These Daring Aircraft Designs Paved the Way for the US Air Force

This year marks two aviation anniversaries. One is the 75th anniversary of the US Air Force, born when President Harry Truman signed the National Security Act of 1947, which on Sept. 18 of that year separated the Air Force out of the US Army. The other is the 115th anniversary of the very first Army unit dedicated to flying machines: the Aeronautical Division of the US Signal Corps, which came into being on Aug. 1, 1907. 

This slideshow looks at the 40 years of aircraft from 1907 to 1947. A second slideshow looks at the 75 years starting 1947, from jet prototypes to stealth aircraft.

The jaunty gent above is Capt. Eddie Rickenbacker, the top US ace of World War I with 26 confirmed victories. He's standing in front of his Spad S.XIII biplane.   

Originally published July 27, 2017, to mark the 70th anniversary of the US Air Force.

A decade before Rickenbacker's glory days, military aviation had a lot to figure out. Like, could we get something better than a balloon? One answer to that question was the dirigible -- still lighter than air, but its flight could be controlled. In the summer of 1908, the Aeronautical Division acquired a nonrigid dirigible designed by Thomas Scott Baldwin as its very first powered aircraft. It would be scrapped in 1912.

The precursors to the US Air Force went by many names, all under the overall command of the US Army: the Aeronautical Division (1907-14) and the Aviation Section (1914-18) of the Signal Corps; the Army Air Service (1918-26), the Army Air Corps (1926-41) and the Army Air Forces (1941-47).

The first heavier-than-air aircraft bought by the Aeronautical Division came from none other than the Wright brothers. But even those pioneers, not long removed from their monumental 1903 flight, had to prove their machine could meet the War Department's requirements: It had to be able to stay in the air for more than an hour, carry a passenger for at least 125 miles at a speed of 40 miles per hour, be steerable in all directions at all times and land without damage.

Here, Orville Wright makes a pass over Fort Myer, Virginia, on July 1, 1909. On Aug. 2 of that year, the US government formally accepted the Wright Flyer at a price of $30,000 and designated it Signal Corps Airplane No. 1.

A closer look at the Signal Corps' first airplane, parked in front of a hangar at Fort Myer in 1910.

In its first decade, the Signal Corps established -- and often relocated -- several flight schools. One of them was on North Island in San Diego Bay. Here, Signal Corps aircraft No. 2 (a) and its pilot, Lt. L.E. Goodier Jr., come in for a landing at the North Island aviation station in February 1913.

At North Island in San Diego Bay, pilots could learn how to perform landings and takeoffs on water as well as on land. Flying boats, like this Curtiss-built one, were all the rage in the early years of powered aviation.

In the earliest years of powered flight, flyers didn't sit inside the plane so much as they sat on it, out in the open. And everything was an experiment, a "first of" something. Here, an Army officer shows how, on Aug. 20, 1910, he fired the first gunshot from an airplane, directing a rifle at a 3-by-5-foot target from an altitude of 100 feet, according to the National Museum of the US Air Force. The pilot here is from the Curtiss Aircraft company, suggesting that this is a Curtiss aircraft.

Here's an oddity: the Burgess Dunne aircraft. The Army took delivery of the tailless, swept-wing biplane, with a pusher propeller in the rear, in December 1914 as Signal Corps No. 36.

This is Signal Corps airplane No. 39, a Wright Model F, also known as the Tin Cow. Largely similar to earlier Wright designs, it does deviate in having a covered compartment for the pilot and a passenger.

The Curtiss JN-4 Jenny served as the primary flight training aircraft for the Signal Corps during World War I. The JN-4D model of the two-seat biplane had a 90-horsepower engine and flew at a top speed of 90 mph. The Curtiss Aeroplane and Motor Company delivered more than 6,000 to the Army, most of them the 4D variant.

When the US entered World War I in 1917, it had only 132 aircraft, and all of them were obsolete, according to the National Museum of the US Air Force. Three US manufacturers began building planes built on the design of a two-seat British aircraft, the De Havilland DH-4, and equipped with the American-made 12-cylinder, 410-horsepower "Liberty" engine. Used primarily for daytime bombing and observation, these "Liberty Planes" were the only US-built aircraft to see combat during the Great War.

