http://www.flightglobal.com/news/articl ... ht-413382/
A Siberian aerospace research center has achieved first flight of a highly modified Antonov An-2 biplane with redesigned, winglet-like braces and carbonfibre wing structures, Sukhoi announced on 10 June.
The Siberian Research Institute of Aviation (SIBNIA) produced the "light multipurpose aircraft" to demonstrate the aerodynamic and structural changes planned for an An-2 replacement, Sukhoi says.
The aircraft involved in the flight also was equipped with a five-bladed turboprop engine. That engine was not identified, but is most likely the Honeywell TPE331 already installed on a modernized version of the An-2 that entered service last year.
That design change improves the speed of the An-2 by 50%, Sukhoi says in the press release. The testing also shows the minimum flying speed of the aircraft is “close to zero”.