Aircraft Engine and Engine Parts Manufacturing (U.S.) — NAICS 336412

An investor's primer. Figures are the most recent available; forward-looking statements are framed as judgments, not facts.

1. Overview

This is the industry that designs, builds, tests, and overhauls the engines that propel aircraft — the turbofans under an airliner's wings, the turboshafts in helicopters, the afterburning fighter engines in military jets, and the small turbofans on business jets — plus the high-value parts inside them (turbine blades, discs, combustors, fuel systems). It is one of the most concentrated, most capital-intensive, and most profitable corners of manufacturing anywhere. Just four companies build roughly 97% of the world's large commercial engines [4], and building a clean-sheet engine takes on the order of eight years and billions of dollars before the first one is certified [17].

Why an investor cares: an aircraft engine is sold near cost — sometimes at a loss — and then earns money for 20–40 years through mandatory overhauls and proprietary spare parts at rich margins. RTX explicitly states that certain commercial OEM products are sold at a loss when the combined OEM and aftermarket campaign is expected to be profitable [28]. It is one of the best "installed-base annuity" business models in the economy, and it is currently in a multi-year aftermarket upcycle as a huge, heavily used global fleet comes due for shop visits.

• Public-market route: buy the engine makers (GE Aerospace, RTX's Pratt & Whitney) or the component and aftermarket specialists (Howmet, ATI, HEICO, TransDigm, Woodward, StandardAero). See sections 4 and 10.
• Private route: private equity owns much of the parts and maintenance supply chain (Apollo took Barnes Group private in 2025 [12]; Carlyle floated StandardAero), and spare-engine leasing and part-out is a distinct asset class. See section 10.

2. What it is and how it's structured

Scope (what's in 336412). The U.S. Census defines this industry as establishments that primarily manufacture aircraft engines or engine parts, build prototypes, perform major propulsion-system conversions, or overhaul and rebuild propulsion systems to original specifications [1][25]. So the code captures both the factories that assemble engines and, importantly, much of the parts and overhaul activity around them.

What it excludes (name the neighbors). The classification deliberately draws tight lines. Census places ordinary engine repair, stand-alone research without prototype production, aeronautical instruments, and certain items such as aircraft-engine pistons, valves, and filters in other industries [25]:

• NAICS 336411 — Aircraft Manufacturing: the airframe and the complete airplane. The engine maker and the airframer (Boeing, Airbus) are different businesses.
• NAICS 336413 — Other Aircraft Parts and Auxiliary Equipment: landing gear, propellers, and non-engine parts.
• NAICS 336415 — Guided Missile and Space Vehicle Propulsion Units and Parts: rocket and missile engines belong here, not in 336412, even though the technologies overlap.
• NAICS 333611 — Turbine and Turbine Generator Set Units: land-based industrial gas turbines for power generation (e.g., the units GE Vernova sells), even though many derive from aero-engine cores.
• NAICS 336310 — Motor Vehicle Gasoline Engine and Engine Parts: aircraft carburetors, pistons, piston rings, and valves are specifically excluded from 336412 and classified here [1].
• Some third-party maintenance and airline in-house engine work is classified in air-transport support (NAICS 488190) or repair codes rather than here.

Ownership mix. The revenue sits with a handful of large, mostly publicly traded corporations and their joint ventures: GE Aerospace and RTX (Pratt & Whitney) in the U.S.; Rolls-Royce (UK-listed, with major U.S. operations in Indianapolis) and Safran (France-listed) abroad; Honeywell in business-jet engines and auxiliary power units (APUs). The workhorse narrowbody engine, the CFM LEAP, is built by CFM International, a 50/50 joint venture between GE Aerospace and Safran that dates to 1974 [5][6]. Ownership structures make simple market-share claims unreliable: CFM is a non-consolidated, equal GE–Safran venture, and Pratt participates in engine programs through collaboration arrangements whose third-party interests ranged from 13% to 49% by program at year-end 2025 [27][28]. Underneath the OEMs is a long tail of specialist suppliers — investment-casting houses, forging shops, blade and fuel-nozzle machinists — many privately held or private-equity-owned. Williams International, a leading small-business-jet engine maker, is privately held [16].

