Kenny Keller explains onset and contributing factors for loss of tail rotor effectiveness (LTE) in a short online ground-school video. He highlights three main risk groups: high gross weight/high density altitude, low rotor RPM, and low airspeeds (below ETL — ~30 knots), and discusses wind directions (quartering and tailwinds) that can precipitate LTE. The clip uses a summertime departure example and closes with examiner/airmanship reminders.
Chapters
I want to talk about loss of tail rotor effectiveness. We also quite often mention it as lte. There's three things you need to think about that these situations can put you into the onset of LTE or get you into lte. The first one being high gross weight, high density altitude. I put those two together because you can always count high gross weight and high density altitude almost every single time you talk about anything bad performance wise or helicopter emergencies or retreating blades stall, all these bad things that can happen to us. Anytime you have high gross weight and high density altitude, just about anything is a concern. So got a picture up of one of these situations. I'm talking about leaving my dad's house in the summertime. It's hot, got a bunch of fuel on and I really working that thing coming out of a yard. And that picture just makes me think about the summertime when you got loaded up with fuel and it's a hot summer day. There's your high gross weight, high density altitude. The next I want to mention is low rpm. Anytime you let your rotor RPM fall below the top of your operating range, as your main rotor slows down, your tail rotor slows down as well. So you don't have as much tail rotor authority. So you have to be careful. Anytime that the RPM starts creeping down, it's a good reason to stay on top of that RPM and get it right back up to the top of the green range. And then the last one is low airspeeds or airspeeds less than ETL or you could say airspeed less than 30. 30 knots, 30 mile per hour. 30 is still a good number. Anytime you're below ETL you have to be careful. You have to be careful of out of ground effect hovers with high power demand. Got to be careful of tailwinds. So these are some of the things you need to be thinking about on the lte. An LTE is one that maybe we don't always think about quite as much as what we should. And helicopters do get wrecked over the LTE and guys putting themselves in kind of a bad position and not being on top of the RPM and pedal control on top of everything. So these are things that you need to be aware of and you need to be thinking about them and have in your mind and be using your good pilot technique to help avoid these things. And of course back to the old checkride examiner is going to ask you about lte. He's going to want you to understand how it can happen, what the winds are. We already covered that in one of the earlier ones, and we'll throw them in again, quartering from the front on a counterclockwise system, the wind blowing the vortices off the rotor system into the tail rotor, a wind coming directly from the side blowing the turbulence from the tail rotor back into itself. And then anytime you have a tailwind, you're on top of those pedals, moving them back and forth, and you have to stay on top of those pedals. So those three wins are the other three parts of the LTE we like to talk about. So thanks for stopping by. Please click the like button. Please leave comments with feedback if you get time, and we will see you on day number 22.
