Allison Model 250 C20 Turboshaft Operational range
Allison Model 250 C20 Turboshaft Operational range
(OP)
Hi,
Any RR or Allison engineers or others that could help me with these 2 questions?
1. I know that in a MD-520 Helicopter the engine (Allison Model 250 C20 Turboshaft) is installed with engine axis under 45° compressor up, while the same engine is installed in many other helicopters and aircraft engine axis more or less 0° .
Besides the fact that it would not be recommended for dirt ingestion, do you think that the engine can also be installed and operated 45° compressor down?
If so, it would be possible to use this engine for certain VTOL applications where the engine is tilted over an angle range of 90°.
2. If the above question does not answer with a yes. Say I install the engine with engine axis in transverse direction, do you think it is capable of operating in a rolled (I mean rolled about engine axis) attitude of +45° through -45°?
Even though I would be so happy if one of these two questions would be answered with a yes, do not say yes if you are not really sure.
Thanks.
OneMoreChance
Any RR or Allison engineers or others that could help me with these 2 questions?
1. I know that in a MD-520 Helicopter the engine (Allison Model 250 C20 Turboshaft) is installed with engine axis under 45° compressor up, while the same engine is installed in many other helicopters and aircraft engine axis more or less 0° .
Besides the fact that it would not be recommended for dirt ingestion, do you think that the engine can also be installed and operated 45° compressor down?
If so, it would be possible to use this engine for certain VTOL applications where the engine is tilted over an angle range of 90°.
2. If the above question does not answer with a yes. Say I install the engine with engine axis in transverse direction, do you think it is capable of operating in a rolled (I mean rolled about engine axis) attitude of +45° through -45°?
Even though I would be so happy if one of these two questions would be answered with a yes, do not say yes if you are not really sure.
Thanks.
OneMoreChance





RE: Allison Model 250 C20 Turboshaft Operational range
RE: Allison Model 250 C20 Turboshaft Operational range
Stache
RE: Allison Model 250 C20 Turboshaft Operational range
Thank you for the phone nr. I will do that.
OneMoreChance
RE: Allison Model 250 C20 Turboshaft Operational range
As I asked Rolls Royce Customer Services about this I had the following information:
The Allison Model 250 C20B engine (420SHP MaxTO) as certified, is capable of starting, operating continuously and stopping when mounted with the engine centerline at any attitude from 75 degrees above horizontal (compressor up) to 30 degrees below horizontal (compressor down).
The oiling system is designed to cope with this attitude range, except the oil tank, which is provided by the airframe and is not part of the engine. But a flexible pick-up tube or an aerobatics oil tank would solve that problem.