| A | To keep things simple, consider the case where all flights have been in the same Make & Model (Category/Class and Type) of aircraft. To calculate the "expiration" dates for takeoff & landing currency, AeroLog first calculates the starting and ending dates of a ''window'' in time from the current date (the date entered in the currency report setup window) back 90 days. Then, beginning with the latest flight in this window, it scans backwards (reverse chronological order) through the flights, accumulating independent totals of Day Takeoffs, Day Landings, Night Takeoffs and Night Landings. After each flight is scanned, AeroLog checks to see if the totals have met or exceeded the minimum required (3, with the current regs). Since night T&L count toward day currency, it does a combined check for day. If minimums have been met, it stores the date of the flight which pushed to total "over the top". Specifically, it does four different checks, and remembers four different dates (Day_Takeoff_Date, Day_Landing_Date, Night_Takeoff_Date, and Night_Landing_Date): - If (Day Takeoffs + Night Takeoffs) is greater than 3, set the Day_Takeoff_Date to the departure date of the flight. \r\n
- If (Day Landings + Night Landings) is greater than 3, set the Day_Landing_Date to the arrival date of the flight. \r\n
- If Night Takeoffs is greater than 3, set the Night_Takeoff_Date to the departure date of the flight.
- If Night Landings is greater than 3, set the Night_Landing_Date to the arrival date of the flight.
The scan and totaling continues until all flights in the time "window" have been totaled. However, once a date as been stored, it is never overwritten with an earlier date. At the end of the process the program has four dates which indicat
e the respective dates when the currency requirements were met. However, as we all know, the regs specifically state that you must do 3 takeoffs and landings. So, the program must combine the two "day" dates (Day_Takeoff_Date & Day_Landing_Date) and the two "night" dates (Night_Takeoff_Date & Night_Landing_Date). Here the program simply selects the earlier of the two. For example, if the scan shows that your day takeoffs minimum was met on 9/15/02, but your day landing minimum was not met until back on 8/30/02, then the date you met the minimum for day takeoffs and landings was on 8/30/02. The combination produces two dates -- the date when Day T&L minimums were met, and the date when Night T&L minimums were met. To get the corresponding "expiration" dates, the program simply advances each date by 90 days. The entire process described above is done for each Make & Model (Cat/Class/Type) of aircraft flown in the 90-day time "window". In addition, the program does totaling by Category/Class alone. The resulting totals and dates are reported in the Pilot Currency Summary report. |
