Monoplane

Curtiss-Wright X-100

TerryLeave a comment

The Curtiss-Wright X-100 was a short-lived research program used to demonstrate the lift concept being developed for the Curtiss-Wright M-200 aircraft, which eventually became the X-19. The X-100 was to test the lift force concept and the gimbaled nacelles needed for a tilt prop configuration, and to test the glass fiber propellers needed to enable the use of radial lift. The X-100 was successful in that it verified the characteristics of the props, and produced data on noise, vibration, downwash, ground effect, stability, and control, and the piloting techniques needed to hover and transition a tilt prop VTOL.
The airframe was all aluminum except for the aft half of the fuselage starting just aft of the cockpit, which was fabric covered. Design and fabrication was completed in just over a year, using concurrent design and construction. The design, fabrication, testing, and documentation of components occurred in a continuous and ongoing process.
The X-100 was a high wing with T-tail and conventional landing gear. The fuselage was 8.6m long and consisted of welded tube construction. The shoulder mounted wing, with a span of 4.9m and an area of 2.1sq.m, had a wing loading of 560kg/sq.m. This was intentional so that the radial force produced by props could be demonstrated beyond any doubt. A three bladed, 3m diameter propeller was mounted on a gimbaled nacelle at each wing tip, and the two props rotated in opposite directions to balance yawing moments. Gross weight was 1580kg. The two-place cockpit had side by side seating. A rectangular engine intake was just behind the cockpit on the top of the fuselage. The T-tail, with an area of 2.1sq.m, was chosen to keep the stabilizer out of the props’ slipstream, giving the X-100 an overall height of 3.28m.
To control pitch and yaw during hover, the engine exhaust was ducted out the rear of the fuselage and could be vectored up or down, and left or right by a device called a jetivator. This device was chosen for simplicity and to reduce weight. As a control effector, the jetivator could produce 63kg of pitch force and 18kg of yaw force. Roll control during hover was by differential control of the prop pitch. Altitude control was by means of the throttle.
The X-100 originally had a rigid conventional landing gear. It eventually was replaced by tricycle gear to improve landing characteristics.
The props were made of foamed plastic molded onto a metal shank and covered with a layer of urethane elastomer. Blades were wide and had a considerable amount of twist to maximize the amount of radial lift. The relatively low tip speed of 200m/s in hover minimized the amount of noise.
The nacelles could rotate from pointing vertical to 12 degrees above horizontal. They rotated forward slowly at 2 degrees per second to allow the pilot to adjust power and attitude in order to prevent settling during the transition to cruise flight. They rotated back to vertical at 5 degrees per second.
Curtiss-Wright’s program managers selected a Lycoming YT-53-L-1 turboshaft engine of either 650 or 825 horsepower. The U.S. Army, who had numerous YT-53-L-1 engines on hand, loaned two of them for the X-100 project. In exchange, Curtiss-Wright agreed to write a report on the engines’ performance. The fuselage had to be enlarged to accommodate the Lycoming engine.
The design process started in February 1958. The first prop assembly was fabricated soon after and tested in NASA’s 12m x 24m wind tunnel starting in October 1958. It was run through the expected power operating range and at shaft angles from 0 to 90 degrees. These tests demonstrated that thrust in hover would be 10 percent below prediction (which was later confirmed in flight test), but there was enough excess thrust that the 10 percent loss was acceptable. Preliminary wind tunnel tests using models were performed at the Massachusetts Institute of Technology, then a powered model was run in the wind tunnel to determine stability and control characteristics. Tests using the actual aircraft eventually were run in NASA’s 12m x 24m wind tunnel. Reasonable correlation was achieved between wind tunnel tests and flight tests.
Roll out of the completed X-100 was on December 22, 1958, at Curtiss-Wright’s Caldwell, NJ, facility, and the first engine run was performed on January 14, 1959. The first hover was made in a tether rig on April 20, 1959, to verify control power and feel. The first free hover test was performed on September 12, 1959, but extra weight was added to prevent the X-100 from getting out of ground effect. After three days of testing, hover flights of up to 20 minutes duration were made. The outflow velocities of air along the ground at various distances from the hovering X-100 proved to be similar to those of a helicopter of similar weight.
Hover proved to be difficult as the pitch and yaw thrust provided by the jetivator was insufficient. Roll and yaw motions tended to couple together. The throttle was used to maintain height during hover, and lags in the engine response further compounded the problem. The X-100 also tended to weathervane into the wind during hover due to yaw moments produced by the wind hitting the props at an angle, which the jetivator’s yaw control could not counter adequately.

