Thousands of jetliners propelled by turbofan engines conduct commercial flights on a daily basis. If the primary power source malfunctions, pilots can typically rely on the aircraft’s Auxiliary Power Unit (APU). Nonetheless, aircraft manufacturers must also account for the possibility that the APU will malfunction in certain circumstances. Ram Air Turbines, commonly referred to as RATs, are mounted in aircraft for this purpose. But could you explain how to use this device?

How precisely does a RAT operate?

The Ram Air Turbine is a miniature auxiliary propeller that an aircraft can deploy if it loses power. For effective operation, it generates electricity from the airflow that flows over it while the aircraft is in flight. This results in the turbine rotating. In certain configurations, the generator or the hydraulic pump can be connected to the turbine. Thus, it can contribute to either the aircraft’s electrical or control systems.

The scale of the RAT is anticipated to be comparable to that of the aircraft on which it is mounted. Given that its diameter is 1.63 meters, it should not come as a surprise that the Airbus A380 use to have the biggest RAT among contemporary airliners. A typical RAT, when activated in an emergency situation, will have a width of about 80 centimeters and the capacity to generate between 5 and 70 kW of electricity.

“Gimli Glider” refers to the emergency use of the RAT

There have been other instances in which the RAT of an aircraft has been used to provide emergency power. According to Collins Aerospace, the device has averted up to 1,700 fatalities in 16 separate confirmed incidents. The most notable of these was the accident of Air Canada flight 143. In 1983, while operating between Montreal and Edmonton, this domestic service ran out of gasoline.

After successfully gliding down in altitude from 41,000 feet, the crew of the Boeing 767 was able to perform an emergency landing at the RCAF Station Gimli in Manitoba. Due to this, the event became known as the ‘Gimli Glider.’ The crew’s pre-landing maneuvers caused airflow disturbances around the RAT, delaying the touchdown. This reduced the aircraft’s hydraulic power even further, making it more difficult to operate. Despite this, the pilots and flight attendants were able to land the aircraft securely, with no fatalities and only ten minor injuries reported among the 69 passengers.

Notable RAT operations conducted in the twenty-first century

In addition, the RAT was employed in 2001 during an emergency fuel depletion situation involving Air Transat flight 236. After running out of fuel over the Atlantic Ocean, the Toronto-to-Lisbon-bound Airbus A330 glided for more than 100 miles during this incident. The plane made a successful emergency landing at Lajes Airport in the Azores, with no casualties and only 18 injuries among the 306 passengers and crew members on board.

A number of other factors, such as a collision with a bird, can also cause an aircraft to lose power. 2009’s bird attack on US Airways flight 1549 is likely the most recognizable incident involving recent bird strikes. In this instance, a departing Airbus A320 collided with a flock of geese, causing the aircraft to lose all of its propulsion over New York.