During Preflight, You Push the Right Aileron Down and the Left Also Goes Down — Is That Normal?

The Short Answer: Ground That Aircraft Immediately

When you push the right aileron down during your preflight walk-around and the left aileron also deflects downward, something is seriously wrong. That aircraft does not leave the ground until a certificated mechanic inspects and corrects the problem. This is not a judgment call, a write-it-up-and-see situation, or something you mention to your instructor after the flight. It is a flight-critical defect, and recognizing it confidently is exactly the kind of aeronautical decision-making your Designated Pilot Examiner wants to see on checkride day.

The Airplane Flying Handbook (AFH, FAA-H-8083-3) addresses control surface inspection and rigging verification as a deliberate, eyes-on process — not a casual glance while walking past the wing. Students who treat the preflight as a ritual rather than a genuine airworthiness check are setting themselves up for both a failed checkride and, far more seriously, a dangerous situation in the air.

How Ailerons Are Actually Supposed to Move

Ailerons are designed to work in opposition to each other, and that differential movement is fundamental to how an airplane rolls. When you apply right aileron input — or when you physically push the right aileron down during preflight — the left aileron must rise. When the left aileron goes down, the right must come up. Every time, without exception.

The physics behind this are straightforward. The aileron that deflects downward increases the camber of that wing, generating more lift. The aileron that deflects upward disrupts the smooth airflow over the opposite wing, reducing lift on that side. The resulting difference in lift between the two wings produces a rolling moment toward the wing with the raised aileron. This is how the aircraft banks — and it only works because the surfaces move in opposite directions.

A common point of confusion among students is mixing up aileron movement with flap deployment. Flaps extend symmetrically on both wings to increase lift and drag uniformly. Ailerons do the opposite — they move asymmetrically on purpose. If you find yourself thinking both control surfaces should go the same way, you are likely conflating these two very different systems.

What a Rigging Error Actually Means

When both ailerons deflect downward simultaneously, the control linkage or rigging has failed in a fundamental way. Rigging refers to the precise mechanical relationship between the cockpit controls and the control surfaces — the cables, pushrods, bellcranks, and associated hardware that translate your yoke or stick input into surface movement. When that system is misrigged, your control inputs will not produce the expected aircraft response.

Think about what this means in flight. You roll into a left bank on final approach and need right aileron to level the wings. You apply the input — but instead of the left aileron rising to reduce lift on that wing, it also deflects downward, adding lift. The aircraft does not respond the way physics demands. At low altitude with limited energy, that is a potentially fatal scenario. The FAA does not treat rigging errors as minor discrepancies, and neither should you.

During your oral exam, the DPE may follow up this question by asking what you would do next. The answer is clear: do not fly the aircraft, secure it, and report the finding to a mechanic immediately. Attempting to rationalize continuing the flight — even for a short local hop — demonstrates a misunderstanding of both airworthiness standards and pilot-in-command responsibility under 14 CFR Part 91.

What Most Students Get Wrong During the Preflight Control Check

The most common mistake students make is checking for binding or stiffness in the controls without actually verifying the direction of travel. They wiggle the yoke, confirm nothing feels stuck, and move on. That kind of check will not catch a rigging error. You need to physically observe each control surface as you move the controls through their full range of motion.

Here is a practical technique that works: stand at the tail of the aircraft and have a clear sightline to both ailerons while you or a partner moves the yoke. Confirm that right yoke input raises the left aileron and lowers the right. Then confirm the reverse. Do this methodically, not as an afterthought. The AFH is explicit that control surface inspection during preflight is a verification of correct rigging — not merely a check for physical obstructions.

Also worth noting: some students know that ailerons move in opposite directions in the abstract but cannot immediately articulate which way each surface goes for a given input. Your DPE may ask you to trace the full control chain from yoke input to surface response. Know it cold before you walk into that oral.

A rigging defect discovered on the ground is a success story. The same defect discovered at five hundred feet on takeoff is something else entirely. Your preflight is the last line of defense — treat it that way.

If you want to practice questions like this in a realistic oral exam format, try SimulatedCheckride.com.