How Flying Works
What a Stall Actually Is (It’s Not About Losing Power)
On approach to Buffalo on 12 February 2009, Colgan Air Flight 3407’s stick shaker activated — a violent vibration built into the control column specifically to warn a pilot the wing is approaching its critical angle. The captain’s response was to pull back on the controls and add power, the instinctive reaction of someone trying to climb away from danger. It was exactly the wrong input. The aircraft, a Bombardier Q400 operated for Continental Connection, stalled and crashed into a house in Clarence Center, New York, killing all 49 aboard and one person on the ground. The NTSB’s finding was direct: the probable cause was the captain’s inappropriate response to the stick shaker. Understanding why that response was wrong means understanding what a stall genuinely is — and it has almost nothing to do with what most people assume.
It's an angle problem, not a power problem
A stall is not the engines cutting out, and it is not simply “flying too slowly.” It's a purely aerodynamic event, defined by the angle of attack — the angle between the wing's chord line and the oncoming airflow, not the angle between the aircraft and the horizon. Every wing has a critical angle of attack, typically somewhere around 15-18 degrees depending on the airfoil, beyond which the smooth airflow over the top of the wing separates, collapses into turbulent burbling instead of a clean stream, and lift drops off sharply. Below that critical angle, a wing can be stalled at almost any speed if the angle is wrong; above it, the wing keeps producing lift regardless of how slow the aircraft is going. A glider with no engine at all can fly for hours without ever stalling, provided its angle of attack always stays under that critical threshold — which is the cleanest proof that engine power was never really the variable that mattered.
The warning built specifically to stop this
Because a stall is preventable right up until the critical angle is actually reached, modern aircraft carry layered warnings built to intervene before it happens. A stick shaker physically vibrates the control column as the aircraft nears the critical angle — an unmistakable, impossible-to-miss tactile alert. On some aircraft, including the Q400 that Colgan 3407 was flying, a further layer exists: a stick pusher, which automatically pushes the control column forward — reducing angle of attack directly — if the pilot doesn’t respond to the shaker in time. Neither pilot on Flight 3407 had trained on stick pusher activation in a simulator, since the FAA did not mandate it at the time; a jarring, unfamiliar automatic input during an already high-stress approach, on top of icing conditions the crew had discussed just before the accident, compounded an already difficult moment.
Why the instinctive response is exactly backwards
Pulling back on the controls raises the nose, which increases angle of attack — taking the wing closer to, not further from, its critical angle. It feels like the natural response to a warning that something is going wrong with lift, but it does the opposite of what recovery actually requires. The correct response — lower the nose to reduce angle of attack and reattach airflow, then add power to help — is drilled into every airline pilot specifically because the instinctive reaction under pressure runs the wrong way. Colgan 3407 remains one of the clearest, most consequential real-world demonstrations of exactly that gap between instinct and correct technique, and it directly changed US training requirements for stick pusher familiarization afterward.
Sources & Further Reading
Common Questions
Frequently Asked Questions
Can a plane stall with the engines running fine?
Yes, easily — a stall is entirely about the angle between the wing and the oncoming air, not about engine power. An aircraft with both engines at full thrust can still stall if the nose is pitched up too steeply; conversely, a glider with no engine at all can fly for hours without ever stalling, as long as its angle of attack stays below the critical angle.
Does a stall mean the plane falls out of the sky?
It means the wing stops producing enough lift at that angle, not that the aircraft becomes an unresponsive brick. Recovery is a well-defined, heavily trained procedure — reduce the angle of attack (usually by lowering the nose) to reattach airflow over the wing, and add power to help. Every airline pilot drills this in the simulator specifically so the correct response is automatic under pressure.
What is a stick shaker and a stick pusher?
A stick shaker physically vibrates the control column as the aircraft approaches its critical angle of attack — an unmistakable tactile warning before the actual stall. A stick pusher goes further: on some aircraft, it automatically pushes the nose down if the pilot doesn't respond, overriding manual input specifically to prevent a full stall. Colgan 3407's crew experienced a stick shaker and, later, a stick pusher — and had never trained on the pusher's activation in a simulator.
Why did pulling back make things worse on Colgan 3407?
Pulling back increases the angle of attack, which is the exact opposite of what a stall recovery requires — it pushes the wing further past its critical angle rather than back below it. The NTSB's official finding was that the captain's inappropriate response to the stick shaker, pulling back instead of pushing forward, caused an aerodynamic stall the aircraft did not recover from.