Flight control computer problem results in hand flown CAT I ILS runway 5 approach at orf, va.

Attributes
ACN	495770
Time
Date	200012
Day	Sat
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : orf.airport
State Reference	VA
Altitude	agl single value : 0 msl bound upper : 3000
Environment
Flight Conditions	IMC
Weather Elements	Fog
Light	Night
Aircraft 1
Controlling Facilities	tracon : orf.tracon tower : orf.tower
Operator	common carrier : air carrier
Make Model Name	Fokker 100
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 05 other
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : instrument pilot : multi engine pilot : atp pilot : cfi pilot : commercial
Experience	flight time last 90 days : 120 flight time total : 13100 flight time type : 2000
ASRS Report	495778
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : multi engine pilot : instrument
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted other
Consequence	other
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Aircraft

Narrative:

During the CAT I ILS runway 5 approach, the autoplt failed to capture the GS at the intercept altitude. I immediately disconnected the autoplt and manually recaptured the GS and continued the CAT I approach utilizing the flight director. Due to variable tailwinds in this non normal situation, the vertical speed momentarily exceeded 1000 FPM descent while correcting. Aircraft configured, on speed, and GS bracketed. First officer reported loss of his GS indicator. Since my GS, localizer, and all other indicators were normal, and I had the required approach lights and runway environment in sight to continue the CAT I approach, and the RVR more than 6000 ft, I continued the approach to a normal landing. Maintenance notified. One of the flight control computers had faulted.

Original NASA ASRS Text

Title: FLT CTL COMPUTER PROB RESULTS IN HAND FLOWN CAT I ILS RWY 5 APCH AT ORF, VA.

Narrative: DURING THE CAT I ILS RWY 5 APCH, THE AUTOPLT FAILED TO CAPTURE THE GS AT THE INTERCEPT ALT. I IMMEDIATELY DISCONNECTED THE AUTOPLT AND MANUALLY RECAPTURED THE GS AND CONTINUED THE CAT I APCH UTILIZING THE FLT DIRECTOR. DUE TO VARIABLE TAILWINDS IN THIS NON NORMAL SIT, THE VERT SPD MOMENTARILY EXCEEDED 1000 FPM DSCNT WHILE CORRECTING. ACFT CONFIGURED, ON SPD, AND GS BRACKETED. FO RPTED LOSS OF HIS GS INDICATOR. SINCE MY GS, LOC, AND ALL OTHER INDICATORS WERE NORMAL, AND I HAD THE REQUIRED APCH LIGHTS AND RWY ENVIRONMENT IN SIGHT TO CONTINUE THE CAT I APCH, AND THE RVR MORE THAN 6000 FT, I CONTINUED THE APCH TO A NORMAL LNDG. MAINT NOTIFIED. ONE OF THE FLT CTL COMPUTERS HAD FAULTED.

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.