AAR CORP (AIR) stock intrinsic value fair value estimate & owner earnings analysis

AAR is a 100-year-old aviation aftermarket company with about $3.3B of fiscal 2026 sales (year ended May 31, 2026). Roughly 45% comes from Parts Supply (exclusive or near-exclusive distribution of new parts for more than 20 aircraft-part makers, plus used parts), about 35% from Repair, Engineering and Software (airframe maintenance hangars in Indianapolis, Oklahoma City, Miami and elsewhere, component repair, and the Trax maintenance software), about 15% from Government Solutions (including the State Department aircraft-fleet contract and military pallets and shelters) and about 5% from a Legacy Commercial Programs unit being wound down after the fiscal 2026 decision to exit consumables and expendables. How we measure what it earns. We start from operating cash flow, strip out swings in working capital, subtract stock compensation as a real cost, and subtract the spending needed to keep the business running, including purchases of rotable parts pools (these are depreciated like equipment, so we treat them as capital spending). Because we credit almost no growth, we do not also charge the inventory and receivables the company chose to add to grow; holding cash flow flat is the counterpart of that choice. We value the business before its lenders and then subtract what it owes, so cash interest is added back. On that basis business cash flow was about $110M in fiscal 2024, $132M in fiscal 2025 and $220M in fiscal 2026. Fiscal 2025 carried a one-time $55.6M payment under the settlement of the Foreign Corrupt Practices Act investigation (December 2024, a non-prosecution agreement with the Justice Department and an SEC order, as disclosed in the company's fiscal 2025 10-K), so we treat it as about $187M. Because the March 2024 purchase of Triumph's Product Support business ($725M) made this a different company, we measure from fiscal 2025 onward and take the midpoint, about $203M a year. Earlier years, roughly $40M to $140M a year, describe a much smaller business. We did not count the $29.5M bargain-purchase gain on HAECO Americas or the $9.8M gain on the Wood Dale headquarters sale. The first quarter of fiscal 2027 (June to August 2026) supports that level: sales rose 24% to $918M, net income was $40.1M, and operating cash flow was $55.8M against a $44.9M outflow a year earlier, with inventory build slowing to $41M from $52M. Growth credited. Business cash flow rose about 17% in fiscal 2026 on an adjusted basis; we assume about +3% for year one (to about $209M), well below that. The reason for any lift at all is dated: four acquisitions closed part-way through fiscal 2026 (Aerostrat in August 2025, ADI in September 2025, HAECO Americas in November 2025 for $78M, Aircraft Reconfig Technologies in April 2026), and their full-year contribution is already showing in the first quarter. After that we credit no growth. Left out: management's target to double Trax software revenue, double-digit sales growth guidance, share gains and new distribution wins, because none is contracted or a long, steady record funded from the company's own cash. The company has also historically needed about 40 cents of extra working capital per added dollar of sales, so growth adds little value. Base case: about $209M a year held for 15 years, then fading evenly to zero over the next 15. The evidence for durability is positive business cash flow in every one of the last ten years including the 2020 pandemic, exclusive manufacturer distribution rights, and a firm backlog of about $777M. The business is worth about $2.49B; it owes about $0.83B (the $700M of 6.75% senior notes due March 2029, $200M drawn on the revolver that expires December 14, 2027, plus about $12M for the notes' coupon running above our yardstick, less roughly $60M of the $104.5M cash we consider surplus). That leaves about $1.65B, or $41.45 per share on about 39.9M diluted shares. Bear case: air travel has collapsed before; in the 2020 shutdown AAR's cash flow fell by more than half and stayed depressed for about two years. The bear case repeats that from year two: cash flow of about $195M in year one, then about $95M and $100M, after which it recovers only to about $140M (around two-thirds of today's level, still above the pre-Triumph range) because the State Department fleet contract ($92M of fiscal 2026 sales, already shrinking) is lost at its June 2028 renewal and the Legacy Commercial Programs exit removes more sales. That level holds for seven years then fades to zero by year 20. The downturn coincides with the March 2029 notes maturity and the December 2027 revolver expiry, so refinancing costs about 1.5 points more, adding roughly $70M to what is owed. The business is worth about $1.30B, it owes about $0.90B, leaving about $0.39B, or $9.85 per share. Even in the trough year, business cash flow of about $95M exceeds the roughly $60-65M annual interest bill, so lenders should keep extending credit, though with little room to spare. Bull case: the company's own levers execute. The expanded Oklahoma City hangar took its first aircraft in early 2026, the 114,000-square-foot Miami hangar is due in late 2026, and the acquisitions above reach full run-rate. Cash flow is about $220M in year one and $235M from year two, held for 20 years, then fades over 15. The business is worth about $3.06B, it owes about $0.83B, leaving about $2.23B, or $55.95 per share. What changed since our previous estimate (about $6.50 / $39.90 / $54.60): the business itself delivered a strong first quarter of fiscal 2027, with operating cash flow turning positive and sales up 24%, which slightly firms the year-one base level, and the August 2025 note add-on and current cash leave debt a little lower. In the bear case we now place the downturn alongside the 2027-2029 debt maturities and the 2028 State Department renewal explicitly, which leaves the bear value higher than before because the post-downturn level is set from the pandemic-era recovery rather than a flat cut. What could make this wrong. We tested the key assumption that a flat business needs no more inventory: in fiscal 2021 and 2022, with sales roughly flat to down, working capital still absorbed about $93M, partly the reversal of pandemic customer advances. If inventory must keep rising just to stand still, the base case is too high. Two full years after the Triumph deal is a short record, and fiscal 2026 may have benefited from unusually strong aftermarket demand while new aircraft deliveries lagged. Fiscal 2023 net income does not tie to cash flow by about $20M, which we attribute to discontinued operations. Margin of safety price. We are moderately confident in the earnings level: it rests on two full post-acquisition years plus a corroborating first quarter, but it is a cyclical business that has seen cash flow halve before. The worst plausible event is a deep aviation downturn arriving while $900M of debt matures between December 2027 and March 2029; the business has hard assets (parts inventory worth more than $1B of working capital, hangars) and exclusive distribution rights, and even the trough cash flow covers interest, so it should survive, but shareholders could face dilution, and in that world the shares would be worth around $10. If we are wrong about inventory needs or about fiscal 2026 being a normal year, a realistic level is closer to $160-170M, which would put value in the high-$20s. The business pays almost no dividend and has issued shares recently, so all the return must come from value being recognised; the price assumes a three-to-five-year holding period. At $23, base-case cash flow after interest equals roughly 14-15% of the price from the first year, enough that a recovery to even the low-$40s over four years implies about 20% a year, while the bear case implies a heavy but not complete loss. The margin-of-safety price is $23.