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✈️ What is RAT - Ram Air Turbine in Aviation and How It Helps During Emergency Situations
- DAVID AYLING J
- 17 hours ago
- 3 min read
RAT - Ram Air Turbine
Understanding the lifesaving role of the Ram Air Turbine when systems fail mid-air.
A simple explanation of how the Ram Air Turbine powers critical systems when aircraft face total power loss.
In the world of aviation, precision and preparedness are key. Commercial aircraft are equipped with multiple systems designed to ensure safety—even when something goes wrong. One such smart safety feature is the Ram Air Turbine, often abbreviated as RAT. This compact, wind-driven device depends entirely on something known as RAM air.
But what exactly is RAM air in aviation, and how does it help a modern aircraft stay functional during emergencies?
💨 Understanding RAM Air
RAM air in aviation refers to the airflow that enters an opening due to the forward motion of the aircraft. As a plane travels through the air, it essentially "rams" into the surrounding air, forcing it into various inlets and intakes. This airflow is not powered by any engine or mechanical pump—it's generated solely by the aircraft’s speed and movement through the atmosphere.
RAM air is used in several aircraft systems, but its most life-critical application is found in the Ram Air Turbine.
⚙️ What is a Ram Air Turbine (RAT)?
The Ram Air Turbine (RAT) is a small, foldable turbine that is typically installed inside the fuselage or wing fairings of an aircraft. It stays hidden during normal flight operations and is designed to automatically or manually deploy in the event of major system failures, such as:
A complete loss of electrical power
A total hydraulic system failure
Dual engine failure, in certain cases
Once deployed, the RAT spins as air flows through it, using that rotational energy to generate either electrical power, hydraulic pressure, or both—depending on the aircraft model.
This emergency power is then used to operate essential systems such as:
Basic flight controls
Primary flight instruments
Communication and navigation equipment
Hydraulic actuators (in aircraft like Airbus)
🛫 When Does the RAT Deploy?
In most commercial aircraft, RAT deployment is automatic under specific emergency conditions. However, there is often a manual switch in the cockpit that allows pilots to deploy it preemptively if they anticipate a failure or need to conduct a system check.
It's important to understand that the RAT is not intended to restore full functionality to the aircraft. Instead, it provides enough backup power to keep essential flight systems operational long enough for the pilots to manage the emergency and perform a controlled landing.
⚠️ Are There Limitations?
Yes. While the RAT is an incredibly useful backup tool, it has some operational limitations:
Speed Dependency:For the turbine to spin fast enough to generate usable power, the aircraft must be moving at a certain minimum speed (typically over 100 knots, or ~185 km/h).
Altitude Considerations:The RAT becomes most useful when there is sufficient altitude and time for the aircraft to glide while it deploys and begins functioning.
While no universal minimum altitude is officially published across all aircraft types, the turbine needs enough airflow to operate effectively.
If a system failure occurs at very low altitudes, such as during takeoff or final approach (typically below 650 feet), the RAT may not have time or airflow to deploy and stabilize.
Limited Power:It powers only critical systems, not everything on board. Passengers would still experience limited lighting, no air conditioning, and other service disruptions.
✈️ Which Aircraft Use RATs?
Modern airliners and even some military aircraft are equipped with RATs, including:
Airbus A320, A330, A350 series
Boeing 787 Dreamliner
Embraer E-Jets
Some fighter jets like the F-16
Each aircraft model may use the RAT to power slightly different systems, depending on its electrical and hydraulic configurations.
🧠 Final Thoughts
The Ram Air Turbine (RAT) is a remarkable example of how aviation engineering prepares for worst-case scenarios. By using nothing more than the natural flow of air created by the plane’s own motion, it helps pilots retain control and navigate critical moments safely.
While it’s not a magic switch that restores full functionality, its presence ensures that even when multiple systems fail, the aircraft still has a lifeline—powered by nothing but the sky it flies through.
Author
David Ayling J
David Ayling J is an educator, digital content creator, and academic technology consultant involved in giving insights into aviation, education, and emerging technologies. He is passionate about making technical subjects accessible to a wider audience and is actively engaged in content creation, student training, and institutional outreach. His work focuses on empowering learners with relevant, real-world knowledge.
📘 Disclaimer
This article offers a general overview of Ram Air Turbines (RATs) in aviation. It does not serve as a technical manual or operational guideline. For professional or academic use, always refer to official aircraft documentation or certified aviation sources.