PPRuNe Forums - APU Limitations

PPRuNe Forums (https://www.pprune.org/)

- Tech Log (https://www.pprune.org/tech-log-15/)

- - APU Limitations (https://www.pprune.org/tech-log/300273-apu-limitations.html)

tsrp	14th Nov 2007 04:09

APU Limitations

Why is there a Maximum Altitude limitation while the APU is running?

Thanks

tsrp

411A	14th Nov 2007 04:42

On the L1011, it is an APU generator cooling issue.
Max KW reduced as well, while airbourne.

spannersatKL

14th Nov 2007 06:45

APU Surge Margin and basicaly keeping the fire alight!

Chrome

14th Nov 2007 12:14

There is no maximum altitude limitation running the APU on the A320 in a normal 2 engine operation. But at levels greater than FL300 or in greater ISA conditions, APU generator load reduces. There are however limits to APU battery-assisted starts and running the APU for bleed operation.

It has something to do with the pressure, density and temperature at higher levels. Someone else help, I am too hungry now to think :)

All times are GMT. The time now is 17:23.