Airline Cases 2026: Break-Even Load Factor, Worked

The unit that makes airline case arithmetic behave

Airlines measure everything per available seat kilometer, written ASK. Revenue per ASK is RASK, cost per ASK is CASK, and the operating margin is the gap between them. Yield is revenue per revenue passenger kilometer, written RPK, which counts only seats that were sold.

The relationship you need in your head is short. RASK equals yield times load factor. That is the whole reason load factor cannot be read alone: it is one of two factors in the revenue side, and moving it at the expense of the other gets you nowhere.

The Bureau of Transportation Statistics publishes all three for US carriers from its T-100 segment data. In 2025 the reported load factor was 81.89 percent, against 69.86 percent in 2021 and 83.27 percent in 2024, checked 30 September 2026 at transtats.bts.gov. The same page carries 1,640,852,770 thousand revenue passenger miles and 2,003,716,834 thousand available seat miles for 2025. Dividing the first by the second gives 81.890 percent, which reproduces the published figure to three decimals. That check is worth doing once, because it fixes the definition in memory better than a sentence can.

Splitting the cost base in an airline case by what triggers it

Here is the prompt. Meridian Air flies one route pair with 180 seat aircraft over a 2,000 kilometer stage length, ten flights a day, 350 days a year. The chief executive wants to know whether the route earns its keep.

Every figure below is an assumption we are posing, and you should label yours out loud the same way. The Bureau publishes seat miles and passenger miles. It does not publish a cost split between capacity and passenger, which is the split a case actually needs.

1. Capacity. 180 seats times 2,000 kilometers is 360,000 ASK per flight. Ten flights a day for 350 days is 3,500 flights, so 1.26 billion ASK a year.
2. Yield. 8.0 cents per RPK.
3. Capacity cost. 5.1 cents per ASK, covering fuel, crew, aircraft ownership, navigation and airport charges.
4. Passenger cost. 1.125 cents per RPK, covering catering, distribution fees and bag handling.
5. Hurdle. The route has to cover its own capacity cost.

At an 80 percent load factor, RPK is 1.008 billion. Revenue is 1.008 billion times 8.0 cents, so $80,640,000. Capacity cost is 1.26 billion times 5.1 cents, so $64,260,000. Passenger cost is 1.008 billion times 1.125 cents, so $11,340,000. Total cost is $75,600,000, which is a CASK of 6.0 cents, and operating profit is $5,040,000 on a 6.25 percent margin.

Two points of load factor, and six bought with a discount

Now move the load factor from 80 to 82 and hold the fare. RPK becomes 1.0332 billion, revenue becomes $82,656,000, and passenger cost becomes $11,623,500. Capacity cost does not move, because the flights were already scheduled.

Operating profit becomes $82,656,000 minus $64,260,000 minus $11,623,500, so $6,772,500. That is $1,732,500 more than before.

Read the two changes side by side. Revenue rose 2.5 percent. Operating profit rose 34.375 percent, call it roughly 34 percent. The ratio of the two is 13.75, and that ratio is the operating leverage of this route. It exists because $64,260,000 of the $75,600,000 cost base did not respond to the extra passengers at all.

The same arithmetic runs backwards, which is what makes airline cases dangerous. Two points of load factor lost take a third of the profit out.

This is where most candidates lose the case, and the mistake is a good one to understand rather than memorize. Load factor is trivially bought with fare cuts, so it rises on its own whenever an airline discounts hard.

Take the same route and fill it to 86 percent by cutting the yield from 8.0 cents to 7.3 cents. RPK becomes 1.0836 billion. Revenue becomes $79,102,800 and passenger cost becomes $12,190,500, so total cost is $76,450,500 and operating profit is $2,652,300.

Load factor rose six points and operating profit fell 47.4 percent. In per seat kilometer terms, RASK went from 6.400 cents to 6.278 cents while CASK went from 6.000 to 6.067, so the gap collapsed from 0.400 cents to 0.211 cents. A candidate who reports the load factor improvement without the yield has reported the symptom of a price war as though it were a recovery.

The break-even load factor in an airline case, solved twice

Set operating profit to zero and solve for load factor. Contribution per RPK is 8.0 minus 1.125, so 6.875 cents. Multiply by 1.26 billion ASK to get $86,625,000 of contribution at full occupancy. Divide the $64,260,000 capacity cost by that and the break-even load factor is 74.18 percent, call it roughly 74 percent.

