Brian G,
I did a study about 4 years ago, and found that fully 95% of all "LTE" incidents in two different data bases happened to Bell helicopters, and 90% were Bell 206's. I usually raise irate posts from loyal Bell guys, but the data speaks for itself (and with over 1500 hours in Bells, 1000 in combat, I refuse to be labeled an anti-Bell guy).
It is my ernest belief that an adequate tail rotor cannot be forced into "LTE" in any normal flight conditions. The whole idea of LTE masks the true cause - weak tail rotors- and makes it seem that all single rotor helos can suddenly get consumed with the LTE disease and start spinning.
What consumes tail rotor anti-torque capability and makes LTE occur is when main torque is raised too high during otherwise marginal maneuvers. For example, this is when you terminate an approach and raise the collective too high.
Most helos are tested in level, sideward flight to higher and higher speeds, until the tail rotor hits its pedal stops. I believe a more effective way to judge adequacy is to trim to a sideward speed and then command some transient torque increase (a brief collective pitch rise) to see if adequate margin exists.