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104-492: The Nakajima G5N Shinzan originated due to the Imperial Japanese Navy's interest in developing a long-range attack bomber capable of carrying heavy loads of bombs or torpedoes a minimum distance of 3,000 nmi (5,600 km; 3,500 mi). To meet this requirement, it became apparent a four-engine lay-out would be necessary. As Japanese aircraft manufacturers lacked experience in building such large complex aircraft,

208-529: A 212.5 US gal (804 L; 176.9 imp gal) fuel tank located between the inner and outer nacelles, on both sides of the aircraft, providing a total of 1,700 US gal (6,400 L; 1,400 imp gal) of fuel in six tanks. With the fuselage being 3.5 ft (1.1 m) wider than on the B-17, the span had increased from 103 ft 9 in (31.62 m) to 107 ft 3 in (32.69 m) compared to early B-17s. After being modified,

312-498: A Master Bedroom, two bathrooms, a galley and a bar as well as a living room. In 1949, Hughes spent an additional $ 100,000 renovating it so he could sell it, which, like the T&;WA and Pan Am aircraft now included an interior designed by Raymond Loewy . Oil tycoon Glenn McCarthy bought it to coincide with the opening of his new Shamrock Hotel and he renamed it Shamrock and had it repainted, however McCarthy defaulted on payments and it

416-545: A captain) but with civilian insignia. The first ICD service flight began on February 26, when a 307 flew south to Brazil from Washington, before crossing the South Atlantic to Africa, and north to Cairo, before continuing on to Prestwick, Scotland where they arrived on April 20, 1942, having primarily carried 25,000 rounds of armour piercing shells to British troops in Cairo, who were facing Rommel and his Afrika Corps . ICD

520-514: A contract with Douglas to develop the 40 passenger DC-4 (later known as the DC-4E). Each company contributed $ 100,000 to development costs and agreed to not operate other aircraft with a maximum weight of 43,000 to 75,000 lb (20,000 to 34,000 kg) for revenue service. Due to development problems and poor performance, all of the airlines dropped out of the DC-4 program and cancelled their orders, but

624-518: A few weeks later, on September 26, a TWA New York bound Stratoliner at 17,000 ft (5,200 m) with a jetstream providing a strong tailwind reached a ground speed of 387 mph (623 km/h). Flight 45 added additional stops at Philadelphia and Pittsburgh on December 1, 1940. On December 14, 1941, representatives from various airlines as well as the Air Transport Association of America (ATA) met with Colonel Robert Olds of

728-567: A larger more suitable design, and they that they would use it for familiarization training with four engine aircraft. They required that it fly on just two engines, use Pratt & Whitney automatic mixture controls, have a 2,500 mi (4,000 km) range, be able to carry freight or mail, and have moderate tire ground pressure. KLM then requested a quote for three 307s, either with Wright Cyclones and with Pratt & Whitney 1830 engines, fitted with constant speed propellers and automatic carburettor mixture control and with additional fuel to provide

832-574: A loosening of the tightly controlled government access to routes. TWA's fare structure remained the same as pre-war. New TWA flight routes were added with routes 370 & 371 between La Guardia and Spokane with intermediate stops in Chicago, Albuquerque, for fuel, and Burbank and routes 48 & 49 between La Guardia and Kansas City with a stop in St Louis. At this time, the TWA Stratoliners were briefly

936-411: A metal structure, and were aerodynamically balanced and fitted with adjustable trim tabs to lighten flight loads. The rudder and elevators also had hydraulic boost, to lighten control forces. The partially retractable main undercarriage had hydraulic brakes and used Goodyear 55x19x23 tires, and was raised and lowered with electric motors. Manual backups were provided for electrically driven systems, but

1040-511: A power-operated dorsal and one in a tail turret), plus single-mount hand-operated 7.7mm Type 92 machine guns in the nose, ventral and waist positions. The first prototype G5N1 made its maiden flight on 8 April 1941. Overall performance proved disappointingly poor however, due to a combination of excessive weight, the unreliability of the Mamori engines and the complexity of the design. Only three more prototypes were completed. In an attempt to salvage

1144-636: A pressure relief valve prevented the pressure difference from exceeding 2.65 lb/sq ft (12.9 kg/m ). The structure consisted of continuous longitudinal stiffeners spaced every 9 degrees around the fuselage with radial hoop stiffeners mounted every 16 in (410 mm) along the fuselage, reinforcing the similarity to a dirigible. The skin seams were sealed with tape impregnated with sealing compound trapped between lapped joints which were secured with two rows of rivets spaced 5 ⁄ 8  in (16 mm) apart, while doors and hatches were sealed with soft rubber gaskets and control cables entered

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1248-453: A pressurized version, on July 27, 1938, but nothing came of these discussions and ANA never operated the type. The first customer delivery was to millionaire Howard Hughes on July 13, 1939. He bought aircraft serial number 1997 registered as NX19904 for $ 315,000 for a round-the-world flight, hoping to break his own record of 91 hours 14 minutes set between July 10 and 14 in 1938 in a Lockheed Model 14 Super Electra . Hughes' Stratoliner

