Why does the cabin of commercial airplanes always smell like fuel smoke coming out from the internal ventilation a few minutes before taking off, I think when the pilot puts thrust into the engines before going to the runway?

A few days ago I went on a trip and noticed this too, when landing. Is it normal?

What is the reason to have the passengers smoked?


  • 4
    $\begingroup$ Welcome. I don't understand the question: Do you mean why airplanes have a fuel smell before taking-off? $\endgroup$
    – mins
    Feb 19, 2016 at 18:37
  • $\begingroup$ I don't know the term, but it's exactly what Dave answered bellow. Thanks everybody for fixing my grammar errors. I really appreciate the fixes :) $\endgroup$ Feb 21, 2016 at 12:07

1 Answer 1


This is often a result of when the planes push back from the gate or if there is a direct tail wind on the ground. The pressurization system for aircraft uses bleed air from the compression stage of the engine. If the engines are running at push back or idling when a tail wind hits them the brief reversed airflow can cause some vaporous fuel to make its way forward in the engine and come through the air system causing the smell. This page covers it pretty well. Patrick Smith also touches upon it here.

  • $\begingroup$ Those links are VERY interesting. Thanks! $\endgroup$ Feb 21, 2016 at 12:18
  • 2
    $\begingroup$ If you are interested in Aviation in general (as well as the topic here) Patrick Smiths book is a great read and pretty easy to get through (I just finished it). $\endgroup$
    – Dave
    Feb 21, 2016 at 17:22
  • $\begingroup$ It's extremely unlikely that flow would be reversed in the engine. The engines/APU are just ingesting exhaust/fumes from themselves or other aircraft that is blowing around the airport, or possibly oils leaking upstream in the compressors. $\endgroup$
    – fooot
    Dec 10, 2018 at 16:59

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .