What keeps you cool on board an aircraft? | Aviation

Picture the scene. You are boarding a passenger jet bound for sunnier climes. The flight is running a little late, and it’s full. You squeeze into your middle seat between two overly chatty other passengers. It’s warm… Very warm. Despite it being a pleasant 15 degrees celsius outside, here it feels more like 50. You close your eyes and think of the deck chair that awaits you by the pool in just a few short hours. Then comes the most welcome sound known to the expectant passenger. The whoosh of air around the cabin as the air conditioning kicks in. The temperature starts to drop. You feel more alive, more human. You are comfortable – maybe even zen. You are ready for your holiday. 

What you might not know is what to thank for that moment of relief. What magical system has rescued you from the doldrums of humidity? The answer is Bleed Air. 

Bleed Air is one of the most critical systems in modern passenger aircraft, facilitating the most noticeable parts of your passenger experience – namely air conditioning (not sweating too profusely on the ground) and pressurization (being able to breathe at 35,000 feet). Let’s take a dive into what bleed air is and how we use it. 

What is Bleed Air?

Bleed Air is high pressure air that is extracted (or ‘bled’) from the aircraft’s engine compressors and Auxiliary Power Unit (APU) and is used in a myriad of crucial…