Boeing 247

Infobox Aircraft
name = Boeing 247
type = Passenger airliner
manufacturer = Boeing



caption = Boeing 247 prototype at Boeing Field, c. 1933
designer =
first flight = 8 February 1933
introduced = 22 May 1933
retired =
status =
primary user = Boeing Air Transport
more users =
produced =
number built = 75
unit cost =
variants with their own articles =

The Boeing Model 247 was an early United States airliner, considered the first such aircraft to fully incorporate [ [http://www.boeing.com/history/boeing/m247.html Boeing 247.] ] [ Van Der Linden 1991.] advances such as all-metal (anodized aluminum) semi-monocoque construction, a fully cantilevered wing, wing flaps and retractable landing gear. [Bryan 1979, p. 110. The main landing gear did not fully retract; a portion of the wheels extended below the nacelles, typical of designs of the time, as a means of reducing structural damage in a wheels-up landing. The tailwheel was not retractable.] While Boeing's 247 and 247A had speed-ring engine cowlings and fixed-pitch propellers, the Model 247D incorporated NACA cowlings and variable pitch propellers. [ [http://www.acepilots.com/pioneer/boeing_247.html Ace Pilots Pioneer webpage] ]

Other advanced features included control-surface trim tabs, an autopilot, and deicing boots for the wings and tailplane. The 247 first flew on 8 February 1933, and entered service later that year. Subsequently, engines and airframes became larger, and four-engine designs emerged, but no significant changes to this basic formula appeared until cabin pressurization and high-altitude flight were introduced in the early 1940s with the first pressurized airliner, the 307 Stratoliner. Gould 1995, p. 14.]

Design and development

Boeing had eclipsed other aviation manufacturers by introducing a host of aerodynamic and technical features into a commercial airliner. This advanced design which was a progression from earlier Monomail (Models 200, 221, 221A) and B-9 bomber designs, combined speed and safety. The Boeing 247 was faster than the U.S. premier fighter aircraft of its day, the Boeing P-12, which was an open-cockpit biplane. [ Serling 1992, p. 19.] In addition, the 247 was the first twin-engine passenger transport able to fly on one engine. With controllable pitch propellers (standard equipment on the 247D), the 247 could maintain 11,500 ft at maximum gross takeoff weight.Seely 1968, p. 56.] Its combination of features set the standard for the Douglas DC-1 and other airliners before World War II and was ordered "off the drawing board". Originally planned as a 14-passenger airliner powered by Pratt & Whitney R-1690 Hornet radial engines, the preliminary review of the design concept by United Airlines' pilots had resulted in a re-design to a smaller, less capable design configuration. [Serling 1992, p. 20.] Nonetheless, the 247 was a remarkable achievement and was the company's showcase exhibit at the 1933 Chicago World's Fair. [ Serling 1992, p. 22.]

As the 247 emerged from its test and development phase, the company further showcased its capabilities by entering a long-distance air race in 1934, the MacRobertson Race from England to Australia. During the 1930s, aircraft designs were often proven in air races and other aerial contests. A modified 247D was entered, flown by Col.Roscoe Turner and Clyde Pangborn. The 247, race number "57," was essentially a production model but all airliner furnishings were deleted to accommodate additional fuselage fuel tanks (eight in total). The MacRobertson Race attracted aircraft entries from all over the globe including prototypes as well as established production types with the grueling course considered an excellent proving ground as well as an opportunity to gain worldwide attention. Turner and Pangborn came in second place in the transport section (and third overall), behind the Boeing 247's eventual rival, the new Douglas DC-2. [http://www.aviation-history.com/boeing/247.html Boeing Model 247- USA] ]

Winner of the 1934 US Collier Trophy for excellence in aviation design, the first 247 production orders were earmarked for Boeing Air Transport. Boeing Company 1969, p. 35.]

The cockpit windshield (windscreen) of the first 247s was angled forward instead of the conventional aft sweep. This was the Boeing solution to the problem of lighted control-panel instruments reflecting off the windshield at night, but it came at a significant performance penalty - this was one reason that the contemporary DC airliners could post comparable or superior performance while carrying significantly greater loads.Fact|date=March 2008 By the introduction of the 247D, the pilot windshield was sloped aft at about the same angle as the DC-3's windows, and the night-glare problem was resolved by installing an extension {the "glarescreen") over the control panel. [ [http://www.airminded.net/b247/boe247.thml Airminded.net webpage showing initial and final windshield angles, and glarescreen installation in 247D] ]

Operational history

The 247 was capable of crossing the United States from east to west eight hours faster than their predecessors, such as the Ford Trimotor and Curtiss Condor. Entering service on 22 May 1933, a Boeing Air Transport 247D set a cross-country record pace of 19½ hours on its San Francisco to New York inaugural flight.Bryan 1979, p. 109.]

