Once a year the museum opens what is normally closed. The restoration workshop works without its glass wall: you can walk up to the bench, pick up a tool and ask a question of the person who restored the Il-2.

At midday, in the yard, the ASh-62IR piston engine is run on a test stand — the only time in the year that an engine from the collection operates. You can hear it a block away, and it is the most convincing exhibit of the day.

In the afternoon there are meetings with pilots and engineers whose lives are tied to machines in the collection. The format is loose: a few short talks and a conversation in the hall. Recordings go into the museum’s oral archive.

Entry is free for everyone on this day. Because of the numbers, we recommend arriving at opening time.