The Ta152 definitely has LOTS of adverse yaw, but its not in keeping with a sudden departure of controlled flight, followed by an unrecoverable stall. I've never heard of a plane stall and crash because of adverse yaw.
The question to ask is if it's possible. The answer is yes.
Directional divergence can happen in the real world. Our Ta-152 exhibits directional divergence characteristics under specific conditions. "Directional divergence can be 'triggered' or aggravated by lateral control inputs if these control inputs generate significant yawing moments" (USNTPS FTM 103) . This is what's happening with the Ta-152. Thus the yawing moments are key to understanding what could be happening.
Aircraft Yawing MomentsWhat causes an airplane to yaw? Summation of aerodynamic and inertial forces about the cg determines how an airplane pitches, yaws, & rolls. About the yaw axis the moments consists of a bunch of coefficients. Avoiding tequila shots and Tylenols the brain needs to absorb the gory math here's a nice (but not quite complete) diagram that mostly sums the main contributors to yaw.
What's of particular interest to us is what's labeled "adverse yaw". More completely we'll refer to it as yaw due to rolling. An airplane's roll and yaw are coupled for various reasons. If uncoordinated with rudder, when an airplane rolls it naturally yaws, usually in the opposite direction of the roll. This is known as adverse yaw. I'll leave it to the reader to read up on the intuition behind why this happens.
Dynamic Factors of Yaw Due to RollingWhat we want to do is unpack the variables behind it. Fortunately for us the propeller heads at NACA given us an equation to develop understanding. Here it is:
where Cl=lift coefficient, p=roll rate, b=wingspan, V=airspeed.
The first observation that's vital to make is yawing moment due to rolling like all things aerodynamic is not a STATIC value. It's DYNAMIC, meaning it increases or decreases as flight conditions change. With the Ta-152 for it to yaw out of flight means that the yawing moment increases to a point that it overcomes other yawing variables that could balance it out so we're interested in what increases yaw due to rolling.
The obvious variable for the Ta-152 is it's wingspan. Yaw due to rolling increases with an aircraft's wingspan. But this is a static value and we can't stop here. Adverse yaw also dynamically increases with increasing lift coefficient and roll rate, and with decreasing airspeed. Thus adverse yaw increases when an airplane performs maximum maneuvering (generating maximum lift and roll) at slower airspeeds, the more the maneuvering and the lower the airspeed, the greater the adverse yaw.
Max turning at high Cl, max rolling rates, slower speeds describe a broad range of maneuver fighting situations in AH. The Ta-152's longer wingspan exacerbates this. It's in exactly these situations a pilot needs to be more concerned to deal with the dangers.
This explains why Combat Trim increases adverse yaw as airspeed bleeds because elevator trim increases automatically which raises Cl to trim the plane for lower airspeeds. That's why flight tests with CT off the Ta-152 is not as adverse yaw twitchy compared to CT on because elevator stick input with CT on at slower airspeeds is at a higher initial Cl. Cross controlling also makes it worse. Opposite rudder input from roll in a barrel roll maneuver exacerbates the adverse yaw.
For our Ta-152 maximum maneuvering with rolling at slowing airspeeds without proper coordination appears to create enough yaw due to rolling to cause it to tail skid out of control. This is however easily avoided by either rudder coordination to offset and or pushing elevator down to reduce Cl while in a roll.
Real Life Ta-152 Flight TestsFrom the aerodynamics it seems explainable why our Ta-152 can depart out of controlled flight from yaw due to rolling. But what about real life flight testing of the flying qualities of the Ta-152? According to Dietmar Harmann, he summarizes in English the findings from 1944 Rechlin flight tests of the 152-H as thus (thank you moot for the citation):
Notice the statement "Stability about the vertical axis weak. Aircraft has a certain tendency to skid." This seems to describe the weak lateral stability that can lead to directional divergence I mentioned at the start of this post.
We could discuss further details but I'm plum out of time and energy
.