Due to the initial demand from U.S. air carriers, Boeing sold the first 60 247s, an unprecedented $3.5 million order to its affiliated airline, Boeing Air Transport (part of the United Aircraft and Transport Corporation, UATC), at a unit price of $65,000. TWA (Transcontinental & Western Air) also ordered the 247 but UATC declined the order, which resulted in TWA President Jack Frye setting out the requirements for a new airliner and funding Don Douglas to design and build the Douglas DC-1 prototype. Douglas eventually developed the design into the historic and enormously successful DC-3 line.

Although the Boeing design had been the first to enter series production, the 247 proved to have some serious design deficiencies. Air carriers considered its limited capacity a drawback since it only carried ten passengers, in five rows with a seat on each side of the aisle, as well as a flight attendant. Compared to the more capacious DC-2 and later DC-3, the passenger count was too few to make it a commercially viable airliner. Another feature influencing passenger comfort was, the 247's main wing spar ran through the cabin area, so persons moving through the cabin had to make a large step over it. [ Serling 1992, p. 21.] The Lockheed L-10 Electra had a similar configuration and while it was a more compact design, the Electra managed to carry the same number of passengers at a slightly better overall performance, and more importantly, at a lower cost-per-mile.

Seventy-five 247s were built; by contrast, Douglas produced over 10,000 DC-3s, including wartime production of C-47, while the rival Lockheed Electra "family" was eventually to reach over 3,000 in its various civilian and military variants. Boeing Air Transport bought 60 examples, United Aircraft Corp. ten, four went to "Lufthansa", and one a private owner in China. While the industry primarily standardized on Boeing's competitors, many of United's aircraft were later purchased by Western Air Express at "bargain basement prices". [ Serling 1992, p. 23.]

The 247 remained in airline service until World War II, when several were converted into C-73 transports and trainers. No. 121 Squadron Royal Canadian Air Force (RCAF) operated seven Model 247Ds as medium transports during the early part of the war. [ [http://www.rcaf.com/aircraft/transports/247d/index.php?name=Boeing%20247D RCAF Boeing 247D] ] Some 247s were still flying in the late 1960s, converted either into cargo transports or personal business aircraft.

A number of specially modified variants included a Boeing 247Y appropriated from United for Air Corps use as a test aircraft fitted with two machine guns in the nose. The same installation later was fitted to a 247Y owned by Generalissimo Chiang Kai-Shek; this aircraft also featured a Colt .50 caliber machine gun in a flexible mount. [Seely 1968, p. 63.] A 247D purchased by the British Royal Air Force became a test mule for new equipment, featuring a nonstandard nose, new powerplants and non-retracting gear. [Seely 1968, p. 69.]

The Turner/Pangborn 247D still exists. Originally flown on 5 September 1934, it was leased from United Airlines for the 1934 MacRobertson Race and returned to United where it served in regular airline service until 1937. Subsequently, the 247D was sold to the Union Electric Company of St. Louis for use as an executive transport. The Air Safety Board purchased the aircraft in 1939 and it remained in use for 14 years before it was donated to the National Air and Space Museum, Washington, DC. Displayed today with two sets of markings, the left side is marked as "NR257Y", in Colonel Turner's 1934 MacRobertson Race colors, while the right side is painted in United Airlines livery, as "NC13369". [http://www.nasm.si.edu/research/aero/aircraft/boeing_247.htm NASM Boeing 247D] ]

Incidents and accidents

On 10 October 1933, a United Airlines 247 was the victim of the first proven case of sabotage of a commercial airliner. The aircraft, "en route" from Cleveland to Chicago, was destroyed by a nitroglycerin-based explosive device over Chesterton, Indiana. ["Seven die as plane crashes in flames". "New York Times", 11 October 1933, p. 1.]

On 12 January 1937, a Western Air Express 247 flight from Salt Lake City to Burbank crashed near Newhall, California, killing Martin Johnson of Martin and Osa Johnson fame (photographers, explorers, marketers, naturalists and authors). [ [http://kansastravel.org/safarimuseum.htm Martin and Osa Johnson Safari Museum] ]

Operators

Civil operators

;China as ROC
*Private owner operated one aircraft.

;COL
*SCADTA operated 10 aircraft.

;flag|Germany|Nazi
*"Lufthansa" operated four aircraft.

