Gliders from San Diego: the story of the Bowlus Sailplanes Company

The aircraft manufacturers Convair (originally Consolidated, later Consolidated Vultee) and Ryan come to the average aviation historian's mind when it comes to discussing and recording the history of aircraft development in San Diego in the 20th century, no surprise because the Rosie the Riveter mascot originated at the main Convair plant in San Diego and the aircraft used by Charles Lindbergh for his history-making solo transatlantic flight in 1927 was built by Ryan. During a recent visit to the San Diego Air and Space Museum, I happened to learn that San Diego also boasted a glider manufacturer, the Bowlus Sailplanes Company, after learning that one of the aircraft on display there, the Bowlus SP-1 Paperwing (represented at the museum by a replica), was manufactured in San Diego. Since Bowlus Sailplanes deserves the honor of being the first glider manufacturer from California yet is seldom discussed in most published accounts of the San Diego aircraft industry, I am dedicating this post to the history of Bowlus Sailplanes and its aircraft products.

William Hawley Bowlus (1896-1967), founder of the Bowlus Sailplanes Company

The founder of the Bowlus Sailplanes Company, William Hawley Bowlus, was born on May 8, 1896, in the Ohio Township in Bureau County, Illinois. As a teenager, he began his foray into aviation by building homemade gliders, flying them from the hillsides of San Fernando Valley. In 1917, Bowlus joined the US Army Air Service and learned to fly powered aircraft along with T. Claude Ryan (the founder of the Ryan Aeronautical Corporation) after enrolling in the American School of Aviation in Venice, California. When Ryan went to Oregon State College to study engineering after the end of World War I, Bowlus himself quit the USAAS, eventually re-associating with Ryan but also B.F. Mahoney at the new Ryan Aeronautical Company in 1924. As a member of the Ryan company in the 1920s, he was instrumental in design and construction of the Ryan M-1 and M-2 mailplanes for Ryan Airlines, while helping with construction of the NYP (Spirit of St. Louis) used by Charles Lindbergh to fly across the Atlantic Ocean solo in 1927. 

Left: The Bowlus SP-1 sailplane being towed for launch, January 1930.
Right: A replica of the Bowlus SP-1 on display at the San Diego Air and Space Museum.

Buoyed by the success of the Spirit of St. Louis, in 1928 Bowlus undertook design of his sixteenth glider, the SP-1, which had a shoulder-mounted wing and an open cockpit. Construction of the SP-1 was completed in January 1929, and when the aircraft flew for the first time that month, it became the first indigenous American sailplane to fly. The SP-1 had a wingspan of 44 feet (13 meters), an aspect ratio of 11:1, and a wing area of 179 square feet (16.6 m²), and it had an empty weight of 180 lb (81 kg), a gross weight of 305 lb (138 kg), a cruise speed of 22 miles per hour (35 km/h), and a glide ratio of 20:1. Although the SP-1 was largely made from wood and doped fabric, the ring webs of the wings, elevator, and rudder had to be fabricated from craft paper to make the SP-1 as light as possible, hence the aircraft's nickname "Paperwing". William Bowlus piloted the SP-1 in several regional glider meets in southern California, including two at Pacific Beach and one at Redondo Beach, and on October 5, 1929, the SP-1 set a new soaring endurance record when it flew over the cliffs at Point Loma, for 14 minutes and ten seconds. Fourteen days later, on October 19, it became the first American sailplane to attain an endurance of more than one hour when it flew for 1 hour and 21 minutes. Bowlus established the Bowlus Glider School in San Diego to train glider pilots to fly the SP-1, and in 1930, the Bowlus Sailplanes Company  was established. Although just one SP-1 was built, it served as a technology demonstrator for a series of Bowlus glider designs built in the 1930s, including the SP-D, Model A, and S-1000, which differed from the SP-1 in completely utilizing wood and fabric in their construction. The SP-D, Model A, and S-1000 gliders had a wingspan of 60 feet (18.3 meters) and were used by Charles Lindbergh himself and his wife Anne Morrow when obtaining glider licenses in 1930. Of interesting note is the fact that the design philosophy of the SP-1, SP-D, Model A, and S-1000 influenced that of some gliders, particularly the Silver King designed by Harland Ross and the Nighthawk sailplane used by William A. Cocke to set an air endurance record of 21 hours 34 minutes in 1931. The original SP-1 no longer exists, but a replica of this sailplane was built from scratch in the late 1980s and is now on display at the San Diego Air and Space Museum. The S-1000 derived from the SP-1 is displayed at the Wings of History Museum in San Martin, California, and the Nighthawk sailplane was originally placed on display at the Santa Monica Museum of Flying before being moved to the Los Angeles County Museum of Natural History.

