Written by Matthew Copes
Douglas F3D Skyknights were twin-engined, all-weather, carrier-based night fighters that were introduced in the early ‘50s.
But though they saw relatively limited service with the US Navy and Marine Corps, they weren’t generally well-liked by service brass, ground crews or the men who flew them.
Hence, they were most commonly referred to by unflattering names like Willie the Whale and DRUT, the latter of which is “turd” spelled backwards.
Known for their outdated straight wings, lackluster performance and unaesthetic silhouettes, Skyknights were never produced in large numbers, but they served with distinction in limited roles in both Korea and Vietnam.
While they’re nearly forgotten these days compared to other iconic aircraft of the ‘50s and ‘60s, Skynights did shoot down a handful of enemy aircraft over Korea, but they were generally restricted to flying at night when their unremarkable performance wasn’t such a big factor.
There’s no denying that Skyknights weren’t as flashy as many aircraft of the day, but they made up for their deficiencies with powerful radars, cannons and revolutionary Sparrow radar-guided missiles.
To be fair, Skyknights were never meant to be sleek air superiority fighters, so whether the “turd” designation fits is definitely open to debate.
Instead, from the outset they were designed to be standoff night fighters that relied on cutting technology as opposed to performance and agility.
To these ends, Skyknights were crewed by a pilot and a navigator-radar operator, the latter of whom performed tasks that would otherwise have been too tedious and time consuming for pilots to manage themselves.
The concept was conceived at the end of World War II when the Navy issued an RFP for a carrier-based night fighter capable of exceeding 500 mph (805km/h) in level flight, climbing past 40,000 feet (12,200 m), and utilizing powerful radars, fire control systems and missiles to detect and engage enemy aircraft from dozens of miles away.
Led by Douglas’ chief designer Ed Heinemann, the El Segundo, California-based team put together a preliminary design characterized by straight mid-set wings, a deep and exceptionally wide fuselage, and two engines slung low on the fuselage, the nacelles of which actually protruded below the bottom of the aircraft itself.
There’s an old saying in aviation that if a plane looks right it’ll fly right.
The Skyknight didn’t look particularly impressive, but nonetheless it beat out a number of other proposals from competing manufacturers, and a production contract was issued in early April of 1946.
However the Navy wasn’t convinced that it had a winner on its hands, and to hedge its bets the Bureau of Aeronautics also contracted Grumman to build two G-75 prototypes in case Skyknights didn’t make the grade.
Grumman’s initial prototype first took to the air in late March of 1948, and over the next few years two more were produced.
Nearly all of the flight testing was conducted from Muroc Air Force Base (now Edwards Air Force Base) about 100 miles north of El Segundo amidst vast expanses of mountains and desert.
These aircraft were equipped with slightly less powerful engines than the ones that would be fitted into later production models, and when trials were successfully concluded in the summer of 1948 Douglas was awarded another production contract for more than two dozen F3D-1s, the first of which would fly in mid-February of 1950.
Design & Specifications
45 ½ feet (13.8 m) long from nose to tail, exactly 50 feet (15.2 m) from wingtip to wingtip, and with maximum takeoff weights approaching 27,000 pounds (12,250 kg), Skyknights were significantly larger than the F-86 Sabres alongside which they flew in Korea.
Unlike Sabres however, Skyknights had straight wings that created more drag and lift, the latter of which was necessary to get them off carrier decks when fully loaded for battle.
But though their wings limited performance, they made Skynights remarkably stable gun platforms, and with low stall speeds of just 92 miles per hour (149 km/h) they were much easier to land on carrier decks than many Navy aircraft of the day.
Internal fuel capacity was nearly 1,350 US gallons, and one 150 US gallon drop tank could be added under each wing.
Depending on mission parameters, weapons, electronics and fuel loads, combat range was generally between 1,150 and 1,400 miles (1,840 and 2,250 km).
Power initially came from two Westinghouse J34 turbojets, each of which produced about 3,400 pounds of thrust, though later variants got upgraded engines with significantly more muscle.
