👉 Deck fumes refer to the unpleasant, often toxic vapors or odors that can accumulate in enclosed spaces like aircraft decks, particularly during takeoff and landing when engines are running at high power. These fumes are primarily composed of carbon monoxide, unburned hydrocarbons, and other combustion byproducts, which can pose serious health risks to pilots and cabin crew, including headaches, dizziness, nausea, and in severe cases, more acute effects like respiratory distress or even death. The enclosed nature of the deck traps these harmful substances, making ventilation critical to prevent their buildup and ensure a safe environment for everyone on board.