On Tuesday, September 4, 2018 at 4:32:20 PM UTC+1, WB wrote:

I noticed that you did not mention the clearance issue that one pilot reported - do you not consider this to be a problem, or are you mystified?

Tom

If I recall correctly, centrifugal compressors have larger tolerances for clearance of the rotors and housing compared to axial compressors.

....but IIRC in the development stages of the M&D jet JS reported that they found some cases of the engine surging after starting and this was corrected by M&D tightening up the clearance tolerances for the centrifugal compressor to the inlet casing. The jet I had certainly had very close and even fit which I looked at in my pre-flight checks as I finger spun the compressor.