Following on from the success of Avro designs during the Second World War, the Avro 688 and 689 Tudor series provided to be a most unhappy saga for AV Roe & Co Ltd and the Avro Tudor 2 did little to enhance the reputation of this great British aircraft manufacturer.
The Avro 688 Tudor 1 series (Avro Tudor 1, Avro Tudor 3, Avro Tudor 4 and Avro Tudor 8) are described separately but for this web page we concentrate on the Tudor 2, a piston-engined airliner based on the Avro Lincoln.
The original passenger capacity of the Avro 688 Tudor 1 (28 – 32 seats) was considered to be unsatisfactory and so a significantly larger version was developed. Designated the Avro 689 Tudor 2, it was designed as a 60-seat passenger aircraft for BOAC, with the fuselage diameter increased by 1 ft and lengthened by some 26 ft, taking it to 105 ft 7 in. This enlarged fuselage diameter contributed greatly to the aircrafts performance problems.
The Avro 688 Tudor 2 Series comprised the Avro Tudor 2, Avro Tudor 5 and Avro Tudor 7. Numerous variants were constructed with different engine installations and a succession of modifications to try and cure the types inadequate handling and stability problems. To add to the aircraft's list of issues, route-proving trials established problems in terms of fuel consumption and airfield performance.
The prototype Avro 688 Tudor 2 (G-AGSU) first flew on 10th March 1946, at Woodford. During flight testing, it became apparent that airfield performance in hot and high conditions would definitely restrict the payload and so initial orders by BOAC and QANTAS were considerably cut back.
The Avro 688 Tudor 2's poor performance demonstrated during tropical route-proving trials also resulted in BOAC not taking the aircraft into service and as a result only three production Avro 688 Tudor 2s were built.
During further testing, the prototype was destroyed on 23rd August 1947 in a fatal crash on take-off from Woodford, which also claimed the life Avro’s famous Chief Designer Roy Chadwick, and test pilot SA ‘Bill’ Thorn.
However, initial investigations into the tragedy revealed that the cause was a maintenance error rather than any form of design defect.
Six aircraft were built for British South American Airways (BSAA) these being designated as Tudor 5.
The Avro 689 Tudor 5 was a version of the Avro 688 Tudor 2 but equipped with 44 seats. These aircraft were also used as fuel tankers during the Berlin Airlift and in total completed 2,562 supply sorties during the Air Lift.
The second Avro 688 Tudor 2 was modified to accept Bristol Hercules radial engines and the aircraft then became the prototype for the Avro 689 Tudor 7 (G-AGRX), which first flew on 17th April 1946. The Avro 689 Tudor 7 was later fitted with alternate landing gear. This was to overcome ground clearance issues and was subsequently used by the Telecommunications Research Establishment at Defford (Re-registered as VX199). Sadly, it also failed to reach the production stage and was sold for spares in 1954.
The Avro 689 Tudor 8, powered by four Rolls-Royce Nene 4 turbo-jet engines, was developed from the Avro 688 Tudor 1 as an experimental aircraft.
It made its maiden flight at Woodford on 6th September 1948, and was demonstrated at Farnborough Air Show just a few days later. After a series of further tests at Boscombe Down and the Royal Aircraft Establishment (RAE) Farnborough the aircraft was scrapped in 1951, and a further account can be found on the Avro 688 Tudor 1 web page.
The Avro 689 Tudor 8 led to the similar Avro 706 Ashton (originally designated Tudor 9) which was based on the Tudor 2 airframe and is described on a separate web page.
Production of the Avro 689 Tudor series (Tudor 2, 5 and 7) comprised the prototype Avro 689 Tudor 2 (destroyed during flight test), four production Avro 689 Tudor 2, six Avro 689 Tudor 5 and one Avro Tudor 689 Tudor 7, a total of prototype and 10 production aircraft.
A total of thirty-three Avro Tudor aircraft were constructed in no less than seven variants with production consisting of Avro 688 Tudor 1: twelve (one of which was converted to Tudor 4 and then Tudor 8), Avro 689 Tudor 2: four (the prototype was destroyed during testing and three production aircraft), Avro 688 Tudor 3: two, Avro 688 Tudor 4: eight, Avro 689 Tudor 5: six and Avro 689 Tudor 7: one.
The total of Avro 688 Tudor 1 series was 22 aircraft; Avro 689 Tudor 2 series was the prototype (destroyed during flight testing) and 10 production aircraft.
Avro 689 Specifications
|Tudor 2||Tudor 5||Tudor 7|
|Powerplants||Four 1,770 hp R-R Merlin 621 engines||4 1,750 hp Bristol Hercules 120 engines|
|Span||120 ft 0 in|
|Maximum Weight||80,000 lb|
|Capacity||44 passengers(day), 36 (night)||Flight / test crew and test equipment|
|Maximum Speed||295 mph||270 mph|
|Cruising Speed||235 mph||200 mph|
|Range||2,330 miles||2,800 miles|
Variants & Numbers
|Number built and distinguishing features (Avro 689)|
|Avro 689 Tudor 2||60-seat passenger aircraft with the fuselage lengthened to 105 ft 7 in and diameter increased to 11ft. Four 1,750 h.p. Rolls-Royce Merlin 102, or 1,740 h.p. Merlin 600A engines. Prototype (destroyed under flight test) and three production aircraft.|
|Avro 689 Tudor 5||BSAA version of Tudor 2, powered by four 1,770 hp Rolls-Royce Merlin 621 piston engines, six built.|
|Avro 689 Tudor 7||Tudor 2 fitted with four 1,750 hp Bristol Hercules 120 engines, one prototype only.|
|Total built||11 aircraft (Prototype plus 3 Tudor 2, 6 Tudor 5, 1 Tudor 7)|
No Avro 689 Tudor 2 series aircraft survive.
Avro Heritage Museum (www.avroheritagemuseum.co.uk)