by Kent A. Mitchell


Shortly after the Lockheed C-130A Hercules became operational in the U.S. Air Force inventory, the manufacturer submitted a proposal to the military to develop a ski-wheel landing gear for the aircraft. The Air Force was interested in such an aircraft configuration to support its operations in arctic areas and the U.S. Navy wanted several to support their seven stations in Antarctica.


Given a go-ahead, Lockheed made a prototype installation on Air Force C-130A tail number 55-021. A company press release dated January 29, 1957 announced that the ski-and-wheel equipped aircraft had made its first flight from Dobbins Air Force Base, which adjoined the Lockheed plant at Marietta, Georgia. Piloted by Leo J. Sullivan, the company's chief engineering test pilot, the aircraft was flown for 51 minutes in the "wheels down, skis up" configuration. A television camera, mounted in a two-foot diameter fiberglass pod under the right wing outboard of the No. 4 engine, monitored the in-flight behavior of the skis. The camera was connected to a 10-inch TV screen on a table inside the cargo compartment and watched by the flight test engineer. Candy-cane stripes were painted on the skis for better TV visibility. In addition, observers were stationed in the open paratroop doors of the Hercules to watch the aft ends of the 19.5 ft. long skis during the flight.


Lockheed began testing the skis by landing on snow and ice beginning in late February 1957 at Bemidji, Minnesota. As a result of these tests, it was decided that some modifications to the skis were required. The modifications to the skis included a lengthened nose section and a vee-bottom bow in place of the blunt, flat-bottom bow. The main gear ski system was altered to assure a level attitude of the skis during extension and retraction. The nose ski system was also modified to assure a level attitude of the ski during extension and retraction as well as to eliminate a nose wheel shimmy.


The ski modifications having been made, the aircraft was turned over to the Air Force's Wright Air Development Center who scheduled it for testing during the next snow season at

Bemidji beginning about January 1, 1958 through April 15. The objective of the test program was to determine the functional capabilities, applied structural loads, and performance of the C-130A modified prototype ski-wheel installation. The results of the tests would be used in determining a standard design for future C-130 ski-wheel installations.



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