Welcome to This Date in Aviation History, getting of you caught up on milestones, important historical events and people in aviation from May 23 through May 25.


(UK Ministry of Defence)

May 23, 1967 – The first flight of the Hawker Siddeley Nimrod. The de Havilland Comet, the world’s first operational jet airliner, had a somewhat checkered history. After entering service in 1952, it was plagued by a series of unexplained hull failures which resulted in fatal crashes, and the airliner was grounded for a time until the cause could be determined and rectified. Once de Havilland discovered that the problem lay in the design of the windows, the Comet was redesigned and had a useful, though somewhat brief, resurgence, only to be overshadowed by the arrival of the swept-wing Boeing 707. But the story of the Comet didn’t end with its retirement from commercial service.

The de Havilland Comet, which formed the basis for the Hawker Siddeley Nimrod. (Clinton Groves)

On June 4, 1964, the British Government issued Air Staff Requirement 381 to find a successor to the piston-powred Avro Shackleton, a four-engine maritime patrol aircraft developed from the Avro Lincoln bomber. Corrosion from salt air and metal fatigue were beginning to take their toll, and the Shackleton was due for retirement. A number of aircraft companies responded to the request, including Lockheed with their turboprop-powered P-3 Orion, the similarly powered Breguet Atlantic, as well as the turbojet-powered Hawkder Siddeley Trident, BAC One-Eleven and Vickers VC-10. But Hawker Siddeley, who had acquired de Havilland in 1960, offered a version of the Comet, which, like the Shackleton, was nearing the end of its service life. British Prime Minister Harold Wilson announced the decision to adopt the maritime patrol version of the Comet, dubbed the HS.801 by de Havilland, and the first two prototypes were converted from Comet 4 airframes that had not yet been completed as airliners.

Advertisement

Hawker Siddeley Nimrod MR2 photographed in 2008 (Tim Felce)

But taking a commercial airliner off the shelf and making a long-range maritime and antisubmarine warfare (ASW) platform took a significant amount of conversion, and the Nimrod ended up looking quite different from its Comet ancestor. The fuselage was enlarged by the addition of a second tube on top, giving it a “double bubble” cross section. The nose was extended to house powerful radars, the tail was modified to hold electronic warfare sensors, and a magnetic anomaly detector (MAD) boom was installed on the tail to detect submerged submarines. The Comet’s Rolls-Royce Avon turbojets were replaced by four Rolls-Royce Spey turbofans which offered better fuel efficiency and longer range. To further extend the Nimrod’s range during particularly long missions, one or two of the engines could be shut down to save fuel. After these conversions were complete, the Nimrod entered production and was introduced into RAF service in October 1969.

The airborne early warning (AEW) variant of the Nimrod, which was not adopted (Mike Freer)

Advertisement

The initial variant, the MR1, was soon developed into two other variants. The R1 was developed into a signals intelligence aircraft whose mission was to intercept communications and other electronic signals. Three Nimrods were converted to this specification and went into service in 1974, replacing older Comet C2s and English Electric Canberras. (The R1 is is slated for replacement by the Boeing RC-135W Rivet Joint.) The MR2 was a significant upgrade to the original R1, with modern avionics and more powerful radars. Following the Falklands War in 1982, the MR2 was updated with aerial refueling capability, as well as the ability to carry AIM-9 Sidewinder missiles for self defense. Nimrods were deployed in support of the Gulf War in 1990, and again during the wars in Iraq and Afghanistan. But, like its Shackleton predecessor, the ravages of age began to catch up to the Nimrod, and work began on a significantly modernized, and essentially all new replacement. But the Nimrod MRA4 suffered from serious delays and cost overruns, and the project was eventually abandoned in 2010. The RAF decided instead to procure the Boeing E-3 Sentry for the signal intelligence mission, and the Boeing P-8 Poseidon for the maritime patrol and ASW missions. In all, a total of 51 Nimrods were built, and they were officially retired in 2011. 


(US Air Force)

Advertisement

May 25, 1953 – The first flight of the North American F-100 Super Sabre. The 1950s was an extraordinary period for fighter aircraft development. The piston engine of WWII gave way to the new turbojet engine, and straight wings transitioned to swept wings that offered higher speeds and less drag. But perhaps more than anything, the 1950s was an era notable for the quest for ever greater speeds. Fighters had already broken the sound barrier in short bursts of speed, but the US Air Force was looking for a fighter that could fly at sustained supersonic speeds. North American had made a solid reputation for itself in WWII with the remarkable P-51 Mustang, and they followed up the success of the Mustang with the swept-wing F-86 Sabre, which proved its mettle in the skies over Korea during the Korean War and found a place in the pantheon of the greatest warplanes. For their next world-beater, North American turned to the F-86 as a basis for the design of an even more powerful fighter.