X-100 N853

Steady hovering was possible only up to about 4m, while the X-100 was in ground effect. If maximum power was applied on the ground, the X-100 would rise to about 7.6m, settle to within a few feet of the ground, then rise again and repeat several cycles of a slowly damped oscillation in height.
The first transition from hover to forward flight was made on April 13, 1960. The transition itself was fairly simple. The pilot pressed a switch on top of the control stick to rotate the nacelles forward, then added power to prevent sinking. As the nacelles rotated, the X-100 picked up 30km/h of airspeed for each 10 degree of tilt. The conversion was done at 0.9 to 1.5m of altitude and very slowly to prevent settling to the ground. The nacelles were rotated down in 5 degree increments until a speed of 290km/h was achieved with the nacelle at a 15 degrees from horizontal. In general, low speed flight characteristics were unsatisfactory, especially in gusty air. The X-100 demonstrated a high pitch-up moment as forward speed increased, but directional stability, roll control, and longitudinal maneuvering were good in flight at 110km/h. At low altitude and up to 110km/h, the X-100 was notably free of mechanical vibration. Testing at altitude showed the aircraft to be buffet and stall free over a large range of angles of attack.
STOL take-offs and landings were made with nacelle angle at 20 degrees from the vertical. Directional control was poor and was a problem during ground run. Smooth touch-downs also were difficult, much of the problem being caused by the landing gear being too stiff. There was considerable bouncing even at low touchdown speeds.
The basic test program was completed on July 21, 1960. Test pilots from NASA visited Curtiss-Wright and flew the X-100 on August 12 and 13. This concluded test operations for the X-100 at the Caldwell, NJ, facility.
With Curtiss-Wright satisfied that they had proven the radial lift concept, they turned the X-100 over to NASA. It was shipped to the Langley Research Center in October of 1960. It was used to study the effects of downwash on several types of ground surfaces, such as snow, grass, pavement, and packed dirt. NASA also studied problems associated with visibility in snow during hover and slow forward transition. This role was finished by October 1961.

The X-100 was test-flown until August 1965, when a gear case and prop failed. The pilots safely ejected and the ship crashed, but its technology was basis for X-200 and, ultimately, Bell-Boeing XV-22 Osprey.

Following the completion of tests at Langley, the X-100 was donated to the Smithsonian Institution. During its short career, the X-100 completed a total of 14 hours flying time and 220 hours of ground engine run time. It successfully proved the radial force concept, the feasibility of tilting nacelles, and low noise levels.

X-100
Engine: Lycoming YT-53-L-1 turboshaft, 630kW / 825-shp
Wingspan: 7.62m
Length: 8.68m
Height: 3.35m
Empty weight: 1480kg

Curtiss-Wright P-55 Ascender

TerryLeave a comment

The XP-55 (Curtiss Model 249C), along with the XP-54 and XP-56, resulted from Army Air Corps proposal R-40C calling for unconventional aircraft designs. Like the XP-54, the Ascender was initially designed for the Pratt & Whitney X-1800 engine and had to be redesigned when the engine project was canceled. The XP-55 first flew on 13 July 1943 with an Allison V-1710 engine. It was to be one of the last projects supervised by Donovan Berlin before he left Curtiss to work on the P-75 project for Fisher.

Curtiss XP-55 Article

The XP-55 had a pusher engine mounted at rear, swept-back wings and forward canard mountings. The foreplane was not a canard in the true sense, but a free-floating surface with no fixed stabilizer. Its limits were 68 degrees up and down, although the down angle was restricted to 17 degrees for take-offs. Entry to the cockpit was said by test pilots to be rather awkward, requiring a telescoping ladder that was stored behind the pilot’s seat. The XP-55 was essentially a flying wing, having only vestigial vertical surfaces which were distributed on the rear fuselage and outer wings.
The XP-55 was a single-seat single-engine design. The pusher-type engine was mounted to the extreme rear and the wings were highly swept. First drawings and scale models were completed and assessed as early as 1940 to which the Army Air Corps needed more convincing. As a result, Curtiss took it upon itself to produce a flyable full scale model – this one to be designated in-house as the CW-24B. The test aircraft differed some from the final three prototypes developed from the granted contract of 1942. The test bed flew with a Menasco C68-5 powerplant, whereas the final prototype models were fitted each with the Allison V-1710 engine.
Curtiss built a full-scale flying testbed, the company Model CW-24B, powered by a Menasco C65-5 engine. The fabric-covered CW-24B went to a new US Army test site, the airfield at Muroc Dry Lake, California, for 1942 tests. These revealed serious stability problems which were only partly resolved by moving its vertical fins farther out from their initial mid-way position on the swept-back wing. The Curtiss 24 B was not a true canard, in that it had no fixed forward ‘tail’ surface. Essentially it was a flying wing with a nose mounted elevator. The 24 B made 169 flights from California’s Muroc Dry Lake, but after Curtiss-Wright had validated its concept with the CW-24B flying mock-up the USAAC ordered three XP-55 prototypes, on July 10, 1942. Armament for the XP-55 was originally drawn up to include a pair of 20mm cannon to go along with twin 12.7mm (.50 caliber) machine guns. This arrangement was revisited and revised to a quad .50 caliber array during the testing phase and this standard armament stayed with the life of the program.
For Curtiss, it would be its first design to feature a powered tricycle landing gear assembly (though fixed on the initial test models). The absence of a true rudder resulted in smaller vertical surfaces mounted far off onto the wings. The use of forward canards was also revolutionary as was the ejection system – the propeller had to be jettisoned before the pilot could eject himself. The XP-55 used a single rotation, three-bladed propeller instead of the co-axial, contra-rotating type which had been planned.

