Instrument and navigation equipment problems lead to speed and course deviations.

Attributes
ACN	179661
Time
Date	199105
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : dfw
State Reference	TX
Altitude	msl bound lower : 4000 msl bound upper : 4000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : dfw
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 15000
ASRS Report	179661
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical non adherence : clearance other anomaly other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance other other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

Approaching dfw, first officer flying, we were cleared to intercept 17R localizer at 4000'. Nearing localizer capture, first officer instruments indicated need to move to the right for localizer capture while captain instruments showed nearly on course. Due to WX at dfw, we were unable to determine quickly which instruments were correct. At that time first officer HSI and flight director became erratic and approach control ordered a left turn to 150 degrees to reintercept 17R. Assigned altitude 4000'. Aircraft returned almost to localizer capture when preset altitude and airspeed #south disappeared from flight director panel windows. Both were immediately reset, but airspeed was inadvertently set to approach speed of 135 KTS instead of 160 KTS as directed by approach control. Approach control asked our airspeed, then ordered a go around due to spacing. Next approach flown on captain instruments was normal. After flight ended, first officer ADI and HSI were noted ni aircraft log book as being defective.

Original NASA ASRS Text

Title: INSTRUMENT AND NAVIGATION EQUIPMENT PROBLEMS LEAD TO SPEED AND COURSE DEVIATIONS.

Narrative: APCHING DFW, F/O FLYING, WE WERE CLRED TO INTERCEPT 17R LOC AT 4000'. NEARING LOC CAPTURE, F/O INSTRUMENTS INDICATED NEED TO MOVE TO THE RIGHT FOR LOC CAPTURE WHILE CAPT INSTRUMENTS SHOWED NEARLY ON COURSE. DUE TO WX AT DFW, WE WERE UNABLE TO DETERMINE QUICKLY WHICH INSTRUMENTS WERE CORRECT. AT THAT TIME F/O HSI AND FLT DIRECTOR BECAME ERRATIC AND APCH CTL ORDERED A LEFT TURN TO 150 DEGS TO REINTERCEPT 17R. ASSIGNED ALT 4000'. ACFT RETURNED ALMOST TO LOC CAPTURE WHEN PRESET ALT AND AIRSPD #S DISAPPEARED FROM FLT DIRECTOR PANEL WINDOWS. BOTH WERE IMMEDIATELY RESET, BUT AIRSPD WAS INADVERTENTLY SET TO APCH SPD OF 135 KTS INSTEAD OF 160 KTS AS DIRECTED BY APCH CTL. APCH CTL ASKED OUR AIRSPD, THEN ORDERED A GAR DUE TO SPACING. NEXT APCH FLOWN ON CAPT INSTRUMENTS WAS NORMAL. AFTER FLT ENDED, F/O ADI AND HSI WERE NOTED NI ACFT LOG BOOK AS BEING DEFECTIVE.

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.