The North American YF-100, the prototype for the F-100 Super Sabre (US Air Force)

Work on the F-100 began in 1951 with a company-funded aircraft called the Sabre 45, a designation that came from the aircraft’s 45-degree wing sweep (the F-86 employed 35 degrees of sweep). Though much more powerful and more streamlined, the F-100 still shared its predecessor’s nose air intake and single engine, though the Super Sabre used a General Electric J57 engine, which delivered nearly twice the power than the F-86's J47. The Super Sabre also made far more use of titanium in its structure, a metal known for both its lightness and strength. The first prototype Super Sabre reached Mach 1.07 on its first flight, even though it was fitted with a purposefully de-rated engine. Due to delays in production of the Republic F-84F Thunderstreak, the Air Force accepted the Super Sabre immediately in 1953, and delivery to Air Force squadrons began in 1954.

An F-100 gets caught in the “Sabre Dance” and crashes, killing the pilot.

However, the Super Sabre began to show worrying handling characteristics, and a series of crashes caused the fleet to be grounded in November 1954. Flight tests showed that, during roll maneuvers, the F-100 had a nasty inclination to pitch up and down simultaneously, and the highly-swept wings made the Super Sabre susceptible to pitch up at low speeds, something that pilots referred to as the “Sabre dance.” Engineers corrected these problems by enlarging the vertical stabilizer by 27-percent, while also increasing the wingspan by 26 inches. With the control problems solved, deliveries of the Super Sabre restarted and existing aircraft were returned to flying status. But even as the redesigned F-100A began returning to duty, the Air Force began phasing the “Hun” out of service, and it was officially removed from active service by 1961. But that wasn’t the end of the Super Sabre. With Cold War tensions rising in Eastern Europe, the F-100 returned to active duty while North American worked to develop a fighter-bomber version, which became the F-100C. This variant had a still more powerful engine and was developed for nuclear toss bombing.

Advertisement

A US Air Force F-100D Super Sabre launches rockets against ground targets in Vietnam (US Air Force)

But it was the F-100D that served in the greatest numbers and with the greatest effect. The Super Sabre went to war in Vietnam in 1961 and served for 10 years, becoming the longest serving fighter bomber of the conflict. At the end of the war, Huns had fired over four million rounds of 20mm ammunition, dropped 30 million pounds of bombs and delivered over 10 million pounds of napalm. Two-seat F-100F Super Sabres served as forward air controllers, flew reconnaissance missions, and carried out search and rescue missions. In a testament to its incredible speed, the Super Sabre set numerous speed records and won the Bendix Trophy in 1955. It was also the first jet fighter to fly over the North Pole, and was flown by the USAF Thunderbirds from 1956 to 1968. Just under 2,300 Super Sabres were produced, and it was retired from frontline service in 1979, though it continued serving with Air National Guard units until 1988.

An F-100D Super Sabre of the US Air Force Thunderbirds flight demonstration team. (US Air Force)

Advertisement


Short Takeoff


(Author unknown)

Advertisement

May 23, 1915 – The first flight of the Fokker Eindecker, the first in a series of monoplane (eindecker) fighters designed by Dutch aeronautic engineer Anthony Fokker and flown by the German Air Service in WWI. The Eindecker was based on the Fokker M.5, an earlier monoplane scout designed by Fokker that first flew in 1913 and was itself influenced by the Morane-Saulnier H monoplane. The major advance of the Eindecker was Fokker’s development of a synchronizing gear, also called an interrupter, that allowed the machine gun to be fired through the arc of the propeller and gave pilots significantly improved aim during dogfights. German pilots such as aces Max Immelmann and Oswald Boelcke enjoyed a significant advantage over Allied aircraft that were not similarly equipped, allowing the Germans to hold a measure of air superiority for the second half of 1915 until the Allies developed their own interrupter. 