3. How big it is (federal figures)

U.S. ground-truth statistics for NAICS 336412:

Read these carefully — three caveats. First, this is the opposite of an industry undercounted by tiny operators or hidden by government ownership. It is a genuine oligopoly: the top four firms take three-quarters of receipts (CR4 74.8%) [2]. The 440 establishments and 285 firms are mostly small parts machine shops clustered around a few dominant engine builders, so the head count overstates how competitive the industry actually is. An establishment count is not a company count — one large manufacturer may operate several classified establishments [26]. The SBA lets a "small business" here run to 1,500 employees [3] — a tell for how capital- and labor-intensive engine work is.

Second, the employment figures from CBP (75,499 in 2023) and BLS (100,100 in April 2026, preliminary) differ because they use different methodologies — CBP is establishment-based from administrative records while BLS uses a sample survey. The more recent BLS figure suggests continued workforce expansion.

Third, the $40.1 billion federal receipts figure — the value of what U.S.-located establishments shipped and overhauled in 2022 [2] — is much smaller than the revenue of the U.S. engine champions, and that gap is informative rather than contradictory. GE Aerospace booked $45.9 billion in 2025 revenue and Pratt & Whitney (an RTX segment) $32.9 billion [7][9]. The federal number is smaller because (a) a large share of those company revenues is aftermarket services and foreign production counted outside this U.S. manufacturing code, (b) CFM's LEAP revenue is a joint-venture split with French Safran, and (c) much airline and third-party maintenance is classified under repair/support codes. The global segment revenues of OEMs cannot be added to create a NAICS market size. Treat the $40.1 billion as a floor on domestic factory output, not the size of the U.S. engine business.

4. The investable universe

Because the industry is an oligopoly, the "pure plays" are few and large; most exposure comes bundled inside diversified aerospace-and-defense companies or in the parts-and-service ecosystem around the OEMs.

Tickers, scale, and financial data are for the investable-universe and how-to-invest discussion only.

Major private and other owners. Not everything is public. Williams International (small business-jet turbofans) is family-owned [16]. Barnes Aerospace — a precision engine-component and repair specialist — is now private after Apollo Global Management took Barnes Group private in a ~$3.6 billion all-cash deal completed January 2025 [12]. Investment castings, forgings, and hot-section repair are full of private-equity-owned specialists (e.g., Chromalloy), and airlines (Delta's MRO arm, Lufthansa Technik) run large in-house engine shops. Pure-play public exposure to the OEMs themselves is essentially GE, RTX, Rolls-Royce, and Safran — there are no small-cap engine builders, because the barriers to entry (section 8) forbid them.

5. How the money works

The economics here are not like ordinary manufacturing. Three ideas explain almost everything.

The razor-and-blade model. An engine maker sells a new engine at a thin or negative margin — the "razor" — to win a place on an aircraft [4]. The profit is in the "blades": decades of mandatory overhauls and proprietary spare parts. Over an engine's service life the aftermarket typically generates several times the original engine price, at gross margins often in the 40–60% range, because only the OEM or its licensed shops can supply many of the certified parts [4]. Winning an engine slot on a popular aircraft is therefore a bet on a 30-year annuity, which is why OEMs will discount aggressively to be selected.

The installed base is the asset. The number that predicts future profit is not this year's engine sales but the size and age of the flying fleet. GE Aerospace and CFM together power roughly three of every four commercial flights [4], and that installed base is what throws off spare-parts and shop-visit revenue. GE's Commercial Engines & Services segment generated $33.3 billion of 2025 revenue, of which $25.0 billion — about 75% — was services, producing $8.9 billion of segment profit at a 26.6% margin [27]. Management attributed profit growth principally to spare-parts volume, internal shop visits, larger workscopes and pricing [27]. By contrast, Pratt & Whitney reported $32.9 billion of 2025 sales but only $2.6 billion of operating profit (~7.9% margin), reflecting the drag of a younger fleet and ongoing powder-metal remediation costs [28]. Rolls-Royce Civil Aerospace achieved a 20.5% underlying margin, while Safran's propulsion division reported 23.0%, both supported heavily by mature CFM56 aftermarket [29][30].

