No longer were suffocating passengers required to open a side window for ventilation, and consequently inhaling engine fumes, as was customary on older airliners. The closed-window ventilation of the DC-3 also eliminated the chaotic blasts of wind and propwash from open windows, and shielded passengers from the deafening noise of wind and engines.

With these five improvements --

• greater stability,
• high flight over turbulence
• high flight into cooler air,
• better ventilation, and
• soundproofing

Before the DC-3, riding an airliner was much like riding in an old-fashioned stagecoach.

After the DC-3, it was more like riding in a comfortable, modern bus.

ECONOMICS: AFFORDABLE FLIGHT

But most decisive of all, was the radical change in airline economics with the introduction of the DC-3.

With the DC-3 hauling nearly TWO-dozen passengers (in three-abreast seating) to pay for the ride, the cost-per-passenger was much lower -- bringing ticket prices within reach of the typical upper-middle-class North American or European citizen. Prior airliners could only make money if they carried valuable lightweight cargo, such as mail. The DC-3 was the first successful airliner to truly be profitable at hauling only passengers. Other characteristics of the DC-3 improved its economics:

United Airlines crew and their towering DC-3 -- a majestic sight on any airport, then or now. The ring under the nose is a radio direction-finding (DF) loop antenna, a key navigation tool of the 1930s. (CLICK PHOTO TO ENLARGE.)

• The aircraft was extraordinarly well-built, requiring less maintenance than some of the flimsier airliners that had preceded it.

• Greater speed and capacity meant that fewer aircrew hours were required to carry a given number of passengers a given distance, allowing some airlines to pay less, per ticket-mile, for pilots (even while raising pilot salaries).

• The ability to fly at a wider range of altitudes allowed pilots to fly over and around mountains and bad weather more easily, allowing straighter routes and/or riding more-favorable winds aloft, saving more time and money.

• The ability to fly over, or in, more adverse weather, particularly with the advent of anti-icing equipment (first introduced in the rival Boeing 247), allowed the DC-3 to fly more reliably (and, again, more directly and efficiently), improving the reliable flow of revenue to the airlines.

• A much safer airplane than most of its rivals -- for all of the above-noted reasons -- the DC-3 cut airline crash losses and related insurance costs.

• The DC-3's greatly increased affordability, reliability, safety and comfort also greatly increased public trust and acceptance of airlines as a regular means of flight, increasing ticket sales greatly.

With the arrival of the DC-3, the airline industry underwent an explosive growth and transformation -- due directly to the radical, decisive new combination of key virtues found together only in the DC-3.

Between the DC-3's introduction in 1935, and America's entry into the Second World War at the end of 1941, in just 6 years, there was a 600% growth in the number of passenger miles flown across the United States. Those passenger miles were flown mostly on DC-3's. It would be years before any competitor could match the DC-3's virtues for anywhere nearly the same purchase and operating costs. For a decade and a half, the DC-3 remained the pre-eminent American airliner.

But the DC-3 was more than a powerhouse in the American airline industry. With virtues that so completely eclipsed all other airliners, the DC-3 quickly spread throughout the WORLD.

By late 1939,
most of the world's airline travel
was by DC-3.
  (Some experts say over 90%.)
 

AIR CARGO BECOMES PRACTICAL

As DC-3's began to replace older airliners, the older planes' passenger capacity became useful as cargo capacity, and air cargo activity became more practical and widespread. And, along with the development of the DC-3 as an airliner, there was a corresponding (though lesser) development in the DC-3 as a cargo-carrying airplane.

At first, cargo was a small percentage of the load carried by DC-3's, slowed somewhat by the ready availability of older airliners for that purpose -- airliners no longer carrying passengers (due to competition from the DC-3). But airlines soon learned that the vast load-carrying capability of the DC-3 was not limited to people and their personal luggage. Soon, small (but profitable) bits of air cargo were carried along with passengers.

These two new venues for air cargo -- idle old airliners (made available by their replacement by DC-3s), and fast, efficient new DC-3's -- made it increasingly possible for vital cargo to reach distant destinations in a fraction of time that ground transportation allowed.

