Aerospace Product and Parts Manufacturing (United States) — NAICS 3364

A short rollup primer for public-market and private investors. NAICS (North American Industry Classification System) code 3364 is an industry group (the 4-digit level) that contains exactly one child industry, 33641. Because the two levels describe the same set of factories, this page is deliberately brief: it gives 3364's own ground-truth federal statistics and then points you to the full NAICS 33641 primer, where all the detail — the six underlying businesses, the companies, the economics — lives.

1. Overview

NAICS 3364, "Aerospace Product and Parts Manufacturing," is the manufacturing spine of American aerospace and defense (A&D): the factories that build complete aircraft, the engines that power them, the deep base of aircraft parts, and — on the other side of the same industry — guided missiles, rockets and spacecraft, their propulsion, and their parts. It is the largest and most strategically important slice of U.S. advanced manufacturing, and the one that runs the biggest trade surplus of any American manufacturing sector: aircraft and spacecraft exports of roughly $134 billion in 2024, and an A&D trade surplus on the order of $109 billion in 2025.[2][3]

At this level, the single most useful fact is structural: 3364 is effectively identical to its one child, 33641. There is no aggregation to do and no sibling industries to weigh — the group is the industry. The interesting variation sits one level further down, inside 33641's six detailed businesses, which differ enormously in size, concentration, and — most of all — in who an investor can actually buy. This page exists to record 3364's own official numbers and to hand you to that child primer.

2. What's inside — why this level equals its one child

The NAICS hierarchy narrows in steps. The 4-digit industry group 3364 contains exactly one 5-digit industry, 33641 (also called "Aerospace Product and Parts Manufacturing" — the name and scope are the same). Below 33641 sit the six 6-digit U.S. detail industries where the real diversity lives:

• a commercial-aerospace cluster — aircraft (336411, about 46% of the level's receipts, four-firm concentration 83.5%), aircraft engines (336412, 20%, 74.8%), and other aircraft parts (336413, 17%, 44.9%) — roughly 82% of the level, driven by global air travel and the airliner replacement cycle; and
• a missile-and-space cluster — complete missiles and space vehicles (336414, 7%, 96.7%), their propulsion (336415, 10%, 98.4%), and their parts (336419, 1%, 69%) — roughly 18%, driven by the federal budget and geopolitics.[1]

Two contrasts are worth carrying down with you. First, concentration runs in two directions: the assembly and propulsion codes are among the most concentrated industries in all of U.S. manufacturing, while the two parts codes are genuinely fragmented (860 firms in aircraft parts alone).[1] Second, ownership varies more than anything else — aircraft assembly has essentially one listed pure play, propulsion has none, aircraft parts offers a dozen-plus listed specialists, and the deeper supplier tiers belong to private equity and family shops.

Because 3364 has only the one child, every figure below is simultaneously 3364's figure and 33641's figure. For the full breakdown — who makes what, where value concentrates, and how to buy each piece — read the NAICS 33641 primer. The rest of this page is a summary.

3. How big it is (this level's rollup figures)

Federal ground-truth statistics for NAICS 3364 (identical to 33641):

¹ CR4 = combined revenue share of the four largest firms. ² HHI = sum of the squared market shares of all firms; U.S. antitrust agencies treat 1,000–1,800 as moderately concentrated and above 2,500 as highly concentrated.

The commercial/defense split inside the total. The three aircraft codes account for roughly $166.8 billion of receipts and about 353,000 workers; the three missile/space codes for about $36.7 billion and 75,700 workers. Pay is meaningfully higher on the defense/space side — from about $85,700 per worker in aircraft parts to roughly $114,000 in missile/space parts, $131,000 in propulsion, and $148,000 in missile and space vehicle manufacturing — reflecting an engineering-heavy, security-cleared workforce.[1]

Concentration reads "moderate" despite near-monopoly children. The rollup HHI of 1,182.7 sits in the moderate band even though four of the six underlying businesses have four-firm ratios above 74% — four firms make 96.7% of complete missiles and space vehicles and 98.4% of their propulsion, out of 18 and 16 firms respectively. The reason: different firms dominate different pieces — Boeing rules aircraft, GE and RTX rule engines, a fragmented field supplies parts, and the defense primes rule missiles — so aggregating dilutes any one company's share.[1]

