Scandinavian Airlines System Douglas DC-7C LN-MOD, Guttorm Viking (SAS)
24–25 February 1957: Scandinavian Airlines System began flying regularly scheduled passenger flights from Copenhagen to Tokyo, via the North Pole, with the new Douglas DC-7C Seven Seas airliner, LN-MOD, named Guttorm Viking. The route of flight was Copenhagen, Denmark to Anchorage, Alaska, and onward to Tokyo, Japan. The airliner took of at 11:35 a.m. local time (11:35 UTC). The flight crew included Captain Hedell Hansen and Captain Kare Herfjord.
Simultaneously (8:35 p.m., 24 February), Reidar Viking, LN-MOE, took off from Tokyo, en route Copenhagen. The two airliners rendezvoused over the North Pole at 21:37, 24 February, UTC. ¹
En hälsning från Tokio med första reguljära SAS-turen via Nordpolen – den snabbaste hälsning Ni någonsin fått från Japan. “A greeting from Tokio with the first regular SAS-flight via the North Pole – the fastest greeting You ever have got from Japan.” This SAS postcard was mailed 26 February 1957. (Famgus Aviation Post Cards)
The polar route cut 2,000 miles (3,219 kilometers) and took a total of 32 hours, rather than the previous 50 hour flight. The airliner returned on February 28, after 71 hours, 6 minutes.
Scandinavian Airlines System (SAS) had invited hundreds of media representatives and more than a thousand others to attend the send off fromKøbenhavns Lufthavn, Kastrup. To ensure that there were no problems to delay the departure, a second fully-fueled and serviced DC-7C was standing by.
Guttorm Viking, a Scandinavian Airlines System Douglas DC-7C, LN-MOD, at Stockholm-Arlanda Airport, August 1967. (Lars Söderström )
There were 47 passengers aboard the Guttorm Viking, including Prince Axel of Denmark, and Thor Heyerdahl (Kon-Tiki). Reidar Viking carried 45, with the Prince and Princess Mikasa of Japan.
Guttorm Viking made a refueling stop at Anchorage, Alaska, landing at 2:22 a.m. (07:22 UTC, and departing on schedule at 9:00 a.m. (14:00 UTC). It landed at Tokyo at 8:15 a.m., 26 February, Japan Standard Time (23:15, 25 February, UTC), 15 minutes ahead of schedule. The elapsed time of the flight was 32 hours, 31 minutes.
Reidar Viking landed at Copenhagen at 8:45 a.m. local time, Monday 24 February (08:45, 24 February, UTC), 35 hours, 40 minutes after departing Tokyo. The airliner had to make an additional fuel stop at Oslo, Norway, because of unexpected headwinds.
Reidar Viking, a Scandinavian Airlines System Douglas DC-7C, LN-MOE, at Stockholm-Arlanda Airport, May 1967. (Lars Söderström )
The DC-7C Seven Seas was the last piston-engine airliner built by Douglas Aircraft Company, intended for non-stop transcontinental and transatlantic flights. The DC-7 combined the fuselage of a DC-6 with the wings of a DC-4. The DC-7C version had 5 feet (1.524 meters) added to the wing roots for increased fuel capacity. By moving the engines further away from the fuselage, aerodynamic drag was reduced and the passenger cabin was quieter. The DC-7 had an extra 40-inch (1.016 meters) “plug” added to the fuselage just behind the wing. The DC-7C added another 40-inch plug ahead of the wing. The engine nacelles were also lengthened to provide room for additional fuel tanks.
The DC-7C was operated by two pilots, a navigator and a flight engineer. It had a maximum capacity of 105 passengers, requiring 4 flight attendants.
The airliner was 112 feet, 3 inches (34.214 meters) long with a wingspan of 127 feet, 6 inches (38.862 meters) and an overall height of 31 feet, 10 inches (9.703 meters). The empty weight was 72,763 pounds (33,005 kilograms). The maximum takeoff weight was 143,000 pounds (64,864 kilograms).