(For a clear depiction of DC-3 / C-47 cargo capabilities and configuration, on the website of a current British DC-3 cargo operator, click here. Numbers are metric; approximate conversions: 1 m(meter) = 3.3 ft.; 3 km(kilometer) = 2 miles)

The combination of rapid passenger travel and rapid movement of vital cargo helped the acceleration of critical segments of the American and European economies, as they dragged themselves out of the Great Depression, and prepared for the looming possibility of war.

MILITARY AIRLIFT BECOMES A POWERFUL WEAPON

For the same reasons, the DC-3 has been a decisive instrument of war.

Dressed in military livery for World War II, the DC-3 became the military "C-47 Skytrain," "C-53 Skytrooper," "R4D," or "Dakota". (Other variants included C-48, C-49, C-50, C-51, C-52, and C-117). The addition of bigger engines (up to 1,200 hp), stronger flooring, and large cargo doors greatly enhanced the military utility of this big, rugged transport -- the "Gooney Bird" as it was affectionately nicknamed by the troops.

With its great speed, range, ruggedness, carrying capacity, and sheer numbers, the C-47 radically changed the ability of armies to move quickly, and their ability to readily maintain and support far-flung operations.

America and her British Empire allies used thousands of C-47's to quickly transport troops, weapons, munitions, small vehicles, essential equipment and supplies to forward areas.

The C-47, with military seating, could officially haul 32 people, or 28 combat-equipped troops, or evacuate 21 wounded soldiers on stretchers. But in the actual wartime emergencies, these limits were often ignored, and the plane sometimes carried up to twice its official load.

The same was true of its cargo hauling. The C-47 was designed for loads of up to 6,000 pounds -- internally and on cargo hooks under the belly. But those load limits, too, were often ignored -- succesfully. Its huge cargo door could (and did) accept massive items, including an entire Jeep or howitzer.

With the plane's ability to land and take off from rough fields, less than a half-mile long, it could quickly deliver combat men and material close to the front lines, providing great speed and flexibility to ground combat units. Where there was no place to land, but supplies and men were urgently needed, they were delivered by parachute.

"Gooney Birds" often landed or parachuted troops into areas behind enemy lines (massive "paradrop" shown above, left), and evacuated the wounded to distant Allied hospitals (right). Some towed massive "invasion gliders" that held up to a dozen or more troops, or jeeps, howitzers and ammunition -- releasing the gliders to land behind enemy lines.

With these capabilities, swarms of C-47s deployed regiments, battalions, even whole divisions with thousands of troops into critical combat targets. The C-47 gave exceptional airborne speed and mobility to vast numbers of ground troops, firmly establishing the modern concept of "airborne" warfare.

Whether delivering cargo or people -- by landing, or glider, or para-drop -- the abundant, capable C-47 accelerated the pace of ground warfare, establishing aircraft as an essential tool of GROUND warfare.

General Dwight D. Eisenhower, Supreme Allied Commander in Europe during World War II, in his memoirs, praised the C-47 as a critical tool of the war. He credited the C-47 as one of a half-dozen "pieces of equipment that most senior officers came to regard as among the most vital to our success in Africa and Europe." (Crusade in Europe, by Dwight D. Eisenhower, pp.163-164.)  

Certainly the C-47 was exceptional by virtue of its sheer numbers:   over 10,000 were built for the war, and hundreds of civilian DC-3's were pressed into military service, as well.

The capabilities of the C-47 caused allied military forces to develop fundamentally new tactics and strategies for conducting war, accelerating the pace of victory.

The Soviet Union (Russia and its neighbors) also used DC-3's -- and even began their modern air transport manufacturing by building about 2,000 copies of the DC-3 (under license) as the Lisonov Li-2 -- for the war on Germany. Ironically, the Allies' eastern enemy, the Japanese, even used their own copy of the DC-3's predecessor -- the DC-2 -- having built over 400 of them as the Nakajima Ki-34 and Showa L2D.

However assessed, the DC-3 was the most important force ever in the development of military airlift and airborne ground forces.

Although the German Junkers Ju-52/3m tri-motor (right) was a key precursor of airlift's influence, the Douglas C-47 -- with about double the Ju-52's capability, and better in virtually ever other respect -- outperformed and outlived it, doing far more to shape the role of military airlift, and future military transport aviation.

