![airliner - What exactly are those openings in the bellies of many jetliners? - Aviation Stack Exchange airliner - What exactly are those openings in the bellies of many jetliners? - Aviation Stack Exchange](https://i.stack.imgur.com/mJHRy.jpg)
airliner - What exactly are those openings in the bellies of many jetliners? - Aviation Stack Exchange
![File:Air intakes of RAM air for environmental control systems of Boeing 747-8I.jpg - Wikimedia Commons File:Air intakes of RAM air for environmental control systems of Boeing 747-8I.jpg - Wikimedia Commons](https://upload.wikimedia.org/wikipedia/commons/1/1f/Air_intakes_of_RAM_air_for_environmental_control_systems_of_Boeing_747-8I.jpg)
File:Air intakes of RAM air for environmental control systems of Boeing 747-8I.jpg - Wikimedia Commons
The PACK 1 ram air inlet door is seen closing after the APU bleed air was selected to the off position. | By A320 Systems | Facebook
![aerodynamics - Why is an air intake located on the root of the tail on some aircraft? - Aviation Stack Exchange aerodynamics - Why is an air intake located on the root of the tail on some aircraft? - Aviation Stack Exchange](https://i.stack.imgur.com/FUVnR.png)