Kevin commenting on the risks of a damaged plastic fan letting go, he said
the consequences may not be enjoyable
When my first Boomerang crashed I returned the motor to Wren, dye penetrant crack detection revealed a suspect turbine disk and they wisely told me the engine should be written-off unless the turbine disk was replaced. This particular motor peaks at 156,000 rpm.
Second hand turbines are widely available and an unscrupulous seller is unlikely to own up to it having been crashed or even have suffered a heavy landing with no apparent damage. There is a good reason for turbine operators ensuring a minimum 10 metre safety margin in the form of a semi circle from in line with the turbine to directly behind it. Think on!