A correction the revised children force: do not look for child HHIs. Census suppresses the index for aircraft, aircraft engines, aircraft parts, and missile/space propulsion, publishing it only for guided missiles and space vehicles (3,377 — well above the "highly concentrated" line) and other missile/space parts (1,378.8).[1] The suppression is itself a concentration signal rather than a data gap: with so few firms, publishing an index would effectively disclose individual companies. Read the disclosed CR4/CR8 ratios as the evidence inside the children, and do not read this level's moderate 1,182.7 as evidence that its component markets are competitive.

Which employment series you use matters. The 428,728 above is County Business Patterns, the only basis consistent across all six children. The Bureau of Labor Statistics' survey-based count runs materially higher for the two largest — 261,800 in aircraft manufacturing (April 2026) against CBP's 172,941, and about 100,100 in aircraft engines against CBP's 75,499. The methodologies and reference years differ; do not mix them inside one comparison.[1][8]

The figures measure merchant markets, not corporate output. This is the most important interpretive point at every level of this code. Census classifies establishments by primary product, so parts a company makes for its own vehicles are usually counted with the vehicle, not with the parts code: SpaceX and Blue Origin build rocket engines in enormous volume but are classified with launch vehicles and services rather than propulsion, and the primes fabricate much of their own missile structure in-house. Every figure here is therefore a floor on the underlying activity.

Undercount caveat — this code understates the true "aerospace" economy. Aerospace is a corporate, plant-based industry that federal data captures well (there is no cash/gig undercount here). But adjacent codes carve out huge related activity that never lands in 3364: satellites are counted as communications equipment (NAICS 334220), standalone guidance/navigation gear as search-and-navigation equipment (334511), and much missile and space work as research and development (541715). The U.S. Census Bureau sizes the entire U.S. space economy at $142.5 billion of GDP in 2023 across manufacturing, transportation, information, and telecommunications — a figure that overlaps this code only partially [4] — while industry associations size the full A&D footprint on the order of $850 billion, several times this code's $203.5 billion.[2] Corporate reorganizations also shift volume across the boundary: Boeing's ~$4.7 billion reabsorption of Spirit AeroSystems, completed December 8, 2025, pulls fuselage and structures work and roughly 15,000 workers back inside an airframe company, with Spirit's Airbus-supplying sites carved out to Airbus.[10]

A minor technical note: the six children's firm counts sum to about 1,446, more than the level's 1,379, because a firm operating in more than one child is counted once at the parent level but in each child it participates in. Receipts, establishments, employment, and payroll do add up cleanly.[1]

4. Investable universe — where value concentrates

Because 3364 equals 33641, the investable map is the child's map. In brief, value concentrates in a handful of very large companies whose exact NAICS placement reflects corporate structure more than any single code. Full lists, tickers, and pure-play detail are in the 33641 primer. The shape:

• Large anchors span several pieces: Boeing (aircraft + defense/space, and more aircraft parts since Spirit), GE Aerospace (the cleanest engine play), RTX (engines, parts, missiles), and the diversified primes — Lockheed Martin, Northrop Grumman, L3Harris, General Dynamics, Textron. Airbus, Embraer, Rolls-Royce, and Safran are central competitors but trade abroad.
• The richest public menu is aircraft parts (336413): aftermarket compounders and specialist suppliers (TransDigm, HEICO, Loar, Howmet, Hexcel, Moog, Woodward, Curtiss-Wright, RBC Bearings, and others). This is the one piece where a public investor can build a diversified basket of specialists.
• Missiles and space (336414) now has a listed new-space cohort — SpaceX (public since June 2026 at a $1.77 trillion valuation), Rocket Lab, Firefly, Intuitive Machines, Kratos, Voyager — alongside private Blue Origin and ULA.[15]
• Missile/space parts (336419) has one clean pure play in Karman (KRMN), while propulsion (336415) still has none — though L3Harris's "Missile Solutions" solid-rocket-motor carve-out, backed by a ~$1 billion Pentagon investment with an IPO expected in the second half of 2026, would be the first real public read on that business.[13]
• Private capital dominates the supplier tiers — private equity across parts, aftermarket, and propulsion (Apollo/Barnes Group ~$3.6B in January 2025; Warburg Pincus + Berkshire Partners/Triumph ~$3B in July 2025; Trive, which built Karman; and AE Industrial, which agreed in January 2026 to buy 60% of Aerojet's space-propulsion and power business for $845 million) — and venture capital at the electric-air-taxi and commercial-rocket frontier.[23][24][14]
• Sector exchange-traded funds (ETFs) — ITA, PPA, and XAR — own the whole level in one holding and are the lower-volatility way in; space-tilted funds (ARKX, UFO) skew toward the new-space cohort.