Metrics owners and analysts actually watch:

• Engine deliveries / unit volume — not for today's profit but because each engine sold is a future annuity (GE delivered 2,386 engines in 2025, up 25%, including 1,802 LEAPs [15][27]).
• Installed base and fleet age — more engines flying more hours, and aging toward their first heavy overhaul, drives the aftermarket.
• Shop-visit volume and services revenue growth — the direct read on aftermarket health (GE's internal shop-visit revenue grew 24% in 2025 [27]).
• Book-to-bill and backlog — GE Aerospace's ~$190 billion backlog is years of visibility [7].
• Spare-parts catalog pricing — OEMs raise list prices annually, a quiet compounding lever.
• Long-term service agreements — "rate-per-flight-hour" or "power-by-the-hour" contracts that trade fixed pricing for locked-in aftermarket share; these add visibility but create estimation risk if assumptions about future shop visits, parts consumption or inflation prove wrong.
• Program accounting and early-life cash drag — new programs consume cash for years before the aftermarket pays them back.
• For component and MRO firms: content per engine, build-rate exposure, PMA (Parts Manufacturer Approval) parts penetration, shop throughput and turnaround time, and OEM authorizations.

Cyclicality. New-engine demand tracks Boeing/Airbus build rates and airline capital spending, which are cyclical. The aftermarket tracks flying hours, which is steadier — but not immune: in 2020, COVID-19 grounded fleets, and both new-build and aftermarket revenue collapsed before a strong multi-year recovery. The aftermarket is the ballast; new-build is the swing factor.

6. What drives demand

• Air traffic (passenger and cargo). Flying hours drive parts consumption and overhauls. Global passenger traffic was projected to top 10 billion passengers in 2025, up about 6% year over year and more than 16% above 2019, led by Asia-Pacific [18].
• New-aircraft build rates and backlog. The global order backlog stood at roughly 16,133 aircraft, of which 13,314 are narrowbodies [18] — delivery slots that stretch into the 2030s and 2040s. Boeing booked ~1,167 gross orders in 2025 and Airbus ~1,000 [18][19]. Every airframe needs two or more engines plus spares.
• Fleet growth forecasts. The FAA forecasts the U.S. commercial fleet increasing from 7,387 aircraft in 2024 to 10,607 in 2045, equivalent to 1.7% average annual growth, with airlines replacing older narrowbodies with more efficient MAX and neo-family aircraft [35].
• Fleet age and the overhaul wave. As the huge CFM56 fleet ages and the newer LEAP and GTF fleets reach their first heavy shop visits (broadly expected across the late 2020s), aftermarket demand rises — a judgment widely shared across the sector.
• Delayed retirements. Because new aircraft are delivery-constrained, airlines are flying older jets longer, which extends and deepens aftermarket demand — a near-term tailwind for parts and MRO.
• Fuel efficiency and fleet renewal. New engines burn ~15%+ less fuel than the prior generation (LEAP vs. CFM56) [6], pulling demand for re-engined aircraft when fuel prices and emissions rules bite.
• Defense budgets. Fighter-engine production and sustainment (the F135 for the F-35; the F110 and F414 for the F-16 and F/A-18) and new programs (adaptive-cycle sixth-generation engines; the Army's helicopter re-engining) are a distinct, budget-driven demand stream. Defense propulsion diversifies traffic risk but substitutes dependence on appropriations, program decisions, and export approvals.
• Supply-chain recovery. Engine availability has itself been the bottleneck constraining new-aircraft deliveries [18] — so how fast castings, forgings, and skilled-labor capacity recover gates how much of the backlog actually ships.

7. Regulation

Safety certification is the moat and the burden.

• FAA 14 CFR Part 33 (Airworthiness Standards: Aircraft Engines). Every U.S. engine must earn a type certificate against Part 33, and every replacement part — including alternative PMA (Parts Manufacturer Approval) parts — must show compliance with the same standard [20][21][38]. Life-limited parts (discs, shafts) are tracked cycle-by-cycle and retired on schedule; ongoing Airworthiness Directives can mandate inspections or fixes across a fleet.
• PMA and DER repairs are the FAA-sanctioned competitive pathways that let non-OEM suppliers (HEICO, Chromalloy) make approved replacement parts or engineered repairs — the main legal check on OEM aftermarket pricing power [21]. A PMA combines design and production approval [38].
• EASA and bilateral harmonization. Europe's EASA runs a parallel certification regime; the FAA and EASA increasingly harmonize standards (e.g., for engine life-limited parts) so approvals can be mutually recognized [20].
• Emissions and noise. FAA engine-emissions certification covers smoke, hydrocarbons, carbon monoxide, and nitrogen oxides [37]. A fuel-efficiency rule applies to affected airplanes manufactured after January 1, 2028 [36]. ICAO's international standards (via CAEP) push continuous efficiency investment and shape next-generation design.
• Export controls. Military engines are defense articles on the U.S. Munitions List, governed by ITAR (International Traffic in Arms Regulations); some commercial engine technology falls under dual-use export rules. These restrict sales and technology transfer to foreign nationals and countries — a real constraint on where and to whom engines can be sold.
• Post-737 MAX, certification scrutiny across the whole propulsion and airframe chain has intensified.

