Definition
The Avro 642 Eighteen is a British three‑engine, low‑wing biplane airliner designed and built by the Avro aircraft company in the early 1930s. It was intended for short‑ to medium‑range commercial passenger service.
Overview
Developed as a successor to Avro’s earlier commercial types, the 642 Eighteen first flew in 1931 and entered limited service with a few airlines, primarily within the United Kingdom and the British Empire. Only a small number of aircraft were constructed, reflecting the rapid shift in the market toward more modern monoplane designs. The type was overshadowed by newer, faster, and more economical aircraft, and production ceased by the mid‑1930s.
Etymology/Origin
The designation “642” follows Avro’s internal numbering system for civil aircraft, while “Eighteen” denotes the intended passenger capacity of approximately eighteen seats. The name therefore combines the manufacturer’s model number with a descriptive reference to its seating layout.
Characteristics
- Configuration: Biplane with a low‑wing upper wing; fixed tailwheel landing gear.
- Powerplant: Three radial engines; typical installation used Armstrong Siddeley Lynx or Bristol Jupiter engines delivering between 340 hp and 420 hp each.
- Dimensions: Wingspan about 70 ft (21 m); length roughly 55 ft (17 m).
- Capacity: Seating for 18 passengers plus a crew of three (pilot, co‑pilot, and flight engineer).
- Performance: Maximum speed around 150 mph (240 km/h); cruise speed near 130 mph (210 km/h); service ceiling approximately 12,000 ft (3,660 m).
- Construction: Primarily wood and fabric covering over a steel tube fuselage frame, consistent with 1930s aircraft manufacturing practices.
- Operational Use: Employed by airlines such as British Airways Ltd. and regional carriers in the British colonies; also occasionally used for charter and mail flights.
Related Topics
- Avro 618 Ten (predecessor airliner)
- Avro 642 Eighteen’s contemporaries, e.g., de Havilland Dragon Rapide
- Evolution of British commercial aviation in the interwar period
- Transition from biplane to monoplane airliners in the 1930s
- Armstrong Siddeley Lynx and Bristol Jupiter radial engines.