Lycoming HIO-540-A1A
2 aircraft on the U.S. register carry a Lycoming HIO-540-A1A engine, rated at about 290 horsepower. The Bell 47 is the model most often fitted with it (1 aircraft). The aircraft carrying it were built between 1953 and 2026.
The FAA records engines by code, usually at the level of a series ("O-320 series") rather than the exact variant; this page gathers every FAA code that reads as Lycoming HIO-540-A1A. FAA spelling: HIO-540-A1A.
Fitted to model families
Bell 47 · Thor Mcilrath HUMMINGBIRD 300L
Where they are owner's state
Kind of aircraft
When the aircraft were built by decade
What the FAA has certified, ordered and been told about the Lycoming HIO-540-A1A the component layer
The design is held under 1 type certificate (1E4, held by Lycoming Engines). The FAA has issued 15 airworthiness directives (orders that owners must comply with) that name this engine series.
FAA orders 15 airworthiness directives · newest first
Certificates and bulletins
Safety bulletins 3 · advice, not orders
Sources: the FAA's type certificate data sheets, airworthiness directives, supplemental type certificates, special conditions and special airworthiness information bulletins (Dynamic Regulatory System), and the FAA's service difficulty reports. A failure report is what an operator or repair station chose to file; the counts show reporting as much as reliability, and larger and commercial fleets report more. How the systems are grouped.
Connections how this engine series links to the rest of the register
- Bell 47 1 with this engine series
- Washington 1 of these aircraft
- Florida 1 of these aircraft
- FAA orders naming the Lycoming HIO-540-A1A 15 airworthiness directives
These connections as data: /graph/engine/lycoming-hio-540-a1a.json · about the eFlight graph.
Aircraft newest certificates first · 2
| Tail no. | Maker and model | Group | Owner and base | Certificate | Registered | Status |
|---|---|---|---|---|---|---|
| N795KM | Thor Mcilrath HUMMINGBIRD 300L |
Rotorcraft | Individual owner Washington |
Experimental | 2025-09-19 | ValidFAA registration status code V: Valid registration. All codes |
| N10BU | Bell 47G-2 |
Rotorcraft | Individual owner Florida |
Standard | 2024-07-08 | ValidFAA registration status code V: Valid registration. All codes |
Source: FAA Civil Aviation Registry, Releasable Aircraft Database (the engine reference table and each aircraft's engine code), October 5, 2026. Horsepower and thrust are the FAA's figures for the series, not for a particular aircraft.