Boeing Boeing 307 Stratoliner
Страна: США
Год: 1938

Дальнемагистральный пассажирский самолет с экипажем из пяти человек
Boeing 307 Stratoliner
Flight, April 1938

Boeing 307 Stratoliner

Boeing Model 307 Stratoliner (C-75)

   Прототип самолета Model 299 проектировался параллельно с гражданским вариантом Boeing Model 300. Предполагалась высокая степень унификации обоих вариантов: одинаковые крыло, хвостовое оперение и силовая установка. Однако с самого начала гражданский вариант проектировался с фюзеляжем большего объема. По ходу разработки было принято решение об использовании герметичного фюзеляжа круглого сечения. Новый Model 307 предназначался для перевозки пассажиров на высотах до 6100 м, то есть выше основных турбулентных областей атмосферы. Уже после начала эксплуатации самолета в авиакомпаниях хорошие высотные данные Model 307 послужили поводом, чтобы дать ему имя Stratoliner.
   Построили 10 самолетов Model 307, первый из них поднялся в воздух 31 декабря 1938 года, но был потерян раньше, чем его успели передать авиакомпании "Pan American". Из девяти остальных самолетов три получила "Pan American" (под обозначением Model S-307), а пять - авиакомпания TWA (Model SA-307B). Еще один доработанный самолет, единственный Model SB-307B, был отправлен Говарду Хьюзу.
   В 1942 году самолеты авиакомпании TWA передали авиации Армии США под обозначением C-75. Рассчитанные на перевозку 33 пассажиров при экипаже из пяти человек самолеты, согласно контракту с TWA, эксплуатировались Транспортным командованием для перевозок штабных офицеров. За 2,5 года эксплуатации пять самолетов примерно 3000 раз пересекали Атлантику, налетав около 45 000 часов и 12 млн км. Затем самолеты вернули на фирму "Boeing" для переоборудования из военного в гражданский вариант. В ходе модернизации самолеты C-75 получили новые крылья и хвостовые оперения, были установлены более мощные моторы.


   Boeing Model SA-307B Stratoliner

   Тип: дальнемагистральный пассажирский самолет с экипажем из пяти человек
   Силовая установка: четыре звездообразных мотора Wright GR-1820 Cyclone мощностью по 900 л. с. (671 кВт)
   Характеристики: макс, скорость на высоте 5275 м - 396 км/ч; крейсерская скорость на высоте 4785 м - 354 км/ч; начальная скороподъемность 366 м/мин; практический потолок 7985 м; дальность 3846 км
   Масса: пустого 13 608 кг; максимальная взлетная 19050 кг
   Размеры: размах крыла 32,61 м; длина 22,66 м; высота 6,34 м; площадь крыла 138,05 м;
   Вместимость: до 33 пассажиров

Flight, April 1938

Features of the Boeing 307 and 307-A Transports : Operation at 20,000ft.

