Controller reports the descent of a BE58 pilot to 3500 ft without clearance or communication.

Attributes
ACN	723340
Time
Date	200701
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : zzz.vortac
State Reference	US
Altitude	msl bound lower : 3500 msl bound upper : 4000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : zzz.tracon
Operator	general aviation : personal
Make Model Name	Baron 58/58TC
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller limited radar : 12 controller military : 5 controller radar : 13 controller time certified in position1 : 13
ASRS Report	723340
Person 2
Affiliation	other
Function	flight crew : single pilot
Events
Anomaly	aircraft equipment problem : critical altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : far
Independent Detector	other controllera
Resolutory Action	controller : separated traffic
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

While working the north radar position; I accepted a handoff. The aircraft was maintaining 4000 ft; the tower limits of the other sector. I noticed the BE58 descending and tried to call him with no response. I had the other sector call him and they received no response. I informed the other sector that the aircraft was descending and I did not have communications with him. The aircraft leveled off at 3500 ft for several mi. Due to his now lost communication status I descended another IFR aircraft to remain well clear of him while the higher sector kept another aircraft at 5000 ft. At this time we did not know if the pilot had descended or had a bad mode C readout. The BE58 finally called after several mins and I asked his altitude. The pilot stated that he was level at 3500 ft and stated nothing else. I then informed the pilot of a possible pilot deviation and instructed him to call the facility after landing (the pilot was en route to dab). Nothing else was said in relation to the incident and the rest of the route of flight was uneventful. After calling the facility the pilot informed the supervisor that he was experiencing a catastrophic engine failure and was busy with dealing with the issue and was unable to talk/respond to ATC. The pilot stated he felt it was better to descend to a VFR altitude (3500 ft) while he worked on his issue and trying to decide to land at either ZZZ or ZZZ1 (pilot was between those 2 airports). This pilot at no time stated he was experiencing an engine problem or a possible emergency. The pilot at no time stated the need to land at a closer airport because of his emergency and in fact; continued on to ZZZ2 and bypassed 2 closer airports. After talking to the pilot the supervisor decided that the pilot did not meet the requirements of a pilot deviation and that he had good cause for his actions. No pilot deviation was filed on the matter.

Original NASA ASRS Text

Title: CTLR RPTS THE DSCNT OF A BE58 PLT TO 3500 FT WITHOUT CLRNC OR COM.

Narrative: WHILE WORKING THE N RADAR POS; I ACCEPTED A HDOF. THE ACFT WAS MAINTAINING 4000 FT; THE TWR LIMITS OF THE OTHER SECTOR. I NOTICED THE BE58 DSNDING AND TRIED TO CALL HIM WITH NO RESPONSE. I HAD THE OTHER SECTOR CALL HIM AND THEY RECEIVED NO RESPONSE. I INFORMED THE OTHER SECTOR THAT THE ACFT WAS DSNDING AND I DID NOT HAVE COMS WITH HIM. THE ACFT LEVELED OFF AT 3500 FT FOR SEVERAL MI. DUE TO HIS NOW LOST COM STATUS I DSNDED ANOTHER IFR ACFT TO REMAIN WELL CLR OF HIM WHILE THE HIGHER SECTOR KEPT ANOTHER ACFT AT 5000 FT. AT THIS TIME WE DID NOT KNOW IF THE PLT HAD DSNDED OR HAD A BAD MODE C READOUT. THE BE58 FINALLY CALLED AFTER SEVERAL MINS AND I ASKED HIS ALT. THE PLT STATED THAT HE WAS LEVEL AT 3500 FT AND STATED NOTHING ELSE. I THEN INFORMED THE PLT OF A POSSIBLE PLTDEV AND INSTRUCTED HIM TO CALL THE FACILITY AFTER LNDG (THE PLT WAS ENRTE TO DAB). NOTHING ELSE WAS SAID IN RELATION TO THE INCIDENT AND THE REST OF THE RTE OF FLT WAS UNEVENTFUL. AFTER CALLING THE FACILITY THE PLT INFORMED THE SUPVR THAT HE WAS EXPERIENCING A CATASTROPHIC ENG FAILURE AND WAS BUSY WITH DEALING WITH THE ISSUE AND WAS UNABLE TO TALK/RESPOND TO ATC. THE PLT STATED HE FELT IT WAS BETTER TO DSND TO A VFR ALT (3500 FT) WHILE HE WORKED ON HIS ISSUE AND TRYING TO DECIDE TO LAND AT EITHER ZZZ OR ZZZ1 (PLT WAS BTWN THOSE 2 ARPTS). THIS PLT AT NO TIME STATED HE WAS EXPERIENCING AN ENG PROB OR A POSSIBLE EMER. THE PLT AT NO TIME STATED THE NEED TO LAND AT A CLOSER ARPT BECAUSE OF HIS EMER AND IN FACT; CONTINUED ON TO ZZZ2 AND BYPASSED 2 CLOSER ARPTS. AFTER TALKING TO THE PLT THE SUPVR DECIDED THAT THE PLT DID NOT MEET THE REQUIREMENTS OF A PLTDEV AND THAT HE HAD GOOD CAUSE FOR HIS ACTIONS. NO PLTDEV WAS FILED ON THE MATTER.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.