Emergency declared for unknown aircraft equipment problem.

Attributes
ACN	272296
Time
Date	199405
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : hto
State Reference	NY
Altitude	msl bound lower : 31000 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zny tracon : dca tower : dca
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent : approach landing other other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 190 flight time total : 10500 flight time type : 2500
ASRS Report	272296
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

At cruise, FL310, smooth, a sudden loud pop and crack sound was heard in the cockpit, followed by the sound of pieces of plastic or metal rattling and falling. Shortly after the loud pop was heard, a smell of hot rubber was noted by both myself and first officer. A quick check of all system detected no malfunctions, fluctuations or abnormalities except for the rubber smell. We suspected a deflated or blown nose tire because of rubber odor. As a result, we declared an emergency with balance approach and requested ground emergency vehicles to stand by. We performed a low approach by dca tower to verify any discrepancy. None was noted by tower and also an air carrier flight at #1 position, 36 runway dca. A decision was made to land at dca. A missed approach was performed. Gear was left down and vectors received to an uneventful landing. Emergency ground vehicles verified no problems noted and aircraft was taxied to gate.

Original NASA ASRS Text

Title: EMER DECLARED FOR UNKNOWN ACFT EQUIP PROB.

Narrative: AT CRUISE, FL310, SMOOTH, A SUDDEN LOUD POP AND CRACK SOUND WAS HEARD IN THE COCKPIT, FOLLOWED BY THE SOUND OF PIECES OF PLASTIC OR METAL RATTLING AND FALLING. SHORTLY AFTER THE LOUD POP WAS HEARD, A SMELL OF HOT RUBBER WAS NOTED BY BOTH MYSELF AND FO. A QUICK CHK OF ALL SYS DETECTED NO MALFUNCTIONS, FLUCTUATIONS OR ABNORMALITIES EXCEPT FOR THE RUBBER SMELL. WE SUSPECTED A DEFLATED OR BLOWN NOSE TIRE BECAUSE OF RUBBER ODOR. AS A RESULT, WE DECLARED AN EMER WITH BAL APCH AND REQUESTED GND EMER VEHICLES TO STAND BY. WE PERFORMED A LOW APCH BY DCA TWR TO VERIFY ANY DISCREPANCY. NONE WAS NOTED BY TWR AND ALSO AN ACR FLT AT #1 POS, 36 RWY DCA. A DECISION WAS MADE TO LAND AT DCA. A MISSED APCH WAS PERFORMED. GEAR WAS LEFT DOWN AND VECTORS RECEIVED TO AN UNEVENTFUL LNDG. EMER GND VEHICLES VERIFIED NO PROBS NOTED AND ACFT WAS TAXIED TO GATE.

Data retrieved from NASA's ASRS site as of July 2007 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.