Assume that White Knuckle Airlines Inc. operates a regional fifty-seat jet aircraft fleet. White Knuckle expects that there will be a constant demand for this type of flight service, and that the model of aircraft employed will remain in production for the foreseeable future. White Knuckle has predicted the set of operational cash flows shown in Table 6.11 for each aircraft.
If White Knuckle Inc. has a required rate of return of $12 \%$ per annum, determine the optimal aircraft replacement cycle time, in perpetuity.