Yakovlev Yak-46

The Yakovlev Yak-46 was a proposed aircraft design based on the Yak-42 with two contra-rotating propellers on the propfan located at the rear.

[4] Later in 1987, the Soviet civil aviation minister noted that Yakovlev was building a twin-propfan airliner based on its Yak-42 model.

[7] The Yak-46 and the Yak-42M, a 4-metre stretched derivative (13-foot; 4,000-millimetre; 160-inch) of the Yak-42 that would enter service in 1994, would have fly-by-wire (FBW) controls, an electronic flight instrument system (EFIS), a supercritical airfoil wing of added aspect ratio, span, and sweep, seating capacity of 150 passengers or more, and new engines with thrust reversal capability.

The Yak-46 would hold 150-162 seats in a six-abreast, single-aisle configuration, fly as far as 1,540 nautical miles (2,850 km; 1,770 mi), cruise at a speed of 445 to 460 knots (800 to 850 km/h), and be powered by two Lotarev D-27 propfan engines.

To prepare for Yak-46 development, Yakovlev created a joint venture with Ivchenko Progress and the Soviet Ministry of Civil Aviation.

[14] Meanwhile, conflicting reports appeared about the Yak-46 power plant: one article stated that the D-236 would be the eventual engine,[15] but another article said Yakovlev was deciding between a gearless unducted fan, which would yield a fuel consumption of 12 g/km (0.68 oz/mi), and a less-efficient, but now considered more realistic, ducted fan with an ultra-high bypass ratio between 20 and 27.

[16] A Soviet aviation publication named the initial engine as the Progress D-627, a quiet, super-high bypass ratio turbofan.

The subsequent version of the Yak-46 would have the same characteristics and performance outlined for the D-27 earlier, but its cruise TSFC after losses would be 0.47 lb/(lbf⋅h) (13 g/(kN⋅s)) at 460 kn (850 km/h; 530 mph) speed.