The Seven Seas was powered by four 3,347.662-cubic-inch-displacement (54.858 liter) air-cooled, supercharged, fuel-injected, turbocompound Wright Aeronautical Division Cyclone 18 988TC18EA1 or -EA3 two-row, 18-cylinder radial engines (also known as the Duplex-Cyclone), with a Normal Power rating of 2,800 horsepower at 2,600 r.p.m., and 3,700 horsepower at 2,900 r.p.m for takeoff. (A turbocompound engine uses exhaust-driven power recovery turbines to increase power to the crankshaft through a fluid coupling. This increased the engine’s total power output by approximately 20%.) The Cyclone 18 engines drove 13 foot, 11 inch (4.242 meters) diameter, four-bladed, Hamilton Standard Hydromatic 34E60 full-feathering, reversible-pitch, constant-speed propellers through a 0.4375:1 gear reduction. The 988TC18EA1 was 7 feet, 5.53 inches (2.274 meters) in long, 4 feet, 10.59 inches (1.437 meters) in diameter, and weighed 3,645 pounds (1,653 kilograms).
These engines gave the airliner a cruise speed of 308 knots (354 miles per hour/570 kilometers per hour) at 23,500 feet (7,163 meters). The service ceiling was 28,400 feet (8,656 meters) and maximum range was 4,900 nautical miles (5,639 statute miles/9,075 kilometers).
Douglas built 122 DC-7C airliners from 1956 to 1958. Scandinavian Airlines System bought 14 of them. The arrival of the Boeing 707 and Douglas DC-8 turbojet-powered airliners soon made these piston-driven propeller airliners obsolete. Many were converted to freighters, but most were scrapped after only a few years service. Guttorn Viking and Reidar Viking were both scrapped in 1968.
¹ SAS announced that the Guttorm Viking passed the North Pole at 21:37 G.M.T. and the Reidar Viking at 21:43 G.M.T. The planes met at 21:40 G.M.T.
China Airlines’ Boeing 747SP, N4522V. This aircraft few as Dynasty 006, 18 February 1985. (Andrew Hunt)
19 February 1985: At 10:16 a.m., Pacific Standard Time, while enroute from Taipei, Republic of China, to Los Angeles, California, China Airlines’ Flight 006 (call sign “Dynasty Six”), a Boeing 747SP-09, FAA registration N4522V, was cruising at 41,000 feet (12,497 meters), 300 nautical miles (556 kilometers) northwest of San Francisco, California. It had a crew of 23 with 251 passengers. The airliner had a flight crew of five under command of Captain Min-Yuan Ho, with a co-pilot and flight engineer, as well as a relief captain and flight engineer, due to the length of the trans-Pacific flight.
Captain Min-Yuan Ho, describing the incident to reporters at San Francisco Airport, 19 February 1985.
The Number 4 engine, the outboard engine on the airplane’s right wing, a Pratt & Whitney JT9D-7A turbofan, refused to respond with the other engines as the throttles were advanced, and it “hung” and remained at a low power level. It did not flame out, as the crew believed. The crew attempted restart procedures, however they did so incorrectly.
The airliner’s autopilot was engaged and the aircraft began to yaw and bank because of the asymmetric thrust. The copilot, First Officer Ju Yu Chang, used full opposite aileron to stop the roll, but neither pilot or copilot applied any rudder inputs to correct the yaw. (It was later determined that they believed, incorrectly, that the autopilot controlled rudder position.)
The airplane departed controlled flight, rolled over and dived. It lost 30,000 feet (9,144 meters) of altitude before the crew was able to recover, however the airplane was severely damaged, with bent wings, a damaged left aileron, lost parts of its elevators and horizontal stabilizers and damaged landing gear doors. It had experienced acceleration forces as high as 4.8 Gs as it descended through 30,552 feet (9,312 meters) and a peak 5.1 Gs at 19,083 feet (5,816 meters).
This illustration, based on the NTSB accident investigation, shows the various attitudes of China Airlines Flight 006 as it descended out of control, 19 February 1985. (Wikipedia)
Of the 287 persons on board, 24 were injured. Two were seriously hurt and the flight diverted to San Francisco. The 747SP was substantially damaged. It was nearly two years before repairs completed.
China Airlines’ Boeing 747SP-09 N4522V, photographed at Amsterdam, 16 June 1991. (Torsten Maiwald/Wikimedia)
The National Transportation Safety Board investigation made the following findings:
3.1 Findings
1. The flightcrew was properly certificated and qualified.
2. The changing airspeeds encountered by Flight 006 and the resultant compensating throttle adjustments were caused by wind speed variations.
3. The No. 4 engine did not flame out, but “hung” at about 1.0 EPR.
4. During his attempt to recover the No. 4 engine, the flight engineer did not close the bleed air valve switch before advancing the No. 4 throttle.
