https://aviationweek.com/defense/aircraft-propulsion/b-21-inflight-refueling-tests-begin
B-21 Inflight Refueling Tests Begin | Aviation Week
Air refueling testing has begun for the Northrop Grumman B-21 Raider, the U.S. Air Force said late April 14.
b 21inflight refuelingtestsbeginaviation
https://aviationweek.com/aerospacedailydepartments/brief-b-21-inflight-refueling-tests-begin
In Brief: B-21 Inflight Refueling Tests Begin | Aviation Week
in briefinflight refueling21testsbegin