If your elevator trim jams or stops responding, here's how to handle it from cruise flight to landing...

Your Elevator Trim Just Jammed

While jammed trim isn't something you'd usually think of as a "dire" situation like losing aileron or elevator authority, it can still be an emergency situation. Fortunately, elevator pitch trim is often an isolated system with separate control cables. The jam shouldn't affect your elevator control directly.

If you continue trimming, your controls might get stuck in a progressively worse, unrecoverable state. Stop trimming immediately (in either direction), maintain aircraft control, and pull out your checklist or POH.

How Trim Affects Your Aircraft

Trim holds airspeed. If you trim for a speed and let go of the yoke, your plane will keep flying at that speed, regardless of your power setting. If you trim and change your power, your plane will pitch up or down to maintain your trimmed speed. But broken pulleys, cables, hydraulics, or even FOD in the cockpit can render a trim system unusable.

So what should you do if your trim jams?

The First Step: Slow Down

The control input pressure you need on the yoke/stick decreases the slower you go, so in general, the slower you fly, the easier it is to manage the controls. You'll still have to fly using more manual force than you may be used to, but flying slower than normal in cruise flight will help reduce the strain.

Use Flaps When You Need To

If you're stuck with too much nose-up trim, flaps might help lower the nose of your aircraft. That's because, in many aircraft, increasing flaps causes a nose-down pitching moment.

If you're stuck with too much nose-down trim, adding flaps could have the opposite effect, so you may want to limit your flap use to partial or no flaps.

This is one of the easiest ways you can counter jammed trim, and it can relieve a substantial amount of control pressure you've been maintaining.

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 thrust line 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 thrust line passes above the CG. When power is increased in these aircraft, the nose will have a tendency to pitch down.

Keep in mind, though, 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.

Be Prepared For A Go-Around

If you haven't done them before, ask your instructor to demonstrate elevator trim stalls. They're stalls caused by adding full power when flying with substantial nose-up trim, without proper forward pressure on the controls to prevent a high pitch attitude as full power is added.

Imagine flying a perfectly trimmed, hands-off approach to the runway. Elevator trim stalls are supposed to replicate what would happen during a go-around with this kind of trim setting and not enough forward pressure on the yoke. If your trim is jammed, you won't have the option to re-trim, so do your best to anticipate these strong control forces in the event of a go-around.

Add power more gradually than you might with a conventional go-around.

Has this happened to you? Let us know if you've had problems with a trim system in the comments below.