What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) Recieved NY TRACON incident report ^pri^ concerning a challenger 600, N515BP overflying the NY area. A/c declared an emergency @ 17,000' with an APU fire indication and an auto shutdown. They requested immediate descent to kteb. In the VFR descent, controller advised of traffic at 15,000' and for N515BP to stop descent, which the crew did, but bottomed out at 15,500' and lost separation. (500'/2.31NM). The crew stated they had no TCAS indication. Emergency vehicles met the a/c, and there was no visual evidence of fire. An airworthiness representative confirmed that appropriate maintenance checks were done on all systems, including an overweight landing inspection, all accomplished by "millionair" @ teb. The APU was found to be "overserviced", and judged that the crew "put too high a workload on the unit." A detailed written statement by the captain noted: "we had an acu overpressure/acu fail, pilot side ADI flag, burning smell in the cabin, APU fire bell with auto shutdown."
As the FAA filed it
(-23) RECIEVED NY TRACON INCIDENT REPORT ^PRI^ CONCERNING A CHALLENGER 600, N515BP OVERFLYING THE NY AREA. A/C DECLARED AN EMERGENCY @ 17,000' WITH AN APU FIRE INDICATION AND AN AUTO SHUTDOWN. THEY REQUESTED IMMEDIATE DESCENT TO KTEB. IN THE VFR DESCENT, CONTROLLER ADVISED OF TRAFFIC AT 15,000' AND FOR N515BP TO STOP DESCENT, WHICH THE CREW DID, BUT BOTTOMED OUT AT 15,500' AND LOST SEPARATION. (500'/2.31NM). THE CREW STATED THEY HAD NO TCAS INDICATION. EMERGENCY VEHICLES MET THE A/C, AND THERE WAS NO VISUAL EVIDENCE OF FIRE. AN AIRWORTHINESS REPRESENTATIVE CONFIRMED THAT APPROPRIATE MAINTENANCE CHECKS WERE DONE ON ALL SYSTEMS, INCLUDING AN OVERWEIGHT LANDING INSPECTION, ALL ACCOMPLISHED BY "MILLIONAIR" @ TEB. THE APU WAS FOUND TO BE "OVERSERVICED", AND JUDGED THAT THE CREW "PUT TOO HIGH A WORKLOAD ON THE UNIT." A DETAILED WRITTEN STATEMENT BY THE CAPTAIN NOTED: "WE HAD AN ACU OVERPRESSURE/ACU FAIL, PILOT SIDE ADI FLAG, BURNING SMELL IN THE CABIN, APU FIRE BELL WITH AUTO SHUTDOWN."