Acme S-1 Sierra: Torrance's native pusher airplane

As I've long recognized, the Western Museum of Flight in Torrance is ubiquitous for housing a variety of aircraft built in the Los Angeles basin, including those made by Northrop as well as Radioplane (renamed Northrop Ventura in 1962). However, unknown to most aviation enthusiasts, this museum happens to have a very exotic homebuilt airplane on display, built at the very airport in Torrance near which the Western Museum of Flight is located, the Acme S-1 Sierra. Therefore, I am dedicating this post to discussing this unusual homebuilt pusher-engine aircraft from Torrance.

The Acme S-1 Sierra (aka "Sierra Sue") on display at the Western Museum of Flight. Photographed by me on April 21, 2024.

In the late 1940s, two former employees for North American Aviation, Ron Beattie and Walt Fellers, who came to work for the Northrop company after the end of the World War II, proposed a single-seat high-performance aircraft to meet Goodyear Racing Plane specifications and investigate the advantages of an airplane utilizing a pusher propeller layout. This design featured a teardrop-shaped fuselage and a Y-shaped tail empennage with ruddervators on the upper fins, and it had straight wings midway up the fuselage, and large air scoops placed at the forward ends of the wing roots. It was 20 feet 2 in (6.14 meters) long with a wingspan of 18 feet (5.49 meters), an empty weight of 590 lb (268 kg), and a top speed of 200 mph (322 km/h), and power came from one 85 hp (62 kW) Continental O-85 4-cylinder horizontally opposed piston engine situated behind the cockpit and driving a tail-mounted two-bladed pusher propeller. The Acme Aircraft Company based in Torrance, California, was entrusted to build the aircraft, and when this plane was completed in late 1948 it was now called the Acme Sierra, bearing the civil registration N12K (although this aircraft was sometimes nicknamed "Sierra Sue"). The first flight of the Acme Sierra occurred on November 23, 1953, and when Acme Aircraft was renamed Sierradyne Incorporated that year, the Acme Sierra itself received the internal designation S-1.  

The Acme S-1 Sierra at an airfield in Hawthorne in 1967 after being acquired by Northrop for testing the configuration of the N-308 attack aircraft project and rebranded as Northrop Turbo-Pusher (courtesy of Aerofiles).

Although it was not entered in any air races, the S-1 Sierra obtained extensive aerodynamic data during flight testing suggesting some aerodynamic benefits of a pusher-engine aircraft. During the 1960s, it was used by Sierradyne for tests of the aerodynamic benefits of the boundary layer control concept advocated by Swiss-born American aerodynamicist Werner Pfenninger and supported by Northrop. When the US Air Force in the late 1960s began contemplating plans for a purpose-built ground attack aircraft (which led to the A-X requirement), Walt Fellers in 1967 conceived a pusher-engine proposal for Northrop for the A-X program, the N-308, and that same year Northrop acquired the S-1 Sierra for use as a technology demonstrator to test the pusher-engine layout of the N-308, re-labeling it as the Northrop Turbo-Pusher. The S-1 Sierra's final flight ended in mishap on November 24, 1967, when its pilot created so much overload failure by improper operation of the flight controls and/or airbrakes that he crashed-landed the aircraft after a demonstration flight at Langley AFB in Virginia.

By 1970, Northrop dropped the N-308 in favor of the twin-turbofan N-312 and N-320 proposals for the A-X program after the US Air Force judged a turbofan-powered ground attack aircraft to be much faster than its inventory of A-1E Skyraiders compared to a turboprop-powered design, and the N-320 was designated YA-9 after being selected by the Air Force along with the rival Fairchild Republic A-10 for prototyping (the YA-9 itself ended up losing the A-X competition to the A-10 in 1973, but that's another story). Meanwhile, the S-1 Sierra which had ended its flying career as a technology demonstrator for the N-308 was eventually spared from scrapping and found a home at the Western Museum of Flight, which was initially based in Hawthorne before relocating to its present location in Torrance, the very city where the S-1 Sierra was built. 

References:

Chong, T., 2016. Flying Wings & Radical Things: Northrop's Secret Aerospace Projects & Concepts 1939-1994. Forest Lake, MN: Specialty Press.

Underwood, J.W., and Caler, J., 1958. Experimental Light Aircraft and Midget Racers. Fallbrook, CA: Aero Publishers.

