The Irkut MC-21-300 resumed regular test flights outside Moscow on Thursday following an interruption in the program caused by Covid-19-related recommendations from Russian authorities.

United Aircraft Corporation reported a gradual increase in flight test intensity by the four MC-21 flying prototypes since the start of this year. Out of 650 flights needed to obtain a Russian certificate, the program has completed more than 300.

Two of the MC-21 flight test articles carry passenger cabins, one in a two-class, 163-seat layout, and the other in a “super-dense” 211-seat configuration.   

The MC-21s have performed flights at altitudes and speeds typical of revenue service operations, UAC said. The test team has finished flutter testing and most of the tests related to extreme angles of attack. Other tests have involved determining minimum separation speeds, instrument landing system operation, navigation, landing systems, and external lighting equipment at night.  

Meanwhile, the TsAGI engineering institute has performed the bulk of static trials with two ground test articles, including life cycle validation.

Finally, UAC reported that “significant efforts” now center on software development and testing.