Junkers T 27
| Industry | Aerospace |
|---|---|
| Founded | 1895 in Dessau, Germany |
| Headquarters | Dessau , Germany |
The Junkers T 23 was a German-built, two-seat, single-engine experimental trainer developed during the early 1920s. Its unique design allowed it to be operated either as a parasol wing monoplane or as a biplane, facilitating direct comparison of flight characteristics. A total of four units were manufactured.
Design and development
Among the rare aircraft designed for dual configuration, the Junkers T 23 could be flown as either a monoplane or a biplane. The monoplane variant, designated T 23E (with "E" standing for Eindecker), was equipped with a parasol wing, whereas the biplane version, T 23D (Doppeldecker), featured a sesquiplane layout. This model represented an enlarged, two-seat iteration of the parasol-winged Junkers T 19, conceived both for experimental evaluation and entry into the light aircraft sector. Its primary objective was to assess whether the monoplane’s handling qualities could match or surpass those of the biplane, which benefited from lower wing loading, particularly in terms of pilot training suitability.
The monoplane T 23 shared numerous design elements with its predecessor, the T 19, including construction predominantly from duralumin with a tubular framework sheathed in corrugated metal panels. While the wing design was similar, it featured an increased wingspan by 2.5 meters and extended curved ailerons. The wing center section was supported by forward V-shaped cabane struts linking it to the fuselage, with rear struts reminiscent of those found on the T 21. Unlike the monoplane, which had a cantilever parasol wing requiring no external bracing, the biplane T 23D included a smaller lower wing mounted beneath the fuselage at approximately 77% of the upper wing’s span. This lower wing was connected to the upper wing by vertical V-shaped struts near its tips, resulting in a 57% increase in total wing area and adding roughly 75 kilograms to structural weight.
The fuselage was characterized by flat sides and contained tandem seating arrangements: the front cockpit positioned beneath the leading edge of the wing and a rear cockpit accessed through a door on the starboard side. The tail assembly consisted of a horizontal stabilizer mounted atop the fuselage with horn-balanced elevators; a triangular fin supported a flat-topped rudder that extended between elevator cutouts. The main landing gear incorporated shock-absorbing legs attached to upper fuselage longerons, reinforced by forward bracing struts connected to the lower fuselage, while wheels were joined by a hinged axle.
Propulsion was provided by an 80 hp (60 kW) Le Rhône rotary engine enclosed within a circular cowling driving a two-bladed propeller.
Operational history
The inaugural flight of the T 23 occurred on 14 September 1923 in its biplane configuration. Following several months dedicated to flight testing, it underwent conversion into its monoplane form. Compared to the biplane setup, the T 23E monoplane demonstrated increased landing and takeoff speeds alongside longer takeoff runs attributable to higher wing loading. It also achieved approximately 15 km/h greater speed and accommodated about 9% more payload capacity. Upon completion of evaluation activities, all four produced T 23 aircraft were sold to flying clubs.
Variants
- Junkers T 23D
- (D - Doppeldecker - biplane) The initial biplane model of the series.
- Junkers T 23E
- (E - Eindecker - monoplane) A monoplane variant that omits the lower wing.
- Junkers T 26
- A streamlined development of the T 23, equipped with a 62 kW (83 hp) air-cooled Junkers L1 six-cylinder inline engine housed in a circular cowling, increasing the aircraft's length by 280 mm. Offered in both D and E layouts, this version exhibited a slight reduction in speed but nearly doubled its operational range to 345 km (214 mi). Its maiden flight occurred on 23 October 1923, with production limited to approximately eleven units due to its elevated cost for use in flight training.
- Junkers T 27
- A single T 26D model upgraded with a more potent 95 kW (128 hp) nine-cylinder Clerget 9Z rotary engine, first flown in 1925.