Burbank's flying classroom for Canada: The Silver Star

During the near end of my visit to the Planes of Fame Museum in Chino last month, I happened to notice a jet aircraft inside the USS Enterprise Hangar, and the appearance of this airplane was so familiar to me that I wondered if it was a P-80/F-80 Shooting Star jet fighter or the T-33 jet trainer derivative. Oddly, this machine has the vertical stabilizer marked with a civil registration rather than a serial number, so I was curious about its manufacturing and operational history, and after doing online research, it occurred to me that the aircraft with civil registration N133AT was indeed a T-33, albeit a Canadian-built version known by the Canadian military designation CT-133. Given the superfluous operational history of the aircraft which is currently marked N133AT and emblazoned with in US Air Force markings, but also the fact that the T-33 was built under license in Canada, I'm dedicating this post to encapsulating the full history of the T-33 in Canadian service.

A Lockheed T-33A Silver Star Mk. 1 (serial number 14679) at RCAF Chatham in New Brunswick, initially built for the US Air Force with serial number 50-1275.

In the late 1940s the Royal Canadian Air Force was shopping for a jet aircraft able to provide advanced training for its fighter pilots due to the lack of a two-seat trainer version of the F-86 Sabre jet fighter that would be built under license by Canadair and enter service with RCAF fighter squadrons in 1950. After much consideration, the RCAF selected the T-33 to fulfill advanced training needs, and from May 1951 to March 1952, twenty T-33As were obtained second-hand from the US Air Force by the RCAF and assigned the serial numbers 14675/14694, followed by delivery of ten more T-33As were in late 1952 with the serials 516713/516717 and 516743/516747, and these T-33As were dubbed the Silver Star Mk. 1 by the Royal Canadian Air Force. Some of Silver Star Mk. 1 aircraft were later returned to the US Air Force in 1953-1955, but many remained in service with the RCAF until early 1955, when they were retired from service and later transferred to the air forces of Greece and Turkey.

A CT-133 Silver Star Mk. 3 (serial number 21326) in flight 

While the Royal Canadian Air Force began taking deliveries of its first T-33s, in 1951 the homegrown Canadian aircraft company Canadair received a contract to build the T-33 under license, and it assigned the company designation CL-30 to the Canadian version of the T-33, which differed in being powered by a Rolls-Royce Nene 10 turbojet rather than the Allison J33 that powered the T-33. One T-33A (serial number 51-4198) was modified by Lockheed to serve as the prototype for the CL-30, and upon delivery to the Royal Canadian Air Force on November 27, 1951, it was christened the Silver Star Mk. 2 and given the RCAF serial 146595. Lockheed referred to the Silver Star Mk. 2 as the T-33AN-X, and the CL-30 version was known as the T-33AN. On December 22, 1952, the first Canadian-built T-33 made its first flight at Cartierville, Quebec, with test pilot William S. Longhurst at the controls, and deliveries of CL-30/T-33AN to the Royal Canadian Air Force began in 1953 and lasted until 1959, by which time a total of 656 T-33s had been built under license by Canadair. The T-33AN, which became known as the Silver Star Mk. 3, was designated CT-133 by the RCAF, which allocated serial numbers 21001/21656 to the CT-133s. 

The CT-133 had an extremely long service life with the Royal Canadian Air Force. In addition to being the RCAF's premier jet trainer throughout the 1950s and 1960s, it also served with the RCAF's Red Knight aerobatic display team, and CT-133s used by the Red Knight aerobatic team were painted red. The baseline unarmed CT-133 variant was called Silver Star Mk. 3PT, and one variant of the CT-133 was built for gunnery and bombing training, the Silver Star Mk. 3AT, whose armament comprised two .50 caliber Browning machine guns in the nose and underwing pylons for 1,000 lb (454 kg) bombs and HVAR rockets. More than 100 CT-133s were built as Silver Star Mk. 3ATs, and several Mk. 3PTs were converted to Mk. 3AT as well. The Silver Star Mk. 3PR was a photo-reconnaissance variant equipped with photographic reconnaissance equipment in the nose, and one CT-133 (serial number 21257) was built as a Mk. 3PR in 1954, while four existing CT-133s were converted to Mk. 3PR standard in 1963-1964. Other non-training uses of the CT-133 included target towing, threat simulation, and ejection seat testing; the designations ET-133 and TE-133 were allocated to CT-133s optimized for simulating aerial and anti-ship threat simulation respectively, while CT-133s modified as ejection seat testbeds bore the designation CX-133. 

