I’d build the budget from local quotes and the maintenance status of the particular aircraft.
Start with hangarage or parking, insurance and any recurring inspection, administration or subscription costs. Then add fuel, oil, servicing and an allowance for wear and repairs.
Keep a separate line for larger expenses: engine and propeller work, covering repairs and any servicing or replacement due on the installed rescue system. Their timing needs to come from the relevant records and manufacturer’s instructions.
Annual hours make a big difference to the cost per hour. As a simple illustration, a €1,800 annual hangar bill works out at €36 per flying hour if you fly 50 hours, or €18 if you fly 100. Those are example figures, not a quote for C42 hangarage.
COMCO’s inspection schedule also refers engine maintenance to the applicable Rotax manual. Check the exact engine model and maintenance dates when preparing the budget.
For an aircraft such as this Ikarus C42, ask for a list of work expected over the next 12–24 months. Keep purchase costs and any immediate remedial work separate from the normal annual budget.
Reference: COMCO IKARUS manuals and service documents.
C42 owners: what were your annual hours and costs, and which country were you operating in?