8. Competitive dynamics and consolidation

A stable oligopoly. Large commercial propulsion is split among GE Aerospace, Pratt & Whitney, Rolls-Royce, and Safran — about 97% between them [4] — organized through joint ventures (CFM = GE + Safran) so partners share the cost and the annuity. Aircraft/engine pairings set the competitive game: some airframes are sole-source (the 737 MAX takes only CFM LEAP; the Boeing 777X takes only GE's GE9X), while others are dual-source (the A320neo family offers CFM LEAP or Pratt's geared turbofan), which is where head-to-head price competition is fiercest. Competition and sole sourcing occur engine program by engine program; installed-base share, annual delivery share, order share, and aftermarket revenue share answer different investment questions.

Barriers to entry are extreme. A clean-sheet engine costs billions and takes roughly eight years to develop and certify, on top of the metallurgy, aerodynamics, and brand trust required [17]. Qualification requirements mean an OEM cannot necessarily replace a disrupted supplier quickly even when material is available elsewhere [28]. The top firms sit on decades of installed-base data and proprietary part designs. New entrants essentially cannot appear; the competitive action is instead about who captures the aftermarket — OEMs tightening control of shop networks and part supply on new engines, versus independents (StandardAero, Chromalloy, HEICO's PMA parts) competing on price for mature engines where alternatives are allowed.

Consolidation history. The corporate structure was reshaped twice recently: RTX was formed in 2020 by the ~$135 billion "merger of equals" of United Technologies (Pratt & Whitney's parent) and Raytheon [22], and GE Aerospace became a standalone public company on April 2, 2024 when GE spun off GE Vernova [23]. Suppliers keep rolling up too — Howmet emerged from the Arconic/Alcoa split; TransDigm and HEICO grow by serial acquisition; Apollo took Barnes private in 2025 [12]. The upstream materials base (single-crystal turbine-blade casters, forgers, titanium suppliers) is itself highly concentrated.

9. Risks

• Cyclicality and demand shocks. Pandemics, recessions, fuel spikes, and geopolitical shocks hit air travel and OEM build rates; COVID-19 is the recent proof.
• Quality and durability tail risk. A single manufacturing flaw can be enormously costly: Pratt & Whitney's geared-turbofan powder-metal defect (disclosed 2023) forced accelerated inspections. RTX recorded a $2.9 billion pre-tax charge in 2023, used $1.0 billion of the associated accrual in each of 2024 and 2025, and estimated an additional ~$0.7 billion cash impact in 2026 [28]. The episode demonstrates how a problem in one qualified material process can create removals, grounded aircraft, compensation, capacity shortages and litigation. New engines running in hot, harsh environments have also shown shorter-than-hoped time-on-wing, driving warranty and rework costs.
• Supply-chain and labor bottlenecks. In a GAO review, 15 of 17 aviation manufacturers interviewed reported difficulty hiring enough skilled workers, and 15 reported difficulty obtaining needed materials — including engines, engine components, semiconductors, aluminum, and basic hardware [34]. Long training and qualification periods make foundry, machining, inspection, and repair-station labor particularly difficult to replace. Castings, forgings, and titanium remain constrained; engine availability is currently the limiting factor on aircraft deliveries [18].
• Materials and geopolitical exposure. Nickel, cobalt, titanium, and rhenium create price and supply risk. USGS identifies cobalt-bearing superalloys as an important gas-turbine-engine application [33], while RTX reports dependence on foreign or limited sources for several strategic metals [28]. ATI's high-performance segment derived ~68% of 2025 revenue from commercial jet-engine products: nickel-based and specialty alloys 43%, precision forgings/castings/components 40%, and titanium 17% [32]. Titanium supply has historically leaned on Russian sources, a sanctions vulnerability.
• Aftermarket erosion. PMA parts, used serviceable material (USM — parts salvaged from retired engines), and independent MROs undercut OEM aftermarket margins on mature engines, and any regulatory or airline push for more competition pressures the profit engine. FAA approval, airline acceptance, and life-limited-part traceability restrict how quickly that substitution can occur.
• Program and cash-flow risk. New engines burn cash for years before the aftermarket repays them; overruns or a weak-selling airframe can strand that investment.
• Concentration and single-source exposure. Customers are few (Boeing, Airbus, the U.S. Department of Defense), and airframers depend on a handful of engine suppliers — a mutual chokepoint.
• Geopolitics and export controls. ITAR limits, tariffs on aerospace parts, and China exposure (COMAC's C919 uses the CFM LEAP) all create policy risk.
• Regulatory and environmental cost. Certification delays and tightening emissions/noise mandates require sustained, expensive R&D (SAF and hydrogen compatibility, open-fan architectures).