The DC-3 would be a superior military tool in World War II, and would soldier on to be a major player in military forces throughout the world -- clear up until the present day. (It was a major U.S. weapon as recently as the Vietnam War, where it served as a versatile transport, but also pioneered the development of the orbiting-attack heavy-gunship -- with devastating effect. It continued in limited U.S. military service until the early 1980s, and reportedly still remains in the service of some small nations' military forces around the world.).

POSTWAR COMMERCIAL AVIATION BOOM

After World War II, the military sold off thousands of war-surplus C-47 "Gooney Birds". Having survived the harshest possible use, most of these DC-3's were still quite ready for more work. By the thousands, C-47's were repainted in civilian uniforms, and put to work.

In the 1950's, after its dominance in the major airlines had been eclipsed by larger airliners (particularly newer Douglas airliners), the DC-3 formed the backbone of a whole new class of airlines:
short-haul, regional, "feeder" airlines -- which served communities too small for the big airliners to serve economically. (Indeed, many of these communities had airports too small for any modern airliner but the DC-3). In the 1950's and early 1960's, small feeder airlines like Allegheny, Pacific States, Frontier, and Ozark Airways started life with the DC-3, spreading airline service to every nook and cranny of America, Canada and Europe.

At the same time -- having shown themselves capable of carrying anything you could stuff in the door -- the war-surplus Gooney Birds became increasingly valuable as cargo-haulers, and accelerated the development of air-cargo transportation. This further enhanced the booming American and European economies of the 1950's and 1960's.

BRINGING THE POWER OF AVIATION TO THE WORLD

Echoing the growth of American and European modern airlines, the durable, surplus DC-3's -- available cheaply in vast numbers -- found their way into every corner of the world, bringing the benefits of air transport to places long-isolated from the rest of the world.

Douglas DC-3 (Navy R4D), named 'Que Sera Sera', landed on skis at the South Pole in 1956 -- bringing the first humans to the Pole since overland explorers Amundsen & Scott became the first humans there over 40 years before. And half a century later, another DC-3 -- shown below, modified with turboprop engines -- began skiing into Antarctica regularly (Nat'l Science Found. photos; Click to photos enlarge.)"

Many DC-3's were fitted with snow skis, or (very rarely) pontoon floats, to permit landing in unthinkable places (at right, in 1956, the first airplane landed at the South Pole -- an R4D 'Gooney Bird' on skis). The reliability of their wartime Pratt & Whitney engines made them safe to operate far from home. Able to land in short, rough strips that no other large, fast plane could handle, ordinary DC-3's showed up in South American and African jungles, Arab deserts, Asian valleys, Pacific islands, and Arctic tundras.

The DC-3 made it possible to put almost anyone (or anything) anywhere, anytime. Only the helicopter would develop a more complete reach -- but the DC-3 would continue to carry far greater loads, much farther and faster.

Still not retired, 75 years after the DC-3's birth -- three-quarters of a century -- many of them are still in regular use around the world -- despite the fact that even the "newest" ones are at least 65 years old.

In the United States, alone, in 2002, the Federal Aviation Administration showed over 600 DC-3's still registered as active (UPDATE: 8 years later, that still held true! As recently as July, 2010, in the DC-3's 75th Anniversary year, there were 610 of the DC-3 and its military variants still registered with the FAA. At least 30 gathered for a grand arrival at "EAA AirVenture", the world's largest annual airshow, in Oshkosh, Wisconsin, USA). Dozens (possibly hundreds) more -- too useful to scrap -- operate around the world, today.

Some are refitted with turboprop engines, and others with the latest electronics.
A few are sometimes found on skis, and one has even been seen in recent years on pontoon floats. Some have luxurious executive interiors, while others have nothing but bare metal interiors, to make maximum room for big loads. These sturdy birds keep flying around the world -- efficiently and reliably delivering people and cargo to destinations impractical for almost any other large airplane.

SETTING THE SHAPE OF THINGS TO COME

The DC-3 deserves credit for another virtue: it established, firmly, the value of modern aircraft construction: lightweight aluminum, stressed-skin, "semi-monocoque" cylindrical-fuselage construction (as a replacement for boxy, heavy, old-fashioned steel-tube truss construction); and multi-cellular, stressed-skin "fail-safe" wing construction.

To put it more simply, before the DC-3, most airplanes were built like oil derricks, laid on their side, and wrapped in fabric or corrugated tin skins. The DC-3 established, firmly, the virtue of designing airplanes like light-but-stout, round, tin cans -- the basic aerodynamic, lightweight, shape of airplanes today.