A Bowlus BA-100 Baby Albatross in flight, late 1930s.

Elated by the success of its initial glider designs, the Bowlus company built the first American high-performance sailplane, the 1-S-2100 Senior Albatross, which was based on the Super Sailplane with a shoulder-mounted gull wing that was designed by William Bowlus and German glider engineer Martin Schempp and built and flown in Glendale by the Curtiss-Wright Technical Institute in 1932. The wings of the Bowlus 1-S-2100 spanned 61 feet 9 inches (18.82 meters) and had a wing area of 204.75 square feet (19 m²) and aspect ratio of 18.72:1, and the 1-S-2100 itself had an empty weight of 340 lb (154 kg) and a gross weight of 520 lb (236 kg). The Senior Albatross was first flown in 1933, with six 1-S-2100 Senior Albatross sailplanes built, and during the 1930s the Senior Albatross set a number of records for altitude. In the meantime, the Bowlus Sailplanes Company started development of a cheap strut-braced glider design, the Baby Albatross, which had a shoulder-mounted wing like that of the SP-1 and an open cockpit. The wings and horizontal stabilizers of the Baby Albatross were made from wood and covered with fabric, while the tail boom was of all-metal construction and the open cockpit was made of plywood. The baseline version, the single-seat BA-100, first flew in 1937 and a total of 156 Baby Albatross kits were manufactured, with certification occurring in 1938. A two-seat variant of the Baby Albatross, the BA-102, had a slightly longer rear fuselage with two small portal-type windows and with accommodations for a passengers, and three aircraft were built, the first being completed and first flown in 1938. The aerodynamic liability of the Baby Albatross lay in its poor pitch handling characteristics,  the rotation axis of the horizontal tail being located at 35% chord, the horizontal tail rotation hinge having high friction, and the relatively soft pitch axis cable control system storing elastic energy reacting the friction in the tail hinge. With input from aeronautical engineer Irv Culver, the Baby Albatross designed was modified to have the hinge axis moved forward and the pitch control fitted with a downspring. The BS-100 Super Albatross was a mid-wing single-seat glider that combined the fuselage pod and tail boom of the Baby Albatross with the outer wing panels of the Senior Albatross, and like the BA-100, it was of mixed construction, the wings and horizontal stabilizers being made of wood and covered with fabric, and the tail boom being made from metal. The Super Albatros first flew in 1938 but only two examples were manufactured, the first with a mobile horizontal stabilizer and second aircraft with a fixed horizontal stabilizer and flaps.

Left: The XCG-7 prototype (serial number 41-29621) being towed in flight, October 1942.
Right: The sole XCG-8 prototype (serial number 41-29622) at Rogers Dry Lake in the Mojave Desert, 1943. 

