The loss of a primary flight control is something no pilot wants to experience. But if you do lose elevator control, there are some strategies you can use to keep your airplane in the sky.
But First, How Is The Elevator Controlled?
In many airplanes, the elevator is controlled by an "up" cable and a "down" cable. And according to the FAA's Airplane Flying Handbook, a break or disconnect in only one of these cables normally does not result in a total loss of elevator control. In most airplanes, a failed cable just results in a partial loss of pitch control. We'll dig deeper on this below.
Scenario 1: You've Lost "Up" Elevator Control
If the "up" elevator cable fails (the "down" elevator is intact and functional), the control yoke would move aft easily but produces no response. It'd feel similar to pulling the yoke back during a preflight check, with no airflow giving any back pressure feedback.
With the down elevator cable intact, forward control pressure would result in your aircraft pitching down.
If this happens to you, there are a few ways you can attempt to maintain nose-up pitch control:
- Applying considerable nose-up trim
- Pushing the control yoke forward to attain andmaintain desired attitude
- Increasing forward pressure to lower the nose and relaxing forward pressure to raise the nose
- Releasing forward pressure to flare for landing
Scenario 2: You've Lost "Down" Elevator Control
With a failure of the "down" elevator cable, forward movement of the control yoke produces no effect. If the "up" control cable is still intact, you should still have partial control of nose-up pitch attitude with aft control pressure.
If this happens to you, there are a few ways you can attempt to maintain nose-down pitch control:
- Applying considerable nose-down trim
- Pulling the control yoke aft to attain and maintain attitude
- Releasing back pressure to lower the nose and increasing back pressure to raise the nose
- Increasing back pressure to flare for landing
Trim Could Save You
If the entire linkage between the cabin and elevator fails in flight, the elevator could be left to weathervane freely in the wind. This can leave you with no nose-up or nose-down pitch control through the yoke or stick.
Fortunately, elevator pitch trim is often an isolated system with separate control cables. And by using the trim tab, you can move the elevator up or down. Trim becomes less effective at slow speeds, so if you're in a situation where you need use trim to control pitch for a landing, find the longest runway possible, and carry extra airspeed to the runway. Your airplane might will most likely be slow to respond to pitch up and down commands through trim, but at least you have some level of control.
Power Changes Can Help Too
Depending on how your airplane is built, changes in power or thrust settings will affect pitch attitude.
An airplane has a low thrustline when the line of thrust passes below the CG. When power is increased, the nose will have a tendency to pitch up in this case.
The opposite occurs when the line of thrust passes above the CG. When power is increased in these aircraft, the nose will have a tendency to pitch down.
Keep in mind that trim holds airspeed as well. Generally speaking, as you add power and accelerate, your plane will pitch up to maintain the airspeed you're trimmed for. The opposite is true as you slow down. If you reduce power, you'll decelerate, and your plane will pitch down to maintain airspeed.
What If Your Elevator Is Fully Jammed?
According to the AFH, if your elevator is completely jammed, resulting in a total loss of elevator control movement, various combinations of power and flap extension offer a limited amount of pitch control. How you control pitch through power and flap extension depends on your aircraft design, and successful landing under these conditions is challenging, but it can be done.
What Would You Do?
Throughout aviation history, there have a been a few accidents due to primary control system failures. In many examples, pilots were able to maintain aircraft control through abnormal power, flap, and trim settings.
Have you ever experienced a primary flight control failure? What would you do if one ever happened to you? Tell us in the comments below.
