Intended as a Standard Class 15m span single-seater to replace the popular Olympia, the EoN 463, also known as the EoN 460/463, was the production version of the EoN 460 and incorporated the design experience and certain features of the laminar flow Olympia variants, especially the Olympia 403 and 419.

The EoN 460, or Elliotts AP/10 Type 460 as it was also known, first flew in prototype form on 26 April 1960 and only the five prototype 460s were built; the first had an aspect ratio of 20 and an all-up weight of 600 lb, the second and third had an aspect ratio of 18 and an all-up weight of 630 lb, the fourth was the same as the first but with a modified one-piece canopy and the fifth prototype was the same as the fourth but had modified outer wing sections. The tail unit was very similar to the Olympia 419’s and, as on the latter, the tailplane could be folded upwards for transport. The shoulder wings were set slightly lower than the Olympia’s and the centre and forward fuselage were similar to the Olympia 419’s, while the same NACA 64-series laminar flow wing section as on the 419 was used.

The Type 10 C EoN 460 was fitted with a modified cockpit canopy. The Type D was as the Type C but with modified sections to the outer wing. All types were fitted with folding tailplanes and the wings have Frise type ailerons.

The production versions of the EoN 460 were known as the EoN 460/463. They wee as the 460 Type D but with an aspect ratio of 18, and an AUW of 286 kg / 630 lb.

The production EoN 463 first flew in April 1963 and a total of 48 were built; this was practically the same as the fifth prototype 460, with an aspect ratio of 18 and an all-up weight of 630lb. The fabric and stringer top fuselage fairing of the 460 was now replaced by a glassfibre one on the 463, which also had a glassfibre instead of plywood nose section and a new cockpit canopy.

Both the 460 and 463 have wooden wings with light alloy spars, plywood-skinned and with overall fabric covering; the wings are similar to the Olympia 419’s except for the reduced span, the Frise ailerons being fabriccovered and the DFS-type air brakes of plywood. The fuselage, like the 460’s, is a wooden Warren girder type structure with plywood covering and a glassfibre rear fairing. The tail unit is a conventional fabric-covered wooden structure and the tailplane, unlike the all-moving surface of the Olympia 403 and 419, reverts to conventional elevators with a trim tab in the starboard one. There is a fixed unsprung mono-wheel with an internal expanding brake, and a tailwheel. The pilot’s canopy has direct vision panels and a demister, and oxygen and radio can be fitted if desired.

The 463 was followed by the EoN 465, developed for the 1965 World Championships, only two of these being built, the first one, the Series 1, making its maiden flight on 8 March 1965. The 465 had the fuselage height reduced and the pilot seated in a reclining position to reduce cross sectional area and hence drag; the main landing gear skid was deleted and the monowheel centre raised. An all-moving tailplane was reintroduced which did not fold up for storage. Pendulum sealed ailerons were fitted. The EoN 465 Series 1 had an all-up weight of 680lb and the second one, known as the Series 2, had a thinner wing section than the Series 1 and a strengthened main spar; its all-up weight was 700lb and wing area was increased to 140sq ft.

The 465 Srs.1 first flew in March 1965 and the Srs.2 in April 1965.

Following the death of Elliott’s managing director, Mr H. C. G. Buckingham, in the summer of 1965 the firm’s board of directors, after reviewing the situation, decided to end glider production due to its increasing unprofitability.

Type 10 EoN 460 Type A
Wingspan: 15.0 m / 49 ft 2 in
Length: 6.4 m / 21 ft 0 in
Wing area: 11.15 sq.m / 120 sq.ft
Aspect ratio: 20
Wing section: NACA 64,3,618 root / NACA 64,4,421 tip
Empty weight: 159.21 kg / 351 lb
AUW: 272 kg
Max speed: 215 kph / 134 mph
Aerotow speed: 152 kph / 95 mph

Type 10 EoN 460 Type B
Wingspan: 15.0 m / 49 ft 2 in
Length: 6.4 m / 21 ft 0 in
Wing area: 11.15 sq.m / 120 sq.ft
Aspect ratio: 18
Wing section: NACA 64,3,618 root / NACA 64,4,421 tip
Empty weight: 159.21 kg / 351 lb
AUW: 286 kg
Max speed: 215 kph / 134 mph
Aerotow speed: 152 kph / 95 mph

EoN 463
Span: 49 ft 2.5 in / 15.0 m
Length: 21 ft 0 in / 6.4 m
Height: 5ft 8 in
Wing area: 132 sqft / 12.26 sq.m
Aspect ratio: 18.0
Wing section: NACA 643618/421
Empty weight: 400 lb / 181 kg
Max weight: 630 lb / 286 kg
Water ballast: None
Max wing loading: 23.33 kg/sq.m / 4.78 lb/sq ft
Max speed: 136 mph / 117.5 kt / 218 km/h (in smooth air)
Max rough air speed: 74 kt / 137 km/h
Stalling speed: 30 kt / 56 km/h
Min sinking speed: 2.2 ft/sec / 0.67 m/sec at 42.5 mph / 37 kt / 69 km/h
Best glide ratio: 32:1 at 48 mph / 42 kt / 78 km/h

