The Parts Makers and the Used-Parts MarketThin moat
RTX (RTX) — moat facet
RTX admits that airlines and governments can buy parts from firms that never built the engine, and those rivals target the most profitable overhauls.
The most persistent threat to an engine maker's aftermarket is not another engine maker. It is the supplier of an approved alternative part, the shop that repairs a part instead of replacing it, and the dealer in used parts from retired engines. RTX's filing states the risk plainly: customers "may purchase parts from suppliers other than the original equipment manufacturer, which affects spare parts sales"1, and it names governments among those customers.
This rival has no counterweight. It does not buy from RTX, does not share programmes with it and does not need to win a competition at the point of sale. It targets the most profitable parts on the most mature engines, where the design is settled and the volume is high.
The V2500 and older Collins products are the obvious targets. The GTF, still young and still under long-term maintenance agreements, is less exposed today.
RTX's defence is certification and contracts. Long-term maintenance agreements lock the parts decision to Pratt & Whitney for the contract's life, and about 45% of RTX's remaining performance obligations are such contracts2.
The same filing notes that competition in engines includes "substantial discounts and other financial incentives"3 at the point of sale. The parts makers are the reason those discounts are risky: an engine sold cheaply in the expectation of aftermarket income is worth less if that income is shared with suppliers who paid nothing to win the engine.
The pressure would show in the price of spare parts rather than in volume. Watch RTX's commercial aftermarket growth, 18% companywide in the second quarter of 20264; growth that falls well below the growth in flying while airlines keep older aircraft in service would mean the parts makers are taking the most profitable work.
Long-term agreements protect the GTF; mature fleets more exposed.
Whether RTX keeps the overhaul; growth well below flying-hour growth would mean the parts makers are taking share.
Source: RTX Q2 2026 earnings call transcript ↗- ReportedRTX's filing states the risk plainly: customers "may purchase parts from suppliers other than the original equipment manufacturer, which affects spare parts sales", and it names governments among those customers.RTX Form 10-K for fiscal 2025 - Item 1A risk factors: competition on price, delivery and technology; customers buying parts from suppliers other than the original equipment manufacturer; discounts and guarantees to win engine positions; new defence entrants; GTF durability; reputational harm; pension sensitivity to the discount rate; tariffs. — FY2025 · publ. 6 February 2026 · source ↗
- ReportedLong-term maintenance agreements lock the parts decision to Pratt & Whitney for the contract's life, and about 45% of RTX's remaining performance obligations are such contracts.RTX Form 10-Q for the quarter ended 30 June 2026 - backlog of $289 billion ($170 billion commercial, $119 billion defence), remaining performance obligations, the $0.4 billion powder-metal accrual, the Blue Canyon Technologies sale, Patriot awards and the remaining repurchase authority. — Q2 2026 · publ. 23 July 2026 · source ↗
- ReportedThe same filing notes that competition in engines includes "substantial discounts and other financial incentives" at the point of sale.RTX Form 10-K for fiscal 2025 - Item 1A risk factors: competition on price, delivery and technology; customers buying parts from suppliers other than the original equipment manufacturer; discounts and guarantees to win engine positions; new defence entrants; GTF durability; reputational harm; pension sensitivity to the discount rate; tariffs. — FY2025 · publ. 6 February 2026 · source ↗
- ReportedWatch RTX's commercial aftermarket growth, 18% companywide in the second quarter of 2026; growth that falls well below the growth in flying while airlines keep older aircraft in service would mean the parts makers are taking the most profitable work.RTX second-quarter 2026 earnings call transcript (The Motley Fool) - Raytheon bookings and book-to-bill, GTF aircraft-on-ground and MRO output, munitions output, framework agreements, the defence budget request, GTF Advantage, Collins margin plans and segment outlook - commercial: GTF fleet, maintenance output, aftermarket, orders, Collins and the outlook. — Q2 2026 · publ. 24 July 2026 · source ↗