Fighters, Warbirds, and Racers

The high-flying long-range North American P-51 Mustang escort fighter was a war-winning weapon for the United States and its Allies during World War II. As American Mustang pilots protected bombers and pursued their enemies in the air over Europe and the Pacific, they earned a place for themselves and their airplane in the annals of military and aviation history. Designed by a German-born engineer, it reflected the mating of American and British ingenuity in aerodynamics, structures, and propulsion technology. The availability of surplus Mustangs and other fighters such as the Corsair, Bearcat, Airacobra, and Lightning after World War II and into the 1950s helped create what we call the “warbird” community today.

North American P-51 Mustang

The combination of external fuel tanks that could be dropped when needed and six .50 caliber machine guns allowed wartime P-51 squadrons to take the air war deep inside enemy territory. U. S. Air Force, courtesy National Air and Space Museum (USAF-K2667), Smithsonian Institution.

 

Some owners of these fighters, recognizing that they were the fastest propeller-driven production aircraft to ever fly, took them air racing. They remembered the widely-popular pre-war National Air Races at Cleveland where Horatio Alger-like individuals took readily-available technologies and built dedicated air racers to achieve fame and fortune every September in 1930s Depression-era America. The National Air Races resumed in 1946 after its wartime hiatus with warbirds as the main technology.

At Cleveland in the late 1940s, some pilots just painted their otherwise original, or “stock,” aircraft for competition. The Museum’s Bell P-39Q Airacobra flew at Cleveland twice.  In 1946, Charles Bing raced it as Juba. Former WASP Elizabeth Haas took it to the 1948 National Air Races as Galloping Gertie.

 

Galloping Gertie

Galloping Gertie featured a dazzling red-and-white racing scheme.

Others, echoing the long-standing American tradition of technical ingenuity, modification, and “hot-rodding,” worked to transform their warbirds into dedicated air racers. Racing teams carried out their visions of improving upon an original design to make their aircraft faster and lighter and, ultimately, to win as they flew low and fast around the pylons.

The 1949 National Air Races saw the deaths of two innocent bystanders and a racing pilot after a crash into a nearby neighborhood. The lack of infrastructure to conduct continued events, the distraction of the raging conflict in Korea, and the ever-present debate over safety ensured that air racing would not continue in Cleveland in the 1950s.

For air racing enthusiasts, the spirit of the 1930s and 1940s had no venue until the renewal of air racing through the National Championship Air Races centered on the remote town of Reno, Nevada, in 1964. One of the racing classes, the Unlimited, was just that, racers could use any competitive aerodynamic, structural, or propulsion advantage to make their propeller-driven warbirds go even faster. Quickly, the Unlimited Class race became the marquee event of the air races at Reno due to the high speeds and the popularity of World War II-fighters overall, no matter how far different they were from their original configurations.

The National Air and Space Museum has a first generation Unlimited Class racer in its collection, Conquest I, which is based on the Grumman F8F Bearcat platform. The team behind it worked at the super high-tech Lockheed Skunk Works and used their advanced knowledge to create a multiple Unlimited Class winner (1965-1969 and 1971) and world speed record holder in 1969. Conquest I’s design set the tone of innovation where sophisticated original thinking merged with the clever use of found parts and systems from other aircraft.

 

Bearcat

Darryl Greenamyer’s Bearcat racer featured a canopy fashioned from a Lockheed P2V Neptune patrol bomber searchlight lens, a propeller taken from a Douglas A-1 Skyraider ground attack airplane, and a propeller spinner from a P-51H Mustang fighter.

Mustangs flown by Unlimited racing teams underwent a similar transformation as Conquest I. Aerodynamic streamlining, structural modification, and increased horsepower turned an aircraft designed to be a high-altitude, long-range fighter capable of cruising at 352 mph into a racer intended to fly fast and low at speeds approaching 500 mph over the high desert of Nevada.

 

mustang racer

Mustang racers have won the most Unlimited championships at Reno (26 as of 2012). Photo by Jeremy R. Kinney

 

Historic in their own right as racers, these Mustangs have added to the long history of a classic aircraft design. The evolution of the Mustang from a military fighter during World War II to a means of recreation and a vehicle for speed tells us much about the enthusiasm for flight.

Jeremy Kinney curates the air racing collection at the Smithsonian National Air and Space Museum.

