The bug occurs only during airfield (runway) takeoff and is tied to indicated airspeed (IAS). Below 400 km/h, fuel dump fails with the message “fuel dump speed too low”. Above 400 km/h, it also fails, showing “fuel dump speed too high”.
Notably, this issue does not exist during airborne from air. The fuel dump system works normally at all valid speeds in such scenarios, confirming the bug is specific to airfield runway takeoffs.
I tested repeatedly under different weather and loadouts to rule out interferences, but the bug recurs consistently. It impairs the A-4H’s flexibility, especially when fuel dump is needed post-takeoff to adjust weight for maneuvering or missions.