Hawker 800XP flight crew has a malfunctioning generator; emergency declared; landed as a precaution.

Attributes
ACN	721180
Time
Date	200611
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 21000
Environment
Flight Conditions	Mixed
Weather Elements	Ice
Light	Night
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	general aviation : personal
Make Model Name	BAe 125 Series 800
Operating Under FAR Part	Part 91
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 90 flight time total : 6000 flight time type : 1800
ASRS Report	721180
Person 2
Affiliation	other
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	other flight crewa other flight crewb
Resolutory Action	controller : provided flight assist flight crew : landed as precaution flight crew : declared emergency
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

Approximately 1 hour from ZZZ we noticed a vibration in the aircraft; which after further investigation determined to be a faulty generator. After weighing our options; we determined that ZZZ which was reporting VMC conditions; was still to be used as our final destination. In this continued process we determined that the APU generator was to be used; with the deactivation of the faulty generator. This was accomplished upon reaching the appropriate APU operation altitude. An undetermined amount of time after this new generator confign had been entered; when we were advised by ATC that all traffic headed to ZZZ were now to expect holding instructions. Upon receiving holding instructions; it was determined that our holding fix was a good distance out of our current flight plan route; that the efc time was approximately 40 mins away and this would now have us very near a low fuel situation. We relayed this information to ATC along with our concerns of this developing into something more serious. Several xmissions later a phone number was requested by my counterpart so as to try to resolve this matter. Several mins into the phone conversation; I was informed that an emergency had been declared for us by ATC. We now received a clearance back towards ZZZ and proceeded to land safely.

Original NASA ASRS Text

Title: HAWKER 800XP FLT CREW HAS A MALFUNCTIONING GENERATOR; EMER DECLARED; LANDED AS A PRECAUTION.

Narrative: APPROX 1 HR FROM ZZZ WE NOTICED A VIBRATION IN THE ACFT; WHICH AFTER FURTHER INVESTIGATION DETERMINED TO BE A FAULTY GENERATOR. AFTER WEIGHING OUR OPTIONS; WE DETERMINED THAT ZZZ WHICH WAS RPTING VMC CONDITIONS; WAS STILL TO BE USED AS OUR FINAL DEST. IN THIS CONTINUED PROCESS WE DETERMINED THAT THE APU GENERATOR WAS TO BE USED; WITH THE DEACTIVATION OF THE FAULTY GENERATOR. THIS WAS ACCOMPLISHED UPON REACHING THE APPROPRIATE APU OP ALT. AN UNDETERMINED AMOUNT OF TIME AFTER THIS NEW GENERATOR CONFIGN HAD BEEN ENTERED; WHEN WE WERE ADVISED BY ATC THAT ALL TFC HEADED TO ZZZ WERE NOW TO EXPECT HOLDING INSTRUCTIONS. UPON RECEIVING HOLDING INSTRUCTIONS; IT WAS DETERMINED THAT OUR HOLDING FIX WAS A GOOD DISTANCE OUT OF OUR CURRENT FLT PLAN RTE; THAT THE EFC TIME WAS APPROX 40 MINS AWAY AND THIS WOULD NOW HAVE US VERY NEAR A LOW FUEL SITUATION. WE RELAYED THIS INFO TO ATC ALONG WITH OUR CONCERNS OF THIS DEVELOPING INTO SOMETHING MORE SERIOUS. SEVERAL XMISSIONS LATER A PHONE NUMBER WAS REQUESTED BY MY COUNTERPART SO AS TO TRY TO RESOLVE THIS MATTER. SEVERAL MINS INTO THE PHONE CONVERSATION; I WAS INFORMED THAT AN EMER HAD BEEN DECLARED FOR US BY ATC. WE NOW RECEIVED A CLRNC BACK TOWARDS ZZZ AND PROCEEDED TO LAND SAFELY.

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.