Months before the Japanese attack on Pearl Harbor, on April 29, 1941, Bowlus Sailplanes submitted designs for 8- and 15-seat transport gliders in response to a requirement issued in March by the US Army Air Corps (renamed US Army Air Force on June 20) for large gliders capable for carrying troops and war material to the battlefield in anticipation of the moment when the US would enter World War II to help push back against Axis aggression in Europe. The eight-seat design, designated XCG-7, was 53  feet 4 inches (16.26 meters) long with a wingspan of 65 feet (19.81 meters), a wing area of 700 square feet (65 m²), an empty weight of 2,870 lb (1,301 kg), and a gross weight of 4,800 lb (2,177 kg), and could cruise at 120 miles per hour (190 km/h) when towed by a transport plane. The 15-seat design, the XCG-8, was a scaled-up XCG-7 measuring 61 feet (18.6 meters) long with a wingspan of 85 feet 8 inches (26.04 meters), a wing area of 996 square feet (92.5 m²), an empty weight of 3,895 lb (1,767 kg), a gross weight of 6.800 lb (3,084 kg), and a speed of 120 miles per hour (190 km/h) when towed. Both designs featured a podded cabin with a boom aft fuselage and a cruciform tail empennage, and they were primarily made from spruce and birch, while the cantilever wing surfaces had plywood ahead of the spar and fabric behind it, and the fuselage and stabilizers were wrapped in plywood, whereas the movable surfaces used fabric. In late July 1941, one XCG-7 prototype (serial number 41-29621) and one XCG-8 prototype (serial number 41-29622) were ordered along with static test airframes for both designs and a wind tunnel model of the XCG-7. Due to its existing factory being too small for both the XCG-7 and XCG-8 to be manufactured, Bowlus Sailplanes outsourced construction of these gliders to Douglas, which completed the XCG-7 and XCG-8 prototypes at its facility in El Segundo in early 1942. The static test XCG-7 airframe was delivered to Wright Field on February 11, 1942, for loading tests, but it suffered structural failures and repairs to the airframe meant that static tests did not resume until June 16, yet the static test article failed at 40 percent of simulated loadings. Meanwhile, the sole XCG-7 prototype began flight tests on July 15-16, 1942, displaying good handling characteristics and staying aloft in a thermal, and after completing flight tests at Muroc Army Air Base (now Edwards Air Force Base) in early 1943, it was delivered to Wright Field. The XCG-8 static test article was completed in December 1942, and like the XCG-7 static test article failed loading tests as low as 35 percent of the design limit load. The XCG-8 prototype began test flights at El Segundo on March 29-April 1, 1943, and it was subsequently tested at Muroc, after which it was delivered to Wright Field and eventually Clinton County Army Air Field in Wilmington, Ohio. The USAAF decided not to place the XCG-7 or XCG-8 into production due to its commitments to the Waco CG-4, terminating both programs in August 1943. The XCG-7 was eventually tested to destruction on August 25, and the XCG-8 was destroyed in a windstorm at CCAAF on July 17, 1944.

The first and only completed Bowlus XTG-12 training glider (serial number 42-96830) during testing at Twenty-Nine Palms in the late summer of 1942. This aircraft also carried the civil registration NX28386 (visible on the vertical stabilizer).

As full-scale development of the XCG-7 and XCG-8 began, Bowlus Sailplanes envisaged a two-seat trainer derivative of the BA-100 Baby Albatross with a larger cockpit to accommodate men wearing parachutes, known internally as the BM-5. A mockup of the BM-5 was completed in about November 1941, and on April 28, 1942, a contract was awarded for three BM-5 prototypes (serial numbers 42-96830/96832) plus a static test airframe, and the designation XTG-12 was assigned to the BM-5. The first XTG-12 prototype (which also bore the civil registration NX28386) was completed in late spring and began flight tests in San Bernardino County in the summer of 1942, before being delivered to the US Army Air Force later that year. (One Bowlus-DuPont Utility M1PU3 glider previously owned by Orvil Leigh Smith [civil registration NR15314] was impressed into USAAF service with serial number 42-57200 in July 1942 and designated TG-12A, but the Utility glider was unrelated to the XTG-12 and the Bowlus-DuPont company that manufactured it was based in Delaware, not southern California.) Even though the first XTG-12 prototype probably exhibited satisfactory handling characteristics during flight testing, the XTG-12 program was dogged by government demands for design changes given that the BM-5 was based a prewar glider and did not constitute a new design, and after months of effort by Bowlus, the XTG-12 program was terminated on August 5, 1943, with only the first XTG-12 built and the other two cancelled without being completed. The end of the XTG-12 program eventually prompted the Bowlus Sailplanes Company to go out of business in early 1944, by which time William Hawley Bowlus was involved in development of the General Airborne Transport XCG-16 lifting body transport glider and would later join forces with sailplane pilot Ted Nelson to design the Bumblebee, Dragonfly, and Hummingbird motor gliders.

