Aircraft engine makers have an increasingly valuable business beyond selling engines: keeping the ones already flying in service. RTX Corp (RTX)'s latest results show how much that opportunity matters, but GE Aerospace (GE) is chasing the same revenue stream with substantial scale of its own.

The emerging competition is less about engine deliveries alone and more about who captures the spending that follows.

The Aftermarket Is Driving Growth

Pratt & Whitney's commercial aftermarket sales rose 21% year over year in the third quarter, according to RTX's third-quarter earnings presentation. Commercial original-equipment sales, by contrast, fell 5%, with RTX attributing the decline to the mix of large commercial engines.

The split matters because selling a new engine is only one part of its economic life. Maintenance, repairs and replacement parts can generate revenue over years of operation, making the installed engine base an important source of recurring business.

Pratt & Whitney's adjusted sales rose 10% to $9.23 billion, while adjusted operating profit increased 29% to $968 million. Higher commercial aftermarket volume helped drive the profit improvement, although unfavorable engine and aftermarket mix, higher selling, general and administrative expenses, and approximately $160 million in tariff-related cost recovery also affected the results.

The distinction is important for investors: aftermarket growth is contributing to performance, but it does not automatically translate into equivalent profit growth.

GE Aerospace Brings Scale

GE Aerospace's latest results show that the opportunity extends across the industry. Its commercial engines and services segment generated $10.34 billion in third-quarter revenue, up 21% year over year, according to the company's earnings release.

Within that business, services revenue increased 17%, internal engine-shop visit revenue rose 12%, and spare-parts revenue grew more than 20%. GE also reported a commercial services backlog exceeding $170 billion.

The comparison needs context: GE's 21% growth figure covers its broader commercial engines and services segment, rather than aftermarket sales alone. Still, its services growth and backlog underscore the scale of the recurring-revenue opportunity that Pratt & Whitney is pursuing.

GE CEO Larry Culp said the company expects commercial services to grow at a low-double-digit rate in 2027, supported by that backlog.

What Investors Should Watch

The competitive question is whether Pratt & Whitney can sustain aftermarket growth while improving the economics of its engine business. Its reported third-quarter operating profit fell 19% to $608 million, including a $363 million customer-bankruptcy charge, even as adjusted profit increased.

For RTX investors, the next test is whether higher service volumes translate into durable earnings and cash generation without relying on one-time recoveries.

GE's results provide a useful benchmark, but the companies' differing segment definitions mean investors should compare service growth, margins and cash flow—not headline growth rates alone.