Tuk....please don't speak for me as you have difficulty enough on your own.
I said the LTE terminology was invented by Bell to explain the shortcomings in their tail rotor performance....and that language was grabbed by the FAA and others and then applied to all single rotor helicopters.
I did say other types do not have the problems that Bell does in the 204/205/206 series of helicopters re tail rotor performance.
So...back under the bridge with you.
From a post made by Brian Abraham here in Rotorheads a while back that pertains to the discussion of LTE.
The Bold print was my doing....
kflexer - The following is what Nick Lappos has to say on LTE. (Nick was test pilot for Sikorsky and did the work on the 76 - among other things).
The real skinny on LTE is simple and quite easily stated:
All rotors lose thrust when operating in disturbed air, including tail rotors, main rotors and fantails. LTE sets in when there is so little thrust margin that the loss of the maybe 5 or 10% of the thrust is enough to kill you. With a really marginal design, that slight loss of thrust unleashes the massive main rotor torque, and the aircraft bites its pilot big time. I cut my teeth on the old AH-1G snake, with its way too small tail rotor, and had at least my share of 360 turns while trying to get over someplace to cut the throttle.
LTE only affects those helicopters that have too little tail rotor thrust margin. Period. It is really not LTE it is "Not Enough Tail Rotor".
LTE happens when the tail thrust is consumed by several possible upsetting factors, and when the remaining thrust, by marginal design, is simply inadequate. Yes, inadequate. These possible tail thrust reducers are:
1) main wash into the tail rotor, as illustrated in the LTE handouts that we've all seen.
2) using somewhat too much main rotor thrust (collective pitch) at the bottom of an approach, especially in critical tail thrust conditions. I can touch the left pedal stops on any helo by simply raising the collective pitch until main torque washes out all tail margin. One inch more collective and WATCH out! You get LTE, surprise, surprise.
3) terminating an approach with a critical wind condition, where the wind is a few knots more than your helo can stand.
I did a study on "LTE" accidents to support a regulatory change meeting I was attending, and , wow, it was some surprise to find that about 95% of all LTE accidents were restricted to one brand name, and all LTE accidents were experienced by helicopters with very little cross wind capability.
The cure for LTE is quite simple - get a helicopter with a bigger tail rotor, as proven by the certified crosswind capability. Don't get in one that has an LTE history, and don't buy the bull that LTE is a pilot error problem. Don't buy into the new certification rules that allow you to operate with a helo that has no crosswind capability. If you do, get a good helmet, and a good insurance agent.
BTW, the LTE study that I did was opposed by an engineering manager from that particular manufacturer because "LTE is a pilot error problem, plain and simple" I asked how so many bad pilots were flying his helos, and expressed our luck that so few of these dumbos were flying all the other brands.
In the fantail, sometimes I can feel the main rotor wash flow into the tail, the pedal moves a few percent the noise increases, and that is that.
The big tail surfaces on the fenestrons and fantails are because the fan doesn't respond to small yaws, so the aircraft will snake a bit, unless the vertical tail is big enouigh to keep the nose ahead of the tail. On regular tail rotors, the tail rotor responds strongly to change thrust when some sideslip develops, and the yaw stability to small disturbances is strong. In fact the tail rotor area is as powerful as a vertical fin that is about 4 to 8 times bigger than the tail rotor.
This is one of the reasons why the Fantail is able to snap turn, because the fan doesn't care where the wind is from, it keeps its thrust and bending closer to normal. Under big sideslips, a tail rotor is positively screaming from the big stresses it develops. With the same maneuvers, the Fantail is calm as can be.
A quote from the FAA's AC on LTE.....one can form one's own opinion of just what the truth of the matter is....whether the FAA is covering its own Ass by what they say in the AC or what a very experienced Test Pilot and Research Manager has to say.
I put my money on the Accident Statistics, Research, and expertise of Mr. Lappos and definitely not on Bell and the FAA. BELL and the FAA are entitled to their opinions but not their own "facts"....as we all know true "Facts" are obstinate things.
You will notice the FAA mentions mechanical malfunction but ignores design failure when describing the cause of LTE as they stake their position on their standards being adequate. How do they now admit they are not after all these Bell 206's have been built?
LTE is a critical; low-speed aerodynamic flight characteristic which can result in an
uncommanded rapid yaw rate which does not subside of its own accord and, if not corrected, can result in the lossof aircraft control.
6. LTE is not related to a maintenance malfunction and may occur in varying degrees in a single main rotor helicopters at airspeeds less than 30 knots. L T E is not necessarily the result of a control margin deficiency. The anti-torque control margin estab- lished during Federal Aviation Administration (FAA) testing is accurate and has been determined to adequately provide for the approved sideward/rearward flight velocities plus counteraction of gusts of reasonable magnitudes.This testing is predicated on the assumption that the pilot is knowledgeable of the critical wind azimuth for the helicopter operated and maintains control of the helicopter by not allowing excessive yaw rates to develop.