The Slingsby T.3 Primary (a.k.a. Dagling) was a single-seat training glider produced in the 1930s by Fred Slingsby in Kirbymoorside, Yorkshire.
During the 1920s Alexander Lippisch designed a training glider with very low performance to introduce pilots gradually to full-blown gliding. The result was a glider with a very simple structure of an open framework fuselage, with short wings attached by cables to a king post and the base of the fuselage. Lippisch's original design, the Z-gling (Pupil in English) had an all-wood fuselage but Wolf Hirth instigated a redesign of the rear fuselage using steel tubes.
The plans for the modified Z-gling made their way via the United States to the London Gliding Club and Reginald Foster Dagnall, whose RFD company put it into production as the RFD Primary. They built 27 in 1930-31. The type became known as the Dagling, a name formed by combining Dagnall and Z-gling, which later became used informally to cover all types of primary gliders in the UK. Fred Slingsby took over construction in 1934 and production continued up to the outbreak of World War II. The Primary should not be confused with the similar T.38 Grasshopper which was produced for the Air Training Corps in the 1950s.
Specifications
General characteristics
Crew: One
Length: 17 ft 10 in (5.447 m)
Wingspan: 34 ft 4 in (10.35 m)
Wing area: 162 ft2 (15.06 m2)
Aspect ratio: 11.1
Wing profile: G-ttingen 326
Empty weight: 180 lb (82 kg)
Gross weight: 380 lb (173 kg)
Variants
Slingsby T.3 Primary
Derived from the Wolf Hirth-modified Z-gling
RFD Primary Type AT
Production of the Primary by the R.F.D. Co, named Dagling from a contraction of Dagnall and Zögling.
Hawkridge Dagling
A modified Dagnall built post World War II by the Hawkridge Aircraft Co.