Beechcraft Model 34

Beechcraft Model 34

Infobox Aircraft
name= Model 34 "Twin-Quad"
type= Civil airliner
manufacturer= Beechcraft


caption=
designer=
first flight= 1 October 1947
introduced=
retired= 1949
status= prototype only, scrapped
primary user =
more users=
produced=
number built= 1 (two prototypes in production scrapped)
unit cost = $6 million (development)
developed from =
variants with their own articles=

The Beechcraft Model 34 "Twin-Quad" was a prototype airliner designed and built by Beechcraft in the period between World War Two and the Korean War.Phillips 1992] At this time many aircraft manufacturers in the United States anticipated a boom in civil aviation and a large number of designs left the drawing board only to ultimately fail. The Model 34 was one of these failures, partly because of its unusual design, and partly because of the thousands of ex-military transport aircraft that were available at the time for a fraction of the price of a new aircraft.

Design and development

The design was a four-engine high-wing monoplane with tricycle undercarriage, originally designed for 14 (three abreast seating with six additional seats mounted on the side) [Neal 1970, pp. 14–15.] and eventually converted to take 20 passengers.. The side "couch seats" were also able to be folded away so that cargo could be carried internally in the cabin. Individual storage space was provided for each passenger seat on the fuselage side above the seat. In order to accommodate a larger cargo load, a cargo hatch was located near the pilot's compartment.Neal 1970. p. 15.]

The unusual aspects of the design were the butterfly or V-tail and engine layout that led to its popular nickname, "Twin Quad." The four engines were buried in the wings, with each pair of engines connected to a single propeller via clutches and a common gear box. The engines were horizontally opposed eight cylinder air-cooled Lycoming GSO-580s (GSO denoting Geared Supercharged and Opposed, with each engine featuring a built-in reduction gear box in addition to the common propeller gear box). The engines were rated at 400 horsepower at 3,300 rpm. The tail was unusual because unlike the vertical and two horizontal surfaces found on most aircraft, the Twin-Quad's was a two-surface V-tail similar to the tail fitted to Beechcraft's other new product at the time, the Model 35 Bonanza. The V-tail configuration was flight-tested on a twin-engine Beech AT-10.

Another, but more conventional, design aspect was that the belly was made strong enough to sustain minimal damage in the event of a "wheels-up" landing, with built-in integral landing keels or "skids."Neal 1970, pp. 16–17.] The wing measured 70 ft from tip to tip and the fuselage was 53 ft long [ [http://www.aerofiles.com/_beech.html List of Beechcraft Models with basic specifications at www.aerofiles.com] Retrieved: 9 November 2007.] . With the top of the V-tail almost 18 ft above the ground and a design maximum take off weight (MTOW) of 20,000 lbs, the Model 34 is to date the largest and heaviest Beechcraft civil design [The Beechcraft 1900 has a longer fuselage but shorter wingspan, with a significantly lower MTOW, and the Beechcraft Starship is smaller in all dimensions and also has a significantly lower MTOW.] , with only the smaller XA-38 Grizzly military aircraft outweighing it.

Operational history

The Model 34 took to the air for the first time on 1 October 1947, with Beech Chief Pilot Vern L. Cartsens at the controls. [ [http://www.wingsoverkansas.com/history/article.asp?id=92#october "Wings Over Kansas List of Aviation Anniversaries."] Retrieved: 9 November 2007.] The first flight was uneventful and the initial report from the test pilot was, "We have another outstanding Beechcraft!"

The prototype Model 34 had accumulated more than 200 hours of test flying when the reinforced belly was validated in a wheels-up landing. [Simpson 1991, p. 42.] On 17 January 1949, in a severe forced landing a few miles northwest of the Beech plant shortly after taking off, the sole Beech 34 was damaged beyond repair. An inadvertent cutting off of an emergency master switch when battling an electrical fire had resulted in the shut down of all the powerplants, leading to the crash. The co-pilot was killed and the pilot and two flight observers were injured in the crash. Neal 1970, p. 17.]

After the accident, Beech re-evaluated plans to go into series production with the Model 34. At the time, two new prototypes were being manufactured, one for static test and the other to continue the flight test program. One of the main considerations was that the U.S. Civil Aeronautics Board was delaying the licensing of the anticipated "feeder airlines" for which the design was intended. Neal 1970, p. 64.] The Beech 34 ultimately could not compete in major and regional airline operations with the thousands of less-complex and cheaper war surplus transports such as the larger Douglas DC-3/C-47 Skytrain, the similarly-sized C-60 Lodestar and Beechcraft's own smaller Beechcraft Model 18.

Despite its promise, since the "Twin Quad" had attracted no orders, Beech terminated the project, closing down the production line in January 1949.

pecifications (variant)

aerospecs
ref= ["Illustrated Encyclopedia of Aircraft" 1985, p. 534.]
met or eng?= eng

crew=
capacity=20 passengers
length m=16.15
length ft=53
length in=0
span m=21.34
span ft=70
span in=0
swept m=
swept ft=
swept in=
rot number=
rot dia m=
rot dia ft=
rot dia in=
dia m=
dia ft=
dia in=
width m=
width ft=
width in=
height m=5.18
height ft=17
height in=0
wing area sqm=
wing area sqft=
swept area sqm=
swept area sqft=
rot area sqm=
rot area sqft=
volume m3=
volume ft3=
aspect ratio=
empty weight kg=
empty weight lb=
gross weight kg=8,845
gross weight lb=19,500
lift kg=
lift lb=

eng1 number=4
eng1 type=Avco Lycoming GSO-580 flat-eight piston engine
eng1 kw= 280
eng1 hp= 375
eng1 kn=
eng1 lbf=
eng1 kn-ab=
eng1 lbf-ab=
eng2 number=
eng2 type=
eng2 kw=
eng2 hp=
eng2 kn=
eng2 lbf=
eng2 kn-ab=
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max speed kmh=370
max speed mph=230
max speed mach=
cruise speed kmh=
cruise speed mph=
range km=2,335
range miles=1,450
endurance h=
endurance min=
ceiling m=7,010
ceiling ft=23,000
glide ratio=
climb rate ms=
climb rate ftmin=
sink rate ms=
sink rate ftmin=

armament1=
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References

Notes

Bibliography

* "Illustrated Encyclopedia of Aircraft" (Part Work 1982-1985). London: Orbis Publishing, 1985.
* Neal, Ronald D. "Pioneer Without a Cause." "Air Classics", Vol. 6, no. 4 , April 1970.
* Phillips, Edward H. "Beechcraft - Pursuit of Perfection, A History of Beechcraft Airplanes". Eagan, Minnesota: Flying Books, 1992. ISBN 0-911139-11-7.
* Simpson, R.W. "Airlife's General Aviation". Shrewsbury, UK: Airlife Publishing, 1991, ISBN 1-85310-104-X.


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