The first XP-55 (42-78845) was completed on July 13, 1943. It made its first test flight on July 19, 1943 from the Army’s Scott Field near the Curtiss-Wright St Louis plant. The aircraft experienced stability problems and underwent several modifications to increase the canard elevator surface, vertical stabilizer area, and eventually received four-foot wing tip extensions to improve stall characteristics. It was found that excessive speed was required in the take-off run before the nose-mounted elevator could become effective. Before this problem could be addressed, the first machine was lost during spin tests at St Louis on 15 November 1943. The first prototype underwent stall testing and on the third attempt the aircraft pitched forward 180 degrees onto its back and fell into the same inverted descent predicted in original Air Corps wind tunnel tests. The engine quit and nothing the pilot did could break the stall. After a perfectly stable fall of 16,000 feet, the pilot, J. Harvey Gray, bailed out safely. The aircraft continued straight down and dug a large smoking hole in the desert floor. After modifications, stall tests were performed satisfactorily, although the complete lack of any warning prior to the stall and the excessive loss of altitude necessary to return to level flight after the stall were undesirable characteristics.
The second XP-55 was flown in St Louis on 9 January 1944. The third followed on 25 April 1944 and, soon after, went to Eglin Field, Florida, for tests of its nose-mounted 12.7mm machine-guns.
The XP-55 had the advantage of being constructed largely from non-strategic materials and for a time a jet version, the company Model CW-24C, was contemplated. But lingering problems, including generally poor stability, remained unsolved when the third XP-55 was returned to Wright Field, Ohio, for further tests continuing into 1945.

An artificial stall warning device was introduced to try and correct some of these problems, and between September 16 and October 2, 1944, the second Ascender underwent official USAAF trials. The trials indicated that the XP-55 had satisfactory handling characteristics during level and climbing flight, but at low speeds and during landings there was a tendency on the part of the pilot to over-control on the elevators because of a lack of any useful “feel”. Pilot, Russ Schleeh, commented that it was terribly unstable, and that if you took your eyes off the horizon for a moment, even in the landing pattern, the plane would drift wildly off course.

The performance of the XP-55 prototype aircraft built (S/N 42-39347, 42-78845-7) was not very impressive and was in fact inferior to that of the more conventional fighters already in service. Performance was mediocre with the Allison V-1710 engine attaining only 377 mph instead of the hoped-for 500 mph. Engine cooling was also a problem. In addition, by 1944, jet-powered fighter aircraft were clearly the wave of the future. Consequently, no production was undertaken, and further development was abandoned. The third prototype survived the testing program, but was destroyed in an accident on May 27, 1945, at Wright Field, Ohio. The pilot, Captain William C. Glascow, came in low over the field during an air show, attempted a barrel roll at low altitude, and crashed. Not only was the aircraft destroyed but the pilot was killed as well as a passing motorist. The sole surviving XP-55 (42-78846) was flow to Warner Robins Field in Georgia in May of 1945. It was later taken to Freeman Field to await transfer to the National Air Museum at the Smithsonian Institution in Washington. Currently the aircraft is in the Kalamazoo Aviation History Museum undergoing a complete restoration.
The second XP-55 has survived and is among numerous historically valuable airframes held by the Smithsonian Institue’s National Air and Space Museum in Washington D.C.
The name Ascender had originated as a joke on the part of a Curtiss engineer, a reference to the aircrafts rather odd design which was not appreciated by the congressional oversight committee. The name stuck, and eventually became official.

Curtiss-Wright XP-55 Ascender
Engine: 1 x Allison V-1710-95 liquid-cooled V12, 1,275hp, 951kW
Length: 29 ft 7 in (9.02 m)
Wingspan: 40 ft 7 in (later 44 ft 6 ft)
Wing area: 209.0 sq ft / 19.41 sq.m later 21.83 sq.m / 234.98 sq ft
Height: 9.84ft (3.00m)
Empty Weight: 6,354lbs (2,882kg)
Maximum Take-Off Weight: 7,710lbs (3,497kg)
Maximum Speed: 390mph (628kmh; 339kts) at 19,300 ft (5,885 m)
Service Ceiling: 34,600ft (10,500m)
Climb to 20,000 ft (6,095 m): 7 minutes 6 seconds
Range: 635 miles (1,022 km)
Armament: 4 x 12.7mm (0.5 in) Colt Browning M2 machine guns in nose
Crew: 1

CW-24B
Engine: Menasco C68-5, 275 hp, 633kW

Curtiss-Wright CW-25 / AT-9 Fledgling / Jeep

TerryLeave a comment

With the introduction of new high-performance twin-engine aircraft at the U.S. Army Air Corps at the start of the Second World War in Europe it was evident that new aircraft types would be needed for advanced training of future pilots. The gap between the T-6 and types like the B-25 and B-26 bombers had to be closed with a flying course on a twin-engine trainer. Also for the new Lockheed P-38 twin-engine fighter an advanced training course on a twin-engine type was considered as necessary. Beech and Cessna already had their AT-11 Kansas and AT-17 Bobcat twin-engine trainers, but these were more suitable for crew training.