5. How the money works

A few mechanics recur across the level. The installed base is the asset and the aftermarket is the profit — new-build sales are often thin- or negative-margin, and decades of mandatory overhauls and proprietary spares make the money; at the leading engine maker, services generated $25.0 billion of a $33.3 billion commercial segment at a 26.6% margin in 2025.[12] Qualification is the moat, and it is common to all six children: competition happens once, at the design or certification stage, and the winner holds the position for the life of the program, which is why headline fragmentation understates pricing power in the parts codes. Backlog is the scoreboard — contracted future work, book-to-bill above 1.0, and production rate matter more than any single year's deliveries (Boeing alone carried a $567 billion commercial backlog at the end of 2025).[9] Programs, not products: development runs eight-to-ten years before earning a dollar, so segment margins can be negative through a ramp even with a full order book. On the defense side, contract type sets margins (cost-plus reimburses costs plus roughly an 8–12% fee; fixed-price rewards efficiency but makes the contractor eat overruns). And across all six businesses in 2026, supply — not demand — is the binding constraint. See the 33641 primer for the full treatment, including the one exception: reusable commercial launch, where economics turn on flight cadence and cost-per-kilogram rather than an aftermarket annuity, and where scale does not yet guarantee profit — SpaceX flew Falcon 9 165 times in 2025 and handled roughly 85% of U.S. orbital launches while posting a ~$4.9 billion net loss on ~$18 billion of revenue.[16]

6. Demand drivers

Demand splits along the same commercial/defense line as the industry. On the commercial side (~82%): record air-travel volumes in 2025, fleet replacement for more fuel-efficient jets, and a large aging fleet driving a multi-year maintenance, repair, and overhaul (MRO) wave. The sources the children rely on do not agree on the headline traffic count and are not on the same basis — about 5.2 billion travelers with load factors near 84.6% on IATA's measure [5], against more than 10 billion passengers, up about 6% year over year, on another industry tracker's [6] — but the direction, a record comfortably above 2019, is not in dispute. Underneath it, the world fleet is projected to grow from roughly 29,000 aircraft in 2025 to about 38,300 by 2035, with commercial MRO alone running near $100 billion a year.[7] On the defense/space side (~18%): a defense topline near $839 billion for fiscal 2026, with roughly $34 billion of weapons procurement and RDT&E and billions earmarked to expand missile and munitions capacity after aid to Ukraine and Israel [17]; proposed missile defense ("Golden Dome"), whose FY2026 ask is near $13 billion but whose full-architecture cost estimates diverge enormously — roughly $175 billion from the White House against the Congressional Budget Office's ~$1.2 trillion over 20 years, a spread that is itself the best available measure of the program's uncertainty [18]; hypersonics; and a commercial-launch boom in which FAA-licensed launches and reentries rose from 14 in fiscal 2015 to 148 in fiscal 2024, with the agency expecting activity to more than double again by fiscal 2028.[19]