1352-399: A range of 3,400 mi (5,500 km). Boeing responded that the price for three aircraft would be $ 289,000 each if fitted with Cyclone engines or $ 314,000 if fitted with R-1830s, plus $ 3,100 - $ 4,000 per aircraft to increasing fuel capacity to either 1,700 US gal (6,400 L; 1,400 imp gal) or 2,125 US gal (8,040 L; 1,769 imp gal), provided that

1456-471: A requirement for a large 4 engine airliner remained. Donald Webb Tomlinson at T&WA carried out five years of high altitude flight research, with a Northrop Gamma and a Douglas DC-1 , which helped determine that T&WA would need a four-engine airliner with a pressurized cabin. During this period, He also test flew the XB-17 and determined that it would provide an ideal basis for an airliner, and so Boeing

1560-414: A sink, plush upholstered stools, soft indirect lighting provided by fluorescent lamps , ashtrays , hot and cold running water, shelves with towels, and a separate cubicle for the toilet. The men's washroom was in front as the "Men's Lounge", and also had a separate cubicle for the toilet, two sinks, and outlets to run an electric razor . A galley of just 28 sq ft (2.6 m ) provided hot food

1664-1126: A subsidiary, the Intercontinental Division (ICD), whose civilian crews would operate them on behalf of the United States Army Air Forces. Otis Bryan was made head of the ICD The Stratoliners were sold to the USAAF, who assigned the type the C-75 designation, and each of them was given a USAAF serial number. The first of these was accepted by the USAAF on March 1, 1941, and the last one on December 17, 1942. ICD crews included pilots, 1st & 2nd officers, navigators, flight engineers, flight radio operators and pursers. ICD Supervisor pilots and captains were paid $ 1100/month, first officers $ 800/month, Navigators $ 600/month, Flight Engineers (FEs) $ 500/month and Flight Radio Operators (FROs) $ 400/month. Personnel were issued with USAAF uniforms which they wore with rank stripes (two solid stripes for

1768-621: A test-flight on March 18, 1939, killing all 10 occupants, and forced several design changes, of which the fin and rudder are the most immediately obvious. KLM was considering four-engine airliners for the European routes, and a longer ranged four-engine aircraft for their routes to the Netherlands East Indies (now Indonesia). Aircraft considered included the Douglas DC-4 (E), the Boeing 307,

1872-437: A wobble pump, along with a rest area for the crew. A desk was added behind the pilot for a radio operator, who had a 50 watt Bendix TA-12 high frequency Morse transmitter, and a BC-348 tunable receiver. A 400 ft (120 m) trailing wire antenna was used with a 5 lb (2.3 kg) lead weight on the end - which the radio operator needed to remember to reel in, by hand, when landing. Inexperience sometimes led to either

1976-593: Is an American stressed-skin four-engine low-wing tailwheel monoplane airliner derived from the B-17 Flying Fortress bomber, which entered commercial service in July 1940. It was the first airliner in revenue service with a pressurized cabin , which with supercharged engines, allowed it to cruise above the weather. As such it represented a major advance over contemporaries, with a cruising speed of 220 mph (350 km/h) at 20,000 ft (6,100 m) compared to

2080-533: The Air Corps Ferrying Command (later renamed Air Transport Command) over the use of their airliners in wartime. Pan Am had already signed a contract on the 13th, in which it would keep its 307s, but sell the 314s to the government. T&WA sold all five of its 307s to the USAAF, but would then operate them on behalf of the USAAF on a cost plus basis though a new subsidiary. At the time the Stratoliner

2184-557: The Boeing Model 299 B-17 Flying Fortress heavy bomber as the Model 307. It combined the wings, tail, rudder, undercarriage, and engines from the B-17 with a new, much larger pressurized circular cross-section fuselage with a maximum diameter of 138 in (3.5 m). The pressurization system required extensive testing, which was carried out over many months, progressively increasing the air pressure after each successful test, and each time,

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2288-683: The Cosmic Muffin , in which form it still survives. As one of the companies sponsoring the development of the Douglas DC-4, Transcontinental & Western Air lost interest due to delays and poor performance, but the agreement they signed with Douglas limited the maximum weight of any replacement design to 43,000 lbs. After discussing their needs with Boeing, T&WA signed a contract with Boeing to buy six 307s with an option for 13 more for $ 1,590,000 on January 29, 1937, with deliveries to be made in mid-1938. T&WA defaulted on their payments though and

2392-588: The Douglas DC-3 's 160 mph (260 km/h), at 8,000 ft (2,400 m) then in service. When it entered commercial service it had a crew of five to six, including two pilots, a flight engineer , two flight attendants and an optional navigator , and had a capacity for 33 passengers, which later modifications increased, first to 38, and eventually to 60. In 1935, Pan American Airways , United Airlines , American Airlines , Eastern Air Lines and Transcontinental & Western Air (T&WA) had each signed

2496-635: The Gander, Newfoundland - Scotland leg distance. The first aircraft to land at these fields, which were north of the Arctic Circle, was an ICD C-75, on April 20, 1942. Marshall, Eisenhower, "Hap" Arnold and Admirals King and Towers flew to London from Washington via Montreal, Gander and Prestwick on May 23, 1942, and returned to Washington via Prestwick, Reykjavik and Gander. On June 20, 1942, Air Corps Ferrying Command became Air Transport Command The exiled (but not yet deposed) King Peter II of Yugoslavia