We think of unmanned aircraft as a modern invention -- even a little futuristic still -- but people were experimenting with that kind of machinery even a century ago. This is the Kettering aerial torpedo, which used the electronics of the day (and pneumatic controls as well) to fly a preset route toward its target. At the right moment, the wings would detach, and the torpedo would plummet to the ground to deliver its explosive wallop. A few dozen of the bugs were built circa 1917-18, but none ever got sent into combat.

After the war, pilots everywhere pushed the boundaries of flight -- altitude, speed, endurance, every which way. US Air Force pilot Lt. Rudolph Schroeder set altitude records in 1919 and 1920 flying this aircraft, the Packard-Le Père LUSAC-11. On one such flight in 1920, in which he reached a then-record 33,114 feet (temperature in the open-air cockpit: minus 63 degrees Fahrenheit), Schroeder passed out and plunged nearly to the ground before recovering consciousness. Even with his eyes damaged from the deep freeze above, he was able to land at McCook Field, Ohio, seen here.

The Martin MB-2 bomber (at right) joined the Army Air Service in 1920 and flew as the primary multiengine bomber for the peacetime decade ahead. With a four-man crew, it could carry up to a 3,000-pound bomb payload, and in 1922-23, MB-2 aircraft were used to show that battleships were vulnerable to aerial bombing. Because of the immense (for the time ) wingspan, its designers gave it folding wings. At left is a Verville-Sperry M-1 Messenger plane.

Airships never amounted to much as a weapon of war, but in the early years of military aviation, no one knew that would be the case. The rule was trial and error, and this experiment turned out tragically. Shown here in November 1921 is the Roma, making its first flight in the United States at Langley Field, Virginia. Three months later, the Army Air Service sent the 410-foot-long dirigible aloft again, this time with more powerful engines. A crash into high-voltage wires ignited the hydrogen gas inside, and 34 people died.

This is what aerial refueling looked like in the summer of 1923. In June of that year, the two de Havilland DH-4B biplanes you see here took to the skies over San Diego's Rockwell Field to make history, with the first midair transfer of gasoline from one plane to another. A hose was dangled below and behind the lead plane to be grabbed by one of the two Army Air Service officers in the open, rear cockpit of the receiving plane.

The biplane era had meant aircraft built largely with wood frames and fabric skins, and with paired upper and lower wings. By the 1930s, aircraft construction was shifting to monoplanes and metal. Pictured here are two of the earliest of those designs that the Air Corps worked with, both from Boeing and both of which first flew in the early 1930s. The larger is the Y1B-9, a bomber, of which only seven were built, and the smaller is the P-26 Peashooter, a fighter that served roughly till the US entered combat in World War II.

Like many other aircraft here, the Martin B-10 can make a claim to being first -- with specific qualifiers. Here's how the National Museum of the US Air Force describes it: "the first all-metal monoplane bomber produced for the U.S. Army Air Corps in quantity." The twin-engined aircraft entered service with the Air Corps in 1934, but by the late '30s it was being replaced by newer designs.

The Boeing B-17 Flying Fortress heavy bomber inflicted much damage on German industrial targets during World War II. It entered service in 1938, and by the time the war was over, Boeing had built nearly 13,000. The B-17F shown in flight here is the Memphis Belle, which gained fame for surviving 25 bombing missions in six months and for its subsequent morale-boosting mission in the US in 1943, followed by a documentary in 1944 by famed director William Wyler.

The men who flew the Memphis Belle pose for a photo after completing their 25th mission in May 1943.

A Curtiss P-40 Warhawk of the Flying Tigers undergoes repairs in Kunming, China. The Flying Tigers were an all-volunteer group of pilots from the Army Air Corps, as well as the Navy and the Marines Corps, that served in China and first saw battle two weeks after Pearl Harbor. For its first six months or so, the group was officially part of the Chinese Air Force, then was disbanded, and those who served eventually became part of the US 14th Air Force.

