What is Ram Air Turbine in Aviation? The Ram Air Turbine, commonly abbreviated as RAT, is a critical emergency device used in modern aircraft. It is a small turbine that deploys automatically or manually in the event of a major power failure to generate hydraulic or electrical power, ensuring essential flight controls remain operational. The RAT plays a vital role in aviation safety by providing a reliable backup power source when all main systems fail.
Understanding the Function of Ram Air Turbine
The Ram Air Turbine operates by harnessing the relative wind caused by the forward motion of the aircraft. When deployed, the RAT extends into the airstream, and the aerodynamic force spins the turbine blades. This rotational energy is then converted into hydraulic pressure or electrical power through a connected generator. Typically, the turbine measures between 20 to 30 inches in diameter and spins at speeds around 35,000 RPM or more during operation.
In practice, the RAT begins to generate power at speeds as low as 100 knots, providing immediate back-up energy to replace lost engine-driven or auxiliary power unit (APU) systems. The power generated by the RAT is usually sufficient to maintain control over key aircraft functions such as flight controls, instrumentation, and critical avionics. The exact output varies by aircraft model, but electrical power supplied can reach up to 15 kilowatts (kW), while hydraulic systems powered by the RAT maintain pressures around 3,000 psi.
Ram Air Turbine in Aviation Safety
Ram Air Turbine in Aviation is designed as a last-resort safety device, ensuring that pilots maintain sufficient control during catastrophic system failures. One of the most notable aircraft to utilize RATs extensively is the Airbus A320 family, which deploys the RAT automatically if both engines and the main electrical system fail. Similarly, Boeing models such as the 777 and 787 also feature RATs as part of their redundant safety architecture.
The incorporation of Ram Air Turbine in Aviation standards follows strict regulatory criteria from agencies like the FAA and EASA. These regulations demand that RATs be capable of powering at least the essential flight control systems for a minimum duration of 30 minutes. This time frame allows pilots to safely navigate the aircraft to an appropriate landing site in case of a total power loss. The RAT also plays a significant role in elevator, aileron, and rudder control through hydraulic actuation, especially when electric backups are unavailable.
Technical Specifications and Deployment Mechanism of Ram Air Turbine
Ram Air Turbine in Aviation features a robust design engineered to withstand high-speed airflow and adverse environmental conditions. The turbine is usually housed in a compartment within the fuselage or wing root, concealed during normal flight to reduce aerodynamic drag. When a triggering event occurs, such as a loss of engine-driven pumps or main electrical power, the RAT is released by a spring or pyrotechnic mechanism and pivots or slides out into the airstream.
The materials used in RAT construction are often lightweight composites or titanium alloys to optimize performance and durability under airflow speeds exceeding Mach 0.8. The turbine blades typically have a fixed pitch optimized for deployment speed ranges from 100 to 300 knots. Electrical generators connected to the turbine produce a standard 115/200 VAC at 400 Hz frequency or 28 VDC electrical power depending on the aircraft’s electrical architecture.
Additional technical data highlights include the following:
- Diameter: approximately 26 inches (66 cm)
- Rotation speed: ~33,000 – 37,000 RPM
- Hydraulic pressure sustained: ~3,000 psi (pounds per square inch)
- Electrical output: 7 – 15 kW depending on aircraft configuration
- Deployment time: less than 5 seconds after activation
For those interested in a deeper technical dive into RATs, NASA and FAA technical reports provide comprehensive analyses on operational parameters and testing methodologies. More details can be found on authoritative aviation sites such as FAA.gov.
In summary, understanding what is Ram Air Turbine in Aviation offers insights into how aircraft safety is preserved even during complete power failures. The RAT remains a critical backup system that exemplifies the aviation industry’s commitment to redundancy, reliability, and the safeguarding of human lives.