S.G.38 Glider: Technical Specifications and Performance
The S.G.38 is a classic example of early sailplane design, engineered for stability and efficiency in unpowered flight. As a primary glider, it served as a foundational tool for pilots to master the basics of aerodynamics and control before progressing to more complex aircraft.
One notable example of this aircraft's legacy is the specimen at Shuttleworth's Primary. While it began its life as an EoN Primary, it was meticulously restored to the S.G.38 configuration, preserving the historical integrity of the design.
Key Facts
- Crew: Single-pilot operation.
- Empty Weight: Extremely lightweight at 250 lb (113 kg).
- Maximum Speed: Capable of reaching 73 mph (117 km/h).
- Glide Efficiency: Features a maximum glide ratio of 8.
- Stall Speed: Low stall speed of 27 mph (43 km/h).
Design and Physical Characteristics
The S.G.38 is characterized by its lightweight construction and specific geometric proportions designed to maximize lift. The aircraft features a wingspan of 34 ft 0 in (10.36 m) and a total length of 20 ft 6 in (6.25 m), standing 8 ft 0 in (2.44 m) tall.
The wing area totals 180 sq ft (17 m), with an aspect ratio—the ratio of the wingspan to the mean chord—of 6:1. This ratio is a critical factor in determining the aerodynamic efficiency of the wing, balancing lift generation against induced drag.
Flight Performance and Weight
Engineered for low-speed stability, the S.G.38 has a maximum takeoff weight of 490 lb (222 kg). Its performance profile is tailored for gliding, with a maximum speed of 73 mph (117 km/h) and a very manageable stall speed of 27 mph (43 km/h), which is the minimum speed at which the aircraft can maintain level flight.
The aircraft's efficiency is measured by its maximum glide ratio of 8. This means that for every unit of altitude lost, the glider can travel eight units of horizontal distance, provided it is flown at the optimal glide speed.
Technical Specifications Summary
| Category | Metric | Imperial Value | Metric Value |
|---|---|---|---|
| Dimensions | Wingspan | 34 ft 0 in | 10.36 m |
| Dimensions | Length | 20 ft 6 in | 6.25 m |
| Weight | Empty Weight | 250 lb | 113 kg |
| Weight | Max Takeoff Weight | 490 lb | 222 kg |
| Performance | Max Speed | 73 mph | 117 km/h |
| Performance | Stall Speed | 27 mph | 43 km/h |
| Aerodynamics | Max Glide Ratio | 8 | 8 |
Frequently Asked Questions
What is the maximum speed of the S.G.38?
The S.G.38 has a maximum speed of 73 mph (117 km/h or 63 kn).
What is the glide ratio of this aircraft?
The aircraft features a maximum glide ratio of 8, meaning it can travel 8 units of distance for every 1 unit of altitude lost.
How heavy is the S.G.38 when empty?
The empty weight of the S.G.38 is 250 lb (113 kg).
What is the stall speed of the S.G.38?
The stall speed, the minimum speed required to maintain flight, is 27 mph (43 km/h or 23 kn).
What is the aspect ratio of the wings?
The wings of the S.G.38 have an aspect ratio of 6:1.