   A STATEMENT by Mr. C. L. Egtvedt, president of the Boeing Company, goes far towards dispersing the haze of semi-secrecy which for some time has surrounded the Boeing 307 and 307-S four-engined transports now under construction at the company’s Seattle works. The basic design has been christened the Stratoliner, the name having been registered as a trade mark. The new machines will be the first large transports with pressure cabins for high-altitude operation. As in the Albatross the fuselage is of circular cross-section throughout its length. Thirty-three passengers will be accommodated by day and twenty-five by night, and there will be stowage for 2 tons of mail and cargo. Power plants in the standard 307 will be four G102 Wright Cyclones (1,100 h.p. for take-off); these are for operation at moderate altitudes, so presumably similar engines with two-speed blowers will be specified for the 307-S.
   The basic reasons for the Stratoliner are that as height increases not only do atmospheric pressure and density decrease, but movement of the air in prevailing winds becomes swifter and more uniform, and the temperature decreases steadily with altitude - normally about 3 1/2 deg. every 1,000ft. The thermometer drops to 65 deg. below zero Fahrenheit at approximately 35,000ft. (in the temperate zone), and thence upward it ceases to get colder. This region of stable temperature, ex­tending as far up as there is still a trace of atmosphere, is the true stratosphere.
   The Stratoliner’s flight path will, of course, be below the true stratosphere but above the heavy air belt that brews surface weather conditions. This region is in the troposphere, more commonly known as the sub-stratosphere.
   It is here that most of the benefits of the stratosphere can be obtained without becoming involved in the complex problems of flight in the extremely rare atmosphere and low temperature of the true stratosphere. At 20,000ft. there is very little difference between summer and winter. No matter what the weather is below; the thermometer always registers something like 10 deg. below zero. Although the winds are not entirely constant at this level, they are considerably more so than at lower altitudes and the air is virtually free from the turbulence that sometimes gives passengers a rough journey at lower levels.
   Storm clouds and icing conditions, except on rare occasions, he below this flight path. When thunderheads do extend into the upper level they are so localised that they may readily be avoided. Normal clouds at this height are so thin that they appear as thin smoke rather than fog when a machine passes through them.
   The air is sufficiently rarefied to allow high speeds at normal cruising power. On 2,500 h.p. at 20,000ft., the Stratoliner will cruise at 240 m.p.h.
   At sea level the atmospheric pressure is 14.7 Ib./sq. in.; at height up to 10,000ft., where the pressure is a third less, most persons are entirely comfortable. Up to 12,000ft. the human system continues to function quite normally, but at 13,000 and 14,000ft., where the atmospheric pressure is down to 8.6 lb./sq. in., most people are definitely aware that they are "up high": they lose their sea level spryness. Above this point, tests have shown, the low air pressure and resultant shortage of oxygen makes a person mentally drowsy and sluggish in his actions. The effect increases with more altitude.

Compressing and Warming

   At 18,000ft. the atmospheric pressure is half as great as at sea level, and at 20,000ft. it has decreased further to 6.7 Ib./sq. in. But a sample of the air taken at any of these levels shows that the percentage of oxygen and other gases is always' the same. When compressed and warmed, the air at high altitudes resumes its low-altitude condition.
   As the Stratoliner climbs, its mechanical superchargers and pressure regulating apparatus will, come into action to preserve automatically the proper pressure inside the cabin while the outside pressure continues to decrease. The thoroughly sealed cabin, with its heavy pressure-resistant windows, will enhance the plane’s normal soundproofing and should give passengers an exceptionally quiet trip.
   The automatic pressure-regulating system brings a new advantage during ascents and descents. By merely arranging the proper setting on pressure regulating controls, the crew can bring the Stratoliner from an altitude of 15,000ft. to sea level at the rate of 565 ft./min. without discomfort to passengers, because the cabin pressure changes only at the rate of 300 ft./min. This will mean a substantial time saving.
   The cylindrical walls of the Stratoliner’s cabin, including windows, doors, and fittings where controls pass through the shell, are constructed to withstand a pressure difference of 6 lb. /sq. in between inside and outside air. The machine will be operated, however, at a pressure, difference of only 2 1/2 lb./sq. in., which is sufficient to keep the "apparent cabin altitude" at 8,000ft. at a height of 14,700ft., and "at 12,200ft." when 20,000ft. high.
   Fresh air, drawn through the leading edge of each wing, is compressed by two engine-driven superchargers and circulated throughout the cabin after being heated by means of freeze-proof condenser-type steam radiators. Either of the two fully independent sets of supercharging and heating apparatus can handle the entire job alone. Spent air is discharged through an exhaust chamber below the floor.
   The entire system operates automatically with the same ease as a thermostatically controlled home air conditioning and heating system. Controls for hand regulation are also provided.
   An automatically controlled fresh air supply sufficient for 40 persons is furnished by the blowers. The air is conducted directly into the cabin ventilating system, so that individually controlled ventilators at passenger seats supply the same "conditioned air" as do the general circulation vents.
   The circular section of the fuselage was chosen because it is the most practical shape for a pressure cylinder and at the same time is advantageous aerodynamically. Semi-monocoque construction is used, with Alclad aluminium alloy skin covering on Z-section rings and longitudinal stiffeners.
   The low cantilever wing is of the typical Boeing truss and stressed-skin type. Wing covering consists of smooth Alclad skin over aluminium alloy corrugations. Fittings are of high strength steel. The flaps and undercarriage are electrically operated.
   A new semi-monocoque construction making for quick detachability of the engines is used for the nacelles. The four Wright GR-1820-G102 Cyclone engines (in the 307) drive three-bladed Hamilton Standard Hydromatic airscrews, of the constant-speed, full-feathering type.
   Fuel tanks with a capacity of 1,275 U.S. gallons are installed in the inner-wing sections. Additional tanks may be fitted to increase the capacity to 1,700 U.S. gallons. There are no fuel pipes within the fuselage.
   The Stratoliner has a span of 107ft. 3in.; a length of 74ft. 4in.; and an overall height of 17ft. 3in.
   Immediately aft of the cockpit in the nose is the men's dress­ing room, and behind this is the main passenger cabin, the right side of which is divided into four travel compartment - each containing Davenport-type seats for six passengers. Each compartment makes up into two sets of upper and lower berths at night. Along the left side of the cabin are nine reclining chairs.
   Aft of the passenger section is the women's dressing room on the right and the galley at the left. There is a pressure bulkhead just aft of the galley.
   Passengers enter the cabin through a side door, the crew having a separate entrance to the cockpit from below. Cargo is loaded into the hold through this lower doorway.