2600-702: The Junkers Ju 90 , the Focke-Wulf Fw 200 Condor , and the Bloch 160 , of which only the DC-4 and 307 came close to meeting their requirements Boeing made a proposal to KLM on September 20, 1936, for exclusive option on 10 certified 307s for $ 2.4 million with options for 18 aircraft and with first delivery in 14 months. By January 14, 1937, the price had increased for 18 aircraft to $ 265,000 each, not including pressurization equipment. KLM let Boeing know that they were interested in 4 aircraft, for use as an interim measure pending

2704-656: The Lockheed C-69 Constellation would not fly until January 1943, while aircraft with two engines were considered unsafe for ocean crossings with VIPs on board. On the entry of the United States into World War II , Pan Am continued operating its Stratoliners on routes to Central and South America , but under direction of the Army Air Forces' Air Transport Command, All five TWA Stratoliners were withdrawn from operations on December 24, 1941, while TWA created

2808-515: The lend-lease program. From April 22, regular crossings were being made. and ICD was growing rapidly, growing from 71 personnel in January, to 343 by April, and they were now making 16 ocean crossings a month. Following his April 1942 raid on Tokyo , but before it had been made public, Jimmy Doolittle took a C-75 from Karachi in India through Khartoum , Kano , Accra , Robertsfield Airport , crossed

2912-628: The Approved Type Certificate until May 5, 1939. It was used by United Air Lines for in-service evaluation during 1939. On June 9, 1939, when the DC-4 was in Dayton, Ohio, along with Carl Cover, Orville Wright was a passenger on a flight over the city. Although the aircraft was relatively trouble-free, the complex systems proved to be expensive to maintain and performance was below expectations, especially with an increase in seating to 52 and gross weight to 65,000 lb (29,484 kg). The design

3016-618: The Army Chief of Staff General George C. Marshall , General Dwight D. Eisenhower (to command Operation Torch for the invasion of North Africa), Deputy Chief of Staff of Army Ground Forces General Mark W. Clark , Operation Torch Air Force liaison officer Colonel Hoyt Vandenberg , Chief of the Navy's Bureau of Aeronautics Rear Admiral John Henry Towers , who oversaw Navy aircraft procurement and training, and presidential advisors W. Averell Harriman and Harry Hopkins who were crossing to negotiate

3120-617: The Atlantic to Natal in Brazil, and headed north to Belém , and from there with an additional fuel stop to Washington, D.C., arriving in time for the news of the raid to be made public. Many of the surviving members of the raid followed soon after in another Stratoliner. The North Atlantic ferry route was set up with help from former Arctic explorer Colonel Bernt Balchen , who assisted with Bluie East Two and Bluie East Eight in Greenland to reduce

3224-598: The Atlantic. By the time they were withdrawn, over 3000 trans-oceanic crossings had been made, and they had flown 21,284 while in USAAF service with the ICD. The sole accident occurred during night landing at Natal in Brazil when an undercarriage leg was torn off by a mound of dirt. It cost TWA about $ 2 million to have the five aircraft rebuilt by Boeing and the first of them resumed passenger service on April 1, 1945. The CAA recertified these as SA-307B-1 civilian airliners with their original registration numbers. On April 1, 1945,

Nakajima G5N - Misplaced Pages Continue

3328-810: The B-17C mounted low on the fuselage to a constant chord center section faired to the fuselage, with four 1,100 hp (820 kW) Wright GR-1820 Cyclone air-cooled radial engines . TWA examples used GR-1820-G105A engines fitted with two stage superchargers for high altitude performance, while the Pan Am examples used the GR-1820-G102 with a single stage supercharger. Engine exhaust collector rings designed to reduce noise, and exhaust mufflers were installed. TWA aircraft were fitted with cowl flaps, to adjust engine cooling air, while Pan Am aircraft had fixed cowling rings without cowling gills. When operating in cooler conditions,

3432-494: The CAA for overland flights, which were served by a network of beacons across the continent, when the aircraft were not being flown by visual flight rules (VFR). Both T&WA and Pan Am normally carried two flight attendants. T&WA began using Hostesses (as they called them) as cabin crew in late 1935, while Pan Am continued to use male stewards until late in WW2. Following the entry of

3536-453: The DC-3 and would be the first large aircraft with a nosewheel. Other innovations included auxiliary power units, power-boosted flight controls, alternating current electrical system and air conditioning. Cabin pressurization was also planned for production aircraft. The novel tail with three low vertical stabilizers enabled use of existing hangars and provided sufficient vertical fin area to allow

3640-587: The Navy was forced to search for a suitable existing foreign-made model upon which to base the new design. It settled on the American Douglas DC-4E airliner . In 1939 the sole prototype of this airliner (previously rejected by American airline companies) was purchased by Nippon Koku K.K . ( Japan Airlines Co ) and clandestinely handed over to the Nakajima Aircraft Company for dismantling and inspection. The design that emerged from this study

3744-557: The Pan Am aircraft could be fitted with a blanking disk that covered part of the front of the engine. Both versions had sufficient power to maintain altitude on only two engines, one of the KLM requirements. Both used three bladed Hamilton Standard Hydromatic constant speed propellers, and new high octane fuels were developed to help the engines operate under the increased supercharger pressure. Both versions had trailing edge flaps controlled with electric motors, although SA-307B for T&WA and

