Small aircraft has HSI intermittent failure.

Attributes
ACN	290593
Time
Date	199412
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : dfw
State Reference	TX
Altitude	msl bound lower : 9000 msl bound upper : 9500
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : dfw
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 36 flight time total : 375 flight time type : 103
ASRS Report	290593
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : overshoot other spatial deviation
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : overcame equipment problem other
Consequence	Other Other
Supplementary
Primary Problem	Weather
Air Traffic Incident	Pilot Deviation

Narrative:

Altitude and heading deviation from assigned due to HSI failure in heavy WX. Conditions were IMC with heavy rain and light turbulence. Storm scope showed heavy electrical activity nearby and lightening flashes occasionally visible. Navigation flag came on and then went off, only to come back on for good a few mins later. I then disconnected autoplt and was hand flying the plane while trying to diagnose the extent of the problem and copy a routing change from center. While doing so, I allowed the altitude to deviate above assigned. Center controller questioned the altitude and I took corrective action. I also informed center of HSI failure and my request to deviate to a different location for landing. Center suggested one location which I declined as I had checked the local ATIS and determined the ceiling to be too low for a no gyro approach. Flight concluded uneventfully with a landing at gregg county airport. In reviewing the circumstances, I think I should have been quicker to notify center and cover the instrument and save the troubleshooting for a few mins, while I concentrated on flying the plane and changing my scan to adjust for the malfunction. Notifying center sooner may have helped eliminate the additional problem of copying a new routing at a time when I already had my hands full.

Original NASA ASRS Text

Title: SMA HAS HSI INTERMITTENT FAILURE.

Narrative: ALT AND HDG DEV FROM ASSIGNED DUE TO HSI FAILURE IN HVY WX. CONDITIONS WERE IMC WITH HVY RAIN AND LIGHT TURB. STORM SCOPE SHOWED HVY ELECTRICAL ACTIVITY NEARBY AND LIGHTENING FLASHES OCCASIONALLY VISIBLE. NAV FLAG CAME ON AND THEN WENT OFF, ONLY TO COME BACK ON FOR GOOD A FEW MINS LATER. I THEN DISCONNECTED AUTOPLT AND WAS HAND FLYING THE PLANE WHILE TRYING TO DIAGNOSE THE EXTENT OF THE PROB AND COPY A ROUTING CHANGE FROM CTR. WHILE DOING SO, I ALLOWED THE ALT TO DEVIATE ABOVE ASSIGNED. CTR CTLR QUESTIONED THE ALT AND I TOOK CORRECTIVE ACTION. I ALSO INFORMED CTR OF HSI FAILURE AND MY REQUEST TO DEVIATE TO A DIFFERENT LOCATION FOR LNDG. CTR SUGGESTED ONE LOCATION WHICH I DECLINED AS I HAD CHKED THE LCL ATIS AND DETERMINED THE CEILING TO BE TOO LOW FOR A NO GYRO APCH. FLT CONCLUDED UNEVENTFULLY WITH A LNDG AT GREGG COUNTY ARPT. IN REVIEWING THE CIRCUMSTANCES, I THINK I SHOULD HAVE BEEN QUICKER TO NOTIFY CTR AND COVER THE INST AND SAVE THE TROUBLESHOOTING FOR A FEW MINS, WHILE I CONCENTRATED ON FLYING THE PLANE AND CHANGING MY SCAN TO ADJUST FOR THE MALFUNCTION. NOTIFYING CTR SOONER MAY HAVE HELPED ELIMINATE THE ADDITIONAL PROB OF COPYING A NEW ROUTING AT A TIME WHEN I ALREADY HAD MY HANDS FULL.

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.