Narrative:

Taxi out for takeoff at L9A, told to hold short of white concrete. 1 min after stopping, both ADI and 3 HSI went out. This had happened to me on 2 thur 98 with another aircraft at the same spot and I was able to call my chief pilot on the ground and he explained that the problem was a magnetic anomaly. He assured me on 2-X-98 that if I taxied onto runway 13 that the problem would clear itself. I taxied onto runway 13 on 2-X-98 and again it did not clear itself! The tower let me taxi down runway 13 to taxiway aa to taxiway east on both days at which time after 10 min the problem corrected itself on both aircraft, and we taxied and took off without further problem. I have since recommended to my chief pilot and cessna team that there is something that needs to be looked at on this model aircraft. Could there be here at this spot and could it be random? And most of all will it affect other aircraft. An effect on the ground is bad, in the air is much worse! Thank you.

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Original NASA ASRS Text

Title: CE-750 (CITATION X) ACFT EXPERIENCED ADI AND HSI ANOMALIES WHICH WAS ATTRIBUTED TO THE LOCATION ON THE ARPT. THE PROBLEM CORRECTED ITSELF WITHIN 10 MINUTES AND AFTER THE ACFT WAS MOVED.

Narrative: TAXI OUT FOR TKOF AT L9A, TOLD TO HOLD SHORT OF WHITE CONCRETE. 1 MIN AFTER STOPPING, BOTH ADI AND 3 HSI WENT OUT. THIS HAD HAPPENED TO ME ON 2 THUR 98 WITH ANOTHER ACFT AT THE SAME SPOT AND I WAS ABLE TO CALL MY CHIEF PLT ON THE GND AND HE EXPLAINED THAT THE PROBLEM WAS A MAGNETIC ANOMALY. HE ASSURED ME ON 2-X-98 THAT IF I TAXIED ONTO RWY 13 THAT THE PROBLEM WOULD CLR ITSELF. I TAXIED ONTO RWY 13 ON 2-X-98 AND AGAIN IT DID NOT CLR ITSELF! THE TWR LET ME TAXI DOWN RWY 13 TO TXWY AA TO TXWY E ON BOTH DAYS AT WHICH TIME AFTER 10 MIN THE PROBLEM CORRECTED ITSELF ON BOTH ACFT, AND WE TAXIED AND TOOK OFF WITHOUT FURTHER PROBLEM. I HAVE SINCE RECOMMENDED TO MY CHIEF PLT AND CESSNA TEAM THAT THERE IS SOMETHING THAT NEEDS TO BE LOOKED AT ON THIS MODEL ACFT. COULD THERE BE HERE AT THIS SPOT AND COULD IT BE RANDOM? AND MOST OF ALL WILL IT AFFECT OTHER ACFT. AN EFFECT ON THE GND IS BAD, IN THE AIR IS MUCH WORSE! THANK YOU.

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.