Four Wright GR-1820-G102 Cyclone Engines.

Maximum speed on 3,800 h.p 241 m.p.h. at 6,000ft.
Cruising speed on 2,500 h.p. (69.5% power) 215 m.p.h. at 10,000ft.
Cruising speed on 2,180 h.p. (60% power) 202 m.p.h. at 10,000ft
Cruising speed on 1,800 h.p. (50% power) 184 m.p.h. at 10,000ft
Take-off distance at sea level at 4,400 h.p. 1,040 ft
Take-off distance to clear 50ft obstacle 1,900ft.
Take-off distance to clear 50ft obstacle on any three engines after failure of one engine 1,200ft. from start 2,700 ft.
Landing distance to stop over 50ft. obstacle 2,300 ft.
Service ceiling with four engines 23,300 ft.
Service ceiling with any three engines 18,200 ft.
Absolute ceiling with any two engines 10,500 ft.
Absolute ceiling with any two engines at 36,000-lb. gross weight 14,200 ft.
Initial rate of climb with four engines at 840 h.p. each at sea level 1,250 ft./min.
Initial rate of climb with three engines at 840 h.p. each at sea level 700 ft./min.
Initial rate of climb with two engines at 840 h.p. each at sea level 200 ft./min.
Specific fuel consumption 0.44 lb./h.p./hr.
Range with 7,000-lb. (3,180-kg.) payload at maximum gross weight and with standard equipment, furnishings, de-icers, radio, food, water, bedding and 1,275 gals. fuel:
   Optimum cruising - average speed 150 m.p.h. (242 km.p.h.) 1,950 miles.
   Cruising at 50% power or 1,800 h.p.- 184 m.p.h. (290 km.p.h.) 1,750 miles
   Cruising at 60% power or 2,100 h.p. - 202 m.p.h. (325 km.p.h.) 1,000 miles.
   Cruising at 69.5% power or 2,500 h.p. - 215 m.p.h. (348 km.p.h.) 1,475 miles.
Range with 9,750-lb. (4,420-kg.) payload at maximum gross weight and with standard equipment, furnishings, de-icers, radio, food, water, bedding and 850 U.S. gals. of fuel:
   Cruising at 184 m.p.h. 1,150 miles.
   Cruising at 202 m.p.h. 1,050 miles.
   Cruising at 215 m.p.h. 975 miles.
Boeing 307 Stratoliner. Хотя компания "Pan Am" была первым покупателем Stratoliner (стоил 315 000 долларов), TWA имела больше этих машин - пять. Самолет "NX1940" (в реальности NX19906) совершил рекламный тур перед вводом лайнера в эксплуатацию. Stratoliner TWA налетали свыше 7,2 млн километров, прежде чем их "призвали" на военную службу. Все самолеты TWA вернулись на регулярные линии в 1944 году.
Apache - один из самолетов авиакомпании TWA, эксплуатировавшийся ВВС Армии США. Самолет сверху окрашен в светло-оливковый цвет, снизу - в серый.
Earning its place among many dazzling exhibits at the National Air and Space Museum’s Steven F. Udvar-Hazy Center in Washington DC is the sole complete surviving Boeing 307, NC19903, which had a long and dramatic career, including being used as the personal transport of Haitian dictator Francois “Papa Doc” Duvalier in the 1970s.
The author’s splendid colour photograph of Boeing 307 Stratoliner F-BELX (c/n 1999) at Wattay Airport, Vientiane, Laos, on January 23, 1966, while in the service of the International Control Commission. The aircraft later crashed in Cambodia. Of note in the background is the second production Lockheed L-188A Electra, VR-HFN, which had been operating with Cathay Pacific since June 1959.
Boeing SA-307 XW-TFP of Cambodia Air Commercial still wearing the former Air Laos lightning bolt cheat line, 1973.
The ill-fated Model 307 prototype, NX19901, which first flew on December 31, 1938.
31 декабря 1938г.: после первого полета Boeing 307 Stratoliner, созданного на базе бомбардировщика B-17, на него поступили заказы от "Pan Am" и TWA.
The ill-fated Model 307 prototype, NX19901, which first flew on December 31, 1938.
Прототип Boeing 307, NX19901, совершил первый полет 31 декабря 1938 года. От своего прародителя - бомбардировщика Model 299 (B-17) - он получил киль небольшой площади, крыло, горизонтальное оперение и силовую установку.
