Unfortunately, we are unable to recommend a straight-line depreciation profile for the aircraft. We provide an exponential depreciation profile under our Base Value and Soft Market Value projection. Should the end user of our reports wish to use a straight-line depreciation profile for book keeping purposes, it is down to their discretion what profile they adopt, bearing in mind where our Base and Soft Market Values stand at given junctures in time in the future.
It is highly dependent on the holding period of the aircraft. For example, if the aircraft is to be held until an example future year, the end-user may wish to depreciate from the Current Market Value to the Soft Market Value in that future year (as a conservative approach) in a straight line, or for a less conservative approach, from the Current Market Value down to the Base Value in the future year. However, we cannot provide the profile ourselves.
For more information on Values Methodology see here