Though controversial at first, this design soon proved sound. A documentary film about the DC-3, on its 50th anniversary in 1985, reported that not one DC-3 had ever crashed due to an in-flight structural failure.

The "Gooney" also furthered other key technological advancements. It clarified he value of drag-reduction through:

• unbraced "cantilever" wings,
• retractable landing gear, and
• streamlined "NACA" engine cowlings

It further established the merit of:

• wing flaps, and
• variable-pitch propellers

Unlike most previous airliners, the DC-3 (like the DC-2 and Boeing's 247 before it), could easily climb away from the airfield on one engine -- providing a critical element of safety on takeoff (the phase of flight when catastrophic engine-failure is most likely).

The addition of engine turbo-superchargers -- providing additional power in the thin air at high altitudes -- was icing on the DC-3 cake. And to deal with icing on the wings, the DC-3 introduced de-icing boots on wings and tail -- a critical life-saving advance that would make true all-weather flying safe and practical, greatly expanding the capability and reliability of airliners, and all airplanes.

This combination of performance and utility enhancements

Boeing 247 vs. DC-3 The Boeing 247 deserves credit as the first "modern" airliner -- bringing many key innovations together in a fast, efficient aircraft. But it couldn't hold a candle to its soon-to-be rival, the Douglas DC-3, which carried over twice as many passengers, twice as far, and substantially faster. (NASA photo. Click to enlarge)
Airplane	PASSENG-ERS	CRUISE SPEED (mph)	RANGE (statute miles, non-stop)
Ford 4AT-5AT Tri-Motor	10-15 iiiii iiiii iiiii	107-122	560-570
Boeing 247	10-12 iiiii iiiii ii	155-189	485-745
Douglas DC-3	21-24 iiiii iiiii iiiii iiiii iiii	160-207	1,020-2,125

had (for the most part) already been gathered into another all-metal airliner -- brought to market in the smaller, slower (160 mph), shorter-ranged (500 miles), 10-passenger Boeing 247 (shown at left, graph below).

However, the faster (180mph), longer-range (1,000-2,000 miles), heavier-hauling, 21-24 passenger DC-3 made these features far more profitable and persuasive -- ultimately revolutionizing airliners.

A final major advance of airliner aviation, implicitly pioneered by the DC-3, was the use of round, hollow-shell fuselages, rather than rectangular or internally-braced ones -- an essential design transition necessary to develop pressurized airliner cabins, permitting flights in the thin air at higher altitudes (above 10,000 feet -- over turbulence, foul weather and mountains) without oxygen masks.

Although the DC-3 was never pressurized, its establishment of circular cabins as "normal" firmly established a basic airliner design concept that lent itself readily to pressurization.

By comparison, boxy rectangular cabins were not well-suited to pressurization, because of the uneven distribution of air pressure in early pressurized cabins -- easily exceeding 2 pounds of pressure per square inch, pressing out against every square inch of the cabin wall. But circular cabins (like round balloons) were a natural shape for readily containing pressurized air.

Future airliners, like the Boeing 307 Stratoliner, Lockheed Constellation (left), and Douglas's own DC-6 and DC-7 -- along with pressurized, tricycle-geared postwar DC-3 imitators (Convair 220 and Martin 2-0-2, most notably) -- would make good use of pressurization in round fuselages.

Without pressurization, jet airliners would not have been practical, because they only operate efficiently at very high altitudes, where the air is to thin for people to breathe. But the DC-3 rounded-shell fuselage -- a design concept now almost universal in commercial airliners -- has made such shapes, and resulting application of pressurization, quite practical, along with making jet airliners a practical reality.

As if its own contribution to advancing aerospace technology were not enough, the DC-3 was used, as recently as 1984, by NASA -- as a research vehicle for the space program. Among its many tasks: serve as the "glider towplane" for the first wing-less "lifting body" aircraft -- the prototype for what ultimately would become the Space Shuttle.

Over 10,000 DC-3's/C-47's were built in the 1930's and 1940's, and dozens (probably hundreds) are still in civilian or military service around the world, today. Three-quarters of a century since its inception, with all DC-3s now at least 6 decades old, many are still flying, working airplanes, continuing the active influence of the DC-3 design, even today. Perhaps the most talked-about "Holy Grail" in airplane design, for over half a century, has been the fantasy -- never quite realized -- of "a DC-3 replacement."

