AAR Corp. (AIR) Company Overview

AAR CORP. is an NYSE-listed aerospace and defense aftermarket company under ticker AIR. It keeps commercial and government fleets flying through parts supply, airframe and component repair, support programs, and maintenance software. Its official overview describes a global platform headquartered in the Chicago area.

Aircraft remain in service for decades, so airlines, militaries, OEMs, and lessors must continually source certified parts, inspect airframes, overhaul components, and document maintenance. AAR sits inside that recurring workflow. Demand follows fleet utilization, aircraft age, maintenance intervals, defense readiness, and technician availability more than new-aircraft deliveries alone.

How is the company organized now?

In May 2026, AAR realigned its reporting model into four segments: Parts Supply; Repair, Engineering, and Software; Government Solutions; and Legacy Commercial Programs. The change is analytically important because it groups distribution and used serviceable material together, combines physical maintenance with digital fleet-management tools, isolates government activities, and separates a lower-return pool of asset-heavy commercial contracts that management intends to wind down.

AAR earns revenue through related models. Parts Supply sells new and used serviceable components. Repair operations charge for labor, materials, engineering, and overhaul. Software generates license, subscription, implementation, and support revenue. Government Solutions earns contract revenue from maintenance, logistics, and mobility programs. Legacy programs earn flight- or repair-hour fees while requiring more AAR-funded assets.

What did the latest customer mix look like?

For the third quarter of fiscal 2026, commercial customers represented 73% of consolidated sales, while government customers represented approximately 27%. Commercial exposure therefore drives most near-term growth, but government activity provides a separate demand base tied to readiness, logistics, and program funding.

Which activity creates the strongest economics?

The answer is shifting. Under the prior structure, Parts Supply was the largest and highest-margin segment. Under the May 2026 realignment, LTM adjusted EBITDA margins through February 28, 2026 were 14.7% for Parts Supply, 12.7% for Repair, Engineering, and Software, 10.9% for Government Solutions, and 5.3% for Legacy. Winding down the last category reflects a clear judgment: inventory-heavy, low-return revenue is less valuable than distribution, repair, software, or contract expertise.

The newest completed period is the quarter ended February 28, 2026. AAR’s Q3 FY2026 release shows rapid demand- and acquisition-led growth, with leverage and cash conversion still central.

Where did the quarterly growth come from?

Commercial and government sales both increased. ADI and HAECO Americas contributed alongside flight activity, maintenance demand, and constrained aftermarket capacity, so researchers must separate organic expansion from acquired growth.

What does the annual baseline add?

The FY2025 Form 10-K provides the annual baseline: sales were $2.7805 billion, up 19.9%. GAAP operating margin was 6.7%, while adjusted EBITDA was $324 million at an 11.8% margin.

AAR’s history is useful only where it explains the current portfolio. The company evolved from a parts-trading origin into a broader aftermarket platform, then accelerated its transformation through software, component repair, distribution, and airframe-maintenance acquisitions. At the same time, it has sold or isolated activities that do not meet its desired return profile.

1. 1951
   AAR was founded around aviation parts and supply. That origin still appears in the sourcing relationships, inventory expertise, and rapid-response culture of Parts Supply.
2. 2018
   AAR began performing under the U.S. Department of State’s ten-year Worldwide Aviation Support Services contract, strengthening the government-program management capability that now sits in Government Solutions.
3. 2023
   The Trax acquisition added maintenance and fleet-management software supporting approximately 5,000 aircraft at announcement, giving AAR a digital relationship alongside physical parts and repair work.
4. 2024
   AAR completed the $725 million Triumph Product Support acquisition, materially expanding component repair and specialized product-support capabilities.
5. 2025
   AAR sold its Landing Gear Overhaul business and acquired ADI, Aerostrat, and HAECO Americas. The portfolio became broader in distribution, planning software, and airframe MRO while management continued pruning non-core assets.
6. 2026
   AAR added Aircraft Reconfig Technologies and announced the segment realignment and Legacy Commercial Programs wind-down, making return on invested capital a more visible strategic filter.

