CARBON MONOXIDE

Carbon monoxide is an odourless, colourless gas which is present in the smoke from almost all aircraft fires and in aircraft exhaust gases, particularly from piston engines. Inhaled carbon monoxide passes easily into the bloodstream where it enters the red blood cells and binds to the haemoglobin, thus preventing the carriage of oxygen from the lungs to the tissues, so that the tissues become hypoxic.

Whenever it is suspected that carbon monoxide may be present in the air, immediate action is required to avoid poisoning and incapacitation. First of all, an exhaust-driven heating system has to be switched off and the cabin must be ventilated with fresh air. If installed, pilots should don oxygen masks. A diversion to the closest suitable airfield is required in any case. After landing, an aeromedical examiner (AME) should be consulted to assess health effects.

The given options for this question vary each time, depending on the authority. In order to answer correctly keep in mind that in case of carbon monoxide poisoning you should:

• Turn cabin heat OFF.
• INCREASE ventilation of fresh air.
• Open the window if possible.
• Land as soon as possible/practicable.
• Seek medical attention.

Note: Opening the window will bring fresh air in the aircraft.
Note 2: This question is seen as a 'tick box' question in UK CAA (select 4 out of 6 options).