ON TEST: The new Boeing 307 Stratoliner flying at 11,000ft. with its two starboard Wright Cyclones stopped and the airscrews feathered. During this flight the machine had an all-up weight of 45,000 lb. The way in which the rudder is being held over to counteract the drag of the stopped engines is noticeable, but more interesting is the white leading edge of the tailplane. This is a paint coating to record the direction of the flow of fuel in dumping tests during which coloured water was used instead of petrol.
ENTER THE STRATOLINER: A first view of the Boeing 307-s high-altitude transport which rejoices in the registered trade name of Stratoliner. The cabin will be equipped to maintain a pressure differential of 2 1/2 lb., and the machine will normally cruise at 16,000ft. with 33 passengers. The first three Stratoliners will probably be delivered to Pan-American Airways, and one example may be developed for transatlantic work. Transcontinental and Western Air are interested in the machine. The engines are Wright Cyclones driving Curtiss fully feathering electrically variable airscrews.
The second Stratoliner, NX19902, in factory-fresh condition. This aircraft also served with Pan Am, as Clipper Rainbow.
THE NEW STRATOLINER: As already recorded, the second Boeing 307 has recently been carrying out full-scale pressure-cabin experiments. The machine concerned, the 307S., is remarkable for the extra fin area provided. Mr. Howard Hughes is shortly to take delivery of a special long range version of the 307, with tankage for 4,200 British gallons.
The third Stratoliner built was NC19903, Clipper Flying Cloud, for Pan American, to whom it was delivered in February 1940. Now the property of the Smithsonian, this aircraft is displayed at the Pima County Air Museum.
Первым покупателем Stratoliner была авиакомпания "Pan American Airways". Принадлежавшие ей три машины получили обозначение PAA-307 и собственные имена "Flying Cloud", "Comet" и "Rainbow".
NX19903 early in its life, before the application of PAA insignia. It was later registered NC19903. Note the modified fin and rudder.
Three Boeing 307 Stratoliners are on order by P.A.A. One is for experimental landplane service over the Atlantic.
The second TWA Model 307B, NX19906, is seen landing at La Guardia, New York, marked as NC1940, a contrived registration applied to publicise the “1940 Airliner” during a pre-service route tour.
The Boeing Model 307 Stratoliner was the world’s first pressurised airliner and could cruise at 20,000ft, substantially higher than the previous generation of airliners. Introduced into TWA service in July 1940, the Stratoliner represented the application of the lessons learned from Tomlinson’s pioneering research flights in the DC-1 and Gamma
Boeing Model SA-307B Stratoliner in Transcontinental & Western Air livery.
The Boeing 307-B Stratoliner as supplied to Transcontinental and Western Air, Inc.
Only ten Boeing 307 Stratoliners were produced, three going on to serve with Pan American and five being acquired by TWA. The fourth production example was bought by Howard Hughes for a round-the-world flight, but the beginning of the Second World War put paid to the idea. Instead he converted it into a “Flying Penthouse”.
Давление в кабине - 0,18 кг/см2 - соответствовало атмосферному давлению на высоте 2440 м и поддерживалось до высоты полета 4480 м.
Stratoliner, конструкция которого включала множество инноваций, был одним из самых совершенных лайнеров своего времени. Лишь начавшаяся война помешала успеху этого самолета.
Говард Хьюз забрал этот Stratoliner у компании TWA, чтобы попытаться установить на нем мировой рекорд дальности полета. Позднее эту машину за 250 000 долларов переделали в личный самолет Хьюза, и она получила прозвище "The Flying Penthouse".
