Depreciation on aircraft recognized when operational preparations precede airworthiness certificate, affecting tax depreciation timing.
The tribunal treated preparatory expenditures to make a newly acquired aircraft operational as integral to business activity for determining the timing of depreciation, remitted the classification and amortisation of engine improvement and overhaul costs to the assessing officer, allowed component replacement and repair costs as revenue deductions because they did not extend useful life, and confirmed that interest on TDS is not an allowable deduction.