Aerospace & Jet Engines

The global aerospace and defense industry is a massive, complex, and critically important sector, with combined revenues for the top 100 companies reaching approximately $922 billion in 2024. The industry is characterized by long product cycles, high barriers to entry, significant capital investment, and a strong dependence on both government spending and global economic activity.

This primer provides a comprehensive overview for investors and professionals new to the sector, breaking down the industry structure, key players, value chain, and dominant business models. We explore the two primary segments — Commercial Aerospace and Defense Aerospace — and delve into the critical sub-sectors that form the industry's backbone: Aircraft OEMs, Propulsion (Jet Engines), Aerostructures, Systems & Avionics, and the highly profitable Aftermarket.

A central theme is the immense backlog for new commercial aircraft, which stands at over 14,000 planes, representing a full decade of production capacity. This production lag, coupled with a surge in post-pandemic travel, is placing immense strain on the global supply chain and driving a robust aftermarket for maintenance, repair, and overhaul (MRO) services.

The jet engine sub-sector is a clear highlight, dominated by a handful of players who employ a lucrative "razor-and-blade" business model. Engines are often sold at or near cost, with profits generated from decades-long, high-margin service agreements.

The aerospace industry is broadly divided into two main end markets: the Civil Aerospace Sector (CAS) and the Military Aerospace Sector (MAS). While there is some overlap in technology and suppliers, the demand drivers, customers, and procurement processes for each are distinct.

Civil Aerospace encompasses all non-military aviation — large commercial aircraft (the duopoly of Boeing and Airbus), regional jets, business jets, helicopters, and general aviation. The primary customers are global airlines, cargo carriers, and private operators. Demand is cyclical and tightly correlated with global GDP growth, airline profitability, passenger and freight traffic, and fuel prices.

Military Aerospace involves the design, production, and support of aircraft and systems for national security purposes — fighter jets, transport aircraft, unmanned aerial vehicles (UAVs), and military helicopters. Demand is driven by geopolitical tensions, defense budgets, and long-term strategic procurement programs.

The total global aerospace market was estimated at approximately $403 billion in 2025, with projections to reach over $846 billion by 2035, representing a compound annual growth rate (CAGR) of 7.7%. The broader aerospace and defense market is significantly larger, with estimates placing it at $885 billion in 2024.

The Aerospace Value Chain

The commercial aerospace sector is dominated by the duopoly of Airbus and Boeing, who together control the vast majority of the market for large commercial aircraft. This segment is currently defined by a single, overwhelming dynamic: a colossal order backlog that far outstrips current production capacity. As of the end of 2025, the combined backlog for these two giants stood at over 14,000 aircraft, which translates to roughly a decade of production at current rates.

This unprecedented demand is driven by several factors:

• Fleet Modernization — Airlines are aggressively replacing older, less fuel-efficient aircraft. Fuel can account for over 30% of operating expenses, making the 15–20% efficiency gains of new aircraft highly compelling.
• Post-Pandemic Recovery — A strong resurgence in global air travel has airlines scrambling to add capacity.
• Growth in Emerging Markets — Rising middle classes in India and Southeast Asia are fueling long-term demand.

The Boeing-Airbus Duopoly

Tier 1 Suppliers: The Power Behind the Throne

The OEMs, while holding the final brand, are fundamentally integrators of complex systems designed and manufactured by a concentrated group of powerful Tier 1 suppliers. These companies are giants in their own right and often hold significant market power:

• Propulsion (Engines) — The most critical and valuable component. (See Section 05.)
• Aerostructures — The physical frame of the aircraft. Spirit AeroSystems (recently re-acquired by Boeing) is a dominant player.
• Avionics — The "brain" of the aircraft. Collins Aerospace (RTX) and Honeywell are the key players.
• Systems — Includes landing gear, electrical, and hydraulic systems. Safran is a leader in landing gear.

The defense aerospace sector operates on a different rhythm than its commercial counterpart. Instead of being driven by economic cycles, demand is dictated by government defense budgets, geopolitical threats, and long-term national security strategies. The United States is by far the largest market. In 2024, global defense budgets grew by a significant 9%, reflecting a heightened global threat environment.

Key Defense Prime Contractors

Key Demand Drivers & Trends

• Geopolitical Tensions — The primary driver of increased defense spending globally.
• Next-Generation Platforms — 6th-gen fighter jets and advanced bombers (B-21 Raider) represent multi-decade procurement cycles.
• Unmanned Systems — The role of UAVs for ISR and strike missions is expanding rapidly.
• Space as a Warfighting Domain — Military satellites, launch capabilities, and space defense are major priorities.
• Modernization & Sustainment — A significant portion of budgets goes to upgrading and maintaining existing fleets.

The propulsion segment is arguably the most attractive and profitable part of the entire aerospace value chain. The market is a tight oligopoly, dominated by just four major players: GE Aerospace, Pratt & Whitney (a subsidiary of RTX), Rolls-Royce, and Safran, who partners with GE in a 50/50 joint venture, CFM International.

The "Razor-and-Blade" Model: New engines are often sold at a low margin, or even at a loss, to secure a position on a new aircraft platform. The real profits are generated over the subsequent 20–30 year lifespan through spare parts and long-term service agreements (LTSAs). It is estimated that engine OEMs and aircraft lessors capture nearly 90% of the entire commercial aerospace industry's profit pool.

Market Share & Key Platforms

The narrowbody market is the largest segment by volume. It is dominated by CFM International, whose LEAP engine is an option on the A320neo and the exclusive engine on the 737 MAX. Pratt & Whitney competes with its Geared Turbofan (GTF) on the A320neo and is exclusive on the A220 and Embraer E2.

The widebody market is a three-way competition. Rolls-Royce has a strong position with its Trent family on the A350 and A330neo. GE Aerospace is the exclusive provider for the Boeing 777X with its massive GE9X engine.

The global aircraft engine market was valued at nearly $90 billion in 2024 and is projected to grow to over $134 billion by 2030.

While the sale of new aircraft generates headlines, the real profitability in the aerospace industry is found in the aftermarket. This encompasses all products and services provided after the initial sale: maintenance, repairs, overhauls (MRO), spare parts, and software upgrades. The global commercial aerospace MRO market alone was valued at approximately $120 billion in 2025 and is expected to grow to $157 billion by 2035.

MRO Market Segments

The TransDigm & HEICO Model

Companies like TransDigm Group (TDG) and HEICO (HEI) have built incredibly profitable businesses by focusing on the aerospace components aftermarket. Their strategy is a masterclass in value extraction:

1. Acquire Sole-Source Businesses — They acquire companies that manufacture proprietary, sole-source components where they are the only approved supplier.
2. Leverage Pricing Power — With no competition, they command significant pricing power. The cost of a single component is often a rounding error in total aircraft operating cost.
3. Focus on Aftermarket — TransDigm generates an estimated 70%+ EBITDA margins on aftermarket sales, which account for over 60% of its revenue.

HEICO operates a similar model but also produces FAA-approved, non-OEM alternative parts (PMA) that compete at a 30–40% discount to OEM parts. This creates a duopoly in many component markets while still allowing highly attractive margins.

For an investor new to the aerospace sector, understanding the different business models is key to identifying the most attractive opportunities.