Definition
Turbocharging systems installed on a piston aircraft engine after the airplane has left the factory, typically through a Supplemental Type Certificate (STC). These systems use exhaust-driven turbines to compress intake air, allowing the engine to maintain rated power at higher altitudes than it could naturally aspirated, but they are added to an engine that was not originally designed or certified with turbocharging built in.
Plain English
A turbocharger kit added to an aircraft engine after it was built, rather than coming from the factory that way. It lets the engine keep producing more power up high, where the air is thin.
Context Anchor
Seen in induction system discussions, aircraft modification records, and operating instructions for aircraft that were fitted with a turbocharger after original manufacture.
Derivation
‘Aftermarket’ means parts or systems added after the original sale, as opposed to factory-installed. ‘Turbo’ comes from the Latin turbo meaning ‘whirl’ or ‘spinning top’ — a fitting name for a device driven by a fast-spinning turbine wheel.
Why Pilots Care
Pilots must know these systems because they change engine operating limits, require specific maintenance, and affect airworthiness and insurance.
Intuition Check
Aftermarket does not mean homemade or automatically unapproved. It means the system was added after original manufacture; it still must be properly approved and operated according to its own instructions.
Example Sentence 1
The owner installed an aftermarket turbocharging system on his Bonanza so he could cruise comfortably at 16,000 feet.
Example Sentence 2
Before flight, the pilot verified that the aftermarket turbocharging systems were operating within the limits listed in the supplemental type certificate.