As noted in Section 1.4 of the AI Flight Planner user manual and discussed elsewhere in this forum, if an AI aircraft is scheduled to arrive more than about 37 minutes later than it would based on leg distance divided by the cruising speed specified in the aircraft....txt file, it will not materialize for landing. Instead, it will spawn in a parking spot at the destination airport prior to departure for the next leg. I coined the name “the 37-minute problem”. To address this problem, some suppliers of complete AI add-on packages, such as World of AI (WoAI), and of airline AI flight plans, such as AIG Alpha-India Group, specify a cruise speed of 200 kts for all aircraft in the aircraft file.
This artificial cruising speed is problematic when used in conjunction with AI Flight Planner:
• For jet passenger aircraft, the calculated duration of each flight plan leg will be much longer than (2-3 times) the real-world value and, consequently, the calculated ETA will be very late. Hence, you’ll have to specify arrival time in all cases.
• As discussed in Section 1.4 of the user manual, AI Flight Planner has its own solution to the 37-minute problem - halving the specified cruise speed. This results in a cruising speed in the traffic file of only 100kts. Fortunately, with one exception, this will not materially affect AI arrival times - so long as you override system-calculated arrival time. That exception is AI departing from a distant airport (>75-100 miles) and scheduled to do TNGs prior to arrival. They will still be late - how late depending on the aircraft's normal cruising speed.
So, when using such prepared flight plan information, you should restore the aircraft cruise speed to the value in the relevant aircraft.cfg file.
Don
This artificial cruising speed is problematic when used in conjunction with AI Flight Planner:
• For jet passenger aircraft, the calculated duration of each flight plan leg will be much longer than (2-3 times) the real-world value and, consequently, the calculated ETA will be very late. Hence, you’ll have to specify arrival time in all cases.
• As discussed in Section 1.4 of the user manual, AI Flight Planner has its own solution to the 37-minute problem - halving the specified cruise speed. This results in a cruising speed in the traffic file of only 100kts. Fortunately, with one exception, this will not materially affect AI arrival times - so long as you override system-calculated arrival time. That exception is AI departing from a distant airport (>75-100 miles) and scheduled to do TNGs prior to arrival. They will still be late - how late depending on the aircraft's normal cruising speed.
So, when using such prepared flight plan information, you should restore the aircraft cruise speed to the value in the relevant aircraft.cfg file.
Don
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