5. The other three engines did not lose thrust nor did they flame out.
6. The captain did not disengage the autopilot in a timely manner after thrust was lost on the No. 4 engine. The autopilot effectively masked the approaching onset of the loss of control of the airplane.
7. The captain was distracted from his flight monitoring duties by his participation with the flight engineer in the evaluation of the No. 4 engine’s malfunction.
8. With the exception of the loss of thrust on the No. 4 engine, no other airplane malfunction affected the performance of the airplane; the loss of thrust on the No. 4 engine did not contribute to the accident.
9. The captain was also distracted by his attempts to arrest the airplane’s decreasing airspeed, and this also contributed to his failure to detect the airplane’s increasing bank angle.
10. The lateral control deflections required to maintain level flight under conditions of thrust asymmetry and decreasing airspeed exceeded the limits of the autopilot’s lateral control authority, causing the airplane to roll and yaw to the right. The captain lost control of the airplane when, after disengaging the autopilot, he failed to make the proper flight control corrections to recover the airplane.
11. The damage to the airplane was a result of the acceleration forces and high airspeeds that occurred during the upset and recovery maneuvers.
3.2 Probable Cause
The National Transportation Safety Board determines that the probable cause of this accident was the captain’s preoccupation with an inflight malfunction and his failure to monitor properly the airplane’s flight instruments which resulted in his losing control of the airplane.
Contributing to the accident was the captain’s over-reliance on the autopilot after the loss of thrust on the No. 4 engine.
The captain had not slept during his previous rest period and his tiredness was considered a factor in this incident.
Damage to the tail surfaces of Boeing 747SP N4522V.
The Boeing 747SP (“Special Performance”) is a very long range variant of the 747-100 series airliners. It has a shorter fuselage and larger tail surface than the standard model. The weight savings allows it to carry more fuel for longer flights, and it is also faster. Boeing built 45 747SPs.
The 747SP is 184 feet, 9 inches (56.312 meters) long, with a wingspan of 195 feet, 8 inches (59.639 meters). It has an overall height of 65 feet, 10 inches (20.066 meters). It has a maximum takeoff weight of 670,000 pounds.
The airliner has a cruising speed of 0.88 Mach (616 miles per hour, or 991 kilometers per hour) and a maximum speed of 0.92 Mach (680 knots, 1,094 kilometers per hour). The service ceiling is 45,100 feet (13,746 meters) and the range is 7,650 miles (12,311 kilometers), carrying 276 passengers and baggage. The fuel capacity is 47,210 gallons. (178,709 liters).
Damaged horizontal stabilizer and elevators of Boeing 747SP-09 N4522V (NTSB)
Boeing 747 SP N4522V (serial number 22805, line number 564) made its first flight 10 June 1982. It was leased to China Airlines by the Wilmington Trust Company, 15 June 1982 and delivered 29 June 1982.
Following the Flight 006 incident, the airliner was repaired by Boeing and returned to service 25 April 1985. It was leased to Mandarin Airlines from 1 January 1997 to 31 December 1997, then placed in storage at Las Vegas, Nevada.
On 18 December 2001, N4522V was purchased by Global Peace Initiative Inc. The FAA suspended its operating certificate 18 July 2005 for lack of proper maintenance. The airplane has been stored at Tijuana International Airport (TIJ), just south of the U.S./Mexico border, since 16 December 2005.
The FAA registration of N4522V expired 31 December 2016.
Boeing 747SP 09 serial number 22805. The airliner’s U.S. registration expired 31 December 2016. (Global Peace Initiative)Boeing 747SP 09 serial number 22805. The airliner’s U.S. registration expired 31 December 2016. The derelict airliner was photographed at Tijuana, 16 June 2019. (Jorge Perez)
Delta Air Lines’ Convair 880-22-M, N8802E, Delta Queen, retracting its landing gear on takeoff from Atlanta, 15 April 1972. (RuthAS)
10 February 1960: Delta Air Lines’ Superintendant of Flight Operations, Captain Thomas Prioleau Ball, Jr., made the delivery flight of Delta’s first Convair 880 jet airliner, Ship 902, named Delta Queen, FAA registration N8802E, from San Diego, California, to Miami, Florida. Other members of the flight crew were Captain James H. Longino, co-pilot, and First Officer Richard E. Tidwell, flight engineer.
