Winter has come, and with it a seasonal and insidious menace, worse than anything portrayed in the TV drama Game of Thrones.
You can’t see or smell it, and as it progressively poisons you, you lose your capacity to save yourself. It is, of course, carbon monoxide, (CO) an exhaust pollutant of both piston and turbine engines. Carbon monoxide is a particular hazard in piston engine general aviation aircraft, many of which draw hot air from over the engine exhaust for cabin heating. Any leak in the exhaust transforms the heating system into a cabin CO delivery device.
What can you do to protect yourself? Ensure your aircraft’s exhaust system is in good condition and regularly inspected. Carbon monoxide detection patches are a good idea, but fallible, and some have useful lifespans of no more than 60 days. Awareness of the symptoms is important: they include mild headache, nausea, and slightly increased breathing rate, all of which could be interpreted as simple ill health and fatigue, but if you feel these in an aircraft you should assume you are suffering CO-induced hypoxia. In such a case you should open a window, if you can, shut off the heater, and land ASAP.
Carbon monoxide poisoning is yet another reason for pilots to give up smoking. Regular smokers preload their blood with higher levels of CO from cigarettes, and are more likely to experience hypoxia from any CO in an aircraft cabin.