The original Type 688 Tudor was conceived in 1943 to Specification 29/43 as a commercial conversion of the Lancaster for use over the North Atlantic as a quick replacement for the bomber-transports then being used. As then envisaged, the Tudor was to be a modification of the Lancaster IV (later the Lincoln) with a new pressurised fuselage to carry a load of 1,705kg over 6,400km. Following the issue of the specification to Avro in March 1944 two prototypes were ordered and production contracts for BOAC (14 aircraft, plus six later) followed later in the same year and in 1945.

While development of the original Tudor continued - despite many difficulties - a new version with considerably lengthened fuselage was planned. This version was intended for use on the BOAC Empire routes; two prototypes were ordered in 1944, followed by production contracts. By this time the first version of the Tudor was available in its production form, but BOAC requirements had altered. This, and the aircraft's shorter than planned range, meant that the Tudor was no longer required as a passenger-carrying transport. British South American Airways Corporation (BSAAC), however, began using a modified version on their route to South America in 1947, and some of the aircraft laid down for BOAC were turned over to this operator. The Tudor 2 (with the lengthened fuselage) suffered a similar fate, and these were planned for conversion to freighters for BOAC.

Following the unexplained disappearance of two of BSAAC's Tudors in January 1948 and January 1949 while on passenger services, the Minister of Civil Aviation decreed that the type should no longer be used on passenger routes. The ban on passenger carrying lasted until 1954 when a Tudor belonging to Aviation Traders received an unrestricted C of A for passenger flights - following extensive modification to the aircraft which included fitting 1,311kW Rolls-Royce Merlin 623 engines. Virtually all surviving Tudors were similarly modified by Aviation Traders. Five Tudors were later further modified by fitting large freight doors; known thereafter as Super Traders, they remained in service until 1959.

The versions of the Tudor are listed below:

• Avro 688 Tudor 1. Powered by four Rolls-Royce Merlin 102, 621 or 623 engines. The original short-fuselage Tudor for the Atlantic route, seating 12-24 passengers. First flown 14 June 1945;
• Avro 689 Tudor 2. Four Rolls-Royce Merlin 102 or 621 engines. The original long-fuselage version for BOAC South African and Australian routes. Accommodation for up to 60 passengers. Thirty production aircraft ordered in November 1944 and a further 49 in April 1945, plus six to be built in Australia. Order reduced to 50 in 1946 and 18 in 1948. Final 18 were to consist of two Mk 2s for development work, six Mk 5s for BSAAC - and ten modified to freighters for BOAC.
• Avro 688 Tudor 3. Two additional Mk I airframes converted by Armstrong Whitworth for use as VIP transports by ministers.
• Avro 688 Tudor 4. Four Rolls-Royce Merlin 621 or 623 engines. A modification of the Tudor 1 to meet BSAAC requirements. Fuselage lengthened by 1.83m and accommodation for 32 passengers. Four aircraft originally ordered. Subsequently augmented by conversion of BOAC Mk Is.
• Avro 688 Tudor 4B. Two Tudor Is of BOAC contract modified to have lengthened fuselage of the Mk 4 for use by BSAAC, but retaining the flight engineer's station as on Mk I. Accommodation for 28 passengers.
• Type 689 Tudor 5. Four Rolls-Royce Merlin 621 engines. A modification of the Tudor 2, of which six were completed, five for BSAAC. Accommodation for 44 day or 36 night passengers. BSAAC aircraft delivered without passenger seats and used on Berlin Airlift. Sixth airframe converted to have four Bristol Hercules 120 engines.

3-View

A three-view drawing (700 x 669)