View Full Version : APU Limitations
Why is there a Maximum Altitude limitation while the APU is running?
Thanks
tsrp
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 :)