Newspapers reported that Delta Queen‘s wheels started rolling on the runway at San Diego’s Lindbergh Field (SAN) at 10:11:46 a.m., Pacific Standard Time (18:11:46 UTC). The airplane took of and climbed to its cross-country cruising altitude of 33,000 feet (10,058 meters). The Convair 880 landed at Miami International Airport (MIA) at 4:42:08 p.m., Eastern Standard Time (21:42:08 UTC). The official flight time was 3 hours, 31 minutes, 54 seconds, for an average speed of 641.77 miles per hour (1,032.83 kilometers per hour) over the 2,266 mile (3,647 kilometers) route. This was a new United States National Record for Speed Over a Commercial Airline Route. The 880 cut 27 minutes, 1 second, off the time of an Eastern Air Lines Douglas DC-8B over the same route, 4 January 1960.
Delta Queen was placed in scheduled service 15 May 1960.
The Convair 880 was a four-engine, swept-wing turbojet-powered commercial airliner. It was operated by a flight crew of three and could carry up to 110 passengers. The Convair 880-22-M was a modified version of the standard 880-22, intended for shorter range operations. It had leading-edge slats, a higher maximum takeoff weight, stronger landing gear, a tail skid and an improved anti-lock braking system. The Convair 880 was so-named because its design top speed was 880 feet per second (600 miles per hour, or 966 kilometers per hour), faster than its Boeing 707 or Douglas DC-8 rivals.
Miss San Diego, Leona McCurdy, christens Delta Queen with water collected from rivers around the Delta Air Lines system. (Delta Air Lines)
The airplane was 129 feet, 4 inches (39.421 meters) long with a wingspan of 120 feet (36.576 meters) and overall height of 36 feet, 3.75 inches (11.068 meters). The 880 had an empty weight of 94,000 pounds (42,638 kilograms) and maximum takeoff weight was 191,000 pounds (86,636 kilograms).
The Convair 880-22-M was powered by four General Electric CJ805-3B turbojet engines. The CJ805-3B is a single-shaft, axial-flow turbojet with a 17-stage compressor section and 3-stage turbine, based on the military J79. The engine has a maximum continuous power rating of 9,800 pounds of thrust (43.593 kilonewtons) at Sea Level, and 11,650 pounds (51.822 kilonewtons) for Takeoff. The CJ805-3B is 9 feet, 2.4 inches (2.804 meters) long, 3 feet, 3.9 inches (1.013 meters) wide and 4 feet, 0.8 inches (1.240 meters) high. It weighs 2,875 pounds (1,304 kilograms).
The 880-22-M had a cruise speed of 0.82 Mach (556 miles per hour/895 kilometers per hour) at 30,000 feet (9,144 meters). The service ceiling was 41,000 feet (12,497 meters). Maximum range was 5,056 miles (8,137 kilometers).
The Convair Division of General Dynamics built 65 Convair 880 airliners at San Diego, California, between 1959 and 1962. Delta Air Lines retired its last one in January 1974.
Delta Queen, Convair 880-22-M N8802E. (Delta Air Lines)Captain Thomas P. Ball
Thomas Prioleau (“Pre”) Ball, Jr., was a legendary airline captain. He was born 6 September 1906 at Norfolk, Virginia, the second son of Thomas Prioleau Ball, a bookkeeper, and Agnes Mae Bell Ball. He grew up in Florida. Ball learned to fly in 1928, soloing in a World War I Curtiss “Jenny” biplane.
Thomas P. Ball, Jr., married Miss Theresa Augusta Daniel at the Church of the Good Shepherd in Jacksonville, Florida, 27 December 1930. They would have to sons, Thomas Prioleaux Ball III and Espy Daniel Ball.
Ball worked as a station manager for Delta Air Lines at Charleston, South Carolina, and was hired as a copilot by the airline in 1936.
Soon after the United States entered World War II, Ball was commissioned as a second lieutenant in the U.S. Army Air Corps. By the end of the war, he had risen to the rank of colonel, serving as the Chief of the Prevention and Investigation Division of the Army’s Office of Flying Safety.
After the War, Ball returned to Delta Air Lines as a captain and soon became the chief pilot, dedicated to the meticulous training of the company’s pilots. In 1969, Ball became Delta’s Vice President of Flight Operations. On 25 May 1970, Ball was aboard Delta Flight 199, a Convair 880 under the command of Captain Harris B. Wynn, when it was hijacked to Cuba.
