Progress in Power and Safety
- By J.R. Dailey
- AirSpaceMag.com, June 01, 2013
"Viewport," by National Air and Space Museum director J.R. Dailey, opens each issue of Air & Space magazine. The column highlights the Museum's ongoing efforts to preserve the history of aviation and spaceflight. This article appeared in the June/July issue.
Not until 1952, when Pratt & Whitney created the J57 turbojet engine, the first production aircraft engine to be rated at 10,000 pounds of thrust, did jet aviation start to show signs of maturity. The J57 powered the world’s first supersonic fighter—the North American F-100—as well as the Vought F8U Crusader, B-52 bomber, and Lockheed U-2 spyplane. In the Jet Aviation gallery of the National Air and Space Museum, we exhibit a cutaway of this significant milestone in the history of aircraft propulsion.
Pilots always want more power, but to those who flew combat during the Korean War, 10,000 pounds of thrust would have seemed like a dream; they were flying with engines that produced half that much. How did those pilots cope with jet fighters that came along before the J57? With a feature about the Grumman F9F Panther in this issue, the editors are introducing a series on flying early jets.
One factor pilots dealt with more frequently in Panthers than they did in piston aircraft was the effect of density altitude. They had understood the concept that the density of the air affects airplane performance: In thinner air, wings don’t produce as much lift and engines don’t produce as much thrust. Still, understanding a phenomenon and overcoming it are two different things.
On cross-country flights in the early 1950s, Navy aviators would often stop in El Paso, Texas, to refuel. The terrain west of El Paso rises fast, and high temperatures make the air thinner; above a certain temperature, the Panther couldn’t climb quickly enough to avoid the mountains. I’ve never experienced the terror of trying to climb faster than the ground is rising, but I’ve heard that if you watched Panthers launching from El Paso on a summer afternoon, you could see those guys riding ground effect and blowing dust all over west Texas to gain enough lift to get off the runway.
Of course, paying attention to density altitude is critical for the pilots flying in the Alaska Range, where the temperature can change 100 degrees in less than a day. As this issue’s special coverage of aviation in Alaska points out, the state’s weather, especially the fog that can shut down visibility in an instant, contributed to the highest accident rate in the country. That statistic and the population’s reliance on airplanes made Alaska a prime location to test a satellite-based navigation and weather reporting system that will soon form the basis of a national system. Visitors to our new gallery Time and Navigation can learn more about the ADS-B, or Automatic Dependent Surveillance–Broadcast, system that was pioneered in Alaska.
In 2007, the National Aeronautic Association awarded aviation’s highest honor, the Collier Trophy, to 26 organizations for developing ADS-B. The trophy, on permanent display in the Museum, is the first subject of a new magazine department: One More Thing. In 1952, the trophy was awarded to the United Aircraft Corporation’s Leonard Hobbs for leading the development of the J57 jet engine.