Please Help Me, I'm Stalling

I'm always amazed at the reportage of an aircraft accident. The talking heads frantically blather away on something they don't have a clue about which is sucked up in panic by the ignorati of their audience.

Then they cut away to live viddie from their newly post-adolescent affiliate in Diddle Widget, Iowa who interviews some fool on the street who saw a huge ball of flame erupt from the aircraft just as a group of flashing red and blue lights in a saucer shape went roaring back into the darkness. None of it is believable unless you have no background to start with.

Let's start with this breaking news on the Bombardier in Buffalo crash:

Pull UP, No Push DOWN, Ooops

First, let me note that in any multi-person crew, whether a two seat tactical fighter or an airliner, the banter will generally be viewed as innocuous by other aircrew members yet fraught with significance by Joe Sixpack. It is simply humans interacting routinely and nothing more should be read into it without significantly more background.

Then let's get to the key issue. The accident was apparently the result of significant ice build-up on the airplane.

From the earliest days of pilot training every student pilot learns that ice is bad for your airplane. It does two very significant things: it drastically increases the weight of your airplane thereby increasing the demand for increased lift to counter that weight. And, ice deforms the airfoils. Build-up of even the thinnest coat of ice on wings and tail surfaces will disrupt the airflow over those lift producing areas and effectively cut the ability to do their primary function. So, you need more lift because of the weight and your wings can't generate that lift because of the ice.

When an airplane needs more lift, the way to generate that lift is by increasing back-pressure on the controls to increase the angle of attack of the wing. Angle of attack is the usually slight angle between the airfoil and the direction of flight. Increase that angle and you generate more lift. Whether fast or slow, it is the wing angle that controls how much lift you produce. The generation of lift has a by-product in that it also produces drag.

It all works nicely until the point of diminishing returns. Increase angle of attack too much and you create a sudden rise in drag which greatly exceeds the further increases in lift. That point is called stall speed. The aircraft will then either begin to sink in a nose high attitude or it will pitch down enough to relieve the stall condition.

An aircraft stalls aerodynamically, not as a function of engine operation. An aerodynamic stall is exceeding the critical angle of attack. The solution to the stall is to reduce the angle of attack. Then the airplane starts flying again. It is simple, basic and taught to pilots on the first or second flight. The lessons are repeated in all aircraft for as long as one flys. All airplanes work the same way. If you are approaching a stall you ease off the control pressure--you let the nose drop. The fighter pilot cliche is, "unload for control."

Flying on autopilot, the system will try to maintain your altitude. That means as you get heavier with ice buildup the autopilot will try to raise the nose to counter the weight. You will slow down as drag builds. When you approach the stall there will be buffet and aerodynamic warnings. The autopilot will disengage and in most aircraft a beeper, horn or flashing light will alert the pilot. Then he does what he has learned from day one--get the nose down and gain some airspeed back.

That is the problem in this whole story. How did this pair of crew-dogs ever get so far in their brief careers without having that very basic principle beat into their insensitive skulls? How do you let the airspeed erode that much? How do you ignore all that ice? How do you not experience approaches to stalls and stick-pusher operation in a competent simulator program?

There were some real clankers made in this business and it goes well beyond the hapless crew.