At Curtiss the design and development was started on a twin-engine advanced trainer strictly for pilot training with two-seat capacity for instructor and pilot student which had the take-off and landing characteristics of a light bomber aircraft.

Owing much of its low-wing cantilever monoplane design to the earlier CW-19 trainer, the AT-9 was a relatively small twin-engine low-wing monoplane fitted with two radial air-cooled engines. It only had capacity for two seats; entrance was on both sides with a car-type door. The main wheels retracted partially backwards into the engine nacelles and the tail wheel was non-retractable. The CW-25 was powered by two Lycoming R-680-9 radial engines.

The single CW-25 prototype acquired for evaluation was built with a welded steel-tube fuselage covered with fabric. Also wing and tail planes were fabric covered. The production AT-6 was planned to be manufactured from aluminum with a modern monocoque construction and stressed-skin wings.

Prototype

The prototype AT-9 first flew in 1941 and evaluation proving satisfactory, the type was ordered into production under the designation AT-9, officially named the Fledgling, the AT-9 was almost universally known as the Jeep. The production examples differing from the prototype by being of all-metal construction.

A total of 491 AT-9s was produced and these were followed into service by 300 generally similar AT-9A aircraft. They remained in use for a comparatively short time, for the USA’s involvement in World War II in late 1941 resulted in the early development of far more effective training aircraft.

Designated at Curtiss-Wright as CW-25, the new advanced trainer received the military type designation AT-9. Initially it was named the ‘Fledgling’ but it became much more known by its later name the ‘Jeep’. The flight characteristics of the new trainer were purposely made more demanding for the student pilot. Basically it was the intention that future P-38 pilots would made their first solo flight on this fighter after a 70 hours transition training on the AT-9.

When the test flying of the CW-25 was successfully completed in 1941 the Army Air Corps ordered in total 492 AT-9 production models.

Later a final order was placed for 300 additional slightly improved AT-9A models. Main difference was a later model Lycoming R-680-13 engine with slightly more power output (300 hp), and the undercarriage retraction hydraulics were revised and improved.

The AT-9 and AT-9A was produced at Curtiss between 1941 and 1943; production of the last AT-9A was completed in February 1943. The unit costs of the AT-6 model was U.S. $44,965. The unit costs of the AT-6A dropped to U.S. $ 40,286.

Production totals:
CW-25 prototype:
1

AT-9:
41-5754 to 41-5894 (150)
41-11931 to 41-12271 (341)

AT-9A: 42-56853 to 42-57152 (300)

Total: 792 including prototype

The AT-9 and the later AT-9A was assigned from 1942 on to various military flying schools. Although it was quite demanding to fly, it was fully aerobatic and much more maneuverable that the other twin-engine advanced trainers like the AT-11 and AT-17. In spite of this, there were continuous maintenance problems and because of its more difficult flying properties it had a quite high accident rate.

Formation of AT-9 coded ‘CO’ coded based at the Advanced Twin Engine Flying School at Columbus Mississippi. This flying school had some forty AT-9’s on its inventory

Since the AT-9 could not be used for crew training its operational use was in most cases restricted to P-38 training. By the end of 1943 most AT-9’s were removed from flying status.

Since it was only a two-seater it was hardly used as a civil plane after the war when many aircraft were offered as surplus. Some were used after the war as instructional airframes at technical schools.

AT-9’s at Tulsa, Oklahoma, 18 May 1953.

The U.S.A.F. Museum at Dayton Ohio has an AT-9 on display carrying the serial number 41-12150 and field registration ‘909’. It was completely restored for static display inside the museum. The Pima Air & Space Museum in Arizona has a recovered and incomplete AT-9A wreckage (serial no. 42-56882) for future restoration.

Gallery

Curtiss AT 9 Fledgling
Engine: 2 x Lycoming R-680-9 radial, 295 hp (220 kW)
Wingspan: 12.29 m / 40 ft 4 in
Length: 9.65 m / 31 ft 8 in
Height: 3.00 m / 9 ft 10 in
Wing area: 21.65 sq.m / 233.04 sq ft
Wing loading: 25.83 lb/sq.ft / 126.0 kg/sq.m
Max take-off weight: 2722 kg / 6001 lb
Empty weight: 2087 kg / 4601 lb
Max. speed: 171 kts / 317 km/h / 197 mph
Cruise speed: 152 kts / 282 km/h / 175 mph
Range: 652 nm / 1207 km / 750 miles
Service ceiling: 5,791 m / 19,000 ft
Climb to 3,050 m (10,000 ft): 8.6 min
Crew: 2

Curtiss-Wright CW-23

TerryLeave a comment

In April 1939, Curtiss-Wright’s St Louis Airplane Division flew the prototype of the CW-23 basic combat trainer which was essentially a tandem two-seat, lower-powered derivative of the CW-21 single-seat fighter. It introduced inward-retracting, fully-enclosed main undercarriage members and hydraulically-actuated rather than manually-operated flaps, and these features were adopted for a new version of the single-seat fighter, the CW-21B.
It had a 447kW Pratt & Whitney R-1340 Wasp engine and was intended as a basic combat trainer for the US Army. Flown in 1939, official testing led to its rejection for production.

