The answer is by one of the most iconic aircraft ever; from a time when long distance flying was far more, romantic, adventurous and de luxe than it is now: the Pan American Airways Clipper flying boat.
Pan American Airlines originated in the twenties when a Colombia based, but German owned, airline was pitching for the first overseas US Air mail contract. Concerned that this contract would be awarded to a foreign airline, unless a credible US alternative came forward, a group of men, led by Major Henry Arnold of the Army Air Corps put together Pan American in March 1927. Although they had the company on paper, and won the air mail contract to Cuba as a result, they had no planes. In stepped Juan Trippe who had created the Aviation Company of the Americas, really as something to do with an inheritance he had just come into. He also got backing from Cornelius Vanderbilt Whitney and William A Rockefeller. In 1926 he had acquired a small airline with a Florida to Cuba service and all important landing rights in Havana. Trippe suggested that his firm, Pan American and the Atlantic, Gulf, and Caribbean Airways company, established by New York City investment banker Richard Hoyt, should join forces and Pan American Airlines was born with Trippe as operational director (he served as CEO of Pan Am until 1968).
Pan Am's South American routes
Trippe was really interested in oceanic routes, however, but political problems plagued his initial attempts to organiose a trans-Atlantic route and so he turned to the trans-pacific route to China. He had to abandon his initial plan for an Alaska/Japan/China route because of the political instability in the area and the Soviets refused him permission to land in Russia. The only option, therefore was an island hopping route across the huge Pacific Ocean. Eventually he negotiated a Pearl Harbor/ Midway Island/Wake Island/Guam/Subic Bay (Manila) route. Great Britain refused him permission to land in Hong Kong, his ultimate end destination and so the initial service finished in the Philippines. In the meantime he struck a deal with the Portugese and got landing rights in Macau. Following this the British soon caved in and let him land in Hong Kong (in 1936).
The only problem was that no plane existed which could cover this 8,000 mile, largely over water, route. There were very few concrete runways at this time and so flying boats were really the only way that large airliners could be contemplated. Pan Am, therfore, asked aircraft manufactureres to come up with a suitable design.
With these three planes the "Clipper" name, devised by Trippe himself, was used by Pan Am for the first time evoking the days of fast sailing ships. Indeed, Pan Am crews wore naval style uniforms rather than typical flyers uniform, starting a trend that persists in the airline industry to this day. The first three planes were christened Caribbean Clipper, American Clipper and Southern Clipper. Jerry Gray, Glenn Miller's arranger wrote an instrumental called Caribbean Clipper in 1942 and later lyrics were added to it by Sammy Gallop: "Come on aboard the Caribbean Clipper, we'll ride a moonbeam to the little dipper". The only song Agent Triple P knows written about a flying boat! The version performed by The Modernaires, Glenn Miller's vocal backing group, has Paula Kelly as the stewardess offering "coffee, tea or milk?" The reply comes "Er, Miss, the starboard engine is on fire" to which she replies "How about a Martini?" All this, perhaps, reflected the fact that a flight that made the whole distance without some sort of engine trouble was generally cause to celebrate!
The Sikorsky S-42 first flew in March 1934 and whilst not bigger than the S-40 it was this plane that was designed to meet Trippe's specifications of an aircraft that could do the China run. Although the nember of passengers it could carry was similar to the earlier aircraft it was faster and its range was more than tripled to over 3,000 miles. This was the key factor as the longest leg on a trans-Pacific flight was the San Francisco to Hawaii section of 2,400 miles.
At the end of 1934, the Baltimore based Glenn L Martin company flew the Martin M-130 for the first time. Bigger than the Sikorsky it was 91 feet long and had a 130 foot wingspan. It could carry 36 passengers or 16 in night berths. Crucially, it had a range of 3,200 miles.
Given the existence of these two aircraft Trippe felt able to set up a base for Pan Am's Pacific operations in San Francisco on January 1st 1935. A month later a ship charted by Trippe, the New Haven, sailed for Honolulu with equipment to establish facilities on the islands along the route. It carried over 6,000 tons of supplies including the material to build two complete villages, generators, motor launches, water distillations units, 44 airline technicians and a 74-man construction crew.
Captain Musick leaves the Pioneer Clipper in Hawaii on the first test flight April 17th 1935. the men in the fetching swimsuits are the Pan Am ground crew!
The China Clipper's first Hawaiian bound passengers receive a traditional welcome in November 1935
Captain Edwin Musicke piloted another M-130 the China Clipper on this historic flight which carried 110,000 pieces of mail weighing two tons. 21 hours and 20 minutes later (headwinds slowed the plane's progress) the China Clipper touched down in Pearl Harbor to be greeted by another huge crowd of 3,000 people.
A voyage across the Pacific
In October 1936 the first scheduled flight from San Francisco to Manila via Hawaii took off. Nine passengers paid over $1,400 each for a return ticket. This became a weekly service; one plane each making a westwards and an eastwards run. Eventually Pan Am would link up to its own internal Chinese airline, China National Aviation Corporation; a joint venture with the Chinese government.