Boeing 314 Clipper

The Boeing 314 Clipper was a long-range flying boat built by the Boeing Airplane Company between 1938 and 1941. One of the largest aircraft of the time, it used the massive wing of Boeing’s XB-15 bomber prototype to achieve the range needed to cross the Atlantic and Pacific Oceans. Twelve were built; nine flew for Pan Am and were later transferred to the U.S. military. The other three were sold to BOAC by Pan Am and delivered in early 1941. (BOAC's three Short S.26 flying boats had been requisitioned by the RAF).

Design and development


Pan American had requested a flying boat with more range and payload than its trans-Pacific Martin M-130. Boeing's bid was successful and on July 21, 1936, Pan American signed a contract for six. Boeing engineers adapted the cancelled XB-15's 149 ft wing and replaced the 850 hp Pratt & Whitney Twin Wasp radial engines with the 1,500 hp Wright Twin Cyclone. Pan Am ordered six more aircraft with 1600 hp engines as the Boeing 314A.

The huge flying boat was assembled at Boeing's Plant 1 on the Duwamish River and towed to Elliott Bay for taxi and flight tests. The first flight was on June 7, 1938, piloted by Edmund T. "Eddie" Allen. At first the aircraft had a single vertical tail, and Allen found he needed more directional control. The aircraft returned to the factory and was fitted with the endplates on the ends of the horizontal tail in place of the single vertical fin. This too was found to be lacking and the centerline vertical fin was restored. The 314 used heavy ribs and spars in a robust fuselage and cantilevered wing that didn't need drag-inducing struts to brace it. Boeing used Dornier-style sponsons, short wings at the waterline on each side of the hull that stabilized the craft on the water, was an entryway for passengers and contributed lift in flight. Passengers and their baggage were weighed, with each passenger allowed up to 77 lb free baggage allowance (in the later 314 series) but were charged 1% of their fare for each kilogram beyond that. The 314 carried 4,246 USgal of gasoline; the later 314A carried 5400 USgal. 300 USgal of oil was carried for the radial engines.



Pan Am's "Clippers" were built for luxury travel. The seats could be converted into 36 bunks; flights at maximum weight cruised at 135-150 mph) so Pan Am's schedule San Francisco to Honolulu in 1940 was 19 hours. The 314s had a lounge and dining area, and the galleys were crewed by chefs from four-star hotels. Men and women had separate dressing rooms, and white-coated stewards served five and six-course meals with gleaming silver service. The luxury on Pan American's Boeing 314s has rarely been matched on air transport; fare was $675 return from New York to Southampton, comparable to a round trip aboard Concorde in 2006. A one-way ticket from San Francisco to Hong Kong cost $760 ($1,368 round-trip).  Transatlantic flights continued to neutral Lisbon and Éire (Ireland) after war broke out in Europe in September 1939 (and until 1945) but military passengers and cargo got priority and the service was more spartan.

Critical to the 314's success were Pan Am flight crews, skilled at long-distance, over-water flights. For training, many transpacific flights carried a second crew. Only the best and most experienced crews were assigned to the Boeing 314. Before coming aboard, captains as well as first and second officers had thousands of hours of flight time in other seaplanes and flying boats. Training in dead reckoning, timed turns, judging drift from sea current, astral navigation, and radio navigation were conducted. In poor visibility, pilots sometimes made successful landings at fogged-in harbors by landing out to sea, then taxiing the 314 into port.

Operations
The first Boeing test flight across the Pacific left San Francisco on February 23, 1939. The first 314, Honolulu Clipper, happened to be in Manila near the end of March when the CAA approved revenue passenger flights, so the first paying passengers on a 314 flew Manila to Hong Kong. Regular weekly flights from San Francisco to Hong Kong began on March 29. A one-way trip took over six days, as it had on the Martins. Scheduled flights lasted less than three years, ending when the United States entered World War II in December 1941.

Passenger flights across the Atlantic began on June 28, 1939, from Port Washington, New York to Lisbon and Marseilles; the first flight to Southampton left Port Washington on July 8. The northern route stopped at Shediac, New Brunswick, Botwood, Newfoundland, and Foynes, Ireland; the southern route was via Horta, in the Azores, and Bermuda if needed. In August the weekly Southampton trip was scheduled 24 hr 30 min eastward and 29 hr westward.

Pan Am found that a 314 at full weight could not be expected to take off when waves were more than three feet high&mdash; it couldn't gain enough speed hitting such a swell, which in winter was common at Horta. After delays and cancellations in winter 1939-40 Pan Am gave up on winter flights to Horta; after February 1941 winter departures from Lisbon flew south to Bolama, in Portuguese Guinea, then west to Trinidad and north. Thousands of extra miles, but reliability was better.

At the outbreak of the war in the Pacific Pacific Clipper was en route to New Zealand. Rather than risk returning to Honolulu, it was decided to fly west to New York. Starting on December 8, 1941 at Auckland, New Zealand, the Pacific Clipper covered over 31,500 miles (50,694 km) via Surabaya, Karachi, Bahrain, Khartoum and Leopoldville. The Pacific Clipper landed at Pan American's LaGuardia Field seaplane base at 7:12 on the morning of January 6, 1942.