10. How to invest and the outlook

Public routes.

• Engine OEMs: GE Aerospace (GE) is the closest to a pure commercial-and-defense engine play; RTX (RTX) gives Pratt & Whitney engines inside a diversified defense-and-aerospace company. For the CFM joint venture's other half and the widebody makers, Safran (SAFRY) and Rolls-Royce (RYCEY) trade abroad.
• Component and aftermarket specialists: Howmet (HWM) for hot-section castings, ATI (ATI) for nickel superalloys, titanium, and powder-metal products, HEICO (HEI) for PMA parts, TransDigm (TDG) for proprietary components, Woodward (WWD) for fuel controls, StandardAero (SARO) for independent engine MRO, AAR (AIR) for distribution/MRO, and Willis Lease (WLFC) for spare-engine leasing. These may offer better pricing power or program diversification than an engine OEM, but retain customer concentration, qualification, and production-ramp risk.
• ETFs: broad aerospace-and-defense funds (e.g., ITA, PPA, XAR) give diversified exposure but blend in airframers and defense primes, diluting the pure engine thesis.

Private routes.

• Private equity owns much of the parts-and-repair supply chain — Apollo (Barnes Group, since 2025) [12], the many PE-held casting, forging, and component-repair shops. Attractive targets tend to possess scarce approvals, proprietary repairs, installed-base diversity, and capacity in a bottleneck process. Principal diligence traps are customer or engine-program concentration, expiring licenses, underpriced long-term agreements, undocumented capital needs, weak parts traceability, and revenue growth produced by temporary turnaround-time backlogs.
• Engine leasing and asset finance — spare-engine pools, sale-leasebacks, and part-out of retired engines — is a distinct real-asset class (Willis Lease is the public proxy; private funds abound).
• Direct ownership of specialty distributors, PMA developers, and machine shops.
• Venture/frontier: next-generation propulsion startups (hybrid-electric, hydrogen, sustainable aviation) are early-stage and speculative — a small, high-risk slice, not the core of the industry. Open-fan, hotter-core, additive-manufacturing, digital-health-monitoring, and hybrid-electric technologies are active development areas, but near-term substitution threat from electric or hydrogen propulsion is more credible in small aircraft than in large commercial transport.

Near-term drivers (forward-looking judgments).

• An aftermarket upcycle looks set to run for years: record backlogs, an aging and heavily flown fleet, and delayed retirements point to heavy shop-visit demand, with the newest engines (LEAP, GTF) entering their first big overhaul wave broadly across the late 2020s. This favors the aftermarket-levered names.
• Supply-chain normalization is the swing variable — how fast castings, forgings, and labor recover determines how much backlog converts to deliveries.
• Defense demand is firm (F135 upgrades, sixth-generation adaptive-cycle engine programs), though some Army propulsion efforts face funding uncertainty.
• Next-generation technology is real but long-dated: CFM's RISE open-fan program (launched 2021) targets >20% fuel savings with SAF and hydrogen compatibility, with flight testing planned mid-decade and potential entry into service in the mid-2030s [24]. The winners of that transition are a decade away from monetizing it.

The through-line for any investor: in this industry the money is made not on the day an engine is sold but across the decades it flies. Own the installed base — or the parts and shops that keep it flying — and understand that the barriers protecting those profits are exactly what make the industry impossible to enter.

