An aircraft maintenance mechanical reasoning test checks whether you can apply basic physics to practical problems: levers, gears, pulleys, pressure and simple circuits. Employers recruiting engineering apprentices and maintenance technicians use it because the job asks you to reason about how components move and load each other long before you hold a licence.
The questions are usually pictures with a short question underneath. You might see two gears and be asked which way the second one turns, or a beam with weights on it and be asked where the pivot must go. You do not need to memorise formulas from a textbook, but a handful of principles will carry you through most of it.
Why maintenance employers test mechanical reasoning
Aircraft engineers spend their careers working with forces, moments, hydraulics and electrics. The European basic knowledge syllabus for a Part-66 aircraft maintenance licence includes a physics module covering forces, moments, centre of gravity, pressure and mechanical advantage, and an electrical fundamentals module that includes Ohm's law. Another module covers gear ratios, idler gears, belts and pulleys, and control cables.
A selection test is not a licence exam. It simply gives the employer an early sign that you will cope with that material when training starts. If you are thinking about the wider career, our guide to becoming an aircraft engineer sets out the route.
The topics that come up most
Levers and moments
A moment is a force multiplied by its distance from the pivot. When a lever balances, the moments on each side are equal. Longer arm, less force needed.
Gears
Meshing gears turn in opposite directions. A small gear driving a larger one makes the larger gear turn more slowly but with more turning force. An idler gear placed between two others makes the last gear turn the same way as the first, without changing the speed ratio between them.
Pulleys
A single fixed pulley only changes the direction of pull. Each extra rope section supporting a moving pulley shares the load, so two supporting sections halve the effort (ignoring friction), but you pull twice as much rope.
Pressure and fluids
Pressure is force divided by area. In a closed hydraulic system the pressure is the same throughout, so a larger piston produces a larger force. This is the idea behind hydraulic jacks and many aircraft systems.
Electrical basics
Voltage equals current multiplied by resistance (Ohm's law). Resistors in series add up. In parallel, the total resistance is lower than the smallest single resistor, and switches decide which paths carry current.
A worked example with working
Question. A technician uses a straight bar 1.5 m long to lift the edge of a heavy panel. The pivot sits 0.3 m from the end under the panel, and the panel presses down on that end with a force of 600 N. What force must the technician apply at the other end to balance it?
Step 1: find each distance from the pivot. The load is 0.3 m from the pivot. The effort is applied at the far end, so its distance is 1.5 m minus 0.3 m, which is 1.2 m.
Step 2: work out the moment of the load. Moment equals force multiplied by distance: 600 N × 0.3 m = 180 N m.
Step 3: set the moments equal and solve. For balance, effort × 1.2 m must also equal 180 N m. So effort = 180 ÷ 1.2 = 150 N.
Step 4: check it. 150 N × 1.2 m = 180 N m, which matches the load's moment. The bar gives a mechanical advantage of 600 ÷ 150 = 4, which makes sense because the effort arm is four times longer than the load arm.
Answer: 150 N.
The habit worth copying is the check at the end. If the effort you calculate is larger than the load on a lever where your arm is longer, something has gone wrong.
How to prepare
Relearn the principles, not the trivia. Moments, gear direction and speed, pulley sharing, pressure equals force over area, and Ohm's law cover a large share of what you will meet. A secondary school physics revision guide is enough.
Draw it out. Sketch arrows for forces and turning directions. For gear trains, mark each gear clockwise or anticlockwise in turn rather than trying to see the whole chain at once.
Use the answer options. Many questions can be narrowed by sense checking. If a heavy weight balances a light one, the heavy weight must sit closer to the pivot, so any option that puts it further away can go.
Practise under time. Untimed, most people do well. The pressure comes from moving quickly between different topics. Timed sets on our mechanical reasoning practice page help you get used to switching between gears, levers and circuits.
Prepare for the other tests too. Maintenance selection may also include numerical or spatial tests, interviews and technical questions. Our articles on breaking into aircraft maintenance and preparing for an aircraft maintenance interview cover the next stages.
On the day
Read every question in full, because small words such as "fixed", "idler" or "parallel" change the answer. Do not spend long on one diagram. Mark your best answer, move on, and return if time allows. Calm, steady working usually scores better than rushing the first half and guessing the rest.