(Lilienthal Museum; Library of Congress)

Advertisement

May 23, 1848 – The birth of Otto Lillienthal, an early and influential pioneer of manned flight who was known as the Glider King for his experiments with, and development of, unpowered glider flight. Lillienthal worked closely with his brother Gustav and made over 2,000 flights beginning in 1891, some of which covered distances of over 800 feet. While all those flights only accounted for five hours of actual flying, Lillienthal’s influence on the history of aviation far outstripped his hours in the air, and the notoriety he garnered not only popularized the idea of future powered flight, but also influenced the early work of the Wright Brothers and other aviation pioneers. Lillenthal was killed on August 10, 1896 in the crash of one of his gliders when he entered an unrecoverable stall at an altitude of about 50 feet and suffered a broken neck in the subsequent crash.


Advertisement

May 24, 1967 – The first flight of the Aero Spacelines Mini Guppy, an oversized cargo aircraft developed from the Boeing C-97 Stratofreighter. Two Mini Guppies were built using parts salvaged from the Stratofreighter, along with parts from the Boeing 377 Stratocruiser airliner. While the Mini Guppy retained the wings, engine and lower fuselage of the C-97/377, the upper fuselage was significantly enlarged by the addition of a second, oversized fuselage section, and the aircraft was loaded through a hinged tail section. The first Mini Guppy was retired in 1995, while the second was given upgraded Allison 501 turboprop engines and renamed the Mini Guppy Turbine. However, that aircraft was lost in a crash in 1970.


The Storch flown to rescue Benito Mussolini (Deutsches Bundesarchiv)

Advertisement

May 24, 1936 – The first flight of The Fieseler Storch Fi 156, a small aircraft developed for the German Aviation Ministry (Reichsluftfahrtministerium) for liaison, forward air control and medevac duties. The Storch was selected over the other contenders because of its outstanding short takeoff and landing (STOL) characteristics and other design elements such as folding wings that made the Storch easy to tow or transport, and long landing gear with shock absorbers for operations from crude runways. The Storch gained fame for its role in the rescue of ousted Italian Prime Minister Benito Mussolini from the rocky mountaintop ski resort of San Grasso in Operation Eiche (Oak) in 1943. Mussolini had been arrested and held at the mountaintop hotel, but was rescued by German gliderborne paratroops and flown off the rock-strewn mountaintop by a Storch, the only aircraft capable of operating from the site.


(Michael Laughlin)

Advertisement

May 25, 1979 – The crash of American Airlines Flight 191, a regularly scheduled flight from Chicago’s O’Hare International Airport to Los Angeles International Airport. The wide body airliner crashed during takeoff when the left engine of the McDonnell Douglas DC-10-10 (N110AA) separated from the wing, severing hydraulic lines, damaging the left wing’s leading edge, and causing an uncommanded retraction of the leading edge slats. As the aircraft continued to takeoff, the unbalanced configuration of the wing slats caused the left wing to stall while the right wing was still providing lift, and the aircraft rolled to the left until partially inverted before crashing in a nearby field. The crash killed all 271 passengers and crew as well as two people on the ground. It remains the deadliest aviation accident on US soil. The engine separation was found to have been caused by faulty maintenance practices performed by American Airlines, and not a design defect. As a result, American Airlines was fined $500,000 for improper maintenance procedures.


(US Air Force)

Advertisement

May 25, 1976 – The first flight of the Boeing E-3 Sentry, an airborne early warning and control (AEWC) aircraft more commonly known as AWACS that was developed to replace the Lockheed EC-121 Warning Star. The E-3 was derived from the civilian Boeing 707 airliner and uses its dorsal radome and other sensors to monitor the battlefield and the airspace around it. The Sentry then provides enhanced situational awareness to battlefield commanders, and helps control air and ground forces necessary for interdiction, reconnaissance, airlift and close air support. The E-3 entered service with the US Air Force in 1977, and has since been adopted by NATO, the Royal Air Force and Saudi Arabia. Produced from 1977-1992, a total of 68 have been built and it remains operational.


(NASA)

Advertisement

May 25, 1973 – The launch of Skylab 2, the first of three manned missions to Skylab, the United States’ first orbital space station. Skylab was launched on May 14, 1973 (Skylab 1) and remained in orbit for six years. Skylab 2 astronauts Joseph Kerwin, Pete Conrad and Paul Weitz were launched into orbit atop a Saturn IB rocket and docked with the station on May 26. They remained onboard the station for 28 days and set a new record for spaceflight duration. The crew also set records for the greatest distance traveled and the greatest mass docked in space. A primary objective of the mission was to repair a jammed solar array on the station and to cover the station with a solar blanket that took the place of a heat shield damaged during launch. In addition to other repairs, the crew also carried out 392 hours of experiments. The Skylab 2 Command Module returned to Earth on June 22, 1973 and was recovered by the USS Ticonderoga (CV-14) near San Diego.