References:

Byard, J., 2015. On the Wings of an Albatross: Hawley Bowlus and his BA-100 Baby Albatross. Scotts Valley, CA: CreateSpace Independent Publishing Platform.

Fogel, G., 2000. Wind and Wings: The History of Soaring in San Diego. San Diego, CA: Rock Reef Publishing House.

Norton, W. J., 2012. American Military Gliders of World War II: Development, Training, Experimentation, and Tactics of All Aircraft Types. Atglen, PA: Schiffer Publishing.   

Aerial meteors from San Diego: the Ryan FR and F2R Fireball

The Ryan Aeronautical Corporation of San Diego, California, is best known in the annals of early 20th century American aviation history for building the NYP (Spirit of St. Louis) parasol monoplane that Charles Lindbergh famously used to carry out the first non-stop solo flight across the Atlantic Ocean on May 20-21, 1927 as well as the M-1 mail plane and Brougham airliner, but also the ST sports aircraft and military trainer derivatives of the ST for the US armed forces (PT-16, PT-20, PT-21, PT-22, PT-25, NR), not to mention that it also developed the S-C three-seat utility monoplane and YO-51 Dragonfly prototype liaison aircraft. With the US entry into World War II, Ryan did not miss an opportunity to get involved in combat aircraft design, beginning with design studies in 1942 for the US Army Air Force and Navy for the Model 26 dive bomber and Model 27 interceptor, neither of which moved past the design phase. Not too long after the Americans defeated Japanese forces at the Battle of Tarawa in November 1943, Ryan had a stroke of luck when it built one of the world's first mixed jet/piston power combat planes, the FR Fireball, putting Ryan in the same league with Convair in producing a combat aircraft type in quantity in San Diego in World War II.

In late 1942, the US Navy's Bureau of Aeronautics announced a requirement for a fighter plane to utilize a composite piston/turbojet powerplant, an idea first suggested by US Navy Admiral John S. McCain Sr. (the grandfather of the late US Senator John McCain, himself a Vietnam War veteran and the unsuccessful Republican nominee for president in the 2008 presidential election), who noted that early jet engines had sluggish acceleration that would render a fighter aircraft with pure jet power unsafe and unsuitable for carrier operations. In response to this requirement, Ryan proposed the Model 28 fighter with one Wright R-1820 Cyclone radial piston engine and one General Electric J31 turbojet in the rear fuselage, the latter fed by ducts in each wing root, and this proposal was submitted to the Navy in December 1942. The Navy assigned the designation XFR-1 to the Model 28, and on February 11, 1943, a contract was signed for three prototypes (BuNos 48232/48234) plus a static test airframe, with the first two prototypes scheduled for delivery in 14 months. The FR-1 was officially christened Fireball, and on December 2, an order was placed for 100 production FR-1s (BuNos 39647/39746); the Fireball prototypes were known internally as Model 28-1 while the production FR-1 bore the company designation Model 28-2.

FR-1 Fireball (BuNo 39657) on display at the Planes of Fame Museum in Chino, California, photographed by me on April 13, 2019.

