The I.Ae.24 Calquin (a

Mapudungun Mapuche (, Mapuche & Spanish: , or Mapudungun; from ' 'land' and ' 'speak, speech') is an Araucanian language related to Huilliche spoken in south-central Chile and west-central Argentina by the Mapuche people (from ''mapu'' 'land' and ''che ...

word which means "Royal Eagle") was a

tactical bomber Tactical bombing is aerial bombing aimed at targets of immediate military value, such as combatants, military installations, or military equipment. This is in contrast to strategic bombing, or attacking enemy cities and factories to cripple fut ...

designed and built by the ''Instituto Aerotécnico'' at Córdoba, in Argentina in the immediate post-

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

era. Although superficially a "look-alike" for the

de Havilland Mosquito The de Havilland DH.98 Mosquito is a British twin-engined, shoulder-winged, multirole combat aircraft, introduced during the Second World War. Unusual in that its frame was constructed mostly of wood, it was nicknamed the "Wooden Wonder", or ...

, the I.Ae.24 was powered by twin

Pratt & Whitney R-1830 The Pratt & Whitney R-1830 Twin Wasp is an American air-cooled radial aircraft engine. It displaces and its bore and stroke are both . The design traces its history to 1929 experiments at Pratt & Whitney on twin-row designs. Production began ...

-G “Twin Wasp” radials giving it a distinct appearance. After an operational career spanning two decades, the Calquin was retired.

Design and development

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 A cantilever is a rigid structural element that extends horizontally and is supported at only one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a canti ...

mid-mounted wooden (indigenous woods were used throughout) wings with fabric-covered flying surfaces. The conventional main twin-oleo

undercarriage Undercarriage is the part of a moving vehicle that is underneath the main body of the vehicle. The term originally applied to this part of a horse-drawn carriage, and usage has since broadened to include: *The landing gear of an aircraft. *The ch ...

retracted into the engine

nacelle A nacelle ( ) is a "streamlined body, sized according to what it contains", such as an engine, fuel, or equipment on an aircraft. When attached by a pylon entirely outside the airframe, it is sometimes called a pod, in which case it is attached ...

s while the tailwheel retracted into the aft

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...

. The two-man crew were seated side by side under a large transparency constructed partly of

acrylic glass Poly(methyl methacrylate) (PMMA) belongs to a group of materials called engineering plastics. It is a transparent thermoplastic. PMMA is also known as acrylic, acrylic glass, as well as by the trade names and brands Crylux, Plexiglas, Acrylite, ...

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 Merlin The Rolls-Royce Merlin is a British liquid-cooled V-12 piston aero engine of 27-litres (1,650 cu in) capacity. Rolls-Royce designed the engine and first ran it in 1933 as a private venture. Initially known as the PV-12, it was later ...

s 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.Burzaco 1995, p. 65. 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".

Operational history

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 The Northrop A-17, a development of the Northrop Gamma 2F model, was a two-seat, single-engine, monoplane, attack bomber built in 1935 by the Northrop Corporation for the United States Army Air Corps. When in British Commonwealth service during W ...

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.Burzaco 1997, pp. 68–70. 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.

Operators

; *

Argentine Air Force "Argentine Wings" , mascot = , anniversaries = 10 August (anniversary) 1 May (Baptism of fire during the Falklands War) , equipment = 139 aircraft , equipment_label = , battles = * Operation Independence * Operation Soberanía * Falklan ...

Variants

;I.Ae.24 "Calquín" "early": had 4 x 12.7 mm browning ML or DL nationally manufactured heavy machine guns along with bomb ordnance.

;I.Ae.24 "Calquín" "late": had 4 x 20 mm Hispano-Suiza 804 automatic cannons along with bomb and rocket ordnance. IAe

;I.Ae.28 "Super Calquín":Evolved variant of the Calquin with Merlin engines and a look similar to the de Havilland "Mosquito", had a gunner and 4 - 6 x 20 mm cannons. Only a wooden mockup built. Led to the development of the I.Ae. 30 Ñancú.

Specifications (I.Ae.24 "Calquín")

Footnotes

References

Notes

Bibliography

* Burzaco, Ricardo. "I.Ae. 24 Calquin." ''Aeroespacio'', Nro. 52, November–December 1997. * Burzaco, Ricardo. ''Las Alas de Perón: Aeronaútica Argentina 1945/1960'' . Buenos Aires: Ed. Da Vinci, 1995. . * * ''Janes's All the World's Aircraft 1957-1958''. London: Jane's All the World's Aircraft, 1958. * Taylor, John W. R., and Jean Alexander. ''Combat Aircraft of the World.'' New York: G.P. Putnam's Sons, 1969. . * Taylor, Michael J.H. ''Janes's Encyclopedia of Aviation, Vol. 4''. Danbury, Connecticut: Grolier Educational Corporation, 1980. .

External links

I.Ae.24 "Calquin" (in Polish)

* ttps://web.archive.org/web/20080430210106/http://www.hangardigital.com.ar/calquin.html Aircraft history and specifications (in Spanish)
Aircraft history, specifications and colour images (in Spanish)

{{FMA aircraft 1940s Argentine bomber aircraft IAe024 Mid-wing aircraft Aircraft first flown in 1946 Twin piston-engined tractor aircraft