Curtiss-Wright CW-22 / SNC-1 Falcon

TerryLeave a comment
SNC

Two CW-19 company demonstrators were built, c/n 19R-10 (N16417) in January 1937 and A19R-14 (NC16421) also in 1937. N16417 was later converted to CW-22 specifications and sold in May 1940.
This aeroplane was developed within the context of the US Navy’s enormous increase in pilot training during 1940, and an advanced combat trainer evolved from the CW-19 light fighter and trainer project with features such as retractable landing gear from the CW-21 Demon export fighter. The CW-22 prototype resembled the CW-21 with a longer, two-seat fuselage but considerably lower power in the form of the 313-kW (420-hp) Wright R-975 Whirlwind radial.

The landing gear had main units retracting rearward into underwing fairings as on the CW-21 single-seat interceptor. Powered by a 313kW Wright R-975 Whirlwind radial, 36 CW-22s were exported to the Netherlands East Indies, but due to the Japanese advance in that region were delivered to the Dutch in northern Australia during March 1942.

A developed CW-22B version was sold to Turkey (50); the Netherlands East Indies (25); and various Latin American countries (totalling about 25). Several Dutch aircraft were later captured and flown by the Japanese. Both the CW-22 and CW-22B were armed with two machine-guns, one fixed and the other flexibly mounted.
After a demonstrator had been tested by the US Navy, a CW-22N advanced training version went into production. The US Navy applied the designation SNC-1 Falcon to the type, a total of 455 being purchased in three batches of 150, 150 and 155 respectively; the aircraft of the third batch had a modified, higher cockpit canopy. The initial order for 150 aircraft was later bolstered by five impressed aircraft. Many SNC-1s were sold to private owners in the USA after World War II.

CW-22

Some 136 CW-22s were exported.

CW-22 / SNC-1
Engine: one Wright R-975-28 Whirlwind radial, 420 hp (313 kW)
Wingspan: 10.67 m / 35 ft 0 in
Length: 8.23 m / 27 ft 0 in
Height: 3.02 m / 9 ft 11 in
Wing area: 16.14 sq.m / 173.73 sq ft
Max take-off weight: 1718 kg / 3788 lb
Loaded weight: 1241 kg / 2736 lb
Max. speed: 319 km/h / 198 mph at SL
Cruise: 195 mph at 2500 ft
Service ceiling: 6645 m / 21800 ft
Operational range: 1255 km / 780 miles
Armament: 2 x 7.62mm machine-guns
Crew: 2

Curtiss-Wright CW-21 Demon

TerryLeave a comment

In 1938, chief engineer Willis Wells of the St Louis Airplane Division of the Curtiss-Wright Corporation began the development of a single-seat fighter based on the A-19R tandem two-seat military basic trainer. Designated CW-21, it had a Wright R-1820-G5 Cyclone nine-cylinder radial engine rated of 1,000hp for take-off and 850hp at 1830m, and an all-metal stressed-skin structure with a semi-monocoque fuselage. The mainwheels retracted into clamshell-type underwing fairings and armament was two synchronised 12.7mm machine guns.
The prototype CW-21 was flown on 22 September 1938, and shipped to China for demonstration. The prototype was purchased by the Chinese government and a contract placed for three production aircraft and 27 sets of components for assembly by CAMCO. The first production CW-21 was flown on 20 March 1940, and provision was made to increase the armament with a pair of 7.62mm weapons. All three CW-21s built by the parent company were lost as a result of engine failures after taking-off from Lashio while being ferried to Kunming. Assembly of CW-21s by CAMCO at Loi-wing had reached an advanced stage when it was decided to evacuate and, on 1 May 1942, burn the factory to avoid its capture by Japanese forces, the partly-assembled fighters also being destroyed.
In April 1939, Curtiss-Wright’s St Louis Airplane Division flew the prototype of the CW-23 basic combat trainer which was essentially a tandem two-seat, lower-powered derivative of the CW-21 single-seat fighter. It introduced inward-retracting, fully-enclosed main undercarriage members and hydraulically-actuated rather than manually-operated flaps, and these features were adopted for a new version of the single-seat fighter, the CW-21B. On 17 April 1940, the Dutch government signed a contract for 24 CW-21B fighters (of which there was no prototype) and the first of these was flown the following mid-September. The CW-21B retained the R-1820-G5 Cyclone of the earlier CW-21 and armament comprised two 7.62mm Colt machine guns mounted in the forward fuselage. The CW-21B fighters were shipped to Java during October-December 1940, entering service with the MLKNIL. Their light structure and lack of fuel tank protection was to render them particularly vulnerable when committed to operations against Japanese forces in the early months of 1942, the last combat mission being flown by a CW-21B on 5 March.