AAR’s strategic logic is the interaction among supply, maintenance, engineering, and data. A customer sourcing a component may also need inspection, overhaul, planning, records management, or long-term support. Repair work reveals failure patterns and parts demand; software improves maintenance visibility; distribution rights improve access to required components.

Where are the switching costs?

Switching costs are practical rather than purely contractual. Operators must qualify vendors, audit repair stations, integrate software, validate records, and manage safety risk. Reliable suppliers become embedded in routines. The effect strengthens when AAR provides linked services, because replacement can require changes to data interfaces, inventory processes, approved-vendor lists, and maintenance schedules.

How does the HAECO Americas expansion fit the model?

HAECO Americas expands airframe MRO scale at a time when maintenance capacity is constrained. At Investor Day, AAR described approximately $850 million of new contracts through 2030 and a significant sold-out capacity expansion. The strategic value is not only the added sales: more maintenance throughput can generate parts demand, component work, engineering needs, and software touchpoints.

AAR competes across fragmented markets, not against one identical rival. Its FY2025 filing identifies OEMs, airline-owned maintenance operations, and independent parts and MRO providers. Government bidders must also meet technical, security, performance, and pricing requirements. Competition is decided contract by contract and capability by capability.

Is AAR’s advantage durable?

AAR’s advantage is a portfolio of reinforcing resources, not one patent or brand. Scale supports inventory, tooling, training, and global service. Certifications and approvals create entry barriers; distribution agreements improve new-part access; used-material expertise broadens options; software and program relationships raise switching friction. Together, these capabilities create breadth that smaller specialists may struggle to match.

AAR has sufficient liquidity and improving leverage, but inventory, receivables, hangars, tooling, acquisitions, and legacy assets absorb capital. EBITDA must convert into cash fast enough to reduce debt while funding expansion.

Why is cash conversion the key financial test?

Q3 FY2026 operating cash flow improved materially, but inventory remained $958.2 million at February 28, 2026. Inventory supports service levels and parts margins, yet it can trap cash or become obsolete. Cash conversion should therefore be judged across several quarters, not from one favorable working-capital movement.

How is capital being allocated?

Capital allocation favors acquisitions and capacity over dividends. After paying $725 million for Triumph Product Support, AAR added ADI, HAECO Americas, Aerostrat, and ART. A fiscal 2026 equity offering diluted shares but supported investment and deleveraging toward a 2.0x-2.5x target.

AAR has one common share class with one vote per share, not founder super-voting control. The 2025 proxy shows dispersed but institutionally concentrated ownership, giving large asset managers influence through elections, pay votes, and engagement rather than operating control.

What governance signals deserve attention?

The proxy reported 11 of 12 directors as independent and a staggered board. Independence supports oversight of acquisitions, leverage, risk, and pay. Classification provides continuity during integration but slows full-board replacement. Without founder control, capital-allocation credibility and board challenge matter especially.

AAR benefits from fleet growth, older aircraft, constrained maintenance capacity, and outsourced supply demand. Growth also requires technicians, inventory, hangars, systems integration, and working capital, so capacity and cash returns must be tracked together.

Which growth drivers could change the earnings path?

What risks could weaken the outlook?

Why does this matter for valuation?

A DCF should model organic growth, segment mix, EBITDA margin, working capital, capex, integration costs, taxes, dilution, and deleveraging—not revenue alone. Exiting Legacy could raise returns while reducing transition revenue; contract awards matter only when funded demand becomes margin and cash.

AAR occupies the operational layer between aircraft owners and the aftermarket resources required to keep fleets available. Parts access, certified repair, engineering, government programs, and maintenance software can create cross-selling and switching costs, especially when aviation demand exceeds labor and facility capacity.

The current story is also a capital-efficiency test. Sales and adjusted EBITDA are growing, net leverage has improved to 2.17x, and the new segments clarify the higher-margin core. Yet inventory is large, integration is extensive, and Legacy programs contain approximately $160 million of net assets to release over several years.

AAR is a useful case in related diversification: parts, repair, software, and government services reinforce one another only if coordination earns returns above the cost of capital. The decisive evidence is organic growth, segment margin, repair throughput, working-capital discipline, cash conversion, the Legacy wind-down, and leverage control—not revenue growth alone.