The Grasshopper was the military version of the popular Piper J3 Cub civilian aircraft. It was used during World War II for observation, artillery fire direction and courier duties.

This distinctive aircraft is the P-38 Lightning. The first prototype flew in 1939, and by the end of World War II, Lockheed had built more than 10,000. The P-38 was the Army Air Forces' standard fighter in the Pacific Theater.

The sleek P-51 Mustang saw action in the last two years of World War II. One of its primary roles was to escort bombers in raids over Germany. Some Mustangs also flew in the Korean War a few years later, even as jet fighters were becoming the norm.

The Republic P-47 Thunderbolt fighter-bomber had a reputation for ruggedness and durability. The P-47 flew its first combat mission in April 1943 and, by the end of the war, more than 15,000 had been built, more than any other US fighter.

It took several decades after the first airplanes got off the ground before anyone really solved the problem of vertical lift. (Well, aside from balloonists.) Helicopters became a reality for the US Army Air Forces in 1943 with the Sikorsky R-4 Hoverfly, the world's first production helicopter. This one is at the National Museum of the US Air Force.

The Curtiss C-46 carried cargo and troops starting in mid-1942. Its most notable service came in traveling the unforgiving flight path over the Himalayas ("over the Hump") on supply runs from India to China.

During World War Il, gliders were one-way aircraft. Towed to an assault zone, they detached and swooped down to the ground with their cargo of 13 infantrymen or a jeep or quarter-ton truck. The most common glider of the war was the Waco CG-4A Hadrian. Here we see a pair of Waco gliders in June 1944 during the Normandy invasion, still attached to the Douglas C-47 Skytrain aircraft that got them there. Derived from the DC-3 commercial airplane design and known as the "Gooney Bird," the C-47 served as a troop and cargo carrier during World War II -- and continued serving in various roles through the 1950s, during the Vietnam War and beyond.

Bombers in action over Europe. These are Martin B-26 Marauders.

This close-up look at a B-26C Marauder in flight shows the bombardier in the nose, apparently enjoying a cigarette. In the cockpit above are the pilot and copilot, and behind them either the navigator or the radio operator.

B-24 Liberators make a bombing run. If you've read the book Unbroken, or seen the movie, you'll recall that Louis Zamperini flew in a B-24 in action over the Pacific, surviving a crash into the ocean and the harrowing aftermath.

The bomber was apparently not well loved by its crews. As Laura Hillenbrand wrote in Unbroken: "Flying the B-24, one of the world's heaviest aircraft, was like wrestling a bear. ... And the plane had a reputation for frailty, especially in the wings, which could snap off if struck in combat. Some men thought it was a death trap."

Here you see a seemingly endless array of B-24 Liberators on the assembly line at the Consolidated-Vultee plant in Fort Worth, Texas. The US produced more than 18,000 Liberators during World War II.

The North American B-25 Mitchell flew throughout World War II for the Army Air Forces, most famously in the Doolittle raids on Tokyo in April 1942. Here, a B-25 heads upward after a bombing run on a Japanese destroyer in April 1945.

The B-29 Superfortress was the largest aircraft to serve in the Army Air Forces during World War II, and its technological advances -- including a pressurized cabin and remote control of machine gun turrets -- pointed toward the military aircraft of today. It was B-29 aircraft that dropped the atomic bombs on Hiroshima and Nagasaki. The bomber continued to serve through the 1950s.

The big technological breakthrough in aviation during World War II was the development of jet aircraft. This was the first one for the US, the Bell P-59 Airacomet, a rather heavy and underperforming design. Its debut flight took place in October 1942, but the P-59 never saw combat. Only a small number (several dozen) production models entered service for a brief time in the latter part of the 1940s.

In June 1943, the Army gave a thumbs-up to a pitch from Lockheed to build a jet aircraft prototype. The aircraft that came from that agreement was the Lockheed XP-80, seen here, completed at the company's Skunk Works in a remarkable 143 days. The XP-80 made its first flight in January 1944. And while jet aircraft never became a factor in the aerial battles of World War II, a new era was dawning.

For the aircraft that were to come in the following decades, see The US Air Force at 75: From Early Jets to Stealth Aircraft