3848-534: The SA-307B-1s used the wings and elevators from the B-17G with split flaps, and 1,200 hp (890 kW) Cyclones. On most, but not all examples, the leading edges of the wings, horizontal stabilizer and fin were fitted with rubber expanding type de-icing boots, which would inflate and deflate repeatedly to break ice from the flying surfaces. All movable surfaces, including the rudder, ailerons and elevators had fabric over

3952-546: The SB-307B for Hughes featured slotted flaps with prominent external hinges, while the Pan Am examples had simpler split flaps with flush hinges, similar to those used on the B-17s. All of the fuel was carried in the wings, with a 212.5 US gal (804 L; 176.9 imp gal) tank mounted between the inboard nacelle and the fuselage, and a 425 US gal (1,610 L; 354 imp gal) main fuel tank as well as

4056-528: The South Atlantic, and between New York and Prestwick , Scotland, across the North Atlantic. They often flew non-stop the 2,122 mi (3,415 km) between Gander, Newfoundland and Prestwick, Scotland in the north, and the 2,500 mi (4,100 km) between Natal , Brazil and Accra , Ghana in the south. After July 1942 a refueling stop at Ascension Island was added in the South Atlantic. In

4160-410: The Stratoliner underpowered, and the climb suffered accordingly. The overloading burnt out engines and destroyed piston rings, but closely monitoring engine oil consumption often caught failures before they occurred. Passenger facilities were reduced to 4 bunks which when folded away allowed seating for 12, along with 4 seats along the opposite side of the aircraft. Removable tables were provided in

4264-490: The T&WA markings which had already been applied to their airframes were removed. T&WA filed a lawsuit against Boeing for default of contract, and Boeing sued T&WA for breach of contract over the non-payment. Hughes had begun secretly buying up T&WA shares and by March 1939, Hughes has a controlling interest in Trans-World Airlines (or TWA - as it was rebranded once he had taken over), with roughly 46% of

Nakajima G5N - Misplaced Pages Continue

4368-601: The US Government gave export permission on the engines. After not hearing back, Boeing sent a new quote to KLM for $ 300,000 per aircraft, or $ 320,000 for the pressurized version December 20, 1938, the KLM board made the decision to order two four-engine aircraft, with consideration of the Boeing 307 and Focke Wulf Fw 200 Condor, however the Condor was not suitable for the East Indies route. Following T&WA defaulting on payments,

4472-509: The USAAF had amassed sufficient long range transports that it no longer needed the C-75s, and they sold the fleet back to TWA, who paid to have them converted back to civil standard under Boeing's SA-307B-1 designation. CAA concerns over cracks in the wing spar tubing led to the TWA Stratoliners getting new B-17G wings and horizontal tail, with the leading edge of the longer span, narrower chord horizontal stabilizer moved about 3 ft (0.91 m) to

4576-522: The United States into World War II in December 1941, long-range transports were needed to ferry government and military officials around the globe and many aircraft, including T&WA's Boeing 307s, were pressed into service. Beginning in February 1942, these were flown to Albuquerque, New Mexico for conversion, which included the removal of the plush, but heavy civilian fittings, including the massive mirrors in

4680-400: The air, which was then passed through radiator condensers to cool the air, and it was then run through channels to the vents in the cabin. External hookups allowed ground air conditioner units to cool the cabin air when the engines were off. The Stratoliners were normally flown with a pilot and co-pilot, and both Pan Am and T&WA aircraft carried a flight engineer to reduce the workload on

4784-422: The aircraft stalled and entered a spin. It made two to three turns before the pilot was able to stop the spin using the engines, however the ensuing high speed dive and the forces that resulted from attempting to pull up before hitting the ground, resulted in the left outer wing tearing off with one engine still attached, followed by the right wing, just outside the outer engine, both of which also tore off parts of

4888-645: The aircraft to take off with only two engines on one side operating. The wing planform was similar to the DC-3, with a swept leading edge and almost straight trailing edge. The four 1,450 hp (1,080 kW) Pratt & Whitney R-2180-A Twin Hornet 14-cylinder radials were all mounted with noticeable toe-out, particularly the outer pair. The prototype ( NX18100 , s/n 1601) first flew, without incident, on June 7, 1938 from Clover Field in Santa Monica, California , piloted by Carl Cover . Testing issues, however, delayed

4992-432: The antenna being torn off, or lashing against the fuselage. An astrodome was fitted and the perspex top windows which produced excessive parallax were replaced with optically flat glass, to allow the navigator to take star shots (the angle between stars and the horizon could be used to determine how far north or south they were), necessary to determine their position when crossing large bodies of water. The SA-307B-1s retained

5096-421: The astrodomes when converted back from C-75 in 1944. To further aid navigation, a B-3 driftmeter was installed, along with an aperiodic compass that did not lag or lead in turns as a conventional compass does. Mae West life vests and life rafts were also provided. The landing gear was strengthened, and the maximum takeoff weight was increased from 45,000 to 56,000 lb (20,000 to 25,000 kg), leaving

5200-982: The behest of the Imperial Japanese Navy , the DC-4E was transferred to the Nakajima Aircraft Company and reverse-engineered , becoming the basis for the unsuccessful G5N bomber. To conceal its fate, the Japanese press reported shortly after its purchase that the DC-4E had crashed in Tokyo Bay . Data from McDonnell Douglas Aircraft since 1920, Vol. 1 General characteristics Performance Related development Aircraft of comparable role, configuration, and era Related lists Boeing 307 Stratoliner The Boeing Model 307 Stratoliner (or Strato-Clipper in Pan American service, or C-75 in USAAF service)

