Final answer:
To provide a recommendation for which aircraft lease Qantas should use based on payback and discounted payback periods, a thorough capital budgeting analysis using provided financial metrics and taking the cost of capital into account is essential.
Step-by-step explanation:
To determine the lease with the shortest payback and discounted payback period, a detailed capital budgeting analysis must be conducted using all the provided financial metrics including payback period, discounted payback period, net present value (NPV), internal rate of return (IRR), and profitability index (PI). The choice of aircraft (Airbus A380, Boeing 737, or Comac C919) for Qantas's operating lease would depend on the outcomes of these analyses.
In essence, to ascertain which lease is most beneficial for Qantas, each lease's cash flows and costs, including the initial insurance premium, need to be compared against the lease payments, which are a percentage of net revenues, adjusted for revenue growth. The comparison should consider the cost of capital as a discount rate to compute NPV and the IRR which will assess the leases' profitability over time.