Despite their heft and relatively un-aerodynamic airframes, Skyknights were capable of hitting 530 miles per hour (850 km/h), though they typically cruised at about 425 miles per hour (685 km/h) to conserve fuel.
In many respects Skynights were built around the powerful Westinghouse radars housed in their noses, because without them F3Ds wouldn’t have been able to carry out the missions for which they’d been built.
When Westinghouse’s AN/APQ-36 radar and fire control systems entered service they were exceptionally powerful, albeit bulky and heavy.
The various systems worked in conjunction with one another, each performing a distinct acquisition, tracking or targeting function on which the others relied.
Though expensive, complex, and maintenance intensive, the vacuum tube-based system was surprisingly efficient when its components were working properly, and when they were, enemy aircraft could be detected from ranges exceeding 20 miles (32 km).
Armament included four 20 mm Hispano cannons located in recesses in the lower fuselage, each of which had 200 rounds of ammunition.
Depending on mission and variant, Skyknights were also capable of carrying unguided rockets, up to 4,000 pounds (1,820 kg) of bombs or four Sparrow air-to-air missiles.
Since DRUTS were originally intended as Navy aircraft, it came as a huge disappointment when the first F3D-1 variant failed to qualify for carrier operations.
Early deficiencies were overcome in the following F3D-2 and the planes were eventually cleared for carrier use, but overall the Navy wasn’t particularly impressed with the new machines, hence, they kicked many of them down to the Marine Corps.
For starters, Skyknight’s downward pointing exhaust nozzles often charred the wooden deck planks that are standard on American carriers, and their low-slung engines were notorious for sucking in foreign debris which sometimes caused turbine blade and compressor damage.
Likewise, pilots weren’t thrilled with the fact that their aircraft weren’t equipped with traditional ejection seats.
These had been omitted early in the design process to reduce weight, and instead Skyknights were equipped with downward sloping “escape tunnels,” thankfully through which no pilot or radar operator ever had to squeeze during an emergency situation.
This lack of potentially life saving equipment was particularly stressing to naval aviators, because many mishaps occurred during carrier takeoffs and landings.
That said, relatively low power-to-weight ratios and short landing gear components were also persistent issues, the latter of which caused some early variants to bottom out on particularly hard carrier landings.
DRUTS Over Korea
Though primarily designed as carrier-based naval aircraft, most of the Skyknights that saw service in Korea were ground-based variants employed by the Marine Corps beginning in September of 1952.
Heavy bombers aren’t generally associated with the Korean War like they are with World War II, but B-29 Superfortresses like the ones that dropped atomic bombs on Hiroshima and Nagasaki flew thousands of sortes over the peninsula, collectively dumping more than 150,000 tons of ordinance on communist targets.
In the early going some missions were flown unescorted, but despite their abundant defensive firepower the big bombers were always vulnerable to enemy fighters, and the Air Force relied on the Marine Corps to provide the necessary protection.
Known as the “Flying Nightmares,” more than two dozen Marine F3D-2s fulfilled this role with distinction, scoring their first air-to-air victory on the night of November 2, 1952 when pilot Major William Stratton Jr. shot down what he claimed was a Yak-15 that had been dispatched to intercept the B-29s.
Though his superiors and fellow airmen doubted whether the aircraft he’d downed was actually an obsolete Yak-15, the event marked the first encounter in which radar was used to locate and engage an enemy at night.
Then on the night of November 8th northwest of Pyongyan, Captain O.R. Davis became the first Skyknight pilot to down a MiG-15, and in mid-December Lt. Joseph Corvi made history by being the first pilot to track, lock onto and kill an adversary out past visual range using radar and missiles.
Granted the missile destroyed a ‘30s-era Polikarpov Po-2 biplane with a top speed of… wait for it – 92 mph (152 km/h), but still, the kill was an impressive feat.
By the end of the war Skyknights had claimed six air-to-air kills with just one loss, but perhaps more importantly, these engagements highlighted glaring differences between US and Soviet Union.
While Skyknights were subsonic aircraft, their state-of-the-art radar and fire control systems allowed them to track and engage their enemies from great distances without help from the ground.
