Heat, Helicopters and the IMSAFE Rule – How to Keep Cool in the Cockpit
We should never complain about the nice sunny weather… except when it is boiling hot! In the morning before each flying day begins we always check the weather, and one of the first items on the weather briefing is temperature.
The temperature affects both the pilots and the helicopters themselves. There is a tool that 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 is as follows:
- 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 checking 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 too hot to fly? Have I been drinking enough liquid in this heat? All good points to note within the IMSAFE check.
If you look at the heat in terms of the helicopter and its performance, an engine likes a nice cool temperature. The reason behind this is it helps cool down the engine and as cooler air is denser there is more ‘food’ for the air-intake of the engine. You may find the helicopter uses more power to hover, or doesn’t climb as fast because the weather is hotter. 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!
It seems to be that sometimes we complain about cold weather and sometimes we complain about hot weather. It’s hard to get it just right!