Curtiss-Wright CW 21 Demon
Engine: Wright R 1820-G5, 986 hp
Length: 27.165 ft / 8.28 m
Height: 8.924 ft / 2.72 m
Wingspan: 35 ft 0 in / 10.67 m
Wing area: 174.269 sqft / 16.19 sq.m
Max take off weight: 4500.4 lb / 2041.0 kg
Weight empty: 3382.5 lb / 1534.0 kg
Max. speed: 274 kts / 507 km/h
Cruising speed: 245 kts / 454 km/h
Service ceiling: 34301 ft / 10455 m
Wing load: 25.83 lb/sq.ft / 126.0 kg/sq.m
Range: 548 nm / 1014 km
Crew: 1
Armament: 2x cal.30 MG (7,62mm), 2x cal.50 MG (12,7mm)

Curtiss-Wright CW-20 / C-46 Commando / C-55 / C-113 / R5C

TerryLeave a comment

The 1937 design specifications called for the Commando to feature a pressurized cabin for up to 36 combat-ready troops, longer range than anything available to the USAAF and an above average cruising speed. Design headed by George Page the CW-20 first appeared in prototype form on 26 March of 1940 as the twin-rudder CW-20T.

Curtiss-Wright CW-20 Mock-up of twin-tail prototype at 1939 NYC World’s Fair

Because the US Army was impressed with its possibilities, authorisation was obtained for the purchase of a large number as cargo transports. In the meantime the prototype was bought, modified and given the Army designation C-55. It was later re-converted for civil use and sold to the British government.

The 1941 C-55 (Model CW-20A) was a single-tail prototype Curtiss-Wright CW-20T for evaluation as a USAAF transport, rejected in favour of the C-46. A projected name of Skytruck was not officially assigned. Costing $363,600, the one built 41-21041, later went as Lend-Lease to England and BOAC as G-AGDI.

Curtiss C-55 (41-21041)

The CW-20T prototype later evolved into the CW-20A that featured a revised tail in the form of the more recognizable single rudder assembly. Later development focused in on the requirements as put forth by the United States Army Air Corps which put the CW-20A under trials and consequently ordered a production version of the model designated CW-20B. The main compartment of the C-46 could accommodate (in addition to general cargo) 40 fully equipped troops, up to 33 stretchers, five Wright R-3350 engines or their equivalent weight of other goods.

Curtiss C-46A 41-5159

The 1942 Army production model of the CW-20B, designated C-46A, was a redesign not only to suit it to the duties of a military cargo or task-force aircraft but to allow easy large-scale production. It was produced in three large manufacturing plants and was put into widespread use by the US Army Air Transport Command, Air Service Command and Troop Carrier Command, and by the US Naval Air Transport Command and Marine Corps. Two were built by Higgins Industries (boat manufacturer), New Orleans LA. Final trial models were provisioned to fit up to 45 combat-ready troops and fitted with two Pratt & Whitney R-2800-51 radial engines, a large cargo door and folding wall seats. The C-46 entered service with the plain designation of simply C-46 in the Pacific Theatre – and used almost exclusively there up until about March of 1945, to which the Commando would be seen across the European Theatre as well.

The United States Navy utilized a designation of R5C-1 for their own Commando version, transferred from USAAF inventory, with 120 models of the R5C-1 (39492-39611) going to the United States Marine Corps. Ten of these went to the USCG with long-range fuselage fuel tanks used as cargo and personnel haulers until 1950.

Curtiss XC-46B 43-46963

The 1944 C-46D, TC-46D (Model CW-20B-2) troop transport had a revised nose and double loading doors. An unknown number were modified as TC-46D trainers.

Curtiss C-46D with single door 44-77984

The 1944 C-46E (Model CW-20B-3) were C-46A airframes with stepped windshield and single cargo door. Seventeen were built (43-47403/47419).

Curtiss C-46E
Curtiss C-46E Glider tug (43-47404)

In 1944 Curtiss prepared designs and a mock-up of a commercial version of the aircraft for immediate post-war production. Curtiss-Wright hoped to market it as a 36 passenger civil version of the C-46E, with two 2500hp (1860 kW) Wright C18-B2 engines. Although a total of 26 were on order at one time the CW-20E never really had a chance as a new-production post-war airliner.

Curtiss C-46E Post-war civil (N30019)

The 1945 C-46F (Model CW-20B-4) had engine modifications, squared wingtips, and cargo doors on both sides. 234 were built (44-78545/78778).

Curtiss C-46F (44-78774)

To give the C-46s added performance, some C 46Fs were fitted with two Turbomeca Palas turbojets in underwing pods to operate in Brazil (from 1953). Other aircraft were fitted with more powerful engines as ‘Super C 46s’.

The 1945 C-46G (Model CW-20B-5) was powered by two 2100hp R-2800-34W and featured a stepped windshield. The one built was originally scheduled as a C-46C (44-78945), and later converted to XC-113.

