Ask the pilot: Can an aircraft Glide?
Who better to answer such questions than the pilots themselves.
“How long and how far an aircraft can glide depends on its glide ratio and current winds.”
Can an aircraft glide? If so, for how long?
/Daniel
Hi Daniel,
For fuel saving reasons we always aim to make an idle descent all the way to touchdown on every flight, which means staying at our cruising altitude for as long as possible to burn as little fuel as possible before starting our descent. This doesn’t always happen at major airports, especially during peak hours, and because of airspace restrictions. However, at many airports in our route network with less traffic, there’s often arrival routes where we can achieve the optimal descent profile all the way to touchdown.
We use these “green approaches” whenever possible to reduce total track miles flown compared to a conventional approach. The green approaches are often curved around urban areas to reduce both noise and the environmental footprint. When reaching the top of our descent the engines will reduce thrust to idle and the aircraft starts to head down. We’re now exchanging energy by trading the altitude loss to maintain forward airspeed and air flow over the wings. In reality, we’re now actually gliding, which is the aim on every flight.
To answer your question, in the highly unlikely event that all engines fail, the aircraft will, as described above, still be able to glide. In this case, we’d aim for the speed that gives the best lift-to-drag ratio, which gives us the maximum time to glide while performing the procedures for restarting the engines and finding a suitable airport to land at. How long and how far an aircraft can glide depends on its glide ratio and current winds. In still air conditions an aircraft can glide approximately 100 nautical miles (185km) and stay in the air for approximately 20–30 minutes, starting from cruise level.
Pernilla Nilsson
Senior First Officer
Pernilla Nilsson
Title: Senior First Officer
Home base: Copenhagen
Flies: A319, A320, A321
Flight hours: 13,500
Favorite airport: Most of the Norwegian airports. They can be very challenging in harsh weather but a beautiful day it’s unbeatable. The landscape is fantastic with the mountains and fjords. You’ll never get tired of this view.