Tail Stall Recovery

[HF17]

Can anyone explain why the recovery procedure is to pull back on the yoke to recover from a tail stall? Ive read that pulling back decreases the angle of attack on the tail, but wouldn’t it actually increase the angle of attack since the

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[MauleSkinner]

You are correct…everything else being equal, pulling back increases the AOA of the tail. The biggest driver in causing tail stall is increasing flaps, and so decreasing flaps will lower the AOA of the tail and resolve the tail stall.

years ago, NASA had a contact email on their web page that discussed tail stall. I asked what was actually happening when you pull back, and it’s two things.
First, the nose of the airplane will drop abruptly due to tail stall, and the AOA of the tail will decrease, so essentially you’re just pulling out of the dive.
Second, the pressure side of the elevator still has some effect, so while not lowering the AOA, sticking the elevator up into the breeze can still help pull the tail down.

 

[21541803]

Horizontal stab is an "upside down" wing causing a down pressure in flight.
Relative wind determines the AOA. Diagram suspect.
Lets wait for the correct answer though

 

[MauleSkinner]

Also, in some airplanes it’s not actually a tail “stall”, it’s the disrupted airflow reattaching to the elevator and pulling the elevator down. In these airplanes, pulling back will raise the nose, as the tail is still flying.

 

[flyingron]

The tail is still flying even if it is stalled. It's a misconception that lift disappears when a stall occurs. The stall is the point were further AOA increase results in less lift not more. In fact, the lift vs. AOA curve is pretty symmetrical around the stall point.

As others have pointed out, do not confuse lack of effective downforce on the tail with a stall. You can still have sufficient downforce with a stall and you can fail to have sufficient downforce with the tail unstalled.