The Curtiss manufactured JN-4H aircraft was nicknamed the "Jenny." This single engine biplane was used during World War I by the U.S. Army Air Service. Army pilots could easily have joked that the plane was "a bunch of parts flying in formation." The pilots noted that "if you can fly a Jenny, you can fly anything!"
These planes were designed by B. Douglas Thomas. The Post Office Department began using them on May 15, 1918, when the first scheduled airmail service was instituted. Jennies were flown between Washington, D.C., Philadelphia, Pennsylvania, and New York, New York. Army pilots flew the planes for the first 2 months of the service, until the postal service was able to hire its own pilots.
The Jenny's top speed was about 80 mph, with a range of about 175 miles and a ceiling of about 11,000 feet. The plane's wingspan was 43 ft., 7 inches, and the plane weighed just over a ton. Before the planes were taken by the postal service, their 90-horsepower engines were replaced with 150 horsepower Hispano-Suiza engines. The Jenny could carry a little less than 300 pounds of mail per trip.
The front seat was left out of the redesigned planes, in order to carry mail bags. The planes' gas capacity was doubled when a set of gas tanks were hooked together so the plane could fly farther.
Sometimes a liability can also be an asset. When airmail pilot Ernest Allison was asked his opinion of the plane, he said that he considered it safe because the plane's "carburetor would vibrate the plane so badly that it would shake the ice off the wings."