Kalpana Kalpana (Editor)

General Aircraft Monospar

Updated on
Edit
Like
Comment
Share on FacebookTweet on TwitterShare on LinkedInShare on Reddit
Top speed
  
254 km/h

Length
  
8.03 m

Manufacturer
  
General Aircraft Limited

Wingspan
  
12 m

First flight
  
1932

General Aircraft Monospar wwwflightjournalcomwpcontentuploads201112C

The General Aircraft Monospar was a 1930s British family of touring and utility aircraft built by General Aircraft Ltd (GAL).

Contents

General Aircraft Monospar General Aircraft Monospar ST12 Untitled Aviation Photo 1957973

Design and development

General Aircraft Monospar FileMonospar 05651jpg Wikimedia Commons

In 1929, the Monospar Company Ltd was formed to pursue new techniques of designing cantilever wings, based on the work of Swiss engineer Helmuth J. Stieger, who headed the company. Helmuth John Stieger was born in Zurich in 1902 and educated at the Swiss Federal Polytechnic then the Imperial College of Science in London. While working as a designer for William Beardmore and Company, he formed his own ideas about wing design and evolved an improved method of building and stressing wings for which he was later granted a British Patent in December 1927. The principle behind this Patent No. 306,220 was that the wing needed only one spar with torsion loads resisted by an efficient system of strong compression struts with triangulated bracing in the form of thin wires. The design was revolutionary and very light for its strength.

General Aircraft Monospar General Aircraft Monospar ST25 Universal

Based on this design, The Monospar Company designed a twin-engined low-wing aircraft designated the Monospar ST-3, that was built and flown in 1931 by the Gloster Aircraft Company at Brockworth, Gloucestershire. After successful testing of the Monospar ST-3, a new company General Aircraft Ltd was formed to produce aircraft that used the new Monospar wing designs.

General Aircraft Monospar General Aircraft Monospar ST25 Universal

The first production design was the Monospar ST-4, a twin-engined low-wing monoplane with a fixed tailwheel landing gear and folding wings for ground storage. Powered by two Pobjoy R radial engines, the first aircraft (G-ABUZ) first flew in May 1932, and was followed by five production aircraft. The Monospar ST-4 Mk.II, an improved variant with minor differences, followed with a production run of 30. In 1933, the Monospar ST-6 appeared, a similar aircraft to the ST-4 with manually retractable landing gear and room for an extra passenger. The Monospar ST-6 was only the second British aircraft to fly with retractable landing gear (the first, the Airspeed Courier, was flown a few weeks earlier). Another Monospar ST-6 was built, and two ST-4 Mk.IIs were converted. GAL then produced a developed version, the Monospar ST-10, externally the same but powered by two Pobjoy Niagara engines, an improved fuel system, and aerodynamic refinements.

General Aircraft Monospar General Aircraft Monospar ST4 ST12

The Croydon factory closed down in 1934, and a larger factory was opened in 1935 at London Air Park, Hanworth.

Operational history

General Aircraft Monospar General Aircraft Monospar Wikipedia

The Monospar ST-10 prototype (G-ACTS) won the 1934 King's Cup Air Race with an average speed of 134.16 mph. Only one other ST-10 was built, along with two similar ST-11s with de Havilland Gipsy Major engines for export to Australia. A production batch of ten Monospar ST-12 aircraft was based on the ST-11 with fixed landing gear.

Variants

Monospar ST-3
Experimental cantilever monoplane, one built.
Monospar ST-4
Cantilever touring monoplane, seven built.
Monospar ST-4 Mk.II
Improved variant of ST-4, 22 built, two later converted to ST-6 standard.
Monospar ST-6
As ST-4 with manual retractable landing gear, two built and two conversions from ST-4 Mk.IIs.
Monospar ST-10
Improved variant with two Pobjoy Niagara engines, two built.
Monospar ST-11
de Havilland Gipsy Major engined variant, two built.
Monospar ST-12
Fixed landing gear variant with two de Havilland Gipsy Major engines, ten built.
Monospar ST-18
Ten-seat transport with two Pratt and Whitney Wasp Junior engines, one built.
Monospar ST-25 series
Development of Monospar ST-10

Operators

 Portugal
  • Portuguese Navy
  •  South Africa
  • South African Air Force
  •  Spanish Republic
  • Spanish Republican Air Force, 1936 from LAPE
  •  Spain
  • Spanish Air Force
  •  Turkey
  • Turkish Air Force
  • Civil operators

     Brazil
  • VASP, 1933-1938
  • Survivors

  • One Monospar ST-12 (registration VH-UTH) is held by the Newark Air Museum, England
  • Specifications (Monospar ST-12)

    Data from The Illustrated Encyclopedia of Aircraft

    General characteristics

  • Capacity: four
  • Length: 26 ft 4 in (8.03 m)
  • Wingspan: 40 ft 2 in (12.24 m)
  • Height: 7 ft 10 in (2.30 m)
  • Wing area: 217 ft2 (20.16 m2)
  • Empty weight: 1,840 lb (835 kg)
  • Gross weight: 2,875 lb (1,304 kg)
  • Powerplant: 2 × de Havilland Gipsy Major 4-cylinder inverted inline piston engine, 130 hp (97 kW) each
  • Performance

  • Maximum speed: 158 mph (254 km/h)
  • Range: 410 miles (660 km)
  • Service ceiling: 21,000 ft (6,400 m)
  • References

    General Aircraft Monospar Wikipedia


    Similar Topics