As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN/COCKPIT HAS STRONG ACRID STENCH, SUSPECT ATOMIZED TURBINE OIL FROM AIR CYCLE MACHINE PASSED THE LABYRINTH SEAL. REMOVED APU P/N 3800774-1, S/N P-609 DUE TO SMOKE IN THE COCKPIT. INSTALLED A REPAIRED APU. OPS CHECK GOOD. IAW BOMBARDIER CL350 MM CH 49-11-01.