The FR-1 Fireball was 32 feet 4 in (9.86 meters) long with a wingspan of 40 feet (12.19 meters), a wing area of 275 square feet (25.5 m²), and a height of 13 feet 11 in (4.24 meters) (the XFR-1 prototypes measured 12 feet 3 in [3.75 meters] high). The Fireball was similar to the F2A Buffalo, F4F Wildcat, F6F Hellcat, and F8F Hellcat in the design of the inner wing section relative to the wing root, and the cockpit design bore uncanny resemblance to that of the F8F Bearcat. However, the most novel design feature of the FR-1 compared to the Buffalo, Wildcat, Hellcat, and Bearcat was the tricycle landing gear, which had been previously developed for the Douglas SB2D/BTD Destroyer and was also utilized for the Curtiss XF15C and Douglas TB2D Skypirate. Armament consisted of four .50 in (12.7 mm) Browning machine guns in the wing center section outboard of the air ducts for the turbojet, four 5 in (127 mm) HVAR unguided rockets under the outer wing panel, and two 1,000 lb (454 kg) bombs carried under hardpoints beneath the center wing section. The composite piston/turbojet powerplant demanded a piston engine whose output could be perfectly balanced with the maximum thrust of the auxiliary turbojet, and the R-1820 was chosen as the piston engine for the Fireball because its output was comparable to that of the R-1830 and significantly less than that of the R-2600, R-2800, R-3350, and R-4360, in which case the output of both the piston engine and turbojet combined would rival the amount of horsepower yielded by the piston engines used to power the Navy's most advanced carrier-based combat aircraft. Due to the location of the auxiliary turbojet in the rear fuselage, the cross-section of the rear fuselage was circular in contrast to the slab-shaped rear fuselage of the F4F Wildcat.

 

Left: On of the three XFR-1 prototypes in flight, late 1944
Right: Two FR-1s during trials aboard the USS Ranger in May 1945 

The first prototype of the FR Fireball made its first flight on June 25, 1944, running solely on piston power because the auxiliary turbojet had not yet delivered. When General Electric delivered the J31 to Ryan, the first XFR-1 prototype had the auxiliary turbojet installed and began test flights with both the piston engine and turbojet in July. The second prototype took to the skies on September 20, and the third prototype followed suit on October. Despite offering advantages over the Navy's piston-engine fighters in speed, test flights of the Fireball revealed that the circular cross-section of the rear fuselage suffered longitudinal instability compared to the slab-like fuselage of the F4F Wildcat and that the Douglas double-slotted flaps were unsatisfactory. To improve longitudinal stability, the three Fireball prototypes were fitted with larger vertical and horizontal stabilizers, and the three XFR-1s and the first 14 production Fireballs were also modified with single-slotted flaps, which now were being applied during construction of all FR-1s beginning with the 15th production aircraft. The FR-1 began carrier tests in early January 1945, and despite a few problems with the engine's heating system and nosewheel oleo shock strut, trials aboard the escort carrier USS Charger were successful when using both engines. Deliveries of the FR-1 to the newly established squadron VF-66 began that month, and in March the Fireball entered service with VF-66 aboard the USS Ranger. The Navy increased the number of FRs on order on January 31, 1945, when it ordered 600 more FR-1s (BuNos 92702/93301) and also signed a contract for 600 examples (BuNos 104576/105175) of the FR-2 (Model 28-3), a proposed FR-1 variant powered by the 1,450 hp (1,063 kW) R-1820-74W, which was slightly more powerful than the R-1820-72W used on the FR-1. Despite an incident on May 1, 1945, where two of three FR-1s of VF-66 were damaged while landing on the USS Ranger while qualifying a number of pilots to fly combat missions with the FR-1, the pilots assigned to those Fireballs were qualified in June and entered pre-embarkation leave. In the meantime, all three XFR-1s were destroyed during flight tests, with the first and second prototypes lost on October 13, 1944 and March 25, 1945 respectively due to compressibility effects, and the third prototype crashing on April 5, 1945 when the cockpit canopy blew off during a high-speed pass over Lindbergh Field in San Diego. 

An FR-1 taking off from the deck of the escort carrier USS Badoeng Strait in early 1947