EoN 465 Srs.1
Span: 49 ft 2.5 in / 15.0 m
Length: 21 ft 2 in / 6.45 m
Height: 5ft 8 in
Wing area: 132 sqft / 12.26 sq.m
Aspect ratio: 18.0
Wing section: NACA 643618/421
Empty weight: 400 lb / 181 kg
Max weight: 680 lb / 308.44 kg
Water ballast: None
Max wing loading: 23.33 kg/sq.m / 4.78 lb/sq ft
Max speed: 136 mph / 117.5 kt / 218 km/h (in smooth air)
Max rough air speed: 74 kt / 137 km/h
Stalling speed: 30 kt / 56 km/h
Min sinking speed: 2.2 ft/sec / 0.67 m/sec at 42.5 mph / 37 kt / 69 km/h
Best glide ratio: 32:1 at 48 mph / 42 kt / 78 km/h

EoN 465 Srs.2
Span: 49 ft 2.5 in / 15.0 m
Length: 21 ft 2 in / 6.45 m
Height: 5ft 8 in
Wing area: 132 sqft / 12.26 sq.m
Aspect ratio: 18.0
Wing section: NACA 643618/421
Empty weight: 400 lb / 181 kg
Max weight: 700 lb / 317.52 kg
Water ballast: None
Max wing loading: 23.33 kg/sq.m / 4.78 lb/sq ft
Max speed: 136 mph / 117.5 kt / 218 km/h (in smooth air)
Max rough air speed: 74 kt / 137 km/h
Stalling speed: 30 kt / 56 km/h
Min sinking speed: 2.2 ft/sec / 0.67 m/sec at 42.5 mph / 37 kt / 69 km/h
Best glide ratio: 32:1 at 48 mph / 42 kt / 78 km/h

The initial version, known as the Crabpot, was designed by H. Kendall for the 1947 B.G.A. Two-seat Sailplane Competition. Conventional wooden construction, apart from the wings which had several spanwise webs and few ribs. The webs were 15mm thick, and the ribs were spaced at from 900 to 1200 mm pitch.

A cantilever wing, no flaps but airbrakes were fitted. All moving tailplane.

A project only, it won the competition.

Having one the competition, the Crabpot was re-designed. The wing section was altered, a “V” tail introduced, and the fuselage shortened. The wing material was altered and it was decided to manufacture it using an asbestos reinforced low pressure thermos setting plastic structure, a method that involved the use of heated concrete moulds and tailored felts. The wing was manufactured by F.G. Miles Ltd at Redhill Aerodrome, under the designation Miles M.76, but when tested, it broke up at a fraction of the design load. The K.1, as the Crabpot was by then known, was later built, using the traditional wooden construction methods, by Elliots of Newbury, as the EoN Type 9.

Only one was built, the first flight being at Lasham in March 1954, with full span ailerons. No CofA was issued as the K.1 was abandoned due to unsatisfactory flying characteristics, particularly unsolvable spinning problems.

Kendall Crabpot / K.1
Wingspan: 18.3 m / 60 ft 0 in
Length: 8.24 m / 27 ft 0 in
Wing area: 18.58 sq.m / 200 sq.ft
Aspect ratio: 18
Wing section: NACA 43018 root, NACA 43012A tip
Empty weight: 232 kg / 516 lb
AUW: 414 kg / 911 lb
Wing loading: 21.0 kg/sq.m / 4.3 lb/sq.ft
Max L/D: 27 at 77 kph / 49 mph

EoN Type 9
Wingspan: 18.3 m / 60 ft 0 in
Length: 7.01 m / 23 ft 0 in
Wing area: 18.58 sq.m / 200 sq.ft
Aspect ratio: 18
Wing section: NACA 66,3,418, NACA 64,2,415 tip
Empty weight: 300 kg / 661.5 lb
AUW: 453.6 kg / 1000 lb
Max speed: 200 kph / 125 mph
Stall: 64 kph / 40 mph
Max L/D: 35

The EoN Primary, or Elliotts AP/7 Primary EoN as it is known in full, is a more modern but essentially very similar version of the Dagling/SlingsbyT-3 Primary and SG 38 formula of the 1930s for a simple single-seater basic training glider.

The prototype made its first flight in February 1948, and the first production model flew in April that year; the type was used not only by clubs but by the Air Training Corps and Combined Cadet Force under the service name of Eton TX Mk 1 to replace the Daglings previously used for Cadet instruction. It could also be supplied with a static training stand which acted as a simple flight simulator in which the glider was balanced on a pivot and wind forces assisted the trainee pilot to get the feel of the controls.

The constant chord wooden wing is wire-braced and has a high lift section of 12% thickness/chord ratio; it has a plywood leading edge and fabric covering, with fabric-covered wooden ailerons. Plywood leading edge spoilers are featured for use during ground-slides only. The fuselage is a flat wooden open girder-type structure supported by a horizontal beam with the landing skid underneath, with sprung compression legs; the pilot has a single open seat with minimum controls. Unlike the Dagling and Slingsby Primary, the EoN design did not have the option of a nacelle to provide some protection for the pilot. The tail unit is of fabric covered wooden construction and strut and wire braced, effective fin area being provided by filling in part of the open rear fuselage in front of the rudder.

Production of the EoN Primary ended in 1958 after 80 had been built, but a number of these were still at Elliotts’ works at Newbury ready for final assembly in the spring of 1965, not long before Elliotts ceased all glider production.

Span: 34 ft 0 in 10.36 m
Length: 20 ft 6 in / 6.25 m
Height: 8 ft 0 in
Wing area: 180 sqft / 16.72 sq.m
Aspect ratio: 6.0
Empty weight: 250 lb / 113 kg
Max weight: 490 lb / 222 kg
Wing loading: 2.8 lb/sq.ft / 13.7 kg/sq.m
Max speed: 73 mph / 117 kph
Max aero-tow speed: 54 mph / 87 kph
Stalling speed: 27 mph / 43.5 kph
Max L/D: 8