When the newer Canadair CT-114 Tutor jet trainer entered service with the Royal Canadian Air Force in 1963, the RCAF began the phaseout of the CT-133 from training squadrons, and the retirement of the CT-133 from active training duties was completed by 1976. The Red Knight aerobatic team, for its part, replaced its CT-133s with the CT-114 in July 1968 (by which time the RCAF's training units had become the Training Command), although the aerobatic team itself disbanded in 1969 as a result of budget cuts and personnel reductions. Beginning in 1958 and continuing until the 1980s, more than 200 CT-133s were sold to Bolivia, France, Greece, Portugal, and Turkey after being retired from service with the RCAF in the 1950s and 1960s. There were still over 50 CT-133s serving the Canadian Forces well into the 1990s, and nine CT-133s were redesignated CE-133 in 1994 after being modified for electronic warfare training. They were fitted with new avionics as part of the AUP (Avionics Upgrade Program) modernization process from 1996 to 1999, but the majority were eventually phased out in 2002. The Canadian Forces finally retired the CT-133 Silver Star Mk. 3 from service on April 26, 2005, when four remaining examples were phased out by the Aerospace Engineering Test Establishment at CFB Cold Lake, Alberta.

Then and now: CT-133 serial number 21157 on the tarmac at a Royal Canadian Air Force base in Cold Lake, Alberta, 1958 (left); CT-133 serial number 21157 on display at the Planes of Fame Museum with civil registration N133AT, photographed by me on January 21, 2024 (right). 

The CT-133 which I saw at the Planes of Fame Museum last month was given the serial number 21157 when it was delivered to the Royal Canadian Air Force on November 20, 1953, and it also served as a target tug beginning in July 1958. In March 1965, this aircraft was retired from service and eventually sold to numerous civilian owners with the civil registration N155X, which was later changed to the current civil registration N133AT, and it would occasionally be used as a camera ship for several movies. The CT-133 now registered as N133AT was listed for sale on the Internet in April 2006 but it ended up being acquired by aviation enthusiasts for restoration to static display at the Plames of Fame Museum in Chino, California, where it resides to this day.

F-104 Starfighters for Belgium

Much has been written about the operational use of the Lockheed F-104 Starfighter jet fighter with West Germany, Italy, and Japan, bearing in mind the fact that the F-104s operated by the Luftwaffe (the air force of West Germany and ultimately the reunified German nation) were given nicknames like "Flying Coffin" and "Widowmaker" because they suffered a high accident rate. However, almost lost in talk regarding the F-104's operational career with Western and Central European air forces is the service career of the F-104 with the Belgian Air Force.

A Belgian Air Force F-104G Starfighter (serial number FX-82) on outdoor static display at the Planes of Fame Museum, photographed by me on January 21, 2024.

In the late 1950s, the Belgian Air Force was shopping for a new combat jet to replace the subsonic CF-100 Canuck interceptors and F-84F Thunderstreak fighter-bombers in its inventory, especially given that both the Canuck and Thunderstreak were becoming technologically obsolete. With the Luftwaffe as well as the post-World War II Italian air force (Aeronautica Militare) and Royal Netherlands Air Force purchasing the F-104, the Belgian Air Force decided to order the F-104G, and contracts were signed for the purchase of 112 F-104Gs, with twelve TF-104Gs ordered from Lockheed and 100 F-104Gs to be built under license by the homegrown Belgian aircraft manufacturer SABCA. The TF-104Gs were given the serial numbers FC-01/FC-12 while the SABCA-built F-104Gs for bore the serial numbers FX-1 to FX-100; twenty-eight of the F-104Gs ordered by Belgium (three TF-104Gs, 25 F-104Gs) were funded under the Mutual Assistance Program (MAP). Deliveries of the F-104G to the Belgian Air Force began in February 1963, with the F-104Gs and TF-104Gs replacing the F-84F and CF-100 in service with the 23 and 31 squadrons (both of 10 Wing) at Kleine Brogel and the 349 and 350 squadrons (both of 1 Wing) at Beauvechain (Bevekom) respectively. One F-104G ordered by the Belgian Air Force (serial number FX-27) crashed during a training flight at Sart-Dames-Avelines on November 21, 1963 prior to delivery due to a flameout of the turbojet engine, and a new F-104G (c/n 9082) also bearing the serial number FX-27 was built and delivered to replace the crashed aircraft, so a total of 111 F-104Gs and 12 TF-104Gs were built for the Belgian Air Force.

Three Belgian Air Force F-104Gs (serial numbers FX-12, FX-30, FX-82) in flight, 1971. 

