Technical Comparison of Piston, Turbofan, and Turboshaft Engines for Low-Altitude Transport Aircraft
Share
1. Introduction
With the gradual opening of low-altitude airspace and the rising demand for regional transportation and eVTOL development, choosing the right propulsion system becomes crucial. This paper compares three major aircraft engine types—Piston, Turbofan, and Turboshaft—from a technical and application perspective, aiming to guide engineering teams in selecting the optimal aircraft configuration for various low-altitude scenarios.
2. Technical Principles and Core Structures
| Engine Type | Working Principle | Core Components | Highlights |
| Piston Engine | Reciprocating piston compresses fuel-air mixture | Cylinders, crankshaft, pistons, spark plugs | Simple, low-cost, low power-to-weight |
| Turbofan Engine | Fan-compressed air burns fuel; thrust via jet exhaust | Fan, compressor, combustor, turbine | High thrust, efficient, quieter |
| Turboshaft | Jet engine drives output shaft (for rotor or prop) | Compressor, combustor, free turbine, shaft | High power output, ideal for helicopters |
3. Performance Summary
Piston Engine:
- Pros: cost-effective, simple, ideal for small/light aircraft
- Cons: limited altitude and power, poor cold-weather adaptability
Turbofan Engine:
- Pros: high thrust-to-weight, efficient at speed and altitude
- Cons: complex, costly, slow throttle response
Turboshaft Engine:
- Pros: high power density, responsive, VTOL capable
- Cons: expensive to maintain, less fuel efficient at cruise
4. Typical Low-Altitude Use Cases
| Scenario | Flight Pattern | Core Requirements |
| Urban Logistics | Low altitude, frequent cycles | Low noise, compact size, responsive, low cost |
| Regional Commute | <300 km trips | Payload, reliability, moderate range |
| Agricultural Patrol | Low-speed, accurate flight | Hovering, low-speed stability, variable power |
| Mountain Supply | Harsh terrain & altitude | Strong power, environmental adaptability |
5. Engine Type Suitability Matrix
| Use Case | Piston Engine | Turbofan Engine | Turboshaft Engine |
| Urban Logistics | ✅✅✅ | ❌ | ✅✅ |
| Suburban Commute | ✅✅ | ✅✅✅ | ✅✅✅ |
| Mountain Supply | ❌ | ❌ | ✅✅✅✅ |
| Agricultural Use | ✅✅✅ | ❌ | ✅✅✅ |
| Plateau Flight | ❌ | ✅ | ✅✅✅✅ |
6. Representative Aircraft Case Comparison
| Specification | Cessna 172 Skyhawk | HondaJet Elite II | Airbus H145 |
| Engine Type | Piston Engine | Turbofan Engine | Turboshaft Engine |
| Engine Model | Lycoming IO-360-L2A | GE Honda HF120 | Safran Arriel 2E (Dual) |
| Max Takeoff Weight | 1,111 kg | 4,800 kg | 3,800 kg |
| Max Speed | 226 km/h | 782 km/h | 268 km/h |
| Service Ceiling | 4,115 m | 13,106 m | 5,240 m |
| Max Range | 1,289 km | 2,625 km | 662 km |
| Seating Capacity | 4 passengers | 6 passengers | Up to 10 (including crew) |
| Takeoff Distance | 293 m | 950 m | VTOL (Vertical Takeoff) |
| Hover Capability | No | No | Yes |
| Fuel Type | AvGas 100LL | Jet A | Jet A1 |
| Typical Applications | Private use, training, inspection | Regional business travel | Emergency rescue, mountain delivery |
7. Recommendation
- Piston engines suit light-duty, short-range, cost-sensitive roles.
- Turbofans fit mid-range, high-speed, comfortable transport needs.
- Turboshafts are best for VTOL, rugged terrain, and high-power missions.