(US Navy)

Advertisement

May 25, 1968 – The first flight of the Northrop Grumman EA-6B Prowler. Following the success of the two-man Grumman EA-6A “Electric Intruder” electronic warfare aircraft in Vietnam, Grumman stretched the aircraft’s fuselage to add a second row of seating for electronics warfare officers, added an antenna fairing to the vertical stabilizer, and placed more powerful radars in the nose to produce the EA-6B. Introduced in 1971, Prowlers replaced the Douglas EKA-3B Skywarrior and flew 720 sorties in support of US Navy bombers and USAF Boeing B-52 Stratofortresses in Vietnam. The Prowler also served in Grenada, Afghanistan, Iraq and Syria and, though it was recently retired from Navy service and replaced by the newer Boeing EA-18G Growler, the Prowler remains in limited US Marine Corps service, and took part in bombings missions against the Syrian government in April 2018.


(US Air Force)

Advertisement

May 25, 1939 – The first flight of the Henschel 129, a twin-engine ground attack flown by the Luftwaffe during WWII. Based on experience of the German Condor Legion in the Spanish Civil War, the Luftwaffe learned the importance of ground attack aircraft, and the 129 was developed to provide heavy fire against lightly defended targets such as convoys or troop concentrations. Because of its role as a ground attack aircraft, the pilot sat inside a tub of steel sheeting and was protected by armored glass, and the engines were also protected by armor. The 129 was powered by a pair of Gnome-Rhône radial engines because more powerful inline engines were in high demand elsewhere. Thus, the 129 was always underpowered and, when the two machine guns and two canons were replaced with a single 75mm antitank gun, the aircraft was virtually unflyable. Nevertheless, a total of 865 were produced from 1940-1944, and the 129 fought effectively in the early years of the war in North Africa and the Eastern Front.


(Author unknown)

Advertisement

May 25, 1937 – The first flight of the Gasuden Koken, a long-range research aircraft developed by the Tokyo Gas and Electric Industry (Gasuden) in an effort to break the world record for the longest closed circuit flight (taking off and landing from the same point). The plane was powered by a single Kawasaki V-12 engine that provided a top speed of 155 mph and had a wingspan of over 91 feet. The fuselage was constructed of metal, but the outer wings and control surfaces were covered in fabric. Following two unsuccessful attempts at the record, the Gasuden Koken took off from Kisarazu, Chiba on May 13, 1938 and made 29 laps of a 249-mile circuit. It landed two-and-a-half days later, having flown 7,239 miles, the only record ever set by Japan that was recognized by the Fédération Aéronautique Internationale. The record was broken just one year later by an Italian Savoia-Marchetti SM.82 which flew 8,038 mi. 


Advertisement

May 25, 1937 – The first flight of the Sikorsky S-38, a twin-engined amphibious sesquiplane (a biplane in which one wing is significantly smaller than the other) that could accommodate eight passengers and was Igor Sikorsky’s first widely-produced flying boat. Developed from the S-34 and S-36, both amphibious sesquiplanes that were built in very small numbers, the S-38 flew for Pan American Airways, the US Army, where it was known as the C-6, and the US Navy, where it was known as the PS-3. The S-38 was also popular with civilian pilots, and was popular with safari companies in Africa. Sikorsky built a total of 101 S-38s.


(National Air and Space Museum; US Coast Guard; US Navy)

Advertisement

May 25, 1889 – The birth of Igor Sikorsky. Russian-born Igor Sikorsky is best known for the development of one of the first successful helicopters, but he started his career as a designer of fixed-wing aircraft. Before emigrating to the United States in 1919, Sikorsky designed and flew the Russky Vityaz, the world’s first multi-engine fixed-wing aircraft, and the Ilya Muromets, the world’s first large airliner. After coming to the US, Sikorsky founded the Sikorsky Aircraft Corporation in 1923 and produced the S-42 flying boat for Pan American Airways. But it was in rotary-winged aircraft that Sikorsky made his greatest mark on aviation history, first with the VS-300 in 1939, the first helicopter to use a single engine to power both main and tail rotors, and the R-4, the world’s first production helicopter, in 1942.


Connecting Flights


Advertisement


If you enjoy these Aviation History posts, please let me know in the comments. And if you missed any of the past articles, you can find them all at Planelopnik History. You can also find more stories about aviation, aviators and airplane oddities at Wingspan.

Advertisement