Mass & Balance (subject 031) is the EASA ATPL(A) exam that ensures an aeroplane is loaded within its weight and centre-of-gravity limits before every flight — the calculations that keep it controllable, efficient and structurally safe. This guide breaks the syllabus into its 5 official topic areas, shows how the concepts connect, and sets out a study plan to pass the exam at the 75% mark.
Mass & Balance is the practical discipline of loading an aeroplane so that it stays within its certified weight limits and its centre of gravity sits inside the approved envelope. Get it wrong and the aircraft can be unstable, hard to rotate or flare, short on performance, or overstressed — which is why every commercial flight is signed off against a completed mass and balance calculation. Because the subject is built on a small number of definitions and one core equation, it rewards a clean, repeatable method more than memorisation.
EASA structures the 031 syllabus into five topic areas, progressing from why mass and centre of gravity matter, through how an aircraft is loaded and its CG is determined, to cargo handling and the mass documentation that confirms the aeroplane is within limits for departure. The sections below walk through each one.
These are the official EASA topic areas for subject 031, in syllabus order. Each builds on the one before, so work them roughly in sequence rather than jumping around.
Every EASA ATPL(A) theory subject is passed at a minimum of 75%, and each subject is passed independently. Mass & Balance is calculation-heavy but self-contained, so the most reliable route to that mark is method-first:
Note: Exam rules — the pass mark, sittings and attempt limits — are set by EASA Part-FCL and applied by your national authority (NAA). Always confirm the current figures with your ATO/NAA before you plan, as they are periodically updated.
ATPL Training is an all-in-one platform for the theory phase: an ECQB-aligned question bank with worked explanations, structured lessons, built-in spaced-repetition review, and an AI tutor that explains the reasoning behind every answer — at around half the price of the established providers. For a calculation-led subject like Mass & Balance, that combination turns the method into exam marks.
Mass & Balance, EASA learning-objective subject code 031, is the ATPL(A) theory exam covering how an aeroplane is loaded within its weight and centre-of-gravity limits — the defined masses, loading and cargo limitations, centre-of-gravity calculation, and the mass documentation and load sheet used before every flight. It is examined as one of the 13 EASA ATPL theory subjects.
The 031 syllabus is built around five topic areas: the purpose of mass and balance considerations, loading, determination of centre-of-gravity position, cargo holding, and the mass and balance details of the aircraft. Together they progress from why mass and centre of gravity matter, through how an aircraft is loaded and its CG calculated, to the documentation that confirms it is within limits for departure.
Like every EASA ATPL(A) theory subject, Mass & Balance is passed at a minimum of 75%. Each subject is passed independently, so you only re-sit the exams you do not pass. Exam rules are applied by your national authority (NAA), so confirm the current figures with your ATO/NAA.
Mass & Balance is one of the shorter EASA ATPL subjects and is widely considered among the more approachable, but it is calculation-heavy: most questions ask you to work out a centre of gravity, a loaded mass, or whether the aircraft is within limits. Careful, methodical arithmetic with moments and arms — and lots of practice questions — is the reliable route to a comfortable pass.
Master the method before the volume: make sure you can build a moment (mass × arm) table, sum moments about the datum, and read the resulting CG against the forward and aft limits. Then drill ECQB-aligned questions — load-sheet completion, CG shift after loading or fuel burn, and in-limits checks — and review every explanation. Spaced repetition keeps the defined masses and formulae fresh right up to exam day.
Drill ECQB-aligned 031 questions with worked explanations, track your readiness across all five topics, and rehearse with full mock exams at the real 75% pass mark.
