Transportation Equipment & Supplies (except Motor Vehicle) Merchant Wholesalers — A Histometrics Rollup Primer

NAICS 2022 code 42386 · United States

Short page. This is a rollup level that is effectively identical to its one child industry, 423860. This page gives the level's own ground-truth federal statistics and the one-paragraph story, then points you to the full 423860 primer for the complete detail (investable universe, how the money works, risks, and how to invest).

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1. Overview

A merchant wholesaler is a company that buys physical goods — taking legal title and holding inventory — then resells them to businesses rather than to the public. This level covers the wholesale distribution of transportation hardware that isn't a car or truck: above all aircraft and aircraft parts, plus ships and commercial boats (except pleasure craft), railroad cars and equipment, motorized golf carts, and non-truck military vehicles. In practice the level is overwhelmingly an aerospace-parts business — distributors that keep millions of part numbers on the shelf so airlines, repair shops, and defense customers can get the exact component they need, fast.[1]

Why it matters for investors: aircraft fly for 25–30 years and stay grounded until the right part arrives, so the parts trade throws off steady, aftermarket-driven, recurring demand that is far less cyclical than building new aircraft. It is a classic "picks-and-shovels" position in aerospace — a bet on the whole installed fleet flying, not on any single airframe order.

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

The NAICS (North American Industry Classification System) hierarchy narrows step by step. At this 5-digit "industry" level there is a single 6-digit "national industry" beneath it:

Because 42386 has exactly one child, the two are the same industry under two code lengths — the 5-digit rollup and the 6-digit leaf describe the same firms, the same revenue, and the same establishments. There is no aggregation to do and no siblings to blend. The distinction is a bookkeeping artifact of the classification system, not an economic one. Everything substantive — the scope (in and out of the code), how distributors earn money, who owns the industry, and how to invest — lives in the 423860 primer.

The one shape worth carrying up here is the ownership barbell. The federal data count roughly 1,920 firms,[2] and the U.S. Small Business Administration treats anything up to 175 employees as "small" in this code — a threshold that captures the vast majority of them.[3] Against that long tail of small private distributors sits a short head of very large players, most of which are segments of bigger companies (HEICO's distribution arm, Boeing Distribution, Airbus's Satair) or private-equity-backed independents (Incora, Proponent, FDH Aero) rather than standalone listed wholesalers.

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3. Size (this level's figures)

Ground-truth U.S. federal statistics for NAICS 42386 (identical to 423860, since they are the same industry):

Two things stand out. First, very high revenue per employee — roughly $1.4 million of sales per worker — which is normal for wholesale distribution: the "product" is logistics and availability, not labor, so billions of dollars of hardware flow through a modest headcount. Second, the average firm is small — about $25 million in sales — even though a handful of players are enormous.

Undercount caveat (important). The $48.8 billion figure almost certainly understates the true scale of aerospace-parts distribution in the U.S., because much of it is classified elsewhere:

• Captive manufacturer distribution — when Boeing (via Boeing Distribution/Aviall) or Airbus (via Satair) distributes parts, that activity is often booked under the parent's manufacturing or services classification, not under wholesale trade.
• Distribution embedded in diversified firms — HEICO and RTX/Collins run large parts-distribution operations inside companies classified as manufacturers.
• Brokers and agents are excluded — traders who arrange sales without taking title fall in NAICS 425 (wholesale electronic markets and agents/brokers), yet they move a meaningful share of used and surplus aircraft material.
• The code also cuts the other way. The Aviation Suppliers Association warns explicitly against reading the NAICS 423860 total as an aircraft-distribution market size: the statistics include ships, railroad cars, and golf carts, while excluding aviation distribution housed principally in manufacturing plants, airlines, or repair stations.[5] The census number is therefore both too broad and too narrow for the aerospace question most investors are actually asking.

For outside context, industry analysts put the global aerospace-parts distribution market at roughly $22 billion a year, with more than 80% tied to maintenance, repair and overhaul (MRO) rather than new-build.[6] The broader global aircraft aftermarket parts market — distribution plus repair — is estimated in the $46–54 billion range for 2025, growing at a mid-single-digit to ~8% annual rate.[7][8] These global figures are not directly comparable to the U.S. census number, and the estimates themselves span a wide band depending on what each firm counts; but they confirm the same story: a large, growing, aftermarket-anchored business.