Operational use of the F-104G by the Belgian Air Force in its role as an interceptor began in August 1964. Although the 10 Wing and 1 Wing were exclusively tailored to the air defense and tactical nuclear strike roles respectively, the F-104Gs were swapped between the two operational wings to balance airframe fatigue between medium/high-altitude fighter missions and nuclear-armed fighter-bomber missions. In its role as a fighter-bomber for the Belgian Air Force, the F-104G was armed with B61 tactical nuclear free-fall bombs stored at facilities owned by the 52nd Special Ammunition Group at Meeuwen. By 1968, the F-104Gs of the 10 Wing switched to dual air defense/fighter-bomber missions and began training with conventional weapons such as the 20-mm Vulcan rotary cannon, three napalm bombs or two Snakeye bombs or two LAU rocket launcher pods each armed with nineteen 2.75-inch FFAR rockets. Beginning in late 1979, the Belgian Air Force began replacing the F-104G with F-16 Fighting Falcons (the TF-104Gs were phased out in 1980), and the last Belgian Air Force F-104Gs were retired from service on September 26, 1983. Besides the F-104G with serial number FX-27 that crashed in November 1963, a total of 38 F-104Gs and three TF-104Gs were lost in accidents during operational service. In the meantime, 18 Belgian Air Force F-104Gs were transferred to the Turkish Air Force and 23 were given to Taiwan. 

Nuclear-armed stinger from Hawthorne: the Northrop F-89J

In 1955, the Douglas Aircraft Company began full-scale development of a short-range unguided air-to-air rocket to carry a 1.5 kiloton W25 nuclear warhead, the MB-1 Genie, after it became clear that traditional World War II-era US fighter armament would be inadequate to repel a bombing attack by squadrons of the Soviet Union's new gas turbine powered strategic bombers, the Myasishchev M-4, Tupolev Tu-16, and Tupolev Tu-95. The MB-1 Genie obviated the need for precise accuracy when targeting enemy bombers because it was designed with a large nuclear blast radius. Beginning in March 1956, Northrop modified numerous F-89D Scorpion all-weather interceptors from the F-89D-35 to -75 production blocks to carry the MB-1 Genie under Project Bellboy, and the company designation N-160 was allocated to this scheme. The resulting Genie-armed Scorpion, designated F-89J, carried two MB-1 Genies below launching rails that were mounted on the underwing pylons and had the standard wingtip missile pod/tanks replaced with 600 gallon (2,271 liter) fuel tanks, although a few F-89Js retained the wingtip tanks of the F-89D. Later, the F-89J received an extra modification by adding two more underwing pylons inboard of the launching rails for the Genie to carry four Falcon air-to-air missiles tipped with non-nuclear warheads. The F-89J was equipped with the Hughes MG-12 fire-control system (a upgraded and more advanced development of the E-5 fire control system installed on the F-89D), which could allow it to attack enemy bombers at much higher altitudes by making it easier for the crew to launch the Genie rockets while in a nose-up, climbing altitude. During interception of an enemy bomber formation, the MG-12 fire-control radar tracked a target and assigned a Genie to its target, after which the pilot armed the nuclear warhead and fired the Genie at the bomber pack before pulling the interceptor into a tight turn to escape the nuclear detonation and then proceeding to use remote control to allow the Genie's nuclear warhead to explode and destroy enemy bombers.

Left: Two F-89Js (serial numbers 52-1848 and 52-1862) in flight, 1958
Right: An F-89J (serial number 52-1949) at the March Field Air Museum, photographed by me on December 17, 2022.

In November 1956, the US Air Force began taking deliveries of the F-89J, the 84th Fighter Interceptor Squadron based at Hamilton AFB in Novato, California being the first unit to receive the F-89J, and standing active alerts of the F-89J with the Genie started on January 1, 1957. A total of 350 F-89Ds were converted to F-89J standard, with modifications completed by February 1958, and the US Air Force assigned the system code WS-205G (Weapons System 205G) to the F-89J. On July 19, 1957, as part of Operation Plumbbob, the F-89J carried out the first and only live firing of a Genie (codenamed John) when an F-89J with serial number 53-2547 fired an MB-1 Genie over the Yucca Flats Nuclear Test Site in southern Nevada, with the rocket's warhead detonating at an altitude of 15,000 feet (4,500 meters). To prove that the Genie was safe for use over populated areas in the event that Soviet bombers would penetrate US airspace, a group of five Air Force officers volunteered to stand uncovered in their light summer uniforms underneath the blast, and they were apparently spared from the effects of the blast after the live-firing test of the Genie over the Yucca Flats.

Despite proving to the US Air Force that a live-firing of a nuclear-armed unguided air-to-air rocket was feasible, the F-89J was destined to have a brief operational career with the Air Defense Command, and beginning in July 1959 it was replaced in ADC units by the supersonic F-101B Voodoo and F-106 Delta Dart, which also carried the Genie air-to-air rocket. The F-89Js were then transferred to the Air National Guard, operating with ANG until late 1968, when they were retired. In an interesting footnote, in 1963 ten F-89Js were stripped of their nose radars, fitted with additional underwing fuel tanks, and eventually used for testing Nike missile defenses in Japan, being redesignated DF-89J.  

