Airplane Engines Running at a Terminal
Q: If the APU supplies ground power, why do you often see the engines turning while a plane rests at the terminal? Isn’t that a waste of fuel?
Jets almost never run their engines at the gate. What you see is the wind spinning the first stage turbofan. Despite its weight and size, the breeze can rotate that fan like a windmill, sometimes quite rapidly. If that seems impossible when a plane is cornered against a building or facing the wrong direction, that’s because the wind is coming from behind. On a modern jet engine, some 80 percent of intake air is blown around the core of compressors and turbines, providing a clear shot at the fan blades from the rear. The wind blows through this duct between core and cowl and sets the assembly in motion.
This article is part of a collection that originally appeared on Salon.com. Patrick Smith, 38, is an erstwhile airline pilot, retired punk rocker and air travel columnist. His book, Ask the Pilot (Riverhead) was voted “Best Travel Book of 2004″ by Amazon.com. Patrick has traveled to more than 55 countries and always asks for a window seat. He lives near Boston.
Some pages you might find helpful:
- 747 Fly a Loop
- Adjusting Weight on Planes
- Air Force One and Markings of a Jet
- Airline Announcements
- Airline Gags
- Airline Registrations
- Airplane Crash on “Lost”
- Airplane Engines Running at a Terminal
- Airplane Fuel Different From Other Fuel
- Airplane Noise Maneuvers
- Airplane Structure
- Arctic Flights
- Art and the Airplane
- Cleared to Land
- Cool Mapping Systems and 3-Engine Planes
- Destinations for First Timers
- Dinging on Flights
- Do crews eat the same terrible food as the rest of us?
- Exhaust
- Expensive Jet Fuel
- Flight Cancellation Due to Weather
- Flight Logbooks
- Flying Without a Tail
- Fuel Flying Cross USA
- Heavy Airplanes
- Heavy Fliers and Fuel Consumption
- How are pilots evaluated for promotions and raises?
- How Do Engines Start?
- How Does a Jet Engine Work?
- In-Town Airports
- Items Taken at Airports
- Landing at the Wrong Airport
- Left and Right Runways
- Life and Times of Patrick Smith
- Life as a Pilot
- Listening to Pilot Communication
- Noise of Boeing vs. Airbus
- Nonstop to India from the United States
- Office Paper and Other Misfortunes
- Onboard Music Offerings
- Open Window Shade on Landing
- Overpaid Pilots?
- Pet Treatment on Planes
- Pilot Identification
- Pilot Pay and Seniority
- Pink Liquid De-Icing Planes
- Plane Taking Off in Opposite Direction of Destination
- Religion in the Skies
- Rudder Deflection
- Shutting Down an Engine Mid-Flight
- Shutting Down One Engine After Landing
- Slanting Planes
- Southern, Northern Flights and Safety Standards
- Tape on Airplanes
- Top Views from an Airplane
- Unusual Airplanes
- Weight of Planes
- Westbound Red Eye Flights
- What are some ways in which passengers can make the crew’s job easier?
- What are those numbers and letters for on the back of every plane’s fuselage?
- What do the Pilots do?
- What to do with Crews?
- Which airports do pilots dislike most, and which do they enjoy?
- Why Delays After Emergency Landings?
- Why Not Cancel an Empty Flight?