Now redo it at the discounted 7.3 cent yield. Contribution per RPK falls to 6.175 cents, full occupancy contribution falls to $77,805,000, and the break-even load factor rises to 82.59 percent.

Less than a cent of yield moved the break-even bar by 8.4 points. So a break-even load factor quoted without the yield it assumes is not a number, and the follow-up question that earns credit is which fare the figure was computed at.

Fuel, and the threshold an airline case has to clear

Fuel sits inside the capacity term, and it is the one input that moves against the airline after the schedule is published. Suppose 2.0 of the 5.1 cent capacity cost is fuel.

The Energy Information Administration puts Gulf Coast kerosene-type jet fuel spot at $2.024 a gallon in August 2025 and $3.724 in August 2026, checked 30 September 2026 at eia.gov. That is a factor of 1.84, a rise of roughly 84 percent. Applied to a 2.0 cent line it adds 1.68 cents per ASK, and on 1.26 billion ASK that is $21,168,000.

Against an operating profit of $5,040,000, the fuel move alone is 4.2 times the whole result. Say that number out loud in a case. It tells the interviewer that the route's viability is decided in a commodity market the client does not participate in, and it reframes the recommendation from a pricing question to a hedging and fleet question.

For scale on how far capacity heavy industries swing, the Federal Reserve's own release of 18 September 2026 puts total industry capacity utilization at 76.3 percent against a 1972 to 2025 average of 79.4 percent, published at federalreserve.gov.

Before computing anything, ask what bar the answer is measured against. This matters more than it sounds, because published cases disagree. Oliver Wyman's own practice case refuses an entry that earns money, because it "does not align with the client's investment criteria for a five-year payback period", checked 30 September 2026 at oliverwyman.com.

A route that covers its capacity cost passes one bar and fails another. Three bars are in common use: cover capacity cost this year, cover capacity cost plus a return on the aircraft, or return the aircraft's capital inside a stated number of years. Name the one you are using in your first sentence.

Where the points go on a route case

The weights below are ours, read from the rubric code in src/lib/grading, and no consulting firm publishes a rubric of its own.

Drilling an airline case until the unit is automatic

Rework the route with the stage length halved to 1,000 kilometers and everything else held. ASK halves to 630 million, capacity cost halves to $32,130,000, and the break-even load factor is unchanged at 74.18 percent, because both sides of the ratio scaled together. That result is worth deriving by hand once, because it shows which inputs the break-even bar actually depends on.

Then change the aircraft to 220 seats at the original stage length. ASK becomes 220 times 2,000 times 3,500, so 1.54 billion, and capacity cost at 5.1 cents becomes $78,540,000. Contribution at full occupancy is 1.54 billion times 6.875 cents, so $105,875,000, and the break-even load factor is again 74.18 percent. The bar moves only when yield or a per unit cost moves.

Our break-even calculator does that algebra, and the math drill times this kind of chain and reports Answer, Working, Units and Interpretation separately. Both are free and need no sign-in. For the structuring half, run a timed prompt in the structuring drill, and the weights and reasoning are on how an answer is assessed.

For the sibling industries where capacity is also bought before demand arrives, see energy cases and automotive cases. For the case where the airline is already losing money and you have to find out why, see revenue decline cases.

Experience, and the gaps we left open

We looked for a first-hand account of an airline case from a candidate and found none we can cite. Reddit refuses connections from this network, and the session had no transcript tooling for video accounts. The firms that publish practice cases publish no candidate write-ups about them: McKinsey's two recruiting blog posts and Oliver Wyman's two consultant profiles all discuss the process in general. Competitor preparation blogs describe airline cases at length and are not citable sources.

Four gaps are worth naming, because a case turns on all four and none of them is public.

The Bureau of Transportation Statistics publishes seat miles, passenger miles, load factor, operating revenue and net income. It publishes no cost split between capacity and passenger, so the 5.1 cent and 1.125 cent lines above are ours, posed as assumptions and labeled as such.

No carrier publishes its own break-even load factor by route. Aircraft ownership cost is the largest single line inside our capacity term and it is a lease or financing structure, so it varies by carrier and is not disclosed at route level. No firm publishes a threshold for approving a route, which is exactly why the opening question of this page is which bar the client applies. And no one publishes what share of case interviews are airline cases, a figure asserted widely and measured nowhere.