Most banks hire a professional broker/appraiser to allocate a value to an individual aircraft prior to funding. Appraisals usually include an onsite inspection and can be influenced by complex variables such as the year (manufactured year, delivery year, serial number sequence); time on airframe and engines (or until upcoming major inspection and maintenance events); damage (including where/how repaired); logbook and upgrades history; previous owners (number, type usage, and geographic location); maintenance programs (specially approved maintenance schedules and/or power by the hour engine insurance type plans); avionics; options; current mechanical, interior and exterior condition etc.