Built in 1945, the sole C-113 (Model CW-20G) 44-78945 was a C-46G with a four-blade General Electric TG-100 turboprop installed in the right nacelle for tests, retaining its original three-blade Wright R-2800-34W on the left. This proved to be an unmanageable arrangement and the ship was damaged in ground runs and never flew.

Curtiss XC-113 44-78945

Planned modifications for double tailwheels and R-3350-BD engines, the C-46H, XC-46K (Model CW-20E-2) was cancelled by the Armistice, although a few other post-war C-46 mods were labelled as C-46H.

The three 1945 XC-46L (Model CW-20H) conversions were test-beds for 2500hp Wright R-3350-BD Double Cyclones.

In October 1954, Terneo Aircraft Corp. announced a contract to overhaul 87 of’ them. The U.S.A.F. still had some of these veteran wartime passenger-freighter in 1955.

In total, US forces accepted 3144, and the C-46 was officially retired from service in 1968, replaced by the C-130 series of transports.

Curtiss C-46A Commando, S/N 42-3649, for sale at Cal-Aero Field, California, post-WWII

Riddle Airlines produced a modification kit in the mid-1950s which added 40mph (64kmh) to cruising speed and 2,204 lb (1,000 kg) to the payload. The improved model was designated C-46R, and Riddle subsequently converted its own fleet of 32 to have 2,100 hp Pratt & Whitney engines.

Curtiss-Wright CW-20T Article

Gallery

C-46 Commando / CW-20B / R5C
1941
Engines: 2 x P&W R-2800-43, 2000hp
Wingspan: 108 ft 1 in
Length: 76 ft 4 in
Useful load: 23,600 lb
Max speed: 269 mpg
Cruise speed: 183 mph
Range: 1200 mi
Ceiling: 27,600 ft
Number built: 25 (41-5159/5183)
Capacity: 50 troop
Cost: $341,831

CW-20B / C-46A Commando
1942
Engines: 2 x Pratt & Whitney R-2800-51 Double Wasp, 2,000hp
Length: 76.44ft (23.3m)
Wing span: 78.54ft (23.94m)
Height: 21.75ft (6.63m)
Empty Weight: 30,001lbs (13,608kg)
Maximum Take-Off Weight: 55,997lbs (25,400kg)
Maximum Speed: 269mph (433kmh; 234kts)
Maximum Range: 1,199miles (1,930km)
Service Ceiling: 27,559ft (8,400m)
Crew: 4
Number built: 1,491 (41-5184/5204, -12280/12433, -24640/24775, 42-3564/3683, -60942/61091, -96529/96707, -96708/96828, -101036/101235, -107280/107399, 43-43339/43340, -46953/47402, 44-77444, -77446)
Cost: $314,700 (>$354,714), $259,268 (>$271,127) in 1943

CW-20B-1 / XC-46B
1944
Stepped windshield.
Engines: 2 x R-2800-34W, 2100hp
Number built: 1 modified from C-46A (43-46963)

C-46C
Prototype built as C-46G instead.

CW-20B-2 / C-46D Commando / TC-46D
1944
Engine: 2 x Pratt & Whitney R-2800-51 Double Wasp, 1973 hp, 1495kW
Wingspan: 32.9 m / 107 ft 11 in
Length: 23.3 m / 76 ft 5 in
Height: 6.6 m / 21 ft 8 in
Wing area: 1359.924 sqft / 126.340 sq.m
Max take off weight: 56009.2 lb / 25401.0 kg
Weight empty: 32404.7 lb / 14696.0 kg
Max. speed: 234 kts / 433 km/h
Cruising speed: 159 kts / 295 km/h
Service ceiling: 27592 ft / 8410 m
Wing load: 41.21 lb/sq.ft / 201.0 kg/sq.m
Range: 1043 nm / 1931 km
Range w/max.fuel: 2770 km / 1721 miles
Crew: 3
Payload: 54pax
Cost: $233,377
Number built: 1,410 (44-77295/77443, -77445, -77447/78544)

CW-20B-3 / C-46E
1944
Number built: 17 (43-47403/47419)

CW-20B-4 / C-46F
1945
Cost: $221,550
Number built: 234 (44-78545/78778)

CW-20B-5 / C-46G
1945
Engines: 2 x R-2800-34W, 2100hp
Number built: 1 originally scheduled as C-46C (44-78945), converted to XC-113.

CW-20E-2 / C-46H / XC-46K
Planned modifications for double tailwheels and R-3350-BD engines cancelled by the Armistice, although a few other post-war C-46 mods were labelled as C-46H.

C-47J
Designation not used.

CW-20H / XC-46L
1945
Engine test-bed
Engines: Wright R-3350-BD Double Cyclone, 2500hp
3 conversions.

