That Rumble Before Takeoff? It’s Not the Engines 👀 Most people think it’s engine startup but it’s actually the aircraft’s Auxiliary Power Unit (APU) and hydraulics doing their thing during pushback. Disclaimer: Engines are often started during pushback, but this is a generalisation and not airline/procedure-specific. These are my personal views based on experience. This content is for guidance only and does not represent the views of any airline or institution. #fyp #aviation #airlinepilot #thi