Accidents occurred on US Army OH58 helicopters. The phenomenon was initially called "Tail rotor stall" and the pilot was asked to add pedal in the turn direction to "unstall" the tail rotor. I am convinced that it contributed to increase the number of accident untill tests demonstrated that there was no tail rotor stall.
Accidents occurred on UK Army Gazelle helicopters (and almost only there), attibuted to a "Fenestron stall". The pilot was asked to add first pedal in the turn direction to "unstall" the fenestron. I am convinced that this is the reason why so many accidents occurred on the UK Gazelles. I never heard of any accident after this strange procedure was removed.
Wing stall is a physical phenomenon. It is demonstrated daily to student pilots. Whenever you reproduce the stall conditions, it occurs. Fenestron stall is only a mind's creation, not confirmed by any experiment.
This is what happens when you apply full right pedal. The upper curve gives the pedal position and the lower the heading. You may see that the Gazelle was rotating 360° in about 3 seconds. In 2 seconds it was stopped.
In that test, only 75% pedal was applied, quite far from the stop. The rotation was eventually stopped, even if it took more than 720°.
A fully operative helicopter rotating left with full right pedal is a nonsense. Exceeding 360° rotation means that no pedal reaction was done or that opposite pedal reaction was abandonned after an initial attempt that seemed to have no effect.
An improper wording of a phenomenon may have unexpected consequences. I believe that the "Loss of Tail rotor Effectiveness" wording that followed the "Tail rotor stall" is a reason why such accidents still happen. The tail rotor does not lose effectiveness and saying that it does cannot give the pilot confidence in his tail rotor, which is however the best chance he has to exit unanticipated yaw. So please do not use "Fenestron stall" . It does not exist and recommending to "unstall" a fenestron or a tail rotor has already been tested. I can guarantee the result.
Please consider using leprechaun to designate the phenomenon, it will be less harmfull.