No other airplane in history has had so broad and lasting an effect on air transportation.

While many other planes have been important, few (if any) others had nearly so pivotal an impact on aviation or on history as the DC-3. The Douglas DC-3 is the foremost of the eight aircraft which are the "indispensable" aircraft of history -- aircraft with no significant conceivable substitute available at their juncture in history -- which changed history by their presence.

In fact, the DC-3 is arguably the "ultimate" airplane -- more important in every way to civilian aviation than any other aircraft that ever flew, and one of the very most important military aircraft of all time.

In its "C-47" military version, and other military variants, the DC-3 is clearly the most important aircraft in the history of military airlift; no other military transport plane (with the remote possible exception of the German Junkers Ju-52/3m tri-motor, shown at left) ever came close to the DC-3's importance to the development of military airpower -- or military power, generally. The famed, larger, faster, modern Lockheed C-130 Hercules transport, despite its many superior virtues, and worldwide use, still operates almost exclusively within the roles pioneered or shaped by the DC-3's military versions.

And in the civilian arena, absolutely nothing else has ever come close to the impact of the DC-3. At inception, the DC-3's closest competitor was its own very inferior predecessor, the Douglas DC-2.

The Boeing 247, a fast and advanced airliner for its day (which introduced many modern innovations to airliners), was still no match for the much-bigger, generally superior DC-3.

And much-smaller, much-slower, old-fashioned airliners -- like the Ford TriMotor and the Fokker TriMotor (shown above, right), and big biplane-airliners like the Boeing Model 80 and Curtiss Condor -- couldn't hold a candle to it; they couldn't even successfully compete with trains and buses, let alone lead a great advance in air transportation.

It took the DC-3 to make commercial passenger flying popular among a sizeable percentage of the public in the industrial world, finally bringing the airline industry to real fruition.

And it took the DC-3's military versions to make military airlift practical and powerful -- making possible the rapid mobility of vast armies across great distances, and ensuring their sustainability far from home.

And it took the DC-3 to make air cargo truly cost-effective -- accelerating and reinforcing critical aspects of industrial economies -- while connecting the resources of the world through fast, efficient, capable, reliable transportation around the globe.

In short:

Finally, the DC-3 / C-47 established the shape of things to come -- giving overwhelming credibility to a firm standard of modern airplane design that fundamentally changed the way nearly all large airplanes were built, from then until the present day -- and eventually most other airplanes, too.

• The Douglas DC-3 - US Centennial of Flight Commission, a good, "official," one-page summary of DC-3 history, background information and pictures of the DC-3, by the U.S. Centennial of Flight Commission; downplays modern life of the DC-3, but gives good basic historical perspective.

  (Describes DC-3 as "the workhorse of the aviation world," opening with "The Douglas DC-3... one of the most noteworthy aircraft ever built... probably did more than any other plane to... establish air transportation as a normal way of traveling".)

• DC-3 / C-47 Skytrain - Fiddler's Green (a paper model of the plane, PLUS very good, extensive, one-page collection of background information and pictures -- including drawings and specifications -- of the actual Douglas planes).

• The DC-3 Hangar Perhaps the best website on the DC-3 / C-47 / Dakota and its variants. Wide range of excellent documents, images, essays and anecdotes.

• The DC-3 Aviation Museum, Corvallis, Oregon, USA (Despite sloppy front page, menu at bottom of page links to extensive information files -- claimed to be over 1,000 pages, including various documents and data).

• DC-3/Dakota Historical Society A major website on the DC-3 / C-47 / Dakota and its variants (DST, R4D, Super C-53, C-117, C-49, C-47 Skytrain), as well as Douglas Aircraft.

• PBS - "Chasing the Sun" - Douglas DC-3, a TV documentary series, and various supplemental articles and documents online. The Public Broadcasting System, Washington, D.C. (History of U.S. commercial aviation and key airliners, and the history behind them -- with special coverage of the Douglas DC-3, "widely recognized as the most successful passenger plane ever flown.").

• America by Air - National Air & Space Museum, the Smithsonian Institute, Washington, D.C. (NASM's summary of historic U.S. commercial aircraft, and the history behind them -- including the "centerpiece" of the museum's "Air Transportation" wing: the Douglas DC-3).