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Sources

1. U.S. Census Bureau — County Business Patterns 2023, NAICS 336412 (establishments, employment, annual payroll), 2024. https://www.census.gov/programs-surveys/cbp.html
2. U.S. Census Bureau — 2022 Economic Census, Concentration by Largest Firms and receipts, NAICS 336412, 2024. https://www.census.gov/programs-surveys/economic-census.html
3. U.S. Small Business Administration — Table of Small Business Size Standards (NAICS 336412 = 1,500 employees), 2023. https://www.sba.gov/document/support-table-size-standards
4. Mordor Intelligence / Simple Flying — Commercial Aircraft Engine Market: the four-firm ~97% share and razor-and-blade aftermarket model, 2025. https://www.mordorintelligence.com/industry-reports/commercial-aircraft-engines-market
5. Safran — The Story of CFM International (50/50 GE–Safran joint venture, founded 1974), 2023. https://www.safran-group.com/companies/cfm-international
6. Wikipedia — CFM International LEAP (15% lower fuel burn vs. CFM56), 2025. https://en.wikipedia.org/wiki/CFM_International_LEAP
7. GE Aerospace — Fourth Quarter and Full Year 2025 Results (revenue $45.9B, net income ~$10.0B, backlog ~$190B), 2026. https://www.geaerospace.com/news/press-releases/ge-aerospace-announces-fourth-quarter-2025-results
8. Leeham News / Longyield — GE Aerospace FY2025 earnings: services ~$30B vs. equipment; commercial services +26%, 2026. https://leehamnews.com/2026/01/22/ge-aerospace-fy-and-q4-2025-earnings-thrust-higher-propelled-by-services-growth-leap-volume-and-expanding-margins/
9. RTX Corporation — 2025 results and 2026 outlook (group $88.6B; Pratt & Whitney segment $32.9B, +17%), 2026. https://www.rtx.com/news/news-center/2026/01/27/rtx-reports-2025-results-and-announces-2026-outlook-
10. Howmet Aerospace / TransDigm — Howmet FY2025 revenue ~$8.3B; TransDigm FY2026 revenue guidance $10.3–10.4B, 2025–2026. https://www.howmet.com/annualreport/
11. HEICO Corporation — Record Fiscal 2025 results (net sales $4.49B; net income $690.4M), 2025. https://finance.yahoo.com/news/heico-corporation-reports-record-net-211500512.html
12. Apollo Global Management / Barnes Group — Apollo completes ~$3.6B take-private of Barnes Group, January 2025, 2025. https://finance.yahoo.com/news/apollo-funds-complete-acquisition-barnes-140500288.html
13. Woodward / StandardAero — Woodward FY2025 net sales $3.6B; StandardAero FY2025 revenue $6.06B, 2025–2026. https://www.woodward.com/press-release/woodward-reports-record-sales-earnings-for-fiscal-year-2025/
14. StandardAero, Inc. — Pricing of Initial Public Offering (NYSE: SARO, October 2024); independent engine MRO business, 2024. https://ir.standardaero.com/news-events/press-releases/detail/106/standardaero-announces-pricing-of-its-upsized-initial-public-offering
15. Flight Global — GE Aerospace delivered 2,386 engines in 2025 (+25%), including 1,800+ LEAPs, 2026. https://www.flightglobal.com/engines/ge-commercial-engine-deliveries-jumped-25-in-2025-amid-supply-chain-recovery/166035.article
16. Wikipedia — Williams International (privately held small-turbofan maker; FJ44/FJ33), 2025. https://en.wikipedia.org/wiki/Williams_International
17. Fortune Business Insights / Wikipedia — Aircraft engine barriers to entry (~8 years, billions of dollars, certification), 2025. https://en.wikipedia.org/wiki/Aircraft_engine
18. Aerospace industry trackers (Avolon / AeroTime / Aviation Week) — 2025 passenger traffic >10B (+6%); backlog 16,133 aircraft (13,314 narrowbody); engine availability as delivery bottleneck, 2025–2026. https://aerospaceglobalnews.com/news/commercial-aircraft-deliveries-airbus-boeing/
19. Forecast International — Airbus and Boeing 2025 orders and deliveries (~1,000 and ~1,167 gross orders), 2026. https://flightplan.forecastinternational.com/2026/01/15/airbus-and-boeing-report-december-2025-commercial-aircraft-orders-and-deliveries/
20. eCFR / FAA — 14 CFR Part 33, Airworthiness Standards: Aircraft Engines; FAA–EASA harmonization, 2025. https://www.ecfr.gov/current/title-14/chapter-I/subchapter-C/part-33
