APU EGT down to 0-100 °C
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Hi all,
I have a weird behaviour of the APU on the RJ Professional and the 146, which I haven't found on the forum. I am using MSFS 2020, latest patch.
I start the APU normally. RPM and EGT increase normally. APU Gen is on. APU Air is off.
After a few minutes, sometimes more, sometimes less, the APU EGT goes down to 100-200 °C. I also had the EGT just drop instantly to 0 as if I had pressed "Stop". RPM is still 100 %.
Only if I change something with apu air on or off, one pack on or off, the EGT begins to rise again to 450 °C. But this only stands for a few minutes. Then the cycle begins again. I have no idea, what is causing this.
Also, the Cabin Temp sometimes falls to 10. This sometimes happens, if I change my view to the outside view.Has anyone else seen this behaviour?
Thanks in advance.
Best regards,
Chris
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It is expected behaviour that the APU TGT will vary depending on load. The APU has more load when the APU AIR/PACKS are ON, so EGT will increase.
When the APU switch is set to OFF, it is expected behaviour for the APU RPM and TGT needles to instantly drop to 0 in early examples of the 146 (as we have simulated). This is due to power being removed from the APU ECU, which also removes power from the APU instruments (something which an ECU mod changed on later 146/RJ examples).
The cabin temperature in the 146 is simulated to be affected by a variety of factors, including air supply, temperature selection on the Air Conditioning panels, passenger/service door position, and if the aircraft is in direct sunlight. If the aircraft's doors are open in cold weather, the cabin temperature will decrease.
We're not aware of any issues with the APU remaining at 100% after APU shutdown, and we haven't seen any reports of APU EGTs as low as 100/200℃. However, if this is something that is repeatable behaviour, could I kindly ask you to open a ticket with Just Flight Support via the following link: https://www.justflight.com/support
In the ticket, if you are able to provide steps for how to reproduce this behaviour, including the steps taken to set up the aircraft in the state in which this behaviour occurs, as well as the weather at the time, then our support team will be in the best position to assist with further troubleshooting, or pass this information over to the development team if required.
Mark - Just Flight