Four U.S. National Speed Records which were set by Captain Ball remain current. In addition to the record set with the Convair 880, on 6 November 1948, Ball flew a Delta Air Lines Douglas DC-6 from Los Angeles, California, to Charleston, South Carolina, in 6 hours, 24 minutes, 32 seconds, at an average speed of 344.19 miles per hour (553.92 kilometers per hour). On 18 March 1954, he flew a Douglas DC-7 from Los Angeles to Jacksonville, Florida, in 05:29:33, averaging 392.25 miles per hour (631.27 kilometers per hour). Finally, on 24 February 1962, Captain Ball flew a Douglas DC-8 from Miami, Florida, to Atlanta, Georgia, in 01:28:11, for an average of 406.1 miles per hour (653.56 kilometers per hour).
After making the delivery flight of the company’s first Boeing 747, Ball grounded himself when he noticed a deterioration in his eyesight. Thomas Prioleau Ball retired from Delta in 1971. He passed away in 2006 at the age of 99 years.
The world record-setting Convair 880-22-M, c/n 7, now registered N55NW, in Bahamas World livery, circa 1976. (Captain Charles Lindberg)
Convair 880-22-M N8802E, Delta Queen, (c/n 7) remained in service with Delta Air Lines until 1973 when it was sold to Boeing as part of exchange for an order of new Boeing 727-200 airliners. It was then sold to Transexecutive Aviation in 1974 and reregistered as N55NW. In 1976, the 880 flew as a charter airliner for Bahama World. It was then converted to a cargo freighter operating in the Caribbean. In 1979 the Convair was transferred to Groth Air Service, Inc., Castalia, Iowa, and assigned a new FAA registration, N880SR. The record-setting airliner was damaged beyond repair in a fire at Licenciado Benito Juarez International Airport, Mexico City, in May 1983.
Former Delta Air Lines Convair 880, N880SR. (Captain Charles Lindberg)
The prototype Boeing 747, RA001, City of Everett, takes off at Paine Field, 9 February 1969. (The Museum of Flight)
9 February 1969: At 11:34 a.m., Boeing Chief Test Pilot Jack Wadell, with Engineering Test Pilots Brien Singleton Wygle, co-pilot, and Jesse Arthur Wallick, flight engineer, took off from Paine Field, Everett, Washington, aboard RA001, the prototype Boeing 747-121, and made a 1 hour, 15 minute test flight. The ship was named City of Everett after the home of the factory where it was built. It was originally registered N7470.
The test pilots who flew the first Boeing 747: Left to right, Brien S. Wygle, Jack Waddell and Jesse A. Wallick. (Seattle Times)
The 747 was the first “wide body” airliner and was called a “jumbo jet.” It is one of the most widely used airliners and air freighters in service world-wide. The latest version is the 747-8, the “Dash Eight.” After 53 years, production ended with a total of 1,574 747s built.
Boeing 747-121 RA001, City of Everett, 9 February 1969. A Canadair CL-13B Sabre Mk.6, N8686F, is the chase plane, flown by test pilot Paul Bennett. (Boeing/The Seattle Times)
The Boeing 747 is a very large swept wing, four engine commercial transport. The 747-100 series was the first version to be built. It was operated by a flight crew of three—pilot, co-pilot and flight engineer—and was designed to carry 366 to 452 passengers. The airplane is 231 feet, 10.2 inches (70.668 meters) long with a wingspan of 195 feet, 8 inches (59.639 meters) and overall height of 63 feet, 5 inches (19.329 meters). The wings are swept aft to 37° and have a total area of 5,500 square feet (511 square meters). The angle of incidence is 2°, and there are 7° of dihedral.
The interior cabin width is 20 feet (6.096 meters), giving it the name “wide body.” Its empty weight is 370,816 pounds (168,199 kilograms) and the Maximum Takeoff Weight (MTOW) is 735,000 pounds (333,390 kilograms).