• "75 Years of DC-3s in Flight," from AAHS Journal, Winter 2010, Vol. 55, No. 4, American Aviation Historical Society. Informative, multi-page, illustrated history of the DC-3 and its variants, by by Tim L. Williams. Initial paragraphs viewable online, remainder by $5.00 purchase.

• "DC-3 Airliner," from Aviation History magazine, Nov, 1995,. Informative, 6-web-page, text-only history of the DC-3 and its variants, by aviation historian C.V. Glines, on the magazine's parent company website, HistoryNet.com.

• NASA: Quest for Performance: The Evolution of Modern Aircraft
  Part I: THE AGE OF PROPELLERS,
  Chapter 4: Design Revolution 1926-39,
  "Synergistic Developments"

  (quote: "The DC-3 has been used for every conceivable purpose to which an airplane can be put, and surely must be considered as one of the truly outstanding aircraft developments of all time.")

• "The Douglas DC-3 -- Wings of the World" (and other articles) American Aviation Historical Society (AAHS) Journal, Volumes 31-32, 1985-1986. A three-part review of the history & importance of the DC-3, following its 50th anniversary, spread over 3 consecutive issues, starting with the last 1985 issue (Vol.30,#4). For index, click appropriate year:   1985 (Volume 30)   -   1986 (Volume 31)

• World Wide Dakota Club (Very basic one-page info and specs on DC-1, DC-2 and DC-3 -- as well as pages for Boeing 247, and several modern airliners).

• Boeing: History -- Products - Douglas DC-3 Commercial Transport, Official DC-3 website of Boeing (the company which acquired McDonnell-Douglas, which included Douglas Aircraft). Boeing touts its possession's prize achievement, saying, "The Douglas DC-3, which made air travel popular and airline profits possible, is universally recognized as the greatest airplane of its time."

• "Douglas DC-3 History: 1970s - 1980s" - Air-and-Space.com An amateur aviation website, but with a spectacular collection of photos of DC-2 and DC-3 aircraft, and countless variants -- active, exhibited, or inactive -- from rusting wreckage, to flying museum pieces, to working freighters and turboprop conversions.

STRICTLY MILITARY:

• Douglas C-47 Skytrain - American Aircraft of World War II (Good single-page summary and detailed specifications on the WWII Douglas "Gooney Birds," and on most other U.S. aircraft of WWII).

• "C-47 Skytrain" on GlobalSecurity.org, Detailed one-page overview of the C-47 and its history from DC-1 through the Korean War, largely copied from current Boeing publicity documents (Boeing acquired Douglas Aircraft in a merger with McDonnell-Douglas), but also contains critiques of the aircraft. Right column includes links to articles on several other military variants of the DC-3, including VietNam-era AC-47 Spooky gunship, as well as C-47 specifications.

  (quote: "The DC-3, which made air travel popular and airline profits possible, is universally recognized as the greatest airplane of its time. Some would argue that it is the greatest of all time.")

• Douglas C-47D Skytrain - Factsheets - USAF, Official U.S. Air Force Museum "Fact Sheet" on Douglas C-47 Skytrain (the primary military variant of the DC-3). Notes that "Few aircraft are as well known, were so widely used, or used as long, as the C-47." Also repeated on website of Air Force History Support Office.

• Naval Aviation News, November/December 1983 issue (PDF file). Official U.S. Navy / Marine Corps military aviation magazine, with semi-official articles on the history and details of various military DC-3 variants used by them, from WWII to the early 1980s, including combat, transport and arctic research roles, with relevant anecdotes. Includes:
  • pages 10-14:  "The Resolute R4D" by Jan Churchill, R4D pilot.
    
  • page 15:  "Marines and the Gooney Bird" by Maj. John Elliot, USMC (retired).
    
  • pages 16-18:  "Naval Aircraft: The C-117D" (R4D-8) by Harold Andrews.
  
  

• Boeing: History -- Products - "C-47 Skytrain Military Transport", Official C-47 web page of Boeing (the company which acquired McDonnell-Douglas, which included Douglas Aircraft). Boeing touts its possession's legendary military transport, saying, "Every branch of the U.S. military, and all the major allied powers, flew it... By the end of the war, more than 10,000 had been built."