Ropey
Sorry but yes you are wrong...
The annual flight pay is made up of 2 elements:[list=1][*]FLIGHT PAY - paid at £9 (it may be £10 now) per planned flying hour. This will be taxed at your marginal rate.[*]DUTY PAY - paid at about £2.60 per hour from report to clear at end of trip. This is taxed at 18%.[/list=1]
Plan on about 750 flying hours per year [shorthaul LHR] and about [from recollection] 2600 hrs TAFB (Time Away From Base) and you won't be far wrong.
HTH