Medium large transport has complete loss of gyroscopes. Emergency declared.

Attributes
ACN	290697
Time
Date	199412
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : bwi
State Reference	MD
Altitude	msl bound lower : 31000 msl bound upper : 31000
Environment
Flight Conditions	VMC
Aircraft 1
Controlling Facilities	artcc : zdc tracon : bwi
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise other descent other
Route In Use	arrival 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 : 240 flight time total : 8500
ASRS Report	290697
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : atp pilot : commercial
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : declared emergency other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

In cruise on the nancy arrival south of flat rock, loss of FMC navigation system followed by total loss of both IRS gyroscope system. Flying on wet compass, standby horizon and visually. Decided to land bwi, declared emergency with bwi approach. I don't think an infraction occurred but it was very hectic and busy in the cockpit and a little more difficult than usual flying the aircraft, and I'm not sure if altitude or course deviations took place but may have.

Original NASA ASRS Text

Title: MLG HAS COMPLETE LOSS OF GYROSCOPES. EMER DECLARED.

Narrative: IN CRUISE ON THE NANCY ARR S OF FLAT ROCK, LOSS OF FMC NAV SYS FOLLOWED BY TOTAL LOSS OF BOTH IRS GYROSCOPE SYS. FLYING ON WET COMPASS, STANDBY HORIZON AND VISUALLY. DECIDED TO LAND BWI, DECLARED EMER WITH BWI APCH. I DON'T THINK AN INFRACTION OCCURRED BUT IT WAS VERY HECTIC AND BUSY IN THE COCKPIT AND A LITTLE MORE DIFFICULT THAN USUAL FLYING THE ACFT, AND I'M NOT SURE IF ALT OR COURSE DEVS TOOK PLACE BUT MAY HAVE.

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.