Hedgehog, my tips for you if you are flying a turboprop:
- Go high and go early before you lose the performance to out-climb it (especially if it is a long flight).
- Make good use of the SIGWX and mid-level SIGWX charts and note any areas and levels of mod/sev icing. Plan a cruising level above the areas and levels noted if possible.
- Ask ATC if there have been any reports if there are SIGMETS affecting you.
- Fly in clear air whenever possible (ie. amend your cruising level to stay in the clear air between two layers of cloud when able/necessary).
- If you encounter sudden onset heavy icing, change levels. As others have mentioned you may not have to climb or descend much to get out of the worst of it.
- Even aircraft equipped to fly in icing conditions are not designed to fly in sustained heavy icing where ice can form beyond the protected areas. Always be vigilant and observe how the ice is forming.
- When iced up and running de-ice gear expect a hit on your cruise TAS which may have an effect on your fuel planning and performance
- Regarding the previous point, sometimes descending into warmer air and clearing the ice might be the best option
- Think about what you will do if one of the de-icing systems fail (actions will vary a lot based on MEL requirements, which system has failed and the known/forecast weather affecting the flight).