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4. Investable universe (where value concentrates)

Because this level is 423860, the concentration of value is exactly the child's. There are few clean public "wholesaler" pure-plays — most listed exposure comes through aerospace aftermarket companies that combine distribution with repair. The closest listed proxies are AAR Corp. (AIR), about $2.8 billion of sales, whose Parts Supply segment turned over $1.1 billion at a 14.3% operating margin in fiscal 2025,[9] and VSE Corp. (VSEC), now a pure-play aviation aftermarket distributor and MRO after selling its fleet-parts business, with more than $1.1 billion of aviation revenue in 2025 and distribution up 46% year over year.[10] HEICO (HEI/HEI.A) is larger — $4.5 billion of FY2025 net sales, roughly $3.1 billion of it in the Flight Support Group[11] — and blends FAA-approved replacement-parts manufacturing with large-scale distribution following its ~$2.05 billion Wencor acquisition in 2023.[12] Boeing (BA) and RTX (Collins Aerospace) hold enormous distribution arms embedded inside much larger companies; Boeing Distribution alone states it carries more than one million part numbers from more than 65 locations.[13] On the private side, this is an active buy-and-build arena — PE-backed independents (Incora, Proponent, FDH Aero, where Bain Capital took a majority interest in June 2026 with Audax retaining a significant stake[14]) plus thousands of small family-owned distributors that form a long tail of bolt-on targets. Rail-car, commercial-marine, and golf-cart wholesaling exist in the code but are minor, and are mostly sold direct by makers or handled by lessors rather than by wholesalers.

Full company-by-company detail, scale figures, and ownership are in the 423860 primer, Section 4 — see there before acting on any specific name.

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5. How the money works

A parts distributor is essentially a cash-conversion machine wrapped around inventory. Owners make money four ways: buy–sell gross margin (mark up parts bought from makers or acquired as used/surplus); an availability premium — the core value is having the part now, because a grounded jet in an aircraft-on-ground (AOG) situation costs an operator tens of thousands of dollars an hour; inventory turns and working-capital discipline, since moderate margins mean returns are made or lost on how fast stock turns and how tightly receivables and payables are managed; and value-added services such as consignment programs (stocking parts at the customer's site and billing only when a part is used), kitting, and integrated supply agreements that deepen lock-in. Roughly 80% of aerospace-parts distribution is tied to MRO rather than new-build, which is why the demand base is steadier than aircraft production.[6]

The public benchmarks for these economics come from blended distribution-and-MRO companies, so read them directionally rather than as pure wholesale comps: AAR's Parts Supply segment earned a 14.3% operating margin in fiscal 2025, up from 11.4% the year before, on $1.1 billion of sales, with the improvement attributed mainly to higher new-parts distribution volume;[9] VSE shows the working-capital burden, ending 2025 with $554 million of inventory against $1.1 billion of annual revenue.[15] The gauges that matter are fill rate/service level, inventory turns, gross margin by category, cash-conversion cycle, and vendor-rebate income — not the capacity-utilization or same-store-sales measures used in manufacturing or retail. (Full detail in 423860, Section 5.)

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6. Demand drivers

Demand tracks the size and age of the global flying fleet — the installed base of aircraft, not new deliveries; Boeing projects the world commercial fleet roughly doubling toward ~50,000 aircraft by 2044, each needing decades of maintenance,[7] and the FAA's fiscal-2025 forecast has the U.S. commercial fleet growing from 7,387 aircraft in 2024 to 10,607 by 2045 — a 1.7% annual rate — with large cargo jets rising from 861 to 1,399 over the same span.[16] Other drivers: air-travel volumes (more flight hours mean more component wear), new-build production rates (which pull through initial-provisioning and new-parts distribution), defense and government spending, supply-chain tightness (which rewards distributors holding stock, though delayed retirements can also starve the used-material supply), and fleet-retirement/part-out cycles that feed the used-serviceable-material market. (Full detail in 423860, Section 6.)

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7. Regulation

Distributing flight hardware is quality- and safety-regulated even though the distributor doesn't make the part. Parts must trace back to an approved design and production source — the original manufacturer or a Parts Manufacturer Approval (PMA) holder (an FAA authorization to produce approved replacement parts) — and distributors must maintain traceability documentation; a distributor cannot certify a part's airworthiness merely by advertising or selling it, since eligibility and paperwork must support installation.[17][18] The Federal Aviation Administration (FAA) offers voluntary distributor accreditation under Advisory Circular AC 00-56, commonly met via the ASA-100 industry quality standard — strongly endorsed, but not a mandatory distributor license — and runs a Suspected Unapproved Parts (SUP) program to catch bogus or mislabeled components.[17][19][20] Cross-border shipments are subject to U.S. export controls — ITAR (International Traffic in Arms Regulations) and EAR (Export Administration Regulations) — and selling to the U.S. government layers on procurement rules, counterfeit-part avoidance, and small-business set-asides tied to the SBA size standard. Regulation here is a moat as much as a burden: accreditation, traceability systems, and manufacturer authorizations are hard to build, which favors incumbents. (Full detail in 423860, Section 7.)