5304-507: The behest of the Imperial Japanese Navy . The design originated in 1935 from a requirement by United Air Lines . The goal was to develop a much larger and more sophisticated replacement for the DC-3 before the first DC-3 had even flown. Such was the initial interest from other airlines, that American Airlines , Eastern Air Lines , Pan American Airways and Transcontinental and Western Air (TWA) joined United, providing $ 100,000 each toward

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5408-449: The cabin to lay out maps and do paperwork. The exterior was then camouflaged in standard USAAF colours, with olive drab upper surfaces and neutral grey undersides, and each aircraft had its name painted on the nose and over the cabin door, which would also be used by many later operators. The names had previously been used in TWA publicity, but not painted on the aircraft. After three years

5512-523: The carburetor heating themselves and the aircraft was repaired and returned to service. Boeing made claims both in their period advertising and in their current web site that it was the first high-altitude commercial transport, and the first with a flight engineer. However its first flight on December 31, 1938, was later than that of the Renard R-35 which also had a pressurized cabin for passengers, which flew on April 1, 1938, but it crashed, and development

5616-499: The cost of developing the new aircraft. As cost and complexity rose, Pan American and TWA withdrew their funds in favor of the Boeing 307 Stratoliner , which was anticipated to be less costly. With a planned day capacity of 42 passengers (13 rows of two or more seats and a central aisle) or 30 as a sleeper transport (like the DST), the DC-4 (as it was then known) would seat twice as many people as

5720-522: The crossing, and the ICD C-75s would routinely lead flights of USAAF twin-engined aircraft, such as Douglas A-20s across. In November 1943, a C-75 carried Soong Mei-Ling , wife of the Chinese Nationalist warlord Chiang Kai-Shek , from Chungking to Washington to receive medical care and to negotiate military aid for China. Two main routes were flown, between Washington, D.C., and Cairo across

5824-581: The designation G5N2-L Shinzan-Kai Transport . The Allies allocated the code-name "Liz" to the aircraft, in the expectation it would be used as a bomber. Data from Japanese Aircraft of the Pacific War Famous airplanes of the world (1984) General characteristics Performance Armament Related development Aircraft of comparable role, configuration, and era [REDACTED] Media related to Nakajima G5N Shinzan at Wikimedia Commons Douglas DC-4E The Douglas DC-4E

5928-483: The engines that was not needed for the simpler supercharger installation used on the Stratoliner, while one duct opening was retained on each wing between the engine nacelles, to provide additional cabin air. Further mods made by TWA included improved sound proofing and temperature control, and on March 15, 1945, the B-1 recertification tests were completed to the CAA's satisfaction. The estimated cost to repurchase and refurbish

6032-453: The first of 12 C-54s. and Pan Am would also supplement their Stratoliners with 12 C-54s. TWA received two C-54s in August and had 5 by September, and a full allotment of 12 by November, along with the first three C-87s, to supplement the C-75s. At the same time Curtiss C-46 Commandos , Douglas C-47s and C-53s provided feeder links to the C-75s, C-54s and C-87s, as their range was inadequate for

6136-430: The first post-war civil commercial flight was made by Zuni, now as a SA-307B-1, from La Guardia to San Francisco via Pittsburgh, Saint Louis, Kansas City, Albuquerque, and Burbank, but the second transcontinental flight did not happen until a month later, when on May 1, 1945, a flight was made from Washington, DC to Spokane, Washington, via Dayton Municipal Airport , St Louis, Kansas City, Albuquerque and Burbank, reflected

6240-460: The first three T&WA aircraft were offered to KLM in late 1939 but a quick decision was needed by Saturday, March 18, 1939, but KLM was unable to make that decision before the offer expired, and requested an extension. On March 21, 1939, KLM confirmed that they still planned to buy 307s and insisted that they were content with Boeing's progress. Ultimately though, KLM did not buy the 307s because their representatives' test flight insurance coverage

6344-407: The five aircraft was $ 2 million. Ten 307s were built. NC19906 was temporarily marked as NX1940 and NC1940 for publicity purposes. The first Boeing 307 Stratoliner, serial 1994, registration NX19901 , made its first flight from Boeing Field , near Seattle on December 31, 1938, prior to its intended delivery to Pan Am following testing and certification. As related above , it crashed on

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6448-473: The force of the spin prevented their use. The crash delayed the program by over a year, beginning with a three-month investigation by the US Civil Aeronautics Authority , the precursor to the current Federal Aviation Administration , and Boeing to determine the causes. Flight and wind tunnel testing showed that both an extended dorsal fin and an enlarged vertical tail were needed to prevent

6552-467: The highly polished fuselage was coated with soapy water while the fuselage pressurized, for workers to look for the bubbles that would indicate a leak, much like testing a bicycle inner tube. Before the first aircraft had rolled out, T&WA's chief engineer discovered that the extruded metal tubing used for the wing spars was defective, with stress corrosion cracks produced by cold rolling the tubing to increase tensile strength. Affected aircraft included

