Which is cheaper ,Tom... change the APU or risk the engine...? Suggest you e-mail Bernd....
edit; not knowing why/how /what Fod you`ve got in the APU ,I would be inclined not to use it,as residual `stuff could end up in the engine......
however,if the Injuns are coming over the hill,you may consider a `COLD ROTATION`/no ignition/no fuel,and check the `time of the APU cycle,and how many HPC Rpm you get( you need 20 % as an absolute minimum,24 % for a reasonable start).
Remember the `start cycle` for the main engine runs 45 secs,and then cuts out at 43% HPC Rpm...
If you are at a `normal` airport,I would have thought you could find a mechanic who would be familiar with the Saphir..
Further alternative if the Injuns are closing ,get a ground APU ,stuff the hose in the intake and get 15% HPC,then `airborne relight`...
You could also try that with a `friendly jet or C-130` to park in front and get a `blow-job`...!!
PPS.the APU can be used up to 20000ft..
Last edited by sycamore; 17th Mar 2012 at 15:07.