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8. Consolidation

The federal concentration data show an industry that is fragmented overall but consolidating at the top. The top 4 firms hold 29.3% of receipts, the top 8 44.4%, the top 20 57.8%, and the top 50 69.7%; the Herfindahl-Hirschman Index (HHI, a standard concentration gauge where under 1,500 is "unconcentrated") is just 307.7 — no single player dominates.[2] The direction of travel, though, is toward consolidation, and the deal sizes show how much capital is chasing it: manufacturers pulling distribution in-house (Boeing built Boeing Distribution by buying Aviall in 2015 for ~$1.7 billion and KLX Aerospace in 2018 for ~$4.25 billion; Airbus runs Satair), aftermarket champions rolling up independents (HEICO/Wencor at ~$2.05 billion in 2023,[12] VSE/Kellstrom in 2024 and Precision Aviation Group in 2025, AAR/ADI in 2025[21]), and private equity using these businesses as buy-and-build platforms (Bain Capital's 2026 majority investment in FDH Aero[14]). The edges that decide winners are breadth of inventory, manufacturer distribution authorizations, fill rate, traceability reputation, and sheer working-capital scale. (Full detail in 423860, Section 8.)

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9. Risks

The headline risks carry over unchanged from the child: leverage + working capital = fragility — the 2023 Chapter 11 filing of Incora is the cautionary tale of debt-financed inventory meeting a demand dip,[22] and even a healthy operator carries the exposure, with AAR holding $809 million of inventory at fiscal-2025 year-end and its auditor flagging slow-moving-inventory valuation as a critical audit matter;[9] aviation cyclicality and shocks (downturns, pandemics, or aircraft-type groundings cut parts consumption quickly); manufacturer disintermediation (OEMs reclaiming aftermarket margin); inventory and obsolescence risk on parts tied to retiring aircraft; counterfeit/unapproved-parts liability;[20] export-control and tariff exposure (ITAR/EAR penalties, plus export-license delays and input-cost inflation that price increases may not offset);[9] customer and defense-budget concentration; and consolidation pressure on the long tail of small distributors. (Full detail in 423860, Section 9.)

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10. How to invest & outlook

Because 42386 and 423860 are the same industry, the investment routes are identical. Public-market exposure is stock-specific — there is no pure "transportation-equipment wholesaler" index — with AAR (AIR) and VSE (VSEC) the closest listed proxies for independent aviation-parts distribution + MRO, both actively expanding new-parts distribution by acquisition,[10][21] and HEICO (HEI/HEI.A) blending parts manufacturing with distribution;[11] Boeing (BA), RTX, and maker-of-proprietary-parts TransDigm (TDG) offer aftermarket exposure bundled with other businesses. (Specific yields and valuation multiples move constantly; check current data before acting.) The private-market route is arguably more natural: fragmented ownership, recurring aftermarket cash flows, and a proven buy-and-build playbook make it fertile ground for platform and bolt-on deals — with underwriting that separates factory-new distribution, used-serviceable-material trading, repair, and leasing, and diligence on distribution-right renewal, inventory aging by platform, traceability controls, and turns. The caveat, underscored by Incora, is that returns depend on operational discipline (inventory turns, fill rate, rebate capture), not just multiple expansion. On balance, the aftermarket-anchored nature of the business makes it one of the steadier ways to hold aerospace exposure — a bet on the whole fleet flying rather than on any single order book.

For the complete treatment, read the 423860 primer, which carries the full investable universe, economics, regulation, consolidation, risks, and outlook in depth.

