The most comprehensive War Thunder update to launch this month — 1.81 "The Walkyries" — introduces a few new ground vehicles, locations, and a new aircraft. However, the most important change involves the attack helicopters that have been added to the US and Russian branches of vehicles. Sadly, they are not available for everyone yet.
https://www.notebookcheck.net/Update-1-81-The-Walkyries-brings-helicopters-to-War-Thunder.333296.0.html