The Interstate Cadet was an American two-seat tandem, high wing, single-engine monoplane light aircraft. Around 320 of these aircraft were produced between the years 1941 and 1942 by the Interstate Aircraft and Engineering Corporation based in El Segundo, California. The construction techniques employed were a welded steel tube fuselage, wood (spruce) wing structure with metal ribs, and fabric covering, all of which were fairly standard in the 1940s. An Interstate Cadet, flown by aviator

Cornelia Fort Cornelia Clark Fort (February 5, 1919 – March 21, 1943) was a United States aviator who became famous for being part of two aviation-related events. The first occurred while conducting a civilian training flight at Pearl Harbor on December 7, 1 ...

and an unknown student, was one of the first aircraft (if not the first) to be attacked by IJNAS Japanese naval planes en route to the Pearl Harbor attack on December 7, 1941.

Design and development

The original version, the S1 prototype, was powered by the 50 hp Continental A50 engine, but was soon upgraded to the Continental A65 engine and redesignated as the S1-A-65F. This was a common engine used in many small American two-seat aircraft of the time. This aircraft would be used during World War II under the L-6A designation. In 1945 the rights to the aircraft were sold to

Harlow Aircraft Company Harlow Aircraft Company was an American aircraft manufacturer at Alhambra Airport, Alhambra, California. History The company was founded in 1936 by professor Max B. Harlow to build the Harlow PJC-2 a production version of the PJC-1. The aircraf ...

, which in turn resold the tooling and parts to the

Call Aircraft Company The Call Aircraft Company (CAC or CallAir) was established by Reuel Call in 1939 at Afton, Wyoming to build a touring aircraft of his own design. History The Call Aircraft Company hoped to advance the development of its CallAir Model A to the poin ...

of Afton, Wyoming in 1946 for $5,000 ($ in ). Callair rebuilt a number of S-1, S-1A and L-6s, some with engine upgrades, for local ranchers and bush pilots as well as two examples of their own serial numbered CallAir S-1A-90C before stopping production, focusing instead on variations of its original CallAir Model A (which also sold in small numbers, fewer than 200 total units)., One reason the Cadet may not have sold well was that this aircraft cost almost three times the amount of the comparable Piper J-3 Cub. However, a close look at the two aircraft reveals that the Cadet was faster, stronger, and could be operated in a more rugged environment with its Oleo strut/Compression spring suspension system. Popular upgrades for this airframe included larger engines(75/85/90/100 hp), better brakes, and a different tailwheel system. In the late 1960s the type certificates and tooling were bought by the newly formed Arctic Aircraft Company who transformed the S-1B1 into a bush plane by upgrading structural elements of the fuselage, landing gear and wings. This aircraft was designated the S-1B2, was used a Lycoming O-320 160 HP engine and a McCauley propeller for increased performance and was certified in 1975 as the

Arctic Tern The Arctic tern (''Sterna paradisaea'') is a tern in the family Laridae. This bird has a circumpolar breeding distribution covering the Arctic and sub-Arctic regions of Europe (as far south as Brittany), Asia, and North America (as far south a ...

. The new Type certification also covered installing the same engine in otherwise standard Interstate Cadets.

Variants

;S-1 :Certified in 1940 and powered by a Continental A50-8 engine. ;S-1A :Certified in 1941 and powered by a Continental A65-8 engine. Interstate S-1A-65F Cadet

;S-1A-65F :1941 variant powered by a 65hp

Franklin 4AC-176-B2 The Franklin O-175 (company designation 4AC-176) was an American air-cooled aircraft engine of the 1940s. The engine was of horizontally-opposed four-cylinder and displaced . The power output was nominally . A later variant was designated O- ...

engine. ;S-1A-85F :1942 variant powered by an 85hp

Franklin 4AC-199-D2 The Franklin O-200 (company designation 4AC-199) was an American air-cooled aircraft engine of the early 1940s. The engine was of four-cylinder, horizontally-opposed layout and displaced . The power output ranged between and depending on vari ...

engine. ;S-1A-90C :1952 Callair variant powered by a 90hp Continental C90-8 engine.only two built. ;S-1A-90F :1942 variant powered by 90hp

Franklin 4AC-199-E2 The Franklin O-200 (company designation 4AC-199) was an American air-cooled aircraft engine of the early 1940s. The engine was of four-cylinder, horizontally-opposed layout and displaced . The power output ranged between and depending on vari ...

engine. ;S-1B1 :1942 variant with a

Franklin 4ACG-199-H3 The Franklin O-200 (company designation 4AC-199) was an American air-cooled aircraft engine of the early 1940s. The engine was of four-cylinder, horizontally-opposed layout and displaced . The power output ranged between and depending on vari ...

engine. Military production as the L-6 Grasshopper. ;S-1B2 (

) :1975 improved variant of the S-1B1 powered by a

Lycoming O-320-A2B The Lycoming O-320 is a large family of naturally aspirated, air-cooled, four-cylinder, direct-drive engines produced by Lycoming Engines. They are commonly used on light aircraft such as the Cessna 172 and Piper Cherokee. Different variants ...

or B2B engine. ;XO-63 Grasshopper :United States Army designation for one S-1B for evaluation, later designated the XL-6. ;L-6A Grasshopper :United States Army designation for the S-1B1, 250 built. ;L-8A Cadet :United States Army designation for eight S-1As ordered on behalf of the Bolivian Air Force.

Specifications (S-1B1)

References

;Notes ;Bibliography * {{USAAF observation aircraft Interstate aircraft 1940s United States civil utility aircraft High-wing aircraft Single-engined tractor aircraft Aircraft first flown in 1940

Design and development

Variants

Specifications (S-1B1)

See also

References