B737-500 flight crew has air data computer fail and diverts to the nearest suitable airport.

Attributes
ACN	701180
Time
Date	200606
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : mol.vor
State Reference	VA
Altitude	msl single value : 21000
Environment
Weather Elements	Rain
Aircraft 1
Controlling Facilities	artcc : zdc.artcc tower : zzz.tower
Operator	common carrier : air carrier
Make Model Name	B737-500
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 340 flight time total : 13000 flight time type : 1500
ASRS Report	701180
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	aircraft equipment other aircraft equipment : eicas other flight crewa other flight crewb
Resolutory Action	flight crew : landed as precaution flight crew : overcame equipment problem flight crew : diverted to another airport
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance Weather Aircraft
Primary Problem	Aircraft

Narrative:

The captain was flying in a descent toward ric. Aircraft was deviating north of course for WX. The #1 CADC circuit breaker opened and the captain's airspeed indicator and altimeter failed. Coordination with maintenance control and dispatch. Closed the circuit breaker and all equipment operated normal. Continued toward destination until approximately 15 mins later when the CADC circuit breaker failed again. The captain's airspeed indicator and altimeter failed again. The first officer maneuvered the aircraft clear of WX while the captain again coordination with dispatch. The captain elected to deviation to pit to remain clear of WX due to intermittent radar operation. ATC was advised of the loss of instrumentation; no emergency was declared. The aircraft was landed at pit by the first officer with no further problems.

Original NASA ASRS Text

Title: B737-500 FLT CREW HAS AIR DATA COMPUTER FAIL AND DIVERTS TO THE NEAREST SUITABLE ARPT.

Narrative: THE CAPT WAS FLYING IN A DSCNT TOWARD RIC. ACFT WAS DEVIATING N OF COURSE FOR WX. THE #1 CADC CIRCUIT BREAKER OPENED AND THE CAPT'S AIRSPD INDICATOR AND ALTIMETER FAILED. COORD WITH MAINT CTL AND DISPATCH. CLOSED THE CIRCUIT BREAKER AND ALL EQUIP OPERATED NORMAL. CONTINUED TOWARD DEST UNTIL APPROX 15 MINS LATER WHEN THE CADC CIRCUIT BREAKER FAILED AGAIN. THE CAPT'S AIRSPD INDICATOR AND ALTIMETER FAILED AGAIN. THE FO MANEUVERED THE ACFT CLR OF WX WHILE THE CAPT AGAIN COORD WITH DISPATCH. THE CAPT ELECTED TO DEV TO PIT TO REMAIN CLR OF WX DUE TO INTERMITTENT RADAR OP. ATC WAS ADVISED OF THE LOSS OF INSTRUMENTATION; NO EMER WAS DECLARED. THE ACFT WAS LANDED AT PIT BY THE FO WITH NO FURTHER PROBS.

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.