ten days before his 40th birthday), the colorful Merrick was killed in action. He was posthumously awarded the Navy Cross, the second highest award for valor, for the dam-busting mission and one other combat sortie.

The Skyraider continued to fly and fight in Korea and returned for another war in Vietnam, where troops belatedly labeled it the “Spad.”