Boeing 747 RA001 flight crew, left to right, Jack Wadell, Brien Wygle and Jess Wallick. (Image courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)
The 747-100 is powered by four Pratt & Whitney JT9D-7A high-bypass ratio turbofan engines. The JT9D is a two-spool, axial-flow turbofan engine with a single-stage fan section, 14-stage compressor (11 high- and 3 low-pressure stages) and 6-stage turbine (2 high- and 4 low-pressure stages). The engine is rated at 46,950 pounds of thrust (208.844 kilonewtons), or 48,570 pounds (216.050 kilonewtons) with water injection (2½-minute limit). This engine has a maximum diameter of 7 feet, 11.6 inches (2.428 meters), is 12 feet, 10.2 inches (3.917 meters) long and weighs 8,850 pounds (4,014 kilograms).
The 747-100 has a cruise speed of 0.84 Mach (555 miles per hour, 893 kilometers per hour) at 35,000 feet (10,668 meters). The maximum certificated operating speed is 0.92 Mach. The airliner’s maximum range is 6,100 miles (9,817 kilometers).
The prototype Boeing 747 during its first flight. (Boeing)
City of Everett last flew in 1995. It is on static display at The Museum of Flight, Boeing Field, Seattle, Washington.
Boeing 747-121, City of Everett, on take off from Boeing Field. The prototype has been re-registered N1352B. RA001 carried this registration number from July 1970 to April 1975. (The Museum of Flight)
8 February 1933: Boeing test pilot Leslie R. (“Les”) Tower and United Air Lines Captain Louis C. Goldsmith made the first flight of the Boeing Model 247, NX13300, a twin-engine airline transport, at Boeing Field, Seattle, Washington. The first flight lasted 40 minutes and Tower was quite pleased with the airplane. He took it up a second time later in the day.
The Boeing Model 247 instrument panel used gyroscopic-stabilized instruments for instrument flight. (Boeing)
The 247 is considered to be the first modern airliner because of its all-metal semi-monocoque construction, cantilevered wing and retractable landing gear. It was 50 miles per hour (80.5 kilometers per hour) faster than its contemporaries, and could climb on one engine with a full load.
The airplane was built at Boeing’s Oxbow factory on the Duwamish River, then barged to Boeing Field where it was assembled and tested. The 247 was originally named “Skymaster,” but this was soon dropped.
Two months after the first flight, the first production 247, NC13301, was placed in service with United Air Lines. It was the first of ten 247s bought by United.
This postcard illustration shows the interior arrangement of a Boeing 247 airliner. (United Air Lines)
The Model 247 was operated by a pilot, co-pilot and a flight attendant and carried up to ten passengers. The airplane was 51 feet, 5 inches (15.672 meters) long, with a wingspan of 74 feet, 1 inch (22.581 meters) and overall height of 12 feet, 5 inches (3.785 meters). The empty weight was 8,921 pounds (4,046.5 kilograms) with a maximum takeoff weight of 16,805 pounds (7,622.6 kilograms).
The Duralamin skin panels were anodized, rather than painted, for corrosion protection. This saved weight, and resulted in the 247’s characteristic gray-green color.
Boeing 247 NC13301. (Boeing)
The airliner was powered by two air-cooled, supercharged, 1,343.804-cubic-inch-displacement (22.021 liters) Pratt & Whitney Wasp S1H1-G nine-cylinder radial engines with a compression ratio of 6.03:1. The S1H1-G had a Normal power rating of 550 horsepower at 2,200 r.p.m., to 8,000 feet (2,438 meters), and 600 horsepower at 2,250 r.p.m. for Takeoff. They drove three-bladed Hamilton Standard constant-speed propellers through a 3:2 gear reduction. The Wasp S1H1-G was 3 feet, 11.80 inches (1.214 meters) long, 4 feet, 3.61 inches (1.311 meters) in diameter, and weighed 930 pounds (422 kilograms).
The Boeing 247 had a maximum speed of 200 miles per hour (321.9 kilometers per hour) with a cruising speed of 188 miles per hour (302.6 kilometers per hour. It had a range of 745 miles (1,199 kilometers) and a service ceiling of 25,400 feet (7,742 meters).
A contemporary photo post card depicts ten United Air Lines stewardesses with a Boeing Model 247 airliner. The post mark on the reverse side is faintly visible. (United Air Lines)
75 Model 247s were built. 60 were bought by Boeing Air Transport.
NC13301, the first production Boeing Model 247 airliner. (NASM)
[Note: the windshield was canted forward to prevent instrument panel lighting from reflecting into the cockpit at night. Unfortunately, ground lighting was reflected instead. This was soon changed to a rearward slant and resulted in a slight increase in speed.]