7. Regulation

Regulation is the industry's central gatekeeper and, paradoxically, the source of its pricing power. On the commercial side, no aircraft, engine, or part reaches the market until a regulator certifies it — the Federal Aviation Administration (FAA) grants type certificates, and replacement parts need their own approval (most commonly a Parts Manufacturer Approval, or PMA, which is the legal seam that lets independents compete on the aftermarket). Certification can gate revenue directly: after the 2024 door-plug incident the FAA capped 737 MAX output at 38 a month, raised it to 42 in October 2025 and to 47 in 2026, and partially restored Boeing's authority to issue airworthiness certificates.[11] On the defense side, exports are governed by the International Traffic in Arms Regulations (ITAR) and the Export Administration Regulations (EAR), which restrict who can supply, partner, or buy; cost-plus work is cost-audited under federal acquisition rules, and the Nunn-McCurdy statute presumes a program terminated if unit costs breach set thresholds. Commercial launch is licensed under the FAA's Part 450 rule. Full detail is in the 33641 primer.

8. Consolidation

Two consolidation stories run in parallel. On the commercial side: vertical re-integration (airframers pulling outsourced structures back in, headlined by Boeing's December 2025 reacquisition of Spirit AeroSystems) plus aggressive roll-up of the fragmented parts tier by both strategic acquirers and private equity, all atop a stable Boeing–Airbus duopoly in large jets.[10][23][24] On the defense side: a prime-contractor oligopoly — a legacy of 1990s consolidation, and the reason the missile and propulsion codes show 96.7% and 98.4% four-firm concentration [1] — is now being deliberately re-fragmented, with the Pentagon funding new entrants to create third and fourth sources in chokepoints such as solid rocket motors. L3Harris is un-bundling Aerojet from both ends: a motor carve-out headed for a 2026 IPO behind a ~$1 billion Pentagon investment, and the sale of 60% of the space-propulsion and power business to AE Industrial for $845 million.[13][14] The antitrust question is live rather than settled: Northrop has operated since 2018 under a Federal Trade Commission order requiring it to sell solid rocket motors to rivals behind an internal firewall [25], and in 2026 it petitioned to lift that order over Lockheed Martin's public opposition — an outcome that determines whether the two-supplier structure tightens or loosens.[26]

9. Risks

• Two cycles, two shocks. The commercial cluster is exposed to the air-travel cycle (the 2020 pandemic cut global traffic by more than half); the defense cluster is exposed to appropriations (shutdowns and shifting priorities can stall orders). Owning the whole level diversifies across these but eliminates neither.
• Execution and supply-chain fragility. Margins can stay negative through a production ramp even with a full backlog, and output is gated by the slowest input. In a GAO survey, 15 of 17 aviation manufacturers reported difficulty hiring enough skilled workers and 15 reported difficulty obtaining materials — engines, engine components, semiconductors, aluminium, and basic hardware [21] — while on the missile side a single domestic ammonium-perchlorate producer supplies the propellant base.[20]
• Safety, quality, and program risk. Groundings and quality lapses (the 737 MAX saga) put a regulator in direct control of output, and fixed-price development overruns land on the manufacturer — the Sentinel ICBM's 81% cost breach to roughly $141 billion is the scale of the tail.[11][22]
• Concentration and geopolitics. The defense pieces depend on one buyer, the commercial pieces on two airframers, and customer concentration runs down the supplier tiers; export limits and tariffs can move billions. Leverage compounds this in the roll-up and private-equity-owned models.
• Valuation and technology transitions. Years of strong performance have left the best aftermarket franchises and newest space names trading at rich multiples, and eVTOL, reusable launch, and the migration of value toward electronics and software could reshape who makes money — qualification protects an incumbent only as long as the program and the design survive.

10. How to invest, and the outlook

Because the level equals its one child, the practical menu is 33641's menu: sector ETFs (ITA, PPA, XAR) for diversified, lower-volatility exposure to the whole industry; aftermarket-quality compounders (aircraft-parts and engine-service specialists) for regulation-protected, installed-base economics; large-cap anchors (Boeing, GE Aerospace, RTX, Lockheed) for breadth; and higher-risk pure plays (the new-space cohort, Karman, and eventually the L3Harris motor spin-off) for upside.[13] Private routes — private equity across the supplier tiers and venture capital at the eVTOL (electric vertical take-off and landing) and commercial-rocket frontier — reach the parts of the supply chain that never list publicly.

