Sun’s out, Doors off – How to keep cool in the cockpit when it’s hot, hot, hot!
Before we commence flying one of our first tasks is to check the weather and top of the list on the weather briefing is temperature. During the Summer it’s the heat we need to watch out for. Temperature affects both the pilots and the helicopters themselves.
Much of keeping cool in the helicopter is just common sense; Keep well hydrated, Sun cream obviously, a cap and/or sunglasses are a good idea to avoid glare from the windscreen and where possible fly away from the sun. Fly higher helps as the temperature at higher altitude (at least 2000ft amsl) is lower and therefore is more comfortable on hot days. Always keep the cockpit well ventilated and be aware of haze as will be reduced visibility considerably.
There is a ‘tool’ we recommend every pilot uses before each flight to verify that you are actually fit to fly. This tool comes in the form of an acronym – ImSafe
Illness – Any symptoms? Do I feel dehydrated?
Medication – Have you taken any?
Stress – Am I under psychological pressure from the job, financial matters, health problems, or family discord? Am I too hot?
Alcohol – Have I been drinking within 8 hours? Within 24 hours?
Fatigue – Am I tired and not adequately rested? Tired from the heat?
Eating – Am I adequately nourished?
This acronym helps you to double check the most vulnerable part of flying – yourself. There is no shame in cancelling a flight if you do not feel fit for flight. Is it simply too hot to fly? Have I been drinking enough liquid in this heat? All good points to note within the ImSafe check.
Before we move on to how heat affects the aircraft a quick note regarding suncream; be cautious about applying too much to your forehead as can be washed into your eyes as you perspire and cause temporary blindness so watch out for that.
If you look at how heat effects flying in terms of the helicopter surprisingly helicopters favour the winter months. Performance is degraded when it’s hot as the engine and rotor blades are more efficient at lower temperatures. Why? Well when the air is colder this helps cool the engine and as cooler air is denser there is more ‘food’ for the air-intake of the engine. It’s important to keep engine oil level closer to its maximum as it helps cool the engine. You may find the helicopter has less reserve power making hovering more hazardous and look out for potential overheating just as you would expect from your car.
It’s important to note that you should check the helicopter’s performance graphs (in the POH or Flight Manual) before flight so that you are sure of what limits you are operating within and if the helicopter is capable of what you are asking it to do. For example, in certain conditions you may not be able to hover out of ground effect and if you need to do this, it’s a good thing to know before flight!
Lastly when you’ve tried everything else and it’s still too hot then its time to take the doors off!