;flag|United States|1912
*Boeing Air Transport (later United Air Lines) operated 60 aircraft.

*United Aircraft Corporation operated 10 aircraft.

*Western Airlines received some of ex-United Aircraft Corporation aircraft.

Military operators

;flag|Canada|1921
*Royal Canadian Air Force

;UK
*Royal Air Force

;flag|United States|1912
*United States Army Air Corps

urvivors

;c/n 1699, "CF-JRQ":Exhibited in Canada Aviation Museum, Ottawa. Donated to the museum in 1967 by California Standard Oil of Calgary, Alberta. [ [http://www.aviation.technomuses.ca/collections/artifacts/aircraft/Boeing247D.shtml Boeing 247D: Canada Aviation Museum Collection] ]

;c/n 1722, "N18E":Exhibited in the National Museum of Science and Industry, Wroughton, UK

;c/n 1729, "N13347":Still airworthy, exhibited in the Museum of Flight Restoration Center, Paine Field, Snohomish County, Washington, USA.

;c/n 1953, "NC13369" / "NR257Y":Exhibited in the Hall of Air Transportation at the National Air and Space Museum, Washington, DC, USA, with United Air Lines colors and registration as "NC13369" on its right fuselage and wing and as "NR257Y" with MacRobertson Race markings on its left side.

pecifications (Boeing 247D)

aircraft specifications
plane or copter?=plane
jet or prop?=prop
ref="The Concise Guide to American Aircraft of World War II" [Mondey 1996, p. 34.]
crew=
capacity=
payload main=
payload alt=
length main= 51 ft 5 in
length alt= 15.7 m
span main= 74 ft 1 in
span alt= 22.6 m
height main= 12 ft 5 in
height alt= 3.8 m
area main= 836.4 ft²
area alt= 78 m²
airfoil=
empty weight main= 8,921 lb
empty weight alt= 4,055 kg
loaded weight main= 16,770 lb
loaded weight alt= 7,621 kg
useful load main=
useful load alt=
max takeoff weight main= 16,805 lb
max takeoff weight alt= 7,623 kg
more general=
engine (prop)= Pratt & Whitney S1H1-G Wasp
type of prop=radial engine
number of props=2
power main= 550 hp
power alt= 410 kW
power original=
max speed main=200 mph
max speed alt= 320 km/h
cruise speed main= 188 mph
cruise speed alt=304 km/h
stall speed main=
stall speed alt=
never exceed speed main=
never exceed speed alt=
range main= 745 miles
range alt= 1,200 km
ceiling main= 25,400 ft
ceiling alt= 7,620 m
climb rate main= 1,148 ft/min
climb rate alt= 350 m/min
loading main=
loading alt=
thrust/weight=
power/mass main=
power/mass alt=
more performance=
armament=
avionics=

ee also

aircontent
related=
* Boeing 307
similar aircraft=
* Douglas DC-2
* Douglas DC-3
* Junkers Ju 52
* Lockheed Model 10 Electra
lists=
see also=

References

Notes

Bibliography

* Boeing Company. "Pedigree of Champions: Boeing Since 1916, Third Edition". Seattle, WA: The Boeing Company, 1969. No ISBN. [http://worldcat.org/oclc/11569612 WorldCat] .
* Bowers, Peter M. "Boeing aircraft since 1916". London: Putnam Aeronautical Books, 1989. ISBN 0-85177-804-6.
* Bryan, C.D.B. "The National Air and Space Museum". New York: Harry N. Abrams, Inc., 1979. ISBN 0-8109-0666-X.
* Gould, William. "Boeing" (Business in Action). Bath, Avon, UK: Cherrytree Books, 1995. ISBN 0-7451-5178-7.
* Mondey, David, "The Concise Guide to American Aircraft of World War II". London: Chancellor, 1996. ISBN 1-85152-706-0.
* Seely, Victor. "Boeing's Grand Old Lady." "Air Classics", Vol. 4, No. 6, August 1968.
* Serling, Robert J. "Legend & Legacy: The Story of Boeing and its People". New York: St. Martin's Press, 1992. ISBN 0-31205-890-X.
* Van Der Linden, F. Robert. "The Boeing 247: The First Modern Airliner". Seattle, WA: University of Washington, 1991. ISBN 0-29597-094-4.

External links

* [http://www.airminded.net/b247/boe247.html Gallery: Boeing 247 Images] , including two of the interior and one of the retracted main gear
* [http://www.acepilots.com/pioneer/boeing_247.html Boeing Model 247: First modern airliner]