MADISON DEARBORN PARTNERS LLC 4

What Happened

• Madison Dearborn Partners LLC (reported as a 10% owner via affiliated entities) sold 2,273,843 Class A shares at a net offering price of $25.99 on June 5, 2026 — proceeds of about $59.1 million. These sales were reported in connection with AEVEX’s registered offering.
• Related transactions included distributions of small lots of Class A shares to limited partners, and the sale/disposition of 4,757,448 Series B Units (exchangeable for Class A shares one-for-one) to the issuer at $25.99 per unit (approx. $123.6M). Several other pro rata distributions of Class B shares and Series B Units to entities controlled by the Madison Dearborn funds are also reported.

Key Details

• Transaction date: June 5, 2026; reported on Form 4 filed June 8, 2026.
• Price: $25.99 per share/unit for the primary reported transactions.
• Principal open-market sale: 2,273,843 Class A shares for ~$59,097,180.
• Series B Units sold to the issuer: 4,757,448 units at $25.99 (≈$123.65M) per footnote describing the offering.
• Shares owned after transactions (per filing footnotes): entities controlled by Madison Dearborn hold 22,694,184 Class A shares (ATS PubCo Holdings) and 164,662 Class A shares (ATS Management Holdings); ATS Investment Holdings holds 57,153,106 Class B shares/Series B Units and ATS Management Holdings holds 411,724 Class B shares/Series B Units.
• Notable footnotes: sales and distributions occurred in connection with AEVEX’s S-1 offering (Registration No. 333-296396). Series B Units are exchangeable for Class A Shares on a one-for-one basis and do not expire.
• Filing timeliness: Form 4 was filed 2026-06-08 disclosing transactions dated 2026-06-05.

Context

• This filing reflects institutional transactions tied to the company’s registered offering and internal distributions among Madison Dearborn-controlled entities — not a typical insider purchase/exit by an individual executive. As a 10% owner and fund general partner, Madison Dearborn’s movements are corporate/institutional actions (offer-related sales and distributions), not routine employee trades.
• Series B Units are derivative/exchangeable instruments (one-for-one for Class A). The dispositions of Series B Units to the issuer and the pro rata distributions are part of the offering mechanics, per the filing’s footnotes.