In event of engine failure, planes have a small emergency turbine that pops out to generate power

Fun fact: In event of engine and backup failure, planes have an emergency turbine that pops out to generate power.https://t.co/s80GZqIiQx pic.twitter.com/b9WJmhokNl

— SwiftOnSecurity (@SwiftOnSecurity) April 13, 2017

Not a joke:

The Airbus A380 has the largest RAT propeller in the world at 1.63 metres (5.3 ft) in diameter, but around 80 centimetres (2.6 ft) is more common. A typical large RAT on a commercial aircraft can be capable of producing 5 to 70 kW

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The following aviation incidents involved the deployment of a ram air turbine:

1983: Air Canada Flight 143; also known as the Gimli Glider incident

1996: The hijacking of Ethiopian Airlines Flight 961

2000: Hapag-Lloyd Flight 3378

2001: Air Transat Flight 236

2004: Pinnacle Airlines Flight 3701

2009: US Airways Flight 1549[4]

2020: Pakistan International Airlines Flight 8303