N75385 was the final identity of NC19910 Clipper Comet, originally built for Pan Am. It was written off in a crash on October 5, 1958.
На службе авиационного Транспортного командования. В годы Второй мировой войны пять Stratoliner компании TWA, получивших обозначение C-75 и камуфляжную окраску, использовались ВВС США. На них летали гражданские экипажи TWA, заключившие контракты с авиационным Транспортным командованием ВВС, перевозившим грузы и пассажиров через Атлантику. В числе пассажиров на борту C-75 побывали генералы Джордж Маршалл, Дуайт Эйзенхауэр и адмирал Дж. Тауэр. За время военной службы самолеты 3000 раз пересекали океан и налетали 45000 часов. Затем их вернули на фирму "Boeing", доработавшую машины до стандарта SA-307B-1. Самолеты были возвращены TWA и использовались до 1951 года, затем их продали другим компаниям.
In contrast to the polished natural metal finish of peacetime, N19908 Apache, a Model 307B of TWA, displays its wartime olive drab plumage in service with USAAF Transport Command as a C-75.
The sixth Boeing 307B Stratoliner F-BHHR for Aigle Azur, Saigon, shown here at New York before delivery
F-BELY, which had also served with Aigle Azur, is here seen after sale to Airnautic GECA.
In service with the French independent operator Aigle Azur, F-BELV was originally N19905 Comanche with TWA.
A welcome visitor to London Airport some time ago was this French U.A.T. Boeing SA-307B Stratoliner F-BELV (c/n. 1996), ex-T.W.A. (NC19905) and Aigle Azur, one of five currently registered in France.
The French-registered Boeing 307 Stratoliner at right was used by the International Control Commission, established by the 1954 Geneva Accords to monitor the “ceasefire".
2003 was the serial given to ex-Pan Am S-307 N19903 when it joined the Corps d'Aviation de l'Armee d'Haiti in 1954. It became the personal aircraft of "Papa Doc" Duvalier.
Rarely illustrated, aircraft of the Haiti Corps d'Aviation de l'Armea seen here at Bowen Field, Port-au-Prince, include a Boeing Model 307 Stratoliner (2003) and a Beech AT-11 Kansan (3516), with unglazed nose.
NC19910 became HC 004 in service with Aerovias Ecuatoriannas CA of Ecuador. It is seen at Miami International in 1954.
N9307R, owned by Flight Investment Co when this picture was taken, still bears the Haitian military serial 2003 prominently on its fin. It was later given back its old registration, N19903.
Stratoliner XW-TFP with Royal Air Lao on March 11, 1975.
The sad sight of the tail of National Air & Space Museum Boeing S307 Stratoliner N19903 ‘Clipper Flying Cloud’ protruding from the waters of Puget Sound following its ditching on March 28, 2002. Luckily, this unique airliner survivor was recovered structurally intact and returned to Boeing Field for assessment.
The wreckage of NX19901 at Adler, Washington, after its fatal crash on March 18, 1939, when all 13 people in the aircraft lost their lives.
An impression of the Boeing 307 "Stratoliner" landplane. At least one of these machines, now being built at Seattle, is likely to be used by P.A.A. for transatlantic work. It will have a pressure cabin for sub-stratosphere flying.
The Ensign's U.S. counterpart: A drawing indicating certain of the salient features of the Boeing 307.
Cabin arrangements of the Boeing Stratoliner, which will accommodate 33 passengers by day or 25 by night. Just aft of the control cabin is the men’s dressing room, and then four compartments - the first two shown made up for night travel. On the near side are nine chairs for short-trip passengers. At the rear are the women’s dressing room and the galley.
Air, drawn in through the leading edge of each wing, is com­pressed by the superchargers, warmed, and circulated as shown in this diagram.
The plan of the Boeing 314’s control cabin.