Are You Sure You Want to Donate This?

“Are you sure you want to donate this?” I asked the intern. “This” was a slightly-used Smartphone, in perfect working condition. The intern, Rebecca Bacheller, was, indeed, willing to donate it. She heard that the Time and Navigation team wanted to disassemble one and showcase the current state of geolocation devices, enabled by the Global Positioning System and other advanced electronics. Our plan was to label the phone’s circuits, and show how they correspond to classical methods of navigation that had been practiced for centuries. Becky was excited that she would be credited in the label; she also had another motive: namely a reason to trade up to the newest version of the popular phone. (This is a never-ending treadmill: once you get on, it is impossible to get off.)

I prepared myself for the transfer by going on-line and special-ordering tools to disassemble it: a “pentalobe” screwdriver, a plastic pry-bar, and a tiny Phillips-head screwdriver. I also downloaded instructions on how to disassemble the phone, and I borrowed a head-mounted magnifier. When the day arrived, fellow curator Andy Johnston and I got to work, surrounded by a few sidewalk superintendants from the Space History Division.

USS Alabama

The USS Alabama was launched in 1984, carried up to 24 Trident ballistic missiles armed with nuclear warheads, and is still in the fleet.

Before describing what we found, I want to mention an important part of the new gallery. One of the centerpieces of Time and Navigation is a “SINS” guidance system, removed from the nuclear-powered submarine USS Alabama. “SINS” stands for “Submarine Inertial Navigation System,” and it was responsible for telling the sub where it was without having to surface to take a fix on stars or otherwise reveal its location. Hence the “inertial” components: a set of gyroscopes and accelerometers that, as its developer Charles Stark Draper called it, was like practicing “astronomy in a closet.”  It was not perfect: the gyros had a tendency to drift, so periodically the sub would come near the surface to receive navigation signals from a Transit satellite orbiting overhead.  (An engineering backup of a Transit will also be on display in the gallery.)  A refrigerator-sized digital computer combined data from these inputs, corrected the gyros’ drift, and computed the sub’s position. The whole ensemble is rather bulky and heavy, and as Heidi Eitel mentioned in an earlier blog post, getting everything to fit in the gallery is quite a challenge.

SINS Typewriter

This modified IBM Selectric typewriter, connected to a special computer system, output data about the operation of two SINS (Submarine Inertial Navigation System) units aboard the nuclear-powered submarine USS Alabama. It could also provide input to the computer in emergencies.

So what does this have to do with the cell phone? As we disassembled it, Andy and I realized that almost every component of the SINS was present, even if you need a high-power magnifier to see it. A three-axis accelerometer? Check.  Gyroscopes? Yes. A radio to receive satellite navigation signals? Yes, although the phone receives signals from GPS, not Transit satellites. A computer? Of course—the phone uses an “A4” processor supplied by the company ARM. It has more processing power than the CRAY-1 that used to be on display in the Beyond the Limits gallery. A keyboard and display to give and receive commands? Yes–the phone’s touch screen even replicates the old-fashioned “QWERTY” keyboard of the electric typewriter used on the submarine. A radio to communicate with the rest of the world?  The phone has several, covering the major cellular frequencies in the UHF region. (The sub communicated by trailing a long wire behind it and receiving “Very-Low-Frequency” (VLF) radio signals—far below the standard AM broadcast band– chosen because they could penetrate water.)  The Smartphone even has a magnetic compass.

Smartphone

This disassembled smartphone showcases the current state of geolocation devices (as of 2012), enabled by the Global Positioning System and other advanced electronics. The phone’s circuits correspond to classical methods of navigation that have been practiced for centuries.

The difference in size between the two systems is breathtaking, but there is another difference that may be even more significant. The SINS was designed to allow the submarine to navigate without anyone, other than the crew, knowing where it was. By contrast, a Smartphone has all kinds of circuits and software on board to let the world know where its owner is, and what he or she is doing. Submariners might be uncomfortable carrying one of these around.

It is going to be a challenge to show this disassembled object to our visitors and convey the magnitude of what they are looking at. Many visitors carry these devices with them and hardly give them a second thought. The gallery opens next spring, and we’ll see how this exhibit works.

Paul Ceruzzi is chair of the Space History Division at the National Air and Space Museum.