By contrast, though MiG-15s were superior dogfighters, they weren’t equipped with radar, which meant that they had to be guided to their targets by ground-based radar operators.
It has also been theorized that this mirrored another major difference between the two air forces.
While the Americans wanted their pilots to think on their feet and adapt to evolving situations as they best saw fit, the Soviets preferred their airmen to leave the thinking up to their superiors back at base.
Either way, though Skyknights were essentially one-trick ponies, they were perfect platforms from which to test various emerging technologies, namely the missiles that were poised to revolutionize aerial combat.
Whereas Skyknights served in direct combat roles like night fighting and bomber escort in Korea, later variants were almost exclusively dedicated electronics warfare platforms in Vietnam, and in this respect they were predecessors to more well-known EA-6B Prowlers.
In fact Skyknights were the only Korean War-era jets that served in Vietnam, and US Marine Corps Squadrons began operating the newly designated EF-10B aircraft out of Da Nang in mid-April of 1965.
According to official statistics there were never more than a dozen in Vietnam at any given time, but despite small numbers they were invaluable due to their ability to “jam” the guidance systems on Soviet built surface-to-air (SAM) missiles that were becoming increasingly lethal threats.
Known as “Fogbound” missions, the first instance of an aircraft jamming a ground-based missile battery occurred in late April of 1965.
Flying alongside or ahead of bombers and ground-attack aircraft, EF-10Bs either electronically neutralized the SAMs or dropped chaf, after which the attack aircraft could engage their targets “only” having to worry about AAA fire.
The first EF-10B was lost to a Soviet SA-2 in mid-March of 1966, and by the end of the year the missions once flown by Skyknights were gradually assumed by newer and more advanced Prowlers.
Skyknights remained in service as backups, though by late 1969 they flew infrequently, and then only in relatively low-threat situations over the South.
All told four EF-10s were lost to enemy action in Vietnam, and the Navy officially retired them in May of 1970, though after the war the Army continued to use some well into the ‘80s as missile and avionics testing platforms based out of the White Sands Missile Range in New Mexico.
Over the life of the aircraft Skynights were produced in more than a dozen variants, many of which were nearly indistinguishable from the aircraft that’d come before them.
As is usually the case, after the first batch of aircraft were ordered, built and delivered, successive variants benefited from everything from more powerful engines and heartier landing gears, to more effective radars and better fire control systems.
The less-than-popular Skyknights may have gotten a new lease on life in the late ‘50s however, when a swept wing variant was proposed with even more powerful Westinghouse J46 engines.
However the project was scrapped not due to the new aircraft’s proposed design, but because engine development was plagued by largely unresolvable issues.
In the end some Skyknights became trainers for various National Guard units, though designer Ed Heinemann wasn’t about to let his beloved subsonic warbirds die slow deaths, at least without a fight.
In fact he suggested that the remaining aircraft shouldn’t be scrapped for their metal value or shipped off to second-rate museums, but should instead be converted into executive jets.
However, one need only to take a close look at a Skyknight to realize that this was a relatively laughable idea, especially when compared to other corporate jets of the time like Lockheed’s JetStar.
Go ahead, take a look.
Which would you choose?
Twilight of the Skyknight
Like many more successful and well-known aircraft, Skyknights went out with a whimper instead of a bang.
Perhaps it was because they were subsonic or lacked ejection seats, burned one too many carrier decks, or because they were just plain ugly.
Whatever the case, by the early ‘70s there were just three left, and with parts becoming scarce two were cannibalized to keep the other operational.
Ultimately, the sole survivor was given a last-minute stay, when in 1988 the General Services Administration transferred ownership to the Combat Air Museum near Topeka, Kansas.
After the paperwork was wrapped up nearly two years later, museum volunteers made the trek from Kansas to New Mexico to pick up their new airplane.
Before transporting it however, the wings had to be sawed off since Skyknights weren’t built with easily removable modular components.
Now the lovingly restored Skyknight adorned with distinct Korean War markings has found a permanent home, as the last remaining example of a once semi-proud line of subsonic night fighter and SAM jammers.