If VF-66 was looking forward to using the FR-1 on its first combat missions in the Pacific theater of World War II, such plans were not to be. On August 14, Japan formally surrendered to the Allies, and after V-J Day, production orders for the FR-1 were reduced to 66 aircraft (BuNos 39647/39712), and thus the FR-1 and FR-2 production contracts signed in January were canceled. On October 18, VF-66 was disbanded and all FR-1s in service and the pilots who flew them transferred to the squadron VF-41. True carrier trials involving the Fireball began on November 5, 1945, aboard the escort carrier USS Wake Island, and on November 6 one FR Fireball unintentionally became the first airplane in history to land on a carrier under jet power when its pilot ignited the J31 for final approach to the Wake Island  after the R-1820 radial engine lost substantial power, eventually catching the arrestor wire before hitting the ship's crash barrier. VF-41 was attempting to qualify its pilots to operate the FR Fireball aboard the Wake Island, but only 14 out of 22 pilots made the six required takeoffs and landings, and accidents occurred when the nose gear failed on landing, although the pilots were partly to blame because they slammed the nose landing wheel onto the deck after landing on the main wheels. By March 1946, the FR-1s of VF-41 began serving aboard the USS Bairoko, but nose gear problems persisted and cut short cruises, and despite Ryan modifying the nosewheels of the Fireball fleet with a steel fork, inspections of the aircraft also revealed evidence of partial wing failures, so the Navy required all Fireball to conduct maneuvers that were not to exceed 5 Gs. After three fatal crashes, one involving a collision between two Fireballs that killed both pilots, VF-41 was renamed VF-1E on November 15, 1946, and in March 1947 the rechristened squadron conducted carrier qualification aboard the USS Badoeng Strait but only eight pilots successfully qualified, largely because the Fireballs lacked the structural strength to endure repeated carrier landings. During one brief deployment in June aboard the USS Rendova, one FR-1 broke in two after a hard landing, and when the US Navy recognized that the entire FR-1 fleet had many signs of structural failure, the Fireball was withdrawn from service on August 1, 1947.  

Top: The XFR-4 (BuNo 39665) in flight
Bottom left: The sole XF2R-1 (BuNo 39661) in flight, early 1947
Bottom right: A full-scale mockup of the XF2R-2 at the Ryan factory in San Diego, mid-1946

Even as the FR-1 began to be deployed, Ryan worked out two variants of the FR-1 with more powerful auxiliary turbojets, and when the US Navy announced the SD399 requirement in mid-1945 for a fighter plane to be powered by a turboprop in the nose and an auxiliary turbojet in the tail empennage, two derivatives of the Fireball with one General Electric T31 turboprop substituted for the R-1820 were conceived, the Model 29 with one General Electric J31 auxiliary turbojet and the Model 30 with one Westinghouse J34 auxiliary turbojet. The XFR-3 (Model 28-4) would have used the R-1820-74W of the FR-2 and replaced the J31 with a 1,985 lb (8.8 kN) thrust General Electric J39 (I-20), and the XFR-4 (Model 28-5) was similar to the XFR-3 but was powered by one Westinghouse J34 turbojet in the rear fuselage, necessitating an extension of the rear fuselage by 8 inches (20 cm),  the wing intake ducts, and installation of NACA-type flush fuselage intakes. The XFR-3 did not leave the design phase before the end of World War II, but the XFR-4 design reached the hardware phase when one FR-1 (BuNo 39665) was converted to XFR-4 configuration, making its first flight in about late 1945 or early 1946*. The XFR-4 exhibited stellar performance during flight testing, being 100 miles per hour (160 km/h) than the FR-1 variant, and since it was intended to test the J34 planned for the Model 30, the Navy was duly so impressed by flights of the XFR-4 that it approved the Models 29 and 30 for full-scale development by late 1945, designating the Model 29 as XF2R-1 and Model 30 as XF2R-2. The XF2R-1 was 36 feet (10.97 meters) long with a wingspan of 42 feet (12.80 meters), a wing area of 305 square feet (28.3 m²), and 14 feet (4.27 meters) in height, and it had a gross weight of 11,000 lb (4,990 kg), a top speed of 497 miles per hour (800 km/h), and provisions for four 0.50 in (12.7 mm) Browning machine guns outboard of the air intakes for the J31 on the leading edges of the wing center section. The XF2R-2 had the same wingspan and wing area as the XF2R-1 but differed in having a slightly longer fuselage measuring 37 feet 4.5 in (11.39 meters) in length to fully accommodate the J34 turbojet in the rear fuselage as well as air intakes for the J34 on the forward fuselage, and it was to have a gross weight of 15,763 lb (7,150 kg), a top speed of 533 miles per hour (858 km/h) with both engines running (386 miles per hour [621 km/h] with the turboprop only), and a service ceiling of 52,200 feet (15,911 meters), while armament would comprise four 20 mm cannons in the wing roots and eight 5 inch (127 mm) HVAR unguided rockets below the inner wing panels. One FR-1 (BuNo 39661) was converted into the sole prototype of the XF2R-1, and two prototypes of the XF2R-2 (BuNos 39713/39714) were ordered in late 1945, with a full-scale mockup of the XF2R-2 being completed for inspection in mid-1946. The first flight of the XF2R-1 took place on November 1, 1946, flown by Ryan test pilot Al Conover, and test flights of the aircraft revealed good performance and maneuverability. On May 2, 1947, the XF2R-1 set an altitude record for a turboprop-powered aircraft when Conover took the aircraft to 39,160 feet (11,936 meters). Although "Dark Shark" is often cited in many publications for the F2R, Ryan company documents indicate that the XF2R-1 and XF2R-2 were actually called Dark Shark Fireball, in which case "Dark Shark" was an unofficial moniker for the F2R by Ryan to point out the shark-like nose of the F2R. Despite being impressed by the performance of the XF2R-1, the Navy did not order the XF2R-1 into production because of the deployment of its first generation of pure jet fighters, and for that reason the XF2R-2 project was canceled before construction of the two prototypes could begin. Before long, Ryan had envisaged a backswept wing derivative of the F2R in April 1946, the Model 34, which would have had a length of 39 feet 4 in (12 meters), a wingspan of 36 feet 8 in (11.18 meters), and a gross weight of 13,390 lb (6,074 kg), while using the same powerplant as the XF2R-2, but this project found no favor with the Navy. 

