The simple undercarriage of the YF-17 had a track of 6 feet 10 3/4 inches. On the F-18, the track was increased to 10 feet 2 1/2 inches for greater stability during carrier landings. It was considerably strengthened to meet the 24 feet/second descent rate requirement for arrested carrier landings. The all-flying horizontal tailplanes are of aluminum honeycomb construction with graphite epoxy skinning. They can be used in concert for pitch control or differentially for roll control, acting as "tailerons" for enhanced roll performance.
