The Alcor Junior was a small, six passenger, twin-engined airliner built in the U.S. and flown in 1938. As on Alcor's earlier Duo-4 and Duo-6, its inline engines were mounted horizontally to minimize their separation and drag. Only one was built; it was lost in a crash less than four months after its first flight.

Design and development

The C-6-1 was a low wing airliner of mixed wood and metal construction. Its wings were tapered in plan, ending in semi-elliptical tips, and were built around twin

spars The United States Coast Guard (USCG) Women's Reserve, also known as the SPARS (SPARS was the acronym for "Semper Paratus—Always Ready"), was the women's branch of the United States Coast Guard Reserve. It was established by the United States ...

. Its ribs were steel tube girder structures in inner, high stress regions around engine and

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 ...

attachment points but were spruce girders elsewhere. Wing covering was largely

plywood Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured ...

, except close to fuel tanks where

duralumin Duralumin (also called duraluminum, duraluminium, duralum, dural(l)ium, or dural) is a trade name for one of the earliest types of age-hardenable aluminium alloys. The term is a combination of '' Dürener'' and ''aluminium''. Its use as a tra ...

was used. The trailing edges carried hydraulically operated flaps and Frise ailerons. Though in the high wing Duo-4 and -6 the engines were mounted on the sides of the forward fuselage, the low wing of the C-6-1 enabled their attachment, cylinder heads together, to the forward wing spars, with steel trusses distributing loads to the rear spars. Their cowlings formed a local, inner extension of the

leading edge The leading edge of an airfoil surface such as a wing is its foremost edge and is therefore the part which first meets the oncoming air.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 305. Aviation Supplies & Academics, ...

s. The engines were , air-cooled,

supercharged In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement. The current categorisation is that a supercharger is a form of forced induct ...

, straight-six Menasco C-6S Super-Buccaneers. Their positioning brought the propeller tips to within . The forward fuselage, which included the engine and wing mountings, had a steel tube frame and was skinned with light alloy. Behind the cockpit the fuselage became a semi- monocoque wooden structure, with

spruce A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfami ...

frame A frame is often a structural system that supports other components of a physical construction and/or steel frame that limits the construction's extent. Frame and FRAME may also refer to: Physical objects In building construction *Framing (con ...

s and

longerons In engineering, a longeron and stringer is the load-bearing component of a framework. The term is commonly used in connection with aircraft fuselages and automobile chassis. Longerons are used in conjunction with stringers to form structural ...

under pressure-formed two-ply shell. The cockpit had seating for two with dual controls and the passenger cabin behind had three rows of seats in pairs either side of a central aisle. At the rear of the cabin there was a toilet and a baggage compartment with a radio cabin behind it. The C-6-1 had a conventional cantilever tail formed from plywood over wood frames. The horizontal tail, mounted on the top of the fuselage, was narrow and straight-edged but the vertical tail was much broader and curved, its dorsal fin rising slowly from the fuselage. Control surfaces were

balanced In telecommunications and professional audio, a balanced line or balanced signal pair is a circuit consisting of two conductors of the same type, both of which have equal impedances along their lengths and equal impedances to ground and to other ...

and fitted with trim tabs. Its main landing gear was retractable, with oleo legs retracting rearwards and rotating axially through 90° so the wheels, equipped with brakes, lay flat in the wings. The faired, oleo-legged tailwheel did not retract but lockably swivelled for ground manoeuvres. The first flight of the C-6-1 was made on March 6, 1938 and a brief development program showed good handling. However, during a test flight on June 27, 1938 the pilot initiated a high speed dive, not part of the flight program, from which he could not recover. The two crew escaped by parachute over

San Francisco Bay San Francisco Bay is a large tidal estuary in the U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the big cities of San Francisco, San Jose, and Oakland. San Francisco Bay drains water from a ...

, but the financial consequences ended Alcor Aircraft.

Specifications

References

{{reflist, refs= {{cite book , title= Jane's All the World's Aircraft 1938, last= Grey , first= C.G. , year=1972, publisher= David & Charles, location= London, isbn=0715 35734 4, page=244c {{cite web , url=https://oldmachinepress.com/2013/10/18/alcor-duo-4-duo-6-and-c-6-1-transports/, title=Old Machine Press - Alcor Duo-4, Duo-6, and C-6-1 Transports, author=William Pearce , date=18 October 2013 , access-date=18 September 2020 Twin piston-engined tractor aircraft Low-wing aircraft 1930s United States airliners Junior Aircraft first flown in 1938