Editing Antonov An-10 (section)

==Design and development==
[[File:СССР-11185 Ан-10.jpg|thumb|left|Antonov An-10A]]
[[File:1958 CPA 2194.jpg|thumb|An-10 on a 1958 Soviet postage stamp]]
Development of a four-engined airliner intended for use on routes from {{convert|500|to|2000|km|mi|abbr=off|sp=us}} began at the end of 1955. Inspired by the '''Izdeliye N''' (''Izdeliye'' – article or product) passenger version of the [[Antonov An-8]], the Antonov design bureau developed the '''Izdeliye U''' ("U" for "Universal"), a four-engined aircraft with a similar layout to the An-8, but with increased dimensions and a circular-section pressurised fuselage.<ref name="Gordon An-12"/> Early in the design process the choice of engines was between the [[Kuznetsov NK-4]] and the [[Ivchenko AI-20]], and despite superior performance the Kuznetsov NK-4 was eliminated and the Ivchenko AI-20 selected, partly due to the Central Committee of the Communist Party of Ukraine, which wanted as many as possible produced in Ukraine, where the Ivchenko factory was.<ref name="Gordon An-12"/>

The first prototype flew on 7 March 1957, revealing poor directional stability which led to a taller vertical fin, and later to hexagonal auxiliary fins at the tips of the tailplane. Entering production at Zavod (factory) No.64, [[Voronezh]] in 1957, the initial three aircraft were delivered with Kuznetsov NK-4 engines, due to non-availability of the Ivchenko AI-20 engines. From 1958, production aircraft were delivered with the Ivchenko AI-20A engines which boasted a longer service life and  performance comparable to the Kuznetsov engines.<ref name="Gordon An-12"/> The new aircraft was displayed to the public for the first time in July 1957; the design was approved for mass production after testing was completed in June 1959.<ref name="Gordon An-12"/> [[Aeroflot]] began operations with the An-10 from 22 July 1959 on the Moscow – [[Simferopol International Airport|Simferopol]] route.

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.<ref name="Gordon An-12"/> Powered by Ivchenko AI-20K engines the An-10A demonstrated superior performance and an increased maximum payload of 14.5 Tonnes (31,970&nbsp;lb). The auxiliary endplate fins eventually gave way to improved splayed ventral fins under the rear fuselage. The directional stability was better 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 placed in an area of flow separation, the new ventral fins 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.<ref name="Gordon An-12"/>