No pilot thinks their flight controls are going to malfunction. Because let's face it...when was the last time you had a flight control failure? They're some of the most rare, yet dangerous emergencies out there.

From your very first flight lesson, you're taught as a new student pilot to do a flight controls check before you take off. So what leads a combined 30,000 hour Gulfstream IV crew to accelerate down the runway, fail to rotate, and subsequently crash due to gust-locked controls?

The Checklist

It doesn't matter what you fly, 1960 Piper Cherokee or 2016 Boeing 787. During one of your pre-takeoff checklists, there's always going to be a flight controls check. It might be found listed in checklists during pre-flight, run-up, just before takeoff, or within multiple checklists. Here's what you should look for:

• Check free and correct motion (flight controls are moving up, down, left, and right as they should).
• Make sure no unusual force is needed for movement (this means either abnormal pressure or looseness).
• Is the autopilot disengaging correctly or are there malfunctions?
• Listen for unusual sounds from cables, linkages, and pulleys.
• Check connection point strength and tightness.
• Make sure no foreign object debris could jam your controls.

What About Flaps?

Of the rare flight control failures, asymmetric flap settings are the most common. It happens when flaps descend, either commanded or un-commanded, and don't match the corresponding flap setting on the other wing. If uncorrected, it'll require substantial aileron and rudder input to attempt directional control and coordinated flight. In the worst cases at slow speeds, full control deflections often won't be enough to counteract the asymmetric flap aerodynamics and turning tendencies.

That's why you'll normally extend and check flaps during a pre-flight. If the flaps have trouble extending normally or the connections are loose, pre-flight is the best time to spot the issues.

Forgetting The Gust Lock

On May 31, 2014, Gulfstream IV N121JM accelerated to rotation speed during takeoff in Bedford, Massachusetts. Both the PIC and SIC had been flying the Gulfstream IV for 7 years at their charter company, amassing thousands of hours of experience in the aircraft. At 162 knots when the airplane failed to rotate, they tried to abort the takeoff with just 1,373 feet of runway remaining. Full braking and reverse thrust was not enough to prevent their airplane from overrunning the runway, crashing into a ravine, and killing all 7 aboard.

Prior to takeoff, the gust lock was not disengaged. The locked position should have prevented the throttles from being advanced to takeoff power, but for some reason the system failed. The NTSB stated that "A review of data from the airplane's quick access recorder revealed that the pilots had neglected to perform complete flight control checks before 98% of their previous 175 takeoffs in the airplane, indicating that this oversight was habitual and not an anomaly."

You read that right. In 171 recent takeoffs, this highly experienced Gulfstream crew failed to do a simple flight controls check on a 73,000 pound, $35 Million jet prior to takeoff. The sad part? It was such an easy problem to avoid. If this 30,000 hour professional crew can make a mistake like this, anyone can. Pilots aren't perfect, and more than a few of you reading this article right now will think back to the times you didn't check flight controls prior to takeoff. So to learn from this example, take the extra few seconds to fully check your flight controls before you taxi onto the runway. It's worth it.

In most Cessna single-engines, the gust lock is only connected to the control wheel. It protects the flight controls from fluttering during high winds on the ground. A metal flag covers part of the ignition switch, making it hard to forget as you start up the airplane. But if you do somehow forget to remove it and begin taxiing with rudder, there's nothing holding you back from accelerating down the runway without even realizing your controls are locked. You probably won't even realize what's happening until you keep trying to pull the yoke back without success.

Follow your checklist, and get in the habit of checking your flight controls thoroughly before you taxi on to the runway. They're the last things you want to fail on your airplane.

Have you ever had a flight control problem? Tell us in the comments below.