Antonov An-24 An-24B

The An-24B was the second production version and the most numerous of the type: 400 aircraft, with production beginning in 1964. It is a passenger aircraft seating up to 52 whose maximum take-off weight rose to 21 tonnes. A window was added on each side and the double-slotted flaps were replaced with single-slotted ones, their poorer performance compensated by an extended centre chord. Some aircraft were delivered with four additional fuel bladders in the centre wing; the Spanish Wikipedia adds that the flap deployment system was modified to work at very low temperatures and that some of those extra-tank aircraft ended up as tactical transports with the Soviet Air Force.

The An-24B airframe carried some of the programme's most peculiar conversions: the An-24LR-1 «Toros» ice reconnaissance aircraft, with SLAR radar on either side of the lower fuselage to guide icebreakers and convoys; the An-24LR-2 «Nit» for surveying natural resources, with its large side-looking radar pod; the four An-24RR nuclear, biological and chemical reconnaissance aircraft with RR8311-100 air sampling pods; the An-24PS search and rescue aircraft, rejected at acceptance trials; and the seven An-24USh navigator trainers, recognisable by the bulged windows at each training station.

The export versions descend from the An-24B: the An-24V and, according to the Spanish Wikipedia, the An-24-I — initial export, 50 seats with AI-24A engines — and An-24-II — later export, 50 seats in passenger, cargo and mixed configurations, with AI-24T engines.