References:

Balzer, G., and Dario, M., 1993. Northrop F-89 Scorpion. Leicester, UK: Aerofax.

Chong, T., 2016. Flying Wings & Radical Things: Northrop's Secret Aerospace Projects & Concepts 1939-1994. Forest Lake, MN: Specialty Press.

Davis, L., and Menard, D., 1990. F-89 Scorpion in Action (Aircraft Number 104). Carrollton, TX: Squadron/Signal Publications.

The miniature bee from San Diego: the Beecraft Wee Bee

Everyone, myself included, has been fascinated with gigantic aircraft from the annals of heavier-than-air powered flight, like the Hughes H-4 Hercules, Antonov An-124 and An-225, Convair B-36 Peacemaker and XC-99, Sikorsky Il'ya Muromets, Tupolev ANT-20, and the Riesenflugzeugen-type bombers built in Germany in World War I. However, very small airplanes have tended to fly under the radar, although many miniature heavier-than-air flying machines existed in the earliest days of homebuilt airplanes, and most people don't know that once upon a time in the late 1940s, the aircraft industry in San Diego built the smallest ultralight plane anywhere in southern California, the Wee Bee. Hence, I am dedicating this post to discussing the oft-neglected story of the smallest aircraft manufactured in San Diego.

 

Convair engineer William "Bill" Chana (1921-2012), who worked on design of the Wee Bee and became one of aircraft's test pilots.

During the late 1940s, the US aviation industry was intoxicated by the nearly-monthly trend of new and improved airplanes appearing in the United States, so in 1947 Convair engineer Kenneth Coward toyed with the notion of a balsa wood airplane having an empty weight of 70 pounds. Despite being the chief designer for his proposed miniature airplane, Coward also enlisted five engineers from Convair, including William "Bill" Chana, Karl Montijo, James Wilder, Tom Bossart, and A.B. Mandeville, to explore the possibility of building an extremely small airplane. Chana himself took a leading role in working out the layout of Coward's proposed aircraft, having built award-winning model planes since he took an interest in aviation at age 6 and studied aeronautical engineering at Purdue University before joining Consolidated Aircraft in June 1941 to become a flight test engineer for a variety of aircraft built by the San Diego division of Consolidated (which became Convair after 1943). Coward, Chana, and other members of the group decided that balsa probably would not be an appropriate building material for use in construction of their proposed aircraft because war-surplus aluminum was available in sufficient quantity and the tooling equipment for fashioning could be readily obtainable. 

The aircraft design by Coward and Chana that soon emerged, dubbed the Wee Bee, was an all-metal monoplane whereby the pilot lay prone atop a girder-like fuselage to allow for a reduction in weight and drag and which had the elevator control beneath the pilot despite being in the same spatial position as in a conventional airplane as well as rudder pedals housed in slots on top of the fuselage. The Wee Bee had a length of 14 feet 2 inches (4.32 meters), a height of 5 feet (1.52 meters), an empty weight of 210 lb (95 kg), and a maximum takeoff weight of 410 lb (186 kg). The Wee Bee's designers formed a new company to undertake manufacture of the aircraft, which was initially called Ken S. Coward & Associates and then was known for a while as Beecraft Aviation Associates before finally changing its name to Bee Aviation Associates, and Bill Chana became president of this new firm.

Left: The Beecraft Wee Bee taking off on its second flight in November 20, 1948.
Right: The Beecraft Wee Bee parked next to the Convair XC-99 prototype heavy-lift transport near the Convair factory, late 1948. The huge size disparity between these two piston-powered planes is evident.

