Stinson Model A

Infobox Aircraft
name = Stinson Model A



caption = Stinson "Model A" in American Airlines colours from a cigarette card by Players, 1936
type = Airliner
national origin =United States
manufacturer = Stinson Aircraft Company
designer =
first flight = April 27, 1934
introduction =
retired =
status =
primary user = American Airlines
more users =
produced =
number built = 31
program cost =
unit cost =
developed from =
variants with their own articles =

The Stinson Model A was a moderately successful airliner of the mid-1930s. It was one of the last commercial airliners designed in the United States of America with a fabric-covered steel tube fuselage before the introduction of stressed skin aluminum construction.

Design History

The Stinson Aircraft Company’s last trimotor was a low wing monoplane, designed in 1933 as an eight-seat feeder-liner for American Airlines. Featuring an unusual double-tapered wing that, combined with its tubby fuselage and forward-raked windscreen, gave it a markedly sinister appearance, it also boasted retractable undercarriage that left the lower part of the wheels exposed below the engine nacelles while in the raised position, as many pilots forgot to lower the undercarriage on landing. Passengers were seated in two rows of three and a paired seat behind the enclosed cockpit, while fitted aft were a hold for 500 pounds of luggage and freight, and that ultimate luxury for the time, an on-board lavatory.

A total of 30 Stinson Model As were built until production ceased in 1936. It was one of many promising designs whose commercial success was cut short by the introduction of the stressed-skin Boeing 247 and Douglas DC-2.

The Stinson Model A in Australia

Airlines of Australia (AOA) ordered three Stinson Model As in January 1936 – because the waiting lists for either the new Boeing or Douglas were already too long. These aircraft were VH-UGG "Lismore " (arrived per s.s. "City of Winchester" on 27 March), VH-UHH "Brisbane" (arrived per s.s. "Wichita" on 22 June) and VH-UKK "Townsville" (arrived 22 July in the s.s. "City of Manilla").

All three were quickly reassembled and entered the Sydney - Brisbane service, proving so successful that in August AOA ordered a fourth example VH-UYY "Grafton" – the very last Stinson Model A to be built – which arrived at Sydney on board s.s. "Port Alma" on 14 December.

Legendary air disasters and their consequences

With posturing from both AOA and Australian National Airways (ANA) to cut into each other’s turf by late 1936, early efforts by ANA to gain a controlling interest in AOA failed, until the tragic losses of VH-UHH Brisbane in the McPherson Ranges on 19 February 1937 and VH-UGG "Lismore" on 28 March halved AOA’s main-line fleet. A merger took effect in March 1937, although the two companies retained separate identities until AOA was formally absorbed into ANA on 1 July 1942. The two surviving Stinsons were then renamed VH-UKK "Binana" and VH-UYY "Tokana", in conformity with ANA nomenclature.

Australian conversion from Trimotor to Twin Engine

During the Second World War spare parts for the Stinsons' aging Lycoming radial engines were impossible to obtain, and it was decided to rebuild both aircraft with twin Pratt & Whitney Wasps. The additional power allowed both aircraft to fly faster and carry higher loads, although fuel dumps had to be fitted to allow them to remain under their maximum landing weight of 10,750lb, in case of an aborted take-off.

On completion at Essendon, Victoria in May 1943, "Binana" returned to the Brisbane-Cairns, Queensland run, while "Tokana" was similarly converted and re-entered service in October on the run between Melbourne (Essendon), Kerang, Victoria, Mildura, Victoria and Broken Hill, New South Wales. "Binana" was later transferred to the Melbourne-Tasmania service.

A final Australian disaster

On the morning of 31 January 1945 "Tokana" was on the Essendon to Kerang leg of its regular service when the port wing separated in flight between Redesdale and Heathcote, fifty miles north of Melbourne. The aircraft then plunged to the ground, killing both crew and the full load of eight passengers. An investigation revealed that metal fatigue had developed in the wing’s lower main spar boom attachment socket, the actual failure possibly being instigated by the aircraft encountering a particularly heavy gust of wind. It was the first known occurrence of this type of accident in an aircraft anywhere in the world, but it was to become a problem all too common in later years where progressively larger aircraft would be built from light-weight alloys that were more susceptible to the underlying metallurgical phenomenon.

It being assumed that the same problems could occur in "Binana", its certificate of airworthiness was cancelled, and the old aircraft was subsequently broken up.

Final years of the Stinson Model A

Outside of Australia, examples of the Stinson Model A soldiered on in such far-flung corners of the globe as Korea and Alaska for some years. One example still survives, having crashed in Alaska in 1947, being recovered and rebuilt in 1979, and finally passing to the Aviation Heritage Museum at Anchorage, Alaska in 1988.

A non-flying scale replica was built for a television movie account of the 1937 McPherson Ranges disaster, "The Riddle of the Stinson".

pecifications

aircraft specifications
plane or copter?=plane
jet or prop?=prop
ref=
crew=Two (pilot and co-pilot)
capacity= 8 passengers
payload main=
payload alt=
length main= 36 ft 10 in
length alt= 11.22 m
span main= 60 ft
span alt= 18.29 m
height main= 11 ft 6 in
height alt= 3.51 m
area main=
area alt=
airfoil=
empty weight main= 7,200 lb
empty weight alt= 3,370 kg
loaded weight main= 10,500 lb
loaded weight alt= 4,760 kg
useful load main=
useful load alt=
max takeoff weight main= 11,200 lb (from 1944, as twin engine)
max takeoff weight alt= 5,080 kg
more general=
engine (prop)= Lycoming R-680-5 nine-cylinder
type of prop= Radial
number of props= 3
power main= 260 hp
power alt= 194 kW
power original=
max speed main=128 mph
max speed alt= 206 km/h
cruise speed main=116 mph
cruise speed alt= 187 km/h
stall speed main=
stall speed alt=
never exceed speed main=
never exceed speed alt=
range main= 490 miles
range alt= 790 km
ceiling main=
ceiling alt=
climb rate main=
climb rate alt=
loading main=
loading alt=
thrust/weight=
power/mass main=
power/mass alt=
more performance=
armament=NIL
avionics=

References

*cite book| author=John Wegg| title=General Dynamics Aircraft and their Predecessors| edition=1990| publisher=Putnam Aeronautical Books| location=London| year 1990|
*cite book| author=Macarthur Job| title=Air Crash, Volumes One and Two| edition=1991-92| publisher=Aerospace Publications | location=Canberra| year 1991-92|