I.Ae. 24 Calquin

https://en.wikipedia.org/wiki/I.Ae._24_Calquin

The I.Ae.24 Calquin (a Mapudungun word which means "Royal Eagle") was a tactical
bomber designed and built by the Instituto Aerotécnico (Córdoba) in Argentina in
the immediate post-World War II era. Although superficially a "look-alike" for
the de Havilland Mosquito, the I.Ae.24 was powered by twin Pratt & Whitney
R-1830-G “Twin Wasp” radials giving it a distinct appearance. After an
operational career spanning two decades, the Calquin was retired.

Patterned after the successful de Havilland Mosquito, the Calquín had a wooden
structure similar to the FMA AeMB.2, and was the first twin-engined aircraft
designed and built in Argentina. The I.Ae.24 design was based on a cantilever
mid-mounted wooden (indigenous woods were used throughout) wings with
fabric-covered flying surfaces. The conventional main twin-oleo undercarriage
retracted into the engine nacelles while the tailwheel retracted into the aft
fuselage. The two-man crew were seated side-by-side under a large transparency
constructed partly of acrylic glass with glass panels. The armament consisted of
four 12.7 mm machine guns grouped in the nose. Some examples later had four 20
mm cannons and an internal bombload of 1,764 lb (800 kg) kg along with 12
rockets (75 mm) mounted under the wings.

Originally the I.Ae. 24 was also intended to be equipped with Rolls-Royce
Merlins but an adequate supply of the powerplants was not possible, consequently
Pratt & Whitney R-1830-G “Twin Wasp” radials of 1,050 hp (782.5 kW) were
substituted. Performance estimates of a Merlin-powered variant would have made
it comparable to the Mosquito but the R-1830-powered prototype was able to
achieve only 273 mph (440 km/h), making the aircraft unstable and prone to
stalling. A later prototype, the I.Ae.28 was equipped with Rolls-Royce Merlins
but the project was superseded by the more capable I.Ae. 30 "Ñancú".

Role
Light Bomber

Manufacturer
Fabrica Militar de Aviones (FMA)

Designer
Juan San Martin

First flight
4 July 1946

Retired
1960

Primary user
Fuerza Aérea Argentina

Produced
1947-1950

Number built
101

Despite the lower performance obtained in testing, the I.Ae.24 Calquin was able
to undertake an attack and light bombing role, replacing the Northrop A-17 in
the Argentine Air Force inventory. A total of 100 aircraft were ordered, with
the first production example flying on 4 July 1946. Fifty pilots and crew
members were killed in accidents related to Calquín operational service and
trials. Test pilots considered the aircraft unstable "on all three axes" and
required careful handling. Series production was completed by 1950, with
operational service continuing until 1957 although a small number of aircraft
were still in squadron use until 1960.

Specifications (I.Ae.24 "Calquín")

General characteristics
Crew: two: pilot, bombardier/navigator
Length: 12 m (39 ft 4 in)
Wingspan: 16.3 m (53 ft 6 in)
Height: 3.4 m (11 ft 2 in)
Gross weight: 6,500 kg (14,330 lb)
Max takeoff weight: 7,200 kg (15,873 lb)
Powerplant: 2 × Pratt & Whitney R-1830-SC-G Twin Wasp 14-cylinder air-cooled
radial piston engines, 780 kW (1,050 hp) each
Propellers: 3-bladed Hamilton Standard Hydromatic 23-E-50

Performance
Maximum speed: 440 km/h (273 mph; 238 kn)
Range: 1,040 km (646 mi; 562 nmi)
Service ceiling: 10,000 m (33,000 ft)
Wing loading: 170.9 kg/m2 (35.0 lb/sq ft)
Power/mass: 4.13 kg/kW (6.8 lb/hp)

Armament

Guns:
4× 12.7 mm browning ML or DL heavy machine guns nationally manufactured on the
early variant
or4× 20 mm Hispano-Suiza 804 cannon with 300 rounds per gun on the later variant
or4× 20 mm Hispano Mk II cannon, 4× .303 in (7.7 mm) Browning machine guns
Rockets:
12 x 75 mm 60 lb (27 kg) rockets (Mk VI) on the later variant
Bombs:
800 kg (1,800 lb) bombs on both early and late variant




*