* Although Norton (2008) notes that the exact date of the XFR-4's first flight is uncertain, he points out that a November 1944 timeframe given by some published sources for the first flight of the XFR-4 is erroneous given the timing of the development of this variant.

After retirement from service, all FR-1s were scrapped except for a few that continued to fly for testing purposes until April 1948, when the last airworthy FR-1 made its last flight en route to the Naval Air Technical Training Center at NAS Memphis in Memphis, Tennessee. This aircraft along with another FR-1 that had been retired to NAS Memphis were later given to the Mississippi State University, two Fireballs were lent to Lewis Institute of Technology in Romeoville, Illinois, as instructional airframes; the current whereabouts of these aircraft are unknown. One FR-1 (BuNo 39657) is now on display at the Planes of Fame Museum in Chino, California, and another Fireball (BuNo 39707) was initially given to the US Navy's airplane collection at the Smithsonian Institution before being placed on display at the San Diego Air and Space Museum, where it remained until it was destroyed by a fire in 1978.

The TR-1 half-scale mockup of the FR-1 (nicknamed "Winged Victory") at the San Diego Tournament of Roses Parade on January 1, 1946 (courtesy of Secret Projects forum).

As a side note, Ryan built a half-scale wooden model of the FR-1 Fireball, called TR-1 (Tournament of Roses, Model 1) by the company, that was used as a float for the Tournament of Roses Parade in San Diego on New Year's Day 1946. The float, which was nicknamed "Winged Victory" (a virtual pun on the Winged Victory of Samothrace, a Hellenistic sculpture of the Greek victory goddess Nike standing on a warship's bow found on the Greek island of Samothrace in the 1860s), received sponsorship from the San Diego city and county governments and as well as the San Diego-California Club and Junior Chamber of Commerce.  

References:

Friedman, N., 2016. Fighters over the Fleet: Naval Air Defence from Biplanes to the Cold War. Barnsley, UK: Seaforth Publishing.

Ginter, S., 1995. Ryan FR-1 Fireball and XF2R-1 Darkshark (Naval Fighters Number 28). Simi Valley, CA: Ginter Books.

McDowell, E., 1995. FR-1 Fireball (Mini in action number 5). Carrollton, TX: Squadron/Signal Publications.

Wagner, R., 2004. American Combat Planes of the 20th Century: A Comprehensive Reference. Reno, Nevada: Jack Bacon & Co. ISBN 0-930083-17-2.