The Wee Bee aircraft was completed in early 1948, eventually receiving the civil registration NX90840. After receiving a few modifications, including replacing the original 15 foot (4.57 meter) wing with a slightly bigger 18 foot (5.49 meter) wing that had a wing area of 44 square feet (4.1 square meters), it began taxi tests at El Cajon's Gillespie Field in August, but the tail skid originally incorporated onto this aircraft carved up with asphalt runways of the airfield, and even though a tail wheel was substituted, it created a ground-looping tendency and the 20 hp (15 kW) Kiekhaefer O-45-1 flat-twin piston engine installed on the Wee Bee did not generate enough power. Therefore, the Wee Bee was fitted with a tricycle landing gear, which not only cured the ground-looping tendency but also allowed the nose to be lifted off the ground at 30 mph (48 km/h). On September 26, 1948, the Wee Bee carried out its first flight with Bill Dana himself at the controls, flying at an altitude of one foot at a distance of less than 100 feet. After a few additional flights by Karl Montijo and William Bouck, which were also hops in ground effect, the Wee Bee was fitted with a more powerful 30 hp (22 kW) O-45-35 engine by a US Navy officer at a hangar in Ream Field at Chana's behest, and on March 12, 1949, Montijo carried out the first "true" flight of the Wee Bee, reaching an altitude of 40 feet (12 meters) and banking to the right in level flight. He  further reduced the weight and drag of the Wee Bee by changing the aircraft's wing incidence to 19 degrees and installed fairings on the wing junctures to the fuselage and engine to fuel tanks while fitting the Wee Bee with a shorter nose gear strut and a new Sensenich propeller. On April 20, 1949, the Wee Bee reached an altitude of 400 feet and flew for 10 minutes on its next flight, and after being fitted with wingtips, it was ferried to the UK via the Queen Mary for a demonstration flight at Gatwick Airport in London. A planned demonstration flight at Belfast, Northern Ireland, was shelved due to bad weather, but the Wee Bee caught the attention of the print media as the smallest plane ever flown when it impressed crowds at the 1949 National Air Races in Cleveland, Ohio, with a flight that lasted seven minutes. Kenneth Coward bolstered his messaging that “the Wee Bee was big enough to lift a man and small enough to be lifted by a man” by wrapping his arm around the airplane and lifting it off the ground. Bill Chana again changed the aircraft's wing incidence again to 12 degrees in order to further enhance performance, and with this modification, the Wee Bee attained a top speed of 82 mph (132 km/h) during a series of flights by Chana himself on March 11, 1950. The thirteenth and last full-fledged flight of the Wee Bee occurred on  April 20, 1950, by which time newsreel companies were utterly impressed by the performance of the Wee Bee.

A replica of the Beecraft Wee Bee on display at the San Diego Air and Space Museum in Balboa Park, San Diego, photographed by me on August 24, 2019.

Even before the last flight of the Wee Bee, Beecraft Aviation Associates proposed a military version of the Wee Bee for the US Air Force, the Military Mite, which would have been armed with six underwing rockets and featured provisions for folding wings to allow for easy ground transportation, while being capable of takeoff and landing from any road. However, the USAF had no interest whatsoever in this proposal. After being retired from flying, the Wee Bee became a static exhibit at US airshows before becoming an exhibit at the San Diego Air and Space Museum in San Diego in 1963. On February 22, 1978, the Wee Bee was destroyed when the original museum building was set on fire by an arsonist, even while plans were underway to move the SDASM and its aircraft collection to the Ford Building in Balboa Park. Despite the loss of the original aircraft, a replica of the Wee Bee was constructed and is now on display at the current home of the San Diego Air and Space Museum in Balboa Park.

Competing designs to the T-45 Goshawk from southern California

The T-45 Goshawk is the most modern advanced jet trainer aircraft in service with the US Navy, jointly built by McDonnell Douglas (which was acquired by Boeing in 1997) and British Aerospace (renamed BAE Systems in 1999) as a derivative of the UK's British Aerospace (Hawker Siddeley) Hawk land-based jet trainer. However, I should emphasize that the T-45 Goshawk did not exist in its own right despite the fact that it owes its heritage to the Hawk jet trainer. During my first visit to the Western Museum of Flight at its current location in Torrance, I happened to notice a wind tunnel of an aircraft on a display stand across from an F-86 Sabre jet fighter, and when I saw a label on the stand identifying the wind tunnel as being of an early 1980s Northrop jet trainer design for the US Navy, I realized than more than one company undertook design studies for a carrier-based advanced jet trainer to replace the Navy's fleet of T-2 Buckeyes. Given that I have in my personal possession a copy of Tony Chong's book Flying Wings & Radical Things: Northrop's Secret Aerospace Projects & Concepts 1939-1994 and thanks to the Secret Projects Forum, it is now possible for me to discuss advanced jet trainer designs from southern California's aircraft industry that competed with T-45 Goshawk.

