ENGINES 2.qxp_Finance 26/01/2022 13:41 Page 1
ENGINES
Engine Overhaul Acronyms: Understanding the Jargon Engine overhauls are a complex area, further complicated for uninitiated aircraft owners by various acronyms. Dave Higdon dissects what’s implied when your LLCs need changing, or an HSI is necessary – and what the TBO for your powerplants implies anyway!
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topic most pilots and operators dread discussing, business airplane overhauls and major inspections loom at set periods in the operating life of every aircraft. They’re an inevitable fact of life. Without an engine maintenance program in place, they can be unpredictably expensive. And even with a program in place, they are time consuming, grounding the jet for a period of weeks. They also need to be understood in order for the owner/operator to keep a handle on planning ahead, and managing the process from their side of the equation. Part of that is to understand exactly what will be involved – which will help explain the high costs and time required. For that, insights into what some of the acronyms stand for is important. 22 Vol 26 Issue 2 2022 AVBUYER MAGAZINE
TBO: Time Between Overhaul
The Time Between Overhaul (TBO) of an engine is set by the engine manufacturer and submitted to the FAA as part of the manufacturer’s typecertificate application. This number usually runs into the thousands-of-hours for mature engines. Operators of turboprop aircraft will find that propellers – especially constant-speed props – also operate with a TBO that is set by the OEM, as do some of the analog flight instruments installed in many a business jet and turboprop panel. In fact, the attraction of longer TBOs is one of the motivations cited by operators who are upgrading their aircraft with digital, glass cockpits. For operators flying well above the average number of annual hours in Business Aviation, the need to overhaul Horizontal Situation Indicators is one incentive cited for moving to digital Primary www.AVBUYER.com