21. FAA — Parts Manufacturer Approval (PMA): design-and-production approval for replacement articles, 2025. https://www.faa.gov/aircraft/air_cert/design_approvals/pma
22. RTX / Britannica — United Technologies–Raytheon merger of equals (2020) forming RTX, 2020. https://www.rtx.com/news/2020/04/03/united-technologies-and-raytheon-complete-merger-of-equals-transaction
23. GE Aerospace — GE Aerospace launches as independent public company following GE Vernova spin-off, April 2, 2024, 2024. https://www.geaerospace.com/news/press-releases/ge-aerospace-launches-independent-investment-grade-public-company-following
24. GE Aerospace / Wikipedia — CFM RISE open-fan program (launched 2021; >20% fuel savings; SAF/hydrogen; mid-2030s target), 2025. https://en.wikipedia.org/wiki/CFM_International_RISE
25. U.S. Census Bureau — 2022 NAICS definition, NAICS 336412, 2022. https://www.census.gov/naics/?details=336412&input=336412&year=2022
26. Bureau of Labor Statistics — Table B-1b, Employment by industry (NAICS 336412: 100,100 employees, April 2026 preliminary), May 2026. https://www.bls.gov/ces/data/employment-and-earnings/2026/table1b_202605.htm
27. GE Aerospace — 2025 Form 10-K (Commercial Engines & Services segment: $33.3B revenue, $25.0B services, 26.6% margin; 2,386 engines delivered including 1,802 LEAPs), 2026. https://www.sec.gov/Archives/edgar/data/40545/000004054526000008/ge-20251231.htm
28. RTX Corporation — 2025 Form 10-K (P&W segment: $32.9B sales, $2.6B operating profit; powder-metal accrual usage; collaboration arrangements 13–49% third-party interests), 2026. https://www.sec.gov/Archives/edgar/data/101829/000010182926000006/rtx-20251231.htm
29. Rolls-Royce Holdings — 2025 Full Year Results (Civil Aerospace: £10.4B revenue, 20.5% underlying margin), 2026. https://www.rolls-royce.com/investors/results-reports-and-presentations/financial-results/rr-holdings-plc-2025-full-year-results.aspx
30. Safran — 2025 Full Year Results (Propulsion division 23.0% recurring operating margin), 2026. https://www.safran-group.com/pressroom/safran-reports-excellent-financial-performance-2025-and-raises-its-2028-ambitions-2026-02-13
31. Howmet Aerospace — 2025 Form 10-K (~70% of revenue from aerospace; engine airfoils and structural parts from nickel superalloys, titanium, aluminum), 2026. https://www.sec.gov/Archives/edgar/data/4281/000000428126000012/hwm-20251231.htm
32. ATI Inc. — 2025 Form 10-K (High-performance segment: ~68% from commercial jet engines; nickel alloys 43%, forgings/castings 40%, titanium 17%; $1.76B/39% of sales from commercial jet-engine products), 2026. https://www.sec.gov/Archives/edgar/data/1018963/000162828026010140/ati-20251228.htm
33. U.S. Geological Survey — Cobalt Statistics and Information (cobalt-bearing superalloys in gas-turbine engines), 2025. https://www.usgs.gov/centers/national-minerals-information-center/cobalt-statistics-and-information
34. U.S. Government Accountability Office — GAO-24-106493: Aviation Manufacturing Supply Chain (15/17 manufacturers reported labor and materials difficulties), 2024. https://www.gao.gov/products/gao-24-106493
35. FAA — Aerospace Forecast FY 2025–2045 (U.S. commercial fleet: 7,387 aircraft in 2024 to 10,607 in 2045; 1.7% CAGR), 2025. https://www.faa.gov/data_research/aviation/aerospace_forecasts/FY-2025-2045-Full-Forecast-Document-and-Tables.pdf
36. FAA — Fuel Efficiency Rule (applies to affected airplanes manufactured after January 1, 2028), 2024. https://www.faa.gov/newsroom/faa-finalizes-rule-reduce-carbon-pollution-new-jets-and-turboprops
37. FAA — Engine Emissions Certification (smoke, hydrocarbons, CO, NOx), 2025. https://www.faa.gov/about/office_org/headquarters_offices/apl/aee/emissions/certification
38. FAA — Engine PMA Approvals (design and production approval requirements), 2025. https://www.faa.gov/aircraft/air_cert/design_approvals/engine_prop/engine_approvals/engines_pma_approvals
39. StandardAero, Inc. — 2025 Form 10-K ($6.06B revenue, +15.8% YoY), 2026. https://www.sec.gov/Archives/edgar/data/2025410/000119312526072618/saro-20251231.htm