Configured with 85 seats, the cabin was spacious and well-appointed with comfortable seats widely spaced, giving plenty of legroom, but due to the low cabin floor and wide diameter, there was much unusable space which limited baggage and cargo volume. The inefficient use of cabin volume contributed greatly to the low payload/TOW ratio which was much lower than that of the contemporary Ilyushin Il-18, but which was still higher than the Tupolev Tu-104. A later production version, the An-10A, addressed some of the efficiency concerns by increasing the number of seats from 85 to 89 and 100 (in the two versions of the An-10A), then to 117–118 and finally 132 through reducing seat pitch and changing the cabin layout. Powered by Ivchenko AI-20K engines the An-10A demonstrated superior performance and an increased maximum payload of 14.5 Tonnes (31,970 lb). The auxiliary endplate fins eventually gave way to improved splayed ventral fins under the rear fuselage. The directional stability was now acceptable and the new ventral fins also improved longitudinal stability at high g and on landing approach, as well as delaying the onset of Mach buffet to M0.702. Due to being sited in an area of flow separation, the new ventral fins also caused unpleasant vibrations. Following results of flight tests and at least two fatal crashes, an effective tailplane deicing system was retrofitted to all remaining aircraft.