Intake of fluids and food in the cockpit and intake of medicines
Results of investigation reports of air crashes at home and abroad show without fail that too little attention is paid to the right food and fluid balance. (Gliders, too, are particularly at risk on long flights in hot cockpits). Often it is only an accident report that brings to light that a pilot (often without the knowledge of the aviation medical examiner AME) has taken medicines that are not allowed in the cockpit.
Insufficient fluid intake can lead to dehydration and insufficient food intake causes hypoglycaemia. Both a lack of fluids and hypoglycaemia affect performance as they may cause nausea, vertigo, impaired vision, tiredness, high pulse, headaches and inability to concentrate. Medicines can also have side-effects which, although irrelevant in everyday life, can have quite another impact for pilots.
Feeling thirsty is often a bad indication of fluid level in the body so this must be raised before going on flying duty. At least 2 dl of fluids an hour should be drunk during the flight. It does not make a great deal of difference what the beverage is as long as it is not alcohol. Carbonated drinks (which cause flatulence) or undiluted juices are less suitable. Coffee can increase alertness temporarily but acts as a diuretic which can lead to loss of fluids. Hypoglycaemia due to a long period without any food intake can have similar consequences. Chocolate bars or fruit/cereal bars are good emergency snacks for the crewbag if you have a sudden "low".
Be aware that medicines of any description are strictly forbidden while on flying duty unless the medication has been agreed with the aviation medical examiner. There is always a tendency to underestimate the effect medicines can have on one
another, and side-effects which otherwise are negligible have an impact while on flying duty.
This FOCA publication will not guarantee any revisions and new publications on this topic.