Old 31st May 2019, 16:40
  #47 (permalink)  
Thomas coupling
 
Join Date: Aug 2000
Location: UK
Posts: 3,660
LTE Vs LTA

Ideal aircraft to discuss this as the Jetbox was notorious for tail rotor "issues" to be polite.
Grateful for corrections as I am getting long in the tooth now and much has happened since I flew Jetboxes many years ago, so:

The jetbox had a (unfair?) reputation for becoming unstable in the TR vicinity due to LTA (Loss of tail rotor authority), due to design limits surrounding the OEM TR. I believe this was later redesigned out and the later models have not experienced the same number of issues.
So LTA is where a TR isn't 'man enough' to accomodate a broad spectrum of directional airflow inputs compared to other similar competitive helos. The TR blades simply weren't beefy or big enough to cope with some extreme demnds with pitch and ergo wind direction.

LTE on the other hand is a phenomenon where many helos 'may' suffer, simply because the aircraft ends up in a situation where even the beefy/big TR blades simply can't compensate for the massive increase in the 'big green arrow' and the TR "breaks away" from controlled flight. Obviously this is an aerodynamic phenomenon as opposed to LTA which is a design problem.

In the interim US safety report, notice how the pilot actually states both phenomenon in one paragraph, as he doesn't fully understand the difference between them...something few pilots fully understand, I suspect.

Comments appreciated.
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