6656-423: The inboard flaps were also extended. The first several aircraft, including NC19902, NC19903, and NC19904 were all rolled out with the small tail and then modified later. Test flights resumed on May 19, 1939, after the changes had been incorporated, and on June 20, 1939, the first flight was made with the "supercharged cabin" pressurization system on. On March 13, 1940, Approved Type Certificate (ATC) number 719

6760-481: The last of their five was delivered on June 4, 1940. It was not their first four engine airliner, as one of their parent companies, Western Air Express had operated the Fokker F-32 . All five were named in TWA promotional material for North American Indigenous tribes - names that would be used throughout their careers, continuing long after they left TWA. War intervened in December 1941, and civil aircraft production

6864-470: The maximum landing weight rose to 47,000 lb (21,000 kg). Slots were re-incorporated into the wingtip leading edges, as they had been with the pre-war airliners. The cabin was redesigned and passenger capacity was increased from 33 to 38, with the cabin now divided into a 10-seat front section and a 28-seat rear section, with no sleepers. The cabin pressurization system was never re-installed. The B-17G wings came with turbo-supercharger ducting for

6968-419: The modified undercarriage, and in hard landings, easily exceeded the contract's minimum required 500 ft/m (46 m/ft) descent rate with a successful 800 ft/m (74 m/ft) landing descent. T&WA was also concerned about the engine carburetor intake heaters being deliberately restricted by Boeing to prevent cooking the engines, which could potentially leave crews unable to clear ice. Their point

7072-537: The north, stops at Iceland or Greenland were often necessary, when flying west against unusually strong prevailing winds. As Douglas C-54 Skymasters took over the Gander to Prestwick route, the C-75s operated between Marrakech and Prestwick over the Atlantic. ICD C-75s crossing the Atlantic had to be careful to avoid Allied convoys and German U-boats , to avoid being shot at. Cherokee was returning American troops from Reykjavik to Gander at 1,000 ft (300 m), and

7176-413: The power had to be turned off before being used. A parking brake was provided, along with an emergency air brake system run off a bottle of compressed air, while the tailwheel was fully retractable. The fuselage was described as being dirigible shaped, and was an elongated teardrop, with a constant 11.5 ft (3.5 m) diameter tube lengthening it at its widest point. The circular section fuselage

7280-443: The pressurized cabin through specially developed glands designed to allow free movement of the cables, with a negligible amount of air leakage. The main cockpit windows were made from 5 ⁄ 8  in (16 mm) thick safety glass, while the rest of the windows were made of Plexiglass or Lucite sealed into rubber channels A large ram-air scoop on the cabin roof was provided to supply cooling air while at lower altitudes, and

7384-467: The project, two additional airframes were fitted with 1,530 hp Mitsubishi MK4B 12 " Kasei " engines and redesignated G5N2s. Although the Mitsubishi engines were more reliable than the original Mamori 11s, the aircraft was now even more hopelessly underpowered and further development of the type was halted. Of the six completed Shinzans , four were relegated for use as long-range Navy transports under

7488-697: The prototype, the first Pan Am machine, and some early production B-17s, and resulted in T&WA having to have their engineers manually inspect every tube that was to be incorporated into their aircraft. The first aircraft completed, registration NX19901 , crashed on March 18, 1939. while being demonstrated after having been recently fitted with instruments to measure flight control forces. The Boeing 307 took off at 1257hrs (local time) from Boeing Field in Seattle with ten occupants, and they climbed to an altitude of 11,000 ft (3,400 m) where stability tests were made and while carrying out side-slips near Alder,

7592-525: The rear, while more powerful versions of the same Wright Cyclone engines increased power from 1,100 to 1,200 hp (820 to 890 kW), but without the B-17G's turbosuperchargers. New propellers and landing gear were also installed. The change to the tailplane required that the structural bulkhead supporting the forward spar be moved aft, while the rear bulkhead was reworked and additional fuselage stiffeners were added. The tailwheel switched to using B-17G wheels and 26" smooth tread tires, which required that

7696-448: The rudder stalling in a yaw, and solutions were flight tested on NC19903 , including an intermediate solution consisting of just an extended dorsal fin. The resulting redesign was also incorporated into the redesign of the rear fuselage of the B-17E bomber. The wings were reinforced and Handley Page slots were added to the outer wing leading edges to improve low speed aileron control while

7800-408: The shares. By August 1939, TWA and Boeing had resumed negotiations so TWA would get five 307s, and Hughes would get one. The cost to TWA had risen, and was now $ 1,750,000 or $ 350,000 per aircraft - three times the cost for Douglas DC-3s. In early 1940, Hughes bought up all remaining outstanding TWA shares not otherwise reserved for employees. TWA received its first Stratoliner on May 6, 1940, and

7904-586: The sole four-engine commercial airliner in domestic service in the US. On July 10, 1939, TWA had signed a contract with Lockheed to develop the Constellation , which was to be capable of 5 miles/min (350 mph (560 km/h)) compared to the Stratoliner's 4 miles/min (246 mph (396 km/h)), but with production diverted to military for the duration of the war, the first TWA Constellations did not enter service until February 1946 and were soon grounded dealing with

8008-404: The tail as a result of the aileron cables pulling them against the fuselage, which then caused the aircraft to pancake into a forested area at 1317hrs. All ten aboard were killed, which included T&WA's representative, KLM's technical director, a Dutch Air Ministry representative, Boeing's test pilot, as well as their Chief Aerodynamicist and their Chief Engineer. Parachutes were available but

