You got that right.
You’re thinking and the thinking is good. One would not want to fight a pusher during a tailplane stall – but one might have no choice.. Now lets think some more with relation to the specific accident and see if you can answer your own question..
Hypothetical Scenario
The aircraft is approaching the terminal area. The pilot requests a descent to 6000 ft and is cleared. During the descent the aircraft enters icing conditions. Anti-ice and de-ice systems are activated (correctly) and are functioning (assumed – we don’t know yet).. The crew observes ice accretion and comments about it.; confirms that anti/de-ice is on. Shortly thereafter the aircraft is cleared to 4000 ft and then to 2300ft and for the approach. The aircraft is being flown by the auto pilot.
During the descent from 4000 to 2300 the aircraft enters a localized zone of heavy icing. The aircraft reaches 2300 ft shortly before the outer marker. Altitude is captured and held by the auto pilot. The leading edges are relatively clear of ice – boots working – but a great deal of ice has been accumulated on un-protected areas and behind the boots (due to run-back or flow-back). The crew cannot see this ice and is unaware of its existence. It is both snowing and raining and the temperature is below freezing. The weight of the aircraft has also increased significantly above the calculated landing weight – due to the ice accretion. There is some SLD in the area the aircraft is crossing. The ice accretion is mixed (some rime, some clear).
As the aircraft levels, the auto-pilot trims nose up to hold the altitude as the speed decreases. The nose up trim continues slowly unnoticed by the crew. The auto pilot is also inducing aileron trim at the same time – to keep the wings level - also unobserved. Airspeed decreases further. Glide slope is alive and the captain commands “gear down:” Airspeed is within limits and somewhat higher that intended approach speed. As the gear extends, drag increases, auto pilot inputs some more nose up trim. Flap speed is reached (upper limit).
Unknown to the flight crew, the AOA on both the horizontal stabilizer (neg.) and the wing are each very close to critical. There is turbulence and the yoke is moving back and forth quite a bit. Subconsciously the yoke movement is attributed to the turbulence – but its actual cause is tailplane icing. Glide slope captures and the captain commands “approach flaps” (whatever that might be). The auto pilot is still flying – this is a coupled approach.
As soon as the flaps extend the tailplane stalls and the autopilot disconnects. At the same time a wing drops – due to ice-induced roll that the autopilot was compensating for. The nose pitches up (due to the nose up trim input by the auto pilot). The captain initially counters the pitch-up with nose-down pressure, which agravates the tail stall.
The captain quickly recognizes the tail plane stall, commands “flaps up” and pulls on the yoke. At the same time he is countering the roll with extreme opposite aileron.
Now the wing stalls – shaker activates followed immediately by pusher. [Remember – attitude and AOA are two different things – a wing stall can occur at any attitude or airspeed.]. Pusher activation causes the tail to stall again. Recovery by nose up control input is attempted a second time, the wing stalls again and the pusher activates for the second time. Pitch and roll excursions are severe. In the process direction has changed by close to 180 deg. By this time 1200 ft of altitude has been lost – the aircraft drops off radar. Pitch attitude is 30 – 40 deg. Nose down.
The aircraft breaks out – perhaps a bit earlier. Wings are now level but sink rate is 2500 fpm or more. The pilot is still flying but now sees the terrain. Both pilots pull as hard as they can. The aircraft flattens in pitch and strikes the terrain in a level attitude with an extremely high sink rate.
What has occurred is what we call an upset. It happened when the aircraft was only 1500 ft agl. At that altitude, recovery is impossible – regardless of what the pilots may have done. Time from upset to impact – probably much less than 30 seconds. It takes much longer to write or read this than it does for the scenario to play itself out.
Fate is the Hunter.
Could this accident have been avoided? YES – but not after the upset occurred.
Probable cause? Draw your own conclusions. The above scenario is only hypothetical.