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Sources

1. U.S. Census Bureau — 2022 NAICS Definition, 423860 Transportation Equipment and Supplies (except Motor Vehicle) Merchant Wholesalers (2022). https://www.census.gov/naics/?input=423860&year=2022
2. U.S. Census Bureau — 2022 Economic Census, Wholesale Trade (receipts, firm counts, concentration ratios, HHI) (2022). https://www.census.gov/programs-surveys/economic-census.html
3. U.S. Small Business Administration — Table of Small Business Size Standards (NAICS 423860 = 175 employees) (2023). https://www.sba.gov/document/support-table-size-standards
4. U.S. Census Bureau — County Business Patterns, 2023 (establishments, employment, payroll) (2023). https://www.census.gov/programs-surveys/cbp.html
5. Aviation Suppliers Association — "How Big Is the U.S. Aircraft Parts Distribution Industry?" (NAICS scope caveats) (2020). https://www.aviationsuppliers.org/asa-member-bulletin---feb-2020---how-big-is-the-us-aircraft-parts-distribution-industry
6. Kevin Michaels / AeroDynamic Advisory — "Parts Distribution: The New MRO Battleground" (~$22B distribution market, 80% MRO) (2023). https://www.linkedin.com/pulse/parts-distribution-new-mro-battleground-kevin-michaels
7. GlobalMarketInsights / Boeing fleet forecast — Aircraft Aftermarket Parts Market Size & Share Report, 2025–2034 (fleet to ~50,000 by 2044) (2025). https://www.gminsights.com/industry-analysis/aircraft-aftermarket-parts-market
8. Fortune Business Insights — Aircraft Aftermarket Parts Market Size ($54.4B in 2025) (2025). https://www.fortunebusinessinsights.com/aircraft-aftermarket-parts-market-105451
9. AAR Corp. — Fiscal 2025 Form 10-K (Parts Supply segment financials, inventory, risk factors) (2025). https://www.sec.gov/Archives/edgar/data/1750/000141057825001475/air-20250531x10k.htm
10. VSE Corporation — Fourth Quarter and Full Year 2025 Results (pure-play aviation; aviation revenue >$1B) (2026). https://www.businesswire.com/news/home/20260225618361/en/VSE-Corporation-Announces-Fourth-Quarter-and-Full-Year-2025-Results
11. HEICO Corporation — Reports Record Results for the Fourth Quarter and Full Year of Fiscal 2025 (net sales $4.485B; Flight Support ~$3.1B) (2025). https://www.accessnewswire.com/newsroom/en/aerospace-and-defense/heico-corporation-reports-record-net-income-up-35-on-record-operating-income-1118837
12. HEICO Corporation / Cleary Gottlieb — HEICO to acquire Wencor Group for ~$2.05B (2023). https://www.clearygottlieb.com/news-and-insights/news-listing/warburg-pincus-to-sell-wencor-group-to-heico
13. Boeing Distribution Services — About Us (part numbers, employees, locations) (2025). https://www.boeingdistribution.com/aero/about-us/idex.cfm
14. FDH Aero — FDH Aero Enters Partnership with Bain Capital and Audax Private Equity (2026). https://fdhaero.com/press-release/fdh-aero-enters-partnership-with-bain-capital-and-audax-private-equity/
15. VSE Corporation — Fiscal 2025 Form 10-K (revenue, inventory, segment data) (2026). https://www.sec.gov/Archives/edgar/data/102752/000010275226000015/vsec-20251231.htm
16. Federal Aviation Administration — FAA Aerospace Forecasts Fiscal Years 2025–2045 (U.S. fleet projections) (2025). https://www.faa.gov/data_research/aviation/aerospace_forecasts/FY-2025-2045-Full-Forecast-Document-and-Tables.pdf
17. Federal Aviation Administration — AC 00-56B Change 1, Voluntary Industry Distributor Accreditation Program (2023). https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_00-56B_CHG_1.pdf
18. Federal Aviation Administration — Parts Manufacturer Approval (PMA) guidance (2024). https://www.faa.gov/aircraft/air_cert/design_approvals/pma/pma_des
19. Aviation Suppliers Association — FAA AC 00-56 and ASA-100 accreditation standards (2023). https://www.aviationsuppliers.org/faa-ac00-56
20. Federal Aviation Administration — Suspected Unapproved Parts (SUP) Program (2024). https://www.faa.gov/aircraft/safety/programs/sups
21. AAR Corp. — FY2025 results and ADI American Distributors acquisition (2025). https://www.aarcorp.com/en/newsroom/press-releases/2025/aar-acquires-leading-parts-distributor-adi-american-distributors/
22. Modern Distribution Management — "Aircraft Parts Distributor Incora Files for Bankruptcy" (2023). https://www.mdm.com/news/top-distributor-sectors/aerospace/aircraft-parts-distributor-incora-files-for-bankruptcy/