Top left: Lockheed derivative of the Alpha Jet for the VTX-TS competition
Top right: Artist's impression of the Rockwell International T-2X project
Bottom: Company artwork of the proposed Rockwell International NA-424

In 1978, the US Navy launched VTX-TS requirement for an advanced jet trainer to replace the North American T-2 Buckeye and Douglas TA-4 Skyhawk. In addition to the joint McDonnell Douglas/British Aerospace team, Rockwell International submitted bids for the VTX-TS competition, as did a joint team between Northrop and Vought as well as Lockheed. The Lockheed submission was a navalized derivative of the Dassault/Dornier Alpha Jet jet trainer and light attack aircraft, and it featured nose landing gear modified for nose-tow catapults, a slightly longer nose, reinforced legs of the landing gear, and a stronger arrestor hook. The Lockheed trainer derivative of the Alpha Jet was to be powered by a pair of Teledyne CAE 490 turbofans (a proposed version of the SNECMA Turbomeca Larzac turbofan to be built under license by Teledyne Turbine Engines) on the sides of the fuselage below the wings. In September 1980, a French Air Force Alpha Jet serialled A58) was flown to the US and made a total of 88 demonstration flights at US Navy air bases in Florida, Maryland, Mississippi, and Texas, and 67 Navy pilots carried out those flights. Two Rockwell International designs for the VTX-TS requirement were proposed in 1980, the NA-424 and T-2X. The T-2X was an evolutionary derivative of the T-2 Buckeye which retained the straight wings of the T-2 but differed in having two turbofans with square-shaped air intakes situated in the wing roots, while the NA-424 was to have a new airframe featuring backswept wings, a slightly pointed nose, a dorsal fin protruding from the base of the vertical stabilizer and reaching an area behind the cockpit canopy, and two turbofans on the sides of the fuselage above the wing roots. Two variations of the NA-424 were studied by Rockwell International, one with a low-mounted horizontal stabilizer (in contrast to the T-2 Buckeye's mid-mounted horizontal stabilizer that gave the tail empennage of the Buckeye a cruciform appearance in front view) and another having a T-tail configuration.

Top: A wind tunnel model of the N-351 design at the Western Museum of Flight, photographed by me in June 2016
Bottom left: A three-view drawing of the N-350 from Northrop project documents
Bottom right: An artist's rendering of the N-351 jet trainer preparing for a landing on an aircraft carrier

Now all of this brings my attention to Northrop's bidding for the VTX-TS competition. When the US Navy in 1975 began discussions with aircraft manufacturers about possible replacements for the T-2 Buckeye and TA-4J, Northrop envisaged the N-328 subsonic advanced jet trainer with tandem seating, straight wings, and two turbofan engines (possibly Garrett TFE731s) on the sides of the fuselage and mounted above the wing roots. The N-328 would have been the Navy equivalent of Northrop's N-325 advanced jet trainer proposal for the US Air Force designed in 1974, and Northrop also conceived the N-329 for use by both the Air Force and Navy. The N-328 and N-329 remained design studies only, but in late 1977 Northrop undertook design work on the N-334 project, which was powered by two TFE731 turbofans on the sides of the fuselage above the wing roots and drew its design heritage from the CASA C-101 and AIDC AT-3 jet trainers (single-engine and twin-podded engine configurations were also studied by Northrop for the N-334). The N-334 was submitted to the Navy Air Development Center in early 1978, and following further study under contract from the NADC, Northrop in 1980 submitted the final N-334 design for the VTX-TS requirement. After being selected along with five other companies by the Naval Air Systems Command (NAVAIR) on August 19, 1980, for the next phase of the VTX-TS competition, it teamed up with Chance Vought (which had worked on the V-532B advanced jet trainer project for the US Navy in the late 1970s) to conceive the N-350 advanced jet trainer, for which initial drawings had been devised a few months earlier. The N-350 was 38 feet 8.4 in (11.8 meters) long with a wingspan of 32 feet 4.8 in (9.88 meters), and power was provided by either two 3,500 lb (15.57 kN) thrust Garrett TFE731 turbofans or two 3,300 lb (14.68 kN) thrust Pratt & Whitney JT15D turbofans. By December 1980, the Northrop/Vought team envisaged its final design for the VTX-TS contest under the company designation N-351, which differed from the N-350 in having wings with greater leading edge sweep and a more pointed nose, and which measured 40 feet (12.2 meters) long with a wingspan of 29 feet 7.3 in (9.02 meters).   

The McDonnell Douglas/British Aerospace T-45 Goshawk, which was selected over the NA-424 and N-351 as the winning design for the VTX-TS competition.

On November 19, 1981, the US Navy announced that the proposal by the McDonnell Douglas/British Aerospace for a derivative of the British Aerospace Hawk had been declared the winner of the VTX-TS competition. The winning McDonnell Douglas/British Aerospace design became the T-45 Goshawk and made its first flight on April 16, 1988.