8112-412: The two pilots, by monitoring the engines for any problems and fine tuning them, while they also controlled fuel consumption from each of the tanks to maintain the aircraft's fore-aft and lateral balance. Too much fuel used in one tank could result in the aircraft becoming uncontrollable. They also monitored other aircraft systems, including hydraulics and the cabin pressurization system. The Flight engineer

8216-472: The underside of the fuselage. Extensive use was made of the latest in sound proofing, and the Dynafocal engine shock mounts were designed to reduce vibrations from being felt by the passengers. The air conditioning system used both electrical and mechanical systems, which drew air in through vents in leading edge of each wing near the roots to bring outside air to two engine driven superchargers that compressed

8320-568: The usual teething problems encountered with a new type, from July 11 to September 20, 1946, while the Douglas DC-4s began arriving in 1946 in small numbers and the Douglas DC-6 similarly, from 1947. At the same time, due to strong competition from war-surplus non-sked flights operating cheaply purchased war-surplus Douglas C-54s , in May 1949 the Stratoliner's were downgraded to a coach-only service with

8424-493: The wheel well be enlarged, and structure supporting the tailwheel reinforced. The main undercarriage wheels, tires, tubes & brakes remained unchanged, although the legs themselves were strengthened. The fuselages were stripped to bare metal and rewired with a 24VDC 1800 amp system from the B-29 Superfortress , replacing the original 24VDC 800 amp system. Maximum weight was increased to 54,000 lb (24,000 kg) and

8528-420: The women's "charm room" and the pressurization system to save weight. The sound insulation was also stripped out leaving the cabin much noisier than it had been. The forward men's washroom, and two of the four forward compartments were replaced with five gravity fed 212.5 US gal (804 L; 176.9 imp gal) fuel tanks and a 45 US gal (170 L; 37 imp gal) oil tank fed with

8632-493: Was La Guardia, NY to Chicago, Illinois to Kansas City, Missouri to Albuquerque, New Mexico to Burbank California and the reverse. 1940 was the best year for TWA, with 50% increase in passenger traffic over 1939, but they were still running exclusively in the red. On September 9, 1940, a TWA Stratoliner from Chicago to New York set a commercial speed record flying the 778 mi (1,252 km) in two hours and 52 minutes at an average speed of 271.4 mph (436.8 km/h). and

8736-428: Was abandoned in favor of a marginally smaller, less-complex four-engined design, with a single vertical fin and 21 ft (6.4 m) shorter wingspan. This newer design was also designated DC-4 , leading the earlier design to be redesignated DC-4E (E for "experimental"). In late 1939, the DC-4E was sold to Imperial Japanese Airways , which was buying American aircraft for evaluation and technology transfer during this period. At

8840-436: Was abandoned. As for employing a flight engineer, it was preceded in the US on a commercial aircraft by Maddux Air Lines Ford Trimotors , whose "Mate" had the same responsibilities as a flight engineer. Additionally, all German World War One Riesenflugzeug multi-engine bombers had flight engineers as they were integral to the specification. As built, the Stratoliner used the all-metal stressed-skin cantilever wings from

8944-467: Was also an Aircraft Maintenance Engineer (AME) and aside from operating the radio, which required training in Morse code , he was also responsible for all technical issues, and would carry out repairs and maintenance on the 307s. Pan Am aircraft had one additional crew member compared to T&WA aircraft. Because they made long overwater flights, they carried a navigator, who was not yet considered necessary by

9048-495: Was an American experimental airliner that was developed before World War II . The DC-4E never entered production due to being superseded by an entirely new design, the Douglas DC-4 / C-54 , which proved very successful. Many of the aircraft's innovative design features found their way into the Nakajima G5N bomber after the single DC-4E prototype was sold to a Japanese airline and clandestinely dismantled for study by Nakajima at

9152-481: Was approached with the idea. A ceiling of at least 16,000 ft (4,900 m) was required to avoid summertime "chop" over the Rocky Mountains , and to allow the aircraft to fly around the thunderstorms that can sometimes block mountain passes, which meant a pressurized cabin would be the most comfortable for passengers on long flights. In 1935, Boeing then designed a four-engine airliner using components from

9256-466: Was assigned to the Pan Am Boeing 307s, allowing commercial deliveries to commence. A second ATC was issued for the TWA aircraft, number 726, due to the numerous differences between the Pan Am and T&WA aircraft. T&WA was concerned about excessive undercarriage stiffness from their experience with the test flights with the XB-17, which were to be modified for the airliner. T&WA flight tested

9360-411: Was covered for a replacement cost of $ 500,000, with hull coverage and passenger liability, carried by Aero Insurance Underwriters and Associated Aviation Underwriters, despite the fact that Boeing was offering to sell the aircraft to KLM for much less than that. Another company that Boeing was in discussions with was Australian National Airways , who they quoted $ 310,000 per Stratoliner, or $ 340,000 for

9464-569: Was fitted with extra fuel tanks and was ready for the first leg of the round-the-world attempt when Nazi Germany invaded Poland on September 1, 1939, causing the attempt to be cancelled. Hughes' aircraft was stored in Glendale, California for the duration of the war, prior to being converted into a flying condo. Hughes had the extra fuel tanks removed, and for around $ 250,000, he had it fitted with much more powerful Wright R-2600 engines for its transformation into "The Flying Penthouse", which included