The Clipper fleet went into military service during the war, carrying personnel and equipment to the European and Pacific fronts. The aircraft were purchased by the War and Navy Departments and leased back to Pan Am for a dollar, with the understanding that all would be operated by the Navy once four-engined replacements for the Army's four Clippers were in service. Only the markings on the aircraft changed: the Clippers continued to be flown by their Pan Am civil crews. American military cargo was carried via Natal, Brazil to Liberia, to supply the British forces at Cairo and even the Russians, via Teheran. The 314 was given the military designation C-98. In 1943 President Franklin D. Roosevelt traveled to the Casablanca Conference in Dixie Clipper.

The success of the first six Clippers led Pan Am to order six improved 314As to be delivered in 1941, with the goal of doubling the service across the Atlantic and Pacific. The fall of France in 1940 caused doubt about whether the Atlantic service could continue; passenger numbers had already dropped due to the war, and if Spain or Portugal joined the Axis, flights to Lisbon would have to end. Pan Am considered reducing their order and, in August 1940, reached an agreement to sell three of the six under construction to the United Kingdom. The aircraft were to be operated by the British Overseas Airways Corporation and were mainly intended for the UK - West Africa route, as existing flying boats could not travel this route without stopping in Lisbon. The sale made a small profit for Pan Am - priced at cost plus 5% - and provided a vital communications link for Britain, but was politically controversial. To arrange the sale, the junior minister Harold Balfour had to agree to the contract with no government approval, leading to stern disapproval from Winston Churchill and lengthy debate by the Cabinet over the propriety of the purchase. Churchill later flew on the Bristol and Berwick, which he praised highly, adding to the Clippers’ fame during the war.

After the war several Clippers returned to Pan American, but they were obsolete. The flying boats didn't require long concrete runways, but many such runways had been built during the war for heavy bombers. New long-range airliners such as the Lockheed Constellation and Douglas DC-4 were developed. The new landplanes were faster and more efficient, and did not require the pilot training needed for seaplanes. One of the 314's most experienced pilots said, "We were indeed glad to change to DC-4s, and I argued daily for eliminating all flying boats. The landplanes were much safer. No one in the operations department... had any idea of the hazards of flying boat operations. The main problem now was lack of the very high level of experience and competence required of seaplane pilots".

Retirement
The last Pan Am 314 to be retired in 1946, the California Clipper NC18602, had accumulated more than a million flight miles. Of the 12 Boeing 314 Clippers built three were lost to accidents, but only one resulted in fatalities: 24 passengers and crew aboard the Yankee Clipper NC18603 lost their lives in a landing accident at Lisbon, Portugal on February 22, 1943. Among that flight's passengers were prominent American author and war correspondent Benjamin Robertson who was killed and the American singer and film/TV actress Jane Froman who was seriously injured.

Pan-Am's 314 was removed from scheduled service in 1945-46 and the seven serviceable B-314s were purchased by start-up New World Airways. These sat at San Diego's Lindbergh Field until all were sold for scrap in 1950. The last, the Anzac Clipper NC18611(A), was resold and scrapped at Baltimore, Maryland in late 1951.

BOAC's 314As were withdrawn from the Baltimore-to-Bermuda route in January 1948, replaced by Lockheed Constellations flying from New York and Baltimore to Bermuda.

Variants

 * Model 314
 * Initial production version with 1,500 hp Twin Cyclone engines, six built for Pan Am.


 * Model 314A
 * Improved version with 1,600 hp Twin Cyclones with larger-diameter propellers, additional 1200 USgal fuel capacity, and revised interior. Still air range approx 4,700 miles. Six built, three for Pan Am and three sold to BOAC.


 * B-314
 * Five Model 314s impressed into military service with the U.S. Navy


 * C-98
 * Four Model 314s impressed into military service with the U.S. Army Air Forces


 * Model 306
 * A concept aircraft using a Model 314 fuselage with a tailless delta-wing planform. No examples built.

Operators

 * Pan American World Airways
 * United States Army Air Forces
 * United States Navy
 * British Overseas Airways Corporation
 * British Overseas Airways Corporation
 * British Overseas Airways Corporation

Surviving Aircraft
None of the dozen 314s built between 1939 and 1941 survived beyond 1951 with all 12 having been scrapped, scuttled, cannibalized for parts, or otherwise written off. Underwater Admiralty Sciences, a non-profit oceanographic exploration and science research organization based in Kirkland, Washington, announced in 2005, at the 70th Anniversary of the first China Clipper flight in San Francisco, its plans to survey, photograph, and possibly recover the remains of the hulls of two sunken 314s: NC18601 (Honolulu Clipper), scuttled in the Pacific Ocean in 1945; and NC18612 (Bermuda Sky Queen, formerly Cape Town Clipper), sunk in the Atlantic by the Coast Guard in 1947. UAS has also spent significant time at Pan Am reunions and with individual crewmembers and employees of Pan Am conducting videotaped interviews for the mission's companion documentary. However, as of 2014, no search or recovery had been attempted, with the most recent news from 2011 suggesting that the company was still in need of at least US$8 million to get the plan underway.

A life-size 314 mockup is at the Foynes Flying Boat Museum, Foynes, County Limerick, Ireland. The museum is at the site of the original transatlantic flying-boat port.

Popular culture
The 314 has been featured many times in pop culture, including several novels. The 1940 Alfred Hitchcock film Foreign Correspondent features the 314 in a pivotal in-flight disaster. The best-known example, in the film Raiders of the Lost Ark, actually used a Short Solent Mark III made to resemble a 314 by use of matte effects. The 1991 novel Night Over Water by author Ken Follett centers around a 314 flight from Southampton to New York during the outbreak of World War II.