References:

Chong, T., 2016. Flying Wings & Radical Things: Northrop's Secret Aerospace Projects & Concepts 1939-1994. Forest Lake, MN: Specialty Press.

https://www.secretprojects.co.uk/threads/u-s-navy-vtxts-advanced-jet-trainer-proposals.17230/

https://www.secretprojects.co.uk/threads/northrop-vought-vtxts-jet-trainer-projects-and-derivatives.15677/

https://www.secretprojects.co.uk/threads/lockheed-dornier-alpha-jet-vtxts-advanced-trainer-proposal.12926/

https://www.secretprojects.co.uk/threads/north-american-rockwell-vtxts-proposal-t-2x.17233/

Jayhawk's progeny from San Diego: the AQM-81 Firebolt

In the mid-1960s, the US Air Force launched the Sandpiper program to modify some Beechcraft AQM-37 supersonic target drones with hybrid fuel rocket motor system using a solid grain fuel and liquid oxygen because the liquid-fuel rocket motor used to power the AQM-37 used dangerous hypergolic propellants. In 1968-1969, flight tests of the Sandpiper were conducted and they were so successful that the USAF in the early 1970s initiated the HAST (High Altitude Supersonic Target) program, later renamed HAHST (High Altitude High Speed Target), for a production target drone based on the Sandpiper configuration, and the designation XAQM-81A was assigned to the HAST/HAHST program. However, technical difficulties meant that a definite configuration for the HAST/HAHST program was not settled upon until the late 1970s. By this team, the USAF deemed Beech's offer for a full-scale development contract too expensive, and thus called for competitive bids for HAHST development from the aerospace industry. Among the submissions for the HAST/HAHST competition was a proposal from Teledyne Ryan, the Model 305 Firebolt, and in December 1979, the the XAQM-81A development contract was awarded to Teledyne Ryan, with an order placed for nine XAQM-81As.

An AQM-81A Firebolt on display at the March Field Air Museum in Riverside, California, photographed by me on December 17, 2022

The XAQM-81A Firebolt had the same layout and airframe as the AQM-37, particularly the slender delta wings and triangular vertical fins at the wingtips, but it mainly differed in having a single 1,200 lb (5.3 kN) hybrid-fuel rocket motor built by Chemical Systems Division (CSD) of United Technology which used IRFNA (Inhibited Red Fuming Nitric Acid) as the oxidizer for the solid grain fuel. The thrust of the rocket motor could be adjusted in flight to alter speed and altitude to give interceptor pilots a more flexible and realistic target. The air inlet below the fuselage of the Firebolt utilized a ram air turbine that pressurized the IRFNA oxidizer before delivering it to the thrust chamber of the rocket engine, and it also provided electrical power for the drone. The XAQM-81A was 17 feet (5.18 meters) long with a wingspan of 3 feet 4 inches (1.02 meters), a fuselage diameter of 13 inches (33 cm), and a weight of 1,230 lb (560 kg), and it had a top speed of Mach 4.3 and an endurance of five minutes. The F-4 Phantom II served as the launch platform for the AQM-81A, and after being launched from an F-4 at a speed of Mach 1.5, the Firebolt would ignite its rocket rocket to reach an altitude of 103,000 feet (31,400 meters) at speeds exceeding Mach 4. The XAQM-81A Firebolt could fly a pre-programmed course and/or respond to guidance commands from the ground, and it was equipped with a parachute recovery system to enable either a soft landing or a mid-air retrieval by a helicopter, the latter via the Mid-Air Retrieval System (MARS). The US Navy version of the Firebolt, the AQM-81B (erroneously listed in a few sources as "AQM-81N"), had the same mode of launch and performance characteristics as the planned production AQM-81A but differed in incorporating the Navy's AN/USW-3(V) ITCS (Integrated Tracking and Control System), radar augmentation for ground tracking requirements, and  flotation gear for recovery over water.

The XAQM-81A began flight tests on June 13, 1983, at Eglin AFB in Florida. Even before the Firebolt began its flight test program, the number of Firebolt test vehicles had been increased to 21 drones, including six each of the AQM-81A and AQM-81B. In July 1984, test flights of the AQM-81B began at Point Mugu NAS in southern California, by which time the Air Force had began service tests of the Firebolt. Flight tests of the AQM-81 continued until the fall of 1984, by which time more than twenty flights had been conducted. Although the AQM-81 exhibited outstanding performance during its flight test program, it was not ordered into production because the Air Force and Navy realized that the unit cost of the AQM-81 was far more expensive than the simpler AQM-37. 

References:

Munson, K., 1988. Jane's World Unmanned Aircraft. Coulsdon, UK: Jane's Information Group.

Wagner, W., and Sloan, W.P., 1992. Fireflies and other UAVs (Unmanned Aerial Vehicles). Arlington, TX: Aerofax.