9568-499: Was flown in July 1942 from London to Washington to meet with North American leaders, with the engines leaned out so much that the last leg of the trip was able to skip numerous stops, so that they ended up being in the air for 21 hours 16 minutes when they arrived in Washington. On July 10, 1942, Ascension Island 's airfield opened in South Atlantic, shortening the hazardous transatlantic leg enough that smaller aircraft could now make

9672-516: Was for an all-metal mid-wing monoplane with fabric-covered control surfaces and powered by four 1,870 hp Nakajima NK7A Mamori 11 air-cooled radial engines driving four-bladed propellers. A long ventral bomb-bay, glazed nose and twin tailfins replacing the DC-4E's distinctive triple rudder were included. The DC-4E's retractable tricycle undercarriage was retained, as well as the original wing form and powerplant arrangement. Defensive armament comprised two 20mm Type 99 Model 1 autocannon (one in

9776-455: Was halted, preventing any further deliveries. TWA first service flight was chosen to be on July 8, 1940, to coincide with anniversary of TAT's 48 hour coast-coast service, which had used trains for night legs. TWA's Stratoliners flew between Los Angeles and New York , making three stops. TWA's Burbank - La Guardia flight via Chicago was 2 hours quicker than for a DC-3 (13:40 east and 15:38 west) with 3 stops in each direction. The main route

9880-490: Was initially set up at the crowded Washington Bolling Field but was soon transferred all of their operations to nearby Washington National Airport . Passengers continued to be loaded at Bolling Field, after flying the short hop from Washington National Airport. The first north Atlantic crossing was in March 1942, when a flight from Washington to Prestwick carried senior military and government officials to Europe, which included

9984-443: Was made when icing problems during a test flight on May 17, 1940, with NC19905, while carrying dignitaries in overcast conditions in the mountains resulted in three of the four engines failing, while the fourth was losing power, despite every measure being taken to clear the ice. This resulted in the aircraft making a belly landing in a field with a partially lowered undercarriage, just south of Lamar, Colorado . T&WA then modified

10088-492: Was of all metal construction, skinned with 24ST Alclad and capable of maintaining a cabin pressure equivalent to 8,000 ft (2,400 m) when flying at a 16,000 ft (4,900 m) altitude, and a 12,000 ft (3,700 m) cabin pressure when at 20,000 ft (6,100 m), with a maximum pressure difference of 2.5 lb/sq ft (12 kg/m ). The structure was designed with strength reserves so as to handle as much as 6 lb/sq ft (29 kg/m ), but

10192-470: Was provided with adjustable air conditioning vents, reading lights, and a call button. Nine additional seats were provided along the port side of the aircraft, while washrooms which doubled as dressing rooms were provided at both ends of the cabin. The rear washroom was for women and was named the "ladies charm room". Its walls were covered in heavy plate glass mirrors, and it contained in its 34 sq ft (3.2 m ) area two dressing tables, each with

10296-411: Was rejected, and KLM found Boeing's response to providing for the next of kin unsatisfactory, a disagreement that was not cleared up until after World War 2. The insurance coverage on the aircraft was sufficiently large that it had the insurance industry worried about fallout, and as was the norm at the time, neither passengers nor crew could get coverage from any insurance company, but the aircraft itself

10400-443: Was returned to Hughes. It languished unflown until August 1965, when it was damaged beyond repair by Hurricane Cleo , with only about 500 hours on the airframe. It was then bought for $ 69 by Kenneth W. London, who cut the damaged wings and tail off, built a hull under it, and installed a pair of V-8 engines to convert it into a houseboat which he named Londonaire . After various repossessions, deaths and failed sales later, it became

10504-488: Was shot at by a US Navy ship that left over 200 holes in the aircraft's tail, and which nearly severed the elevator controls. Many transatlantic trips were made at night, so the navigator could get good star sightings. By 1944 the USAAF had enough long range transports that it no longer needed the small number of C-75s it had, and sold the fleet back to TWA, with the aircraft being transferred between January 6, 1944, and December 19, 1944. On August 11, 1942, ICD had received

10608-451: Was shut off when the cabin was pressurized at higher altitudes. The cockpit was fitted with an autopilot, radios and a radio direction finder (RDF) for navigation. The noted industrial designer Raymond Loewy designed the passenger cabin, with furnishings provided by Marshall Field's . It was divided into four compartments, each with six deep comfortable reclining chairs which could be converted into 16 sleeping berths. Each compartment

10712-406: Was situated at the rear of the cabin, behind which was positioned the rear hemispherical pressure bulkhead. Up to 412 cu ft (11.7 m ) or 6,590 lb (2,990 kg) of baggage could be stowed under the floor of the cabin, both between the wing spars, and behind the rear spar, which was accessible in flight through a hatch in the cabin floor, or on the ground through three hatches on

10816-574: Was the only available landplane transport capable of transatlantic flights with any payload. Seaplanes were too slow and not numerous enough, while the Douglas C-54 Skymaster would not enter service until March 1942 and took months to be available in any numbers, aside from a few ad-hoc conversions from Consolidated B-24 Liberator bombers, the Consolidated C-87 Liberator Express would not be ready until September 1942, and

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