Welcome back! I'm Jacob and this video covers types of Tail Rotor Issues. These are the types of things that cause helicopters to spin out of control and sadly crash moments later. Be sure to hit like and subscribe and we'll get started.
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Truthfully each category could be it's own video. But there are 4 big categories to cover with the first being Loss of Tail Rotor Effectiveness (LTE). I've got an entire video ( • Loss of Tail Rotor Eff... ) that outlines this but simply put, this is an uncommanded rapid right yaw rate that doesn't stop on its own. This can cause loss of aircraft control. In these examples I'll refer to spins to the right for Counter Clockwise rotor systems. It's reversed for clockwise spinning rotors. LTE is a wind issue, not a mechanical issue. It happens when the aircraft is operating Out of Ground Effect (OGE) or near max torque available and a wind gust hits the aircraft at just the right direction and velocity to cause a spin to start. For more info on where the wind has to come from, check out my LTE video. Generally this occurs when the helicopter is at a hover or less than Effective Translational Lift (ETL) and is once again, a wind issue.
The next tail rotor issue is Loss of Tail Rotor Authority (LTA). The only written reference I've found for this is from the Naval helicopter manuals. This tail rotor issue is commonly associated with running out of left pedal. It's when the tail rotor hits an Angle of Attack (AoA) limit and literally cannot produce any more thrust or anti-torque ability. Generally this occurs at high gross weights and density altitudes or when the main rotor is drooping (slowing due to excessive drag) due to engine limiting. The pilot has a lot of collective applied, the pilot applies left pedal but hits a physical stop and the aircraft begins to yaw. This is a mechanical limitation. Some manuals lump this into LTE while others separate it. It can happen with our without wind gusts and sometimes wind gusts can aggravate this condition.
Moving on the next issue is Tail Rotor Fixed Pitch. This can be from a jammed rod or cable in the flight controls or an electronic failure in a flight computer. Either way, the tail the rotor acts as if the pedals are stuck and the pitch in the tail rotor blades doesn't change. In either case, you don't have control of the tail rotor. There are a few instances where this could occur. It could be at a high power setting or low. If it jammed on takeoff it's probably high power setting. If you lower the collective in cruise and the nose goes left, that's the case. If jammed at a cruise or low power setting, the nose may go right as you slow down and increase power for approach. This could be its own video but generally, if the jam is at a high power setting, land with high power (steep and slow). If jammed at a low power setting, land with low power (shallow and faster run-on). If jammed at a hover, you can either try to fly away and land like above OR if hover can be maintained you can droop your way down by slowly reducing collective and throttle/power levers. In any of these, take it slow and be sure to practice these maneuvers in a safe environment so you're ready if it ever happens for real.
The last tail rotor issue I'll cover is lost of Tail Rotor Components. This is a mechanical failure in the form of broken drivetrain, gearboxes, or purely a loss of the tail rotor itself. There's a great video of an Apache in Afghanistan that had a tail rotor completely separate from the aircraft and he flew it 10 miles away and landed it. There are a few instances where this can occur. First is at a hover. Think of the movie Blackhawk Down where the RPG hits the tail rotor (Video: • Black Hawk Down (2001)... ). In this condition the pilot can either fly out or attempt to land by compromising between rate of turn and rate of descent. In the clip, he's in a low airspeed conditions where the ability to fly out isn't likely. It's not a pretty picture but here you've just got to do what you can to survive. If you can fly out, maintain the safe airspeed outlined in your operator's manual. At certain speeds, the vertical fin(s) can offload the tail rotor's anti torque and provide stability in forward flight. If you can do this, you can do a high speed run-on landing adjusting collective and throttle/power levers for heading control. The last ditch effort for this tail rotor issue is to autorotate which eliminates the main rotor torque factor altogether. Once again, practice this in the simulator.
Big takeaway: airspeed is your friend if you lose a tail rotor. Thanks for watching.