CW-20A / CW-20T / C-55
1941
Cost: $363,600
1 built 41-21041 / G-AGDI

CW-20G / C-113
1945
Engines: 1 x General Electric TG-100 turboprop & four-blade prop, 1 x Wright R-2800-34W & three-blade prop.
1 as XC-113 (44-78945)

Curtiss-Wright CW-19

TerryLeave a comment
CW-19R

In 1935, the Curtiss-Wright Corp, in response to an order from the US Bureau of air Commerce, and George Page designed and produced a single prototype of the CW-19L Coupe at its St. Louis, Missouri plant. A development of the CR-2 Coupe design, the model 19L was a two seat, fixed undercarriage low-wing monoplane, powered by a 90 hp 5 cylinder Lambert R-266 radial engine. Of all metal monocoque construction with an enclosed cabin, the CW-19 was envisioned to be sold to private owners.
The two occupants were side-by-side, with a car type door on each side. The fixed undercarriage was enclosed in streamlined spats. Registered as NS69, it was granted an Approval Type Certificate (ATC number 589) on 3 December 1935.
Later repowered with a 145 hp Warner Scarab engine, the sole prototype became the 19W, with a 154 mph maximum and 132 mph cruise speeds.
The performance and cost were too great for private pilots. No production was under taken and the original prototype was the only example built.
Curtiss decided to develop the design as a military trainer. As the model 19R, re-configured into a tandem layout, with the two seats under sliding clear canopies. Still with fixed undercarriage, power was increased, initially to a 350 hp Wright R-760 Whirlwind, and later a 420 hp Wright R-975.
A single, fixed synchronised 0.30 calibre machine gun was mounted in the nose and provision was made for an additional flexible mount machine gun in the rear cockpit (for use as a gunnery trainer). Bomb racks could also be fitted. Two 35 USG were fitted.
A photo-recon variant, with two belly-mounted cameras was also developed and at least one of the Bolivian examples appears to have been delivered in this configuration.
When the flaps were extended a latch was released, allowing the undercarriage struts to fully extend, the wheels dropping an additional 6 inches from the spats. When the aircraft had landed the struts were compressed again, retracting the flaps re-engaging the latch so the wheels were held in their ground position until the flaps were lowered for landing again.
The prototype, c/n 19R-1 was registered NR11781 and was first flown in early 1936. Approved Type Certificate 629 was issued on 19 February 1937. Performance was increased from the model 19L, with maximum 185 mph and cruise 164 mph speeds.
The prototype was written off in Brasil during a sales tour of South America. Orders were received for 23 from several Latin American governments.
Two more company demonstrators were built, c/n 19R-10 (N16417) in January 1937 and A19R-14 (NC16421) also in 1937. N16417 was later converted to CW-22 specifications and sold in May 1940, and NC16421 crashed in Miami in April 1938.
A total of 26 CR-19Rs were built between 1936 and 1938. 23 for export plus 3 company demonstrators.
An unarmed basic trainer version of the CW-19R was built as the CW-A19R. Flown in February 1937 it was tested by the US Army but no production orders followed.
The type is known to have been evaluated by the USAAC at Wright Field in Ohio, and also by USAAC pilots at Bolling Field and US Naval pilots at Anacostia NAS, both in Washington DC.
Ecuador ordered six aircraft in June 1936 and all were delivered in the following September. They were c/ns 19R-2 to 19R-7, and were given the Ecuadorian AF serial numbers 51 to 56. Two were lost in service and the remained served until at least early 1946.
Dominican Republic ordered two (c/ns 19R-11 and –12) in early 1937. One was not repaired after a landing accident in February 1942, and the other was retired in 1946, to be preserved in a museum near Santo Domingo.
Cuba ordered 5 in 1937, all delivered by January 1938. C/ns 19R-8, -9, -13, -15 and –16, they carried serial numbers 50-54 in Cuba. Three survivors were later re-serialed 100-102, all but 102 lost in accidents by 1949, when 102 was retired.
Bolivia bought the last ten produced (c/ns 19R-17 to 19R-26, Bolivian AF 118-127). They were delivered crated in late 1938 to El Alto aerodrome near La Paz and re-assembled under the supervision of Harry Berguer.

Courtesy Yerko Jaldin

CW-19L
Engine: 90 hp / 67 kW Lambert R-266 5 cylinder radial
Max speed: 130 mph
Cruise speed: 115 mph

CW-19W
Engine: 145 hp / 108 kW Warner Scarab
Max speed: 154 mph
Cruise speed: 132 mph

CW-19R
Engine: Wright R-760E2 (J-6-7) Whirlwind, 350 hp / 261kW
Wingspan: 10.67 m / 35 ft 0 in
Length: 8.03 m / 26 ft 4 in
Height: 2.49 m / 8 ft 2 in
Wing area: 16.16 sq.m / 173.94 sq ft
Max take-off weight: 1588 kg / 3501 lb
Empty weight: 904 kg / 1993 lb
Max speed: 298 km/h / 185 mph
Cruise speed: 164 mph
Rate of Climb: 2000 fpm
Armament: 2 x 7.7mm machine-guns, light bombs on underwing racks

CW-19R
Engine: Wright R-975E3 (J-6-9), 336kW