Narrative:

After a missed VOR runway 33 approach to saf, hold and second approach, I was advised to contact ZAB for a possible altitude deviation upon landing in saf. During telephone conversation with ZAB they advised my altitude showed 8800 ft, 9100 ft, 9500 ft, 9200 ft, 9100 ft (approximately 8 seconds between readouts). I told ZAB that myself and copilot never saw an altitude in excess of 9000 ft. Autoplt was engaged and altitude hold used during hold at VOR. At no time during approach was I advised of excessive altitude or that a gulfstream was in the same hold at 10000 ft. Far 91.411 was complied with mar/xx/92 with no defects noted. I will query ATC during next few flts to see if any discrepancies exist. If so, system will be taken in for maintenance immediately. If not, system will be rechked during jun/97 maintenance. Conditions during approach were light turbulence, IMC, rain, snow and icing. After missed approach was announced by my aircraft, saf tower called saf below minimums. Upon missed approach ZAB offered us 9000 ft instead of published 8200 ft. I acknowledged we would hold at 9000 ft, feeling this would provide ZAB with better radar coverage due to mountainous terrain in that area. I am still not certain as to what caused this problem. Cockpit indications were showing on altitude, autoplt engaged and no altitude alert warning. I will say if ZAB heard or saw this threat, an immediate advisory would have been nice. Also, if I was informed another aircraft was in the same hold I would have stayed at 8200 ft for the extra margin. The following day I experienced an autoplt malfunction on my flight to ase. I am awaiting a loaner autoplt computer. It has been an intermittent problem which I hope to confirm.

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Original NASA ASRS Text

Title: LEAR 35 ACFT AFTER MISSED APCH WAS IN HOLDING PATTERN AND, EITHER FLC DEVIATED ALTS OR THE XPONDER WAS RPTING ERRONEOUS ALTS RESULTING IN LESS THAN LEGAL SEPARATION WITH ANOTHER ACFT IN HOLDING 1000 FT ABOVE. AFTER LNDG, RPTR CAPT WAS ADVISED TO CONTACT THE CTR WHO TOLD HIM ABOUT THE DEVS.

Narrative: AFTER A MISSED VOR RWY 33 APCH TO SAF, HOLD AND SECOND APCH, I WAS ADVISED TO CONTACT ZAB FOR A POSSIBLE ALTDEV UPON LNDG IN SAF. DURING TELEPHONE CONVERSATION WITH ZAB THEY ADVISED MY ALT SHOWED 8800 FT, 9100 FT, 9500 FT, 9200 FT, 9100 FT (APPROX 8 SECONDS BTWN READOUTS). I TOLD ZAB THAT MYSELF AND COPLT NEVER SAW AN ALT IN EXCESS OF 9000 FT. AUTOPLT WAS ENGAGED AND ALT HOLD USED DURING HOLD AT VOR. AT NO TIME DURING APCH WAS I ADVISED OF EXCESSIVE ALT OR THAT A GULFSTREAM WAS IN THE SAME HOLD AT 10000 FT. FAR 91.411 WAS COMPLIED WITH MAR/XX/92 WITH NO DEFECTS NOTED. I WILL QUERY ATC DURING NEXT FEW FLTS TO SEE IF ANY DISCREPANCIES EXIST. IF SO, SYS WILL BE TAKEN IN FOR MAINT IMMEDIATELY. IF NOT, SYS WILL BE RECHKED DURING JUN/97 MAINT. CONDITIONS DURING APCH WERE LIGHT TURB, IMC, RAIN, SNOW AND ICING. AFTER MISSED APCH WAS ANNOUNCED BY MY ACFT, SAF TWR CALLED SAF BELOW MINIMUMS. UPON MISSED APCH ZAB OFFERED US 9000 FT INSTEAD OF PUBLISHED 8200 FT. I ACKNOWLEDGED WE WOULD HOLD AT 9000 FT, FEELING THIS WOULD PROVIDE ZAB WITH BETTER RADAR COVERAGE DUE TO MOUNTAINOUS TERRAIN IN THAT AREA. I AM STILL NOT CERTAIN AS TO WHAT CAUSED THIS PROB. COCKPIT INDICATIONS WERE SHOWING ON ALT, AUTOPLT ENGAGED AND NO ALT ALERT WARNING. I WILL SAY IF ZAB HEARD OR SAW THIS THREAT, AN IMMEDIATE ADVISORY WOULD HAVE BEEN NICE. ALSO, IF I WAS INFORMED ANOTHER ACFT WAS IN THE SAME HOLD I WOULD HAVE STAYED AT 8200 FT FOR THE EXTRA MARGIN. THE FOLLOWING DAY I EXPERIENCED AN AUTOPLT MALFUNCTION ON MY FLT TO ASE. I AM AWAITING A LOANER AUTOPLT COMPUTER. IT HAS BEEN AN INTERMITTENT PROB WHICH I HOPE TO CONFIRM.

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.