Outlook. The setup across the level is unusually favorable and unusually synchronized: a record commercial backlog — the children's sources put it at more than 17,000 jets on IATA's count and 16,133 aircraft on another industry tracker's, both more than a decade of work at current build rates [5][6] — plus a multi-year engine and parts aftermarket wave, robust defense budgets, a munitions-replenishment surge, and a commercial-launch boom.[17][19] The recurring swing factor is supply, not demand — whether Boeing can hold and raise 737 rates past 42 toward 47 a month [11], whether the engine and structures supply chain keeps pace, and whether solid-rocket-motor and propellant capacity ramps to meet the defense order book.[20] Boeing's return to a full-year net profit in 2025, its first since 2018, while its commercial unit still lost money at a −17.1% operating margin, captures the moment precisely: the order book is the envy of manufacturing, and converting it into margins and cash is the unfinished job.[9] For the company-by-company detail behind every point on this page, read the NAICS 33641 primer.

---

Sources

1. U.S. Census Bureau — County Business Patterns 2023 and 2022 Economic Census (Concentration by Largest Firms / Comparative Statistics), NAICS 3364 / 33641 and its 6-digit children 336411–336419; U.S. Small Business Administration — Table of Small Business Size Standards (2023). (Histometrics ground-truth federal statistics.) https://www.census.gov/programs-surveys/cbp.html
2. Aerospace Industries Association (AIA) — 2025 Facts & Figures: A&D economic contribution (~$850B footprint) and 2024 aircraft/spacecraft exports (~$134B), 2025. https://www.aia-aerospace.org/news/american-aerospace-defense-industry-continues-economic-dominance/
3. Aerospace Industries Association (AIA) — Industry Impact: U.S. aerospace & defense trade surplus (~$109B, 2025), 2025. https://www.aia-aerospace.org/industry-impact/
4. U.S. Census Bureau — Space Economy: New Statistics for a New Industry ($142.5B of GDP, 2023), 2026. https://www.census.gov/library/stories/2026/01/space-economy.html
5. International Air Transport Association (IATA) — Global Outlook for Air Transport: 2025 passenger demand (~5.2 billion travelers, 84.6% load factor) and the 17,000-plus jet backlog, 2026. https://www.iata.org/en/pressroom/2026-releases/2026-01-08-02/
6. Aerospace industry trackers (Avolon / AeroTime / Aviation Week) — 2025 passenger volume above 10 billion (+6%); 16,133-aircraft backlog (13,314 narrowbody); engine availability as the delivery bottleneck, 2025–2026. https://aerospaceglobalnews.com/news/commercial-aircraft-deliveries-airbus-boeing/
7. Oliver Wyman — Global Fleet and MRO Market Forecast 2025–2035 (fleet 29,000 → ~38,300; ~$100B commercial MRO), 2025. https://www.oliverwyman.com/our-expertise/insights/2025/feb/global-fleet-and-mro-market-forecast-2025-2035.html
8. U.S. Bureau of Labor Statistics — Current Employment Statistics, Table 1a (aircraft and aircraft-engine manufacturing employment, April 2026), 2026. https://www.bls.gov/ces/data/employment-and-earnings/2026/table1a_202605.htm
9. The Boeing Company — Form 10-K (FY2025): Commercial Airplanes and Defense, Space & Security segment results; $567B commercial backlog; return to full-year net profit, 2026. https://www.sec.gov/Archives/edgar/data/12927/000162828026004357/ba-20251231.htm
10. The Boeing Company — Boeing Completes Acquisition of Spirit AeroSystems (December 8, 2025), 2025. https://boeing.mediaroom.com/2025-12-08-Boeing-Completes-Acquisition-of-Spirit-AeroSystems
