Avro 626

Infobox Aircraft
name=Avro 626


caption=One of seven Avro Prefects used for navigation training at RAF Andover c. 1933
type=Trainer
manufacturer=Avro
designer=Roy Chadwick
first flight=avyear|1930
introduced=
retired=avyear|1945
status=
primary user=
more users=
produced=
number built=198
unit cost=
variants with their own articles=Avro 621The Avro 626 is a single engined British biplane trainer aircraft produced by Avro during the inter war period.

Design and development

The Model 626 was developed by Avro from the company's Model 621 (Avro Tutor) for export to smaller air forces, the idea being that the 626 would be a single aircraft that could carry out general aircrew training as well as a number of other roles. The types 621 and 626 were both two-seaters, but the latter had an additional cockpit behind the rear seat of the 621 and accessible from it. This additional cockpit was fitted with a Scarff ring and carried equipment for air navigation, wireless and gunnery training. Structurally and aerodynamically it was almost identical to the Tutor: it had a conventional fabric-covered, metal airframe with single bay wings.Most of the 626s, like the Tutors had an Armstrong Siddeley Lynx IVC engines of 240 h.p., but most of those supplied to the Egyptian and Brazilian Air Forces used a 260 h.p. Cheetah V from the same maker.

The usual undercarriage used split, fixed main-wheels and either a tail-skid or later a tail-wheel, but some 621s appeared on floats and on skis.

The prototype was first flown in 1930.

Operational history

Avro utilised an aggressive sales and marketing effort to introduce the Model 626 to customers throughout the world. An early production demonstration aircraft, marked "G-ABFM" [ Jackson 1990, p. 295 ] was sent by sea to South America in 1931. After demonstrations in Buenos Aires and a record-setting flight over the Andes, the aircraft was commandeered by Argentine military officials to help quell a local uprising. The 626 performed so well that an order was immediately placed for 14 additional aircraft. The biggest users were the Air Forces of Chile, Greece and Portugal. Numerous sales were made to foreign air forces up to 1939, some of which survived in second-line service until 1945.

The 621 was not a civil type, though some did briefly appear on the civil registers of the UK (15) and Hong Kong (6) [http://www.goldenyears.ukf.net/reg_VR-H.htm] . These markings were worn for testing, demonstration and export; only two civil machines stayed on the U.K.register pre-war. After the war, two R.A.F. Prefects were civilianised, as was one in New Zealand.

Variants

* Avro 626: Two seat multi-purpose aircraft
* Avro Prefect : RAF and RNZAF name for the 626; in the period most RAF aircraft received names [ Jackson 1990, p. 296-297. Quote: "During their service life these machines were known simply as Avro Prefects without type number, to distinguish them from the Avro 626"] . All RNZAF Prefects had three cockpits. All the RAF machines were two-seat navigational training aircraft "without" the third cockpit installed [ Jackson 1990, p.296] .
* Avro 637 : Armed patrol version of the Avro 626. Pilot had a Vickers gun mounted on the fuselage while the observer/gunner was armed with a Lewis gun on an Avro low-drag mounting. This variant featured slightly larger wingspan with rounded wingtips. Eight aircraft were sold to the Kwangsi Air Force (Government of South China) in China.
* Tatra T-126: Licence built 626, manufactured in Czechoslovakia; two versions produced: one with 355 hp Avia Rk. 17 and export version for Turkey and the Balkans with 260 hp Armstrong Siddeley Cheetah V

Production

198 Avro 626s and Prefects were produced [Jackson pp.296-8 Note: 1965 edition data and pagination. The numbers are for ordered aircraft plus demonstrators left behind] . ;ARG: Received 15.;AUT: Received 7.;BEL: 12, 2 of which were still in service at the time of the German invasion in 1940. [Pacco 2003, p. 83] .;BRA: Received 16. ;flag|Canada|1921: Received 12. RCAF machines featured cold weather cowlings, enclosed cockpits and skis. They were issued to No. 3 Squadron and no. 111 squadron; they survived until early World War II. ;China as ROC: China Probably received 13, certainly 11. May have built one itself. All served in the Second Sino-Japanese War.;CHI: Received 20.;CZS: Received 1. Tatra manufactured an uncertain number under licence.;flag|Egypt|1922: Received 27 - their first military aircraft, as distinct from DH60 Moths. Only 25 served, as two were lost in delivery and replaced Egyptian 626s served from 1933 until 1944. ;EST: Received 4. ;GRE: Received 21 which were in service at the time of the Italian invasion, 3 Hellenic Air Force machines escaped the fall of Greece to join the RAF in the desert. ;IRL: Received 4, which served until 1941.;flag|Lithuania: Received 4. the type was still in service at the time of the Russian invasion.;NZL: Received 4 Lynx-engined but three-cockpit Prefect aircraft for the RNZAF in 1935. These were used by No 1 Flying Training School. "NZ203", c/n 811, survived the war and was purchased by Mr. J. Frogley in 1948 who registered it as "ZK-APC". "'APC" ceased flying in 1958 but in the 1980s it was acquired by the Royal New Zealand Air Force Museum and returned to the air. It is the sole surviving active 621 or Prefect.;POR: Received 26 directly from Avro. A manufacturing licence was issued to the Portuguese factory OGMA, but it is not known how many were built by them.. ;ESP: An uncertain number served with the Republicans in the Spanish Civil War. These did not come direct from Avro. ;UK: Received 7 two-seater Prefects for air navigation training. Delivered in 1935, they operated during World War II on miscellaneous duties.

pecifications (Avro 626 (Lynx IVC engine))

aircraft specifications

plane or copter?=plane
jet or prop?=prop

ref="Avro Aircraft since 1908 [ Jackson 1990, p. 298.]

crew=Two
capacity=
length main= 26 ft 6 in
length alt= (8.08 m)
span main= 34 ft 0 in
span alt= 10.36 m
height main= 9 ft 7 in
height alt= 2.92m
area main= 300 ft²
area alt= 27.9 m²
airfoil=
empty weight main= 1,765 lb
empty weight alt= 801 kg
loaded weight main= 2,750 lb
loaded weight alt= 1,247 kg
useful load main=
useful load alt=
max takeoff weight main=
max takeoff weight alt=
more general=

engine (prop)=Armstrong Siddeley Lynx IVC
type of prop=7-cylinder radial
number of props=1
power main= 210 hp
power alt= 157 kW
power original=
max speed main= 97 knots
max speed alt= 112 mph, 180 km/h
cruise speed main= 83 knots
cruise speed alt= 95 mph, 153 km/h
never exceed speed main=
never exceed speed alt=
stall speed main=
stall speed alt=
range main= 209 nm
range alt= 240 mi, 386 km
ceiling main= 14,800 ft
ceiling alt= 4,511 m
climb rate main= 880 ft/min
climb rate alt= 4.5 m/s
loading main= 9.18 lb/ft²
loading alt= 44.7 kg/m²
thrust/weight=
power/mass main= 0.076 hp/lb
power/mass alt= 0.126 kW/kg
more performance=

armament=

avionics=

References

Notes

Bibliography

* Jackson, A.J. "Avro Aircraft since 1908, 2nd edition". London: Putnam Aeronautical Books, 1990. ISBN 0-85177-834-8.
* Pacco, John. "Avro 626 'Prefect'" "Belgisch Leger/Armee Belge: Het Militair Vliegwezen/l'Aeronautique Militaire 1930-1940". Aartselaar, Belgium, 2003, p. 83. ISBN 90-801136-6-2.

External links

* [http://www.airforcemuseum.co.nz/main/avro626/ RNZAF Museum Prefect page] aircontent

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