11. CNBC / CNN Business — FAA raises the Boeing 737 MAX production cap (38 → 42 → 47 a month), 2025. https://www.cnbc.com/2025/10/17/boeing-737-max-production.html
12. GE Aerospace — 2025 Form 10-K (Commercial Engines & Services: $33.3B revenue, $25.0B services, 26.6% margin), 2026. https://www.sec.gov/Archives/edgar/data/40545/000004054526000008/ge-20251231.htm
13. L3Harris Technologies — L3Harris Accelerates "Arsenal of Freedom" with Creation of a New Missile Solutions Company (~$1B Pentagon investment; ~80% retained; 2026 IPO), 2026. https://www.l3harris.com/newsroom/press-release/2026/01/l3harris-accelerates-arsenal-freedom-creation-new-missile-solutions
14. SpaceNews — L3Harris to sell majority stake in space propulsion unit to AE Industrial for $845 million, 2026. https://spacenews.com/l3harris-to-sell-majority-stake-in-space-propulsion-unit-to-ae-industrial-for-845-million/
15. Fortune — SpaceX reveals share price and record valuation: $1.77 trillion (June 2026), 2026. https://fortune.com/2026/06/03/spacex-ipo-share-price-index-funds-valuation-public/
16. Forbes / Morningstar — SpaceX 2025 financials (~$18B revenue, ~$4.9B net loss), 165 Falcon 9 flights, ~85% of U.S. orbital launches, 2025–2026. https://www.forbes.com/sites/greatspeculations/2025/12/16/spacex-valuation-soars/
17. Congressional Research Service — FY2026 Defense Budget: Funding for Selected Weapon Systems; DoD aircraft procurement and RDT&E; munitions replenishment (R48860), 2026. https://www.congress.gov/crs-product/R48860
18. Center for Arms Control and Non-Proliferation — Fact Sheet: "Golden Dome" (White House ~$175B vs. CBO ~$1.2T; FY2026 funding), 2026. https://armscontrolcenter.org/fact-sheet-golden-dome/
19. U.S. Federal Aviation Administration — New Record: FAA-Licensed Commercial Space Operations (14 in FY2015 → 148 in FY2024; expected to more than double by FY2028), 2024. https://www.faa.gov/newsroom/new-record-faa-licensed-commercial-space-operations-aerospace-rulemaking-committee
20. SpaceNews / NewMarket Corporation — American Pacific Corporation finalizes ~$100M ammonium-perchlorate capacity expansion (sole North American producer), 2025. https://spacenews.com/american-pacific-corporation-finalizes-100-million-capacity-expansion-with-parent-company-approval/
21. U.S. Government Accountability Office — Aerospace Supply Chain: Manufacturers and Suppliers Face Challenges (GAO-24-106493), 2024. https://www.gao.gov/products/gao-24-106493
22. Aerotime / U.S. Department of Defense — Sentinel ICBM 81% cost breach to ~$141B; Nunn-McCurdy review, 2024. https://www.aerotime.aero/articles/us-dod-sentinel-icbm-program-cost-overruns
23. Latham & Watkins — Apollo Completes US$3.6 Billion Acquisition of Barnes Group (January 2025), 2025. https://www.lw.com/en/news/2025/01/latham-watkins-advises-apollo-in-completed-us3-6-billion-acquisition-of-barnes-group
24. Triumph Group Inc. — Form 8-K, Completion of Acquisition by Warburg Pincus and Berkshire Partners (July 24, 2025), 2025. https://www.sec.gov/Archives/edgar/data/1021162/000095017025098396/tgi-ex99_1.htm
25. U.S. Federal Trade Commission — FTC Imposes Conditions on Northrop Grumman's Acquisition of Solid Rocket Motor Supplier Orbital ATK (non-discrimination and firewall order), 2018. https://www.ftc.gov/news-events/news/press-releases/2018/06/ftc-imposes-conditions-northrop-grummans-acquisition-solid-rocket-motor-supplier-orbital-atk-inc
26. Breaking Defense — Lockheed opposes Northrop bid to remove firewall on solid rocket motor business, 2026. https://breakingdefense.com/2026/05/lockheed-opposes-northrop-bid-to-remove-firewall-on-solid-rocket-motor-business/