Narrative:

Had a pop-up test flight with an international customer in a CE525. We were to run through in-flight system check which required IFR clearance to FL310, into the boothill 1 area (ict 235 degree radial, ict 210 degree radial out to 125 DME). After takeoff, departure could not receive transponder. Recycled. Still no reply. Changed to #2 transponder. No reply. Departure asked for intentions. Stated we would work west of ict about 25 NM at 14500 ft VFR. Ict agreed. We ended about 35 NM west during maneuvering at 14500 ft. Ict terminated handling. Approximately 5 mins later, started descent into ict and established contact with approach. Did a 30 degree right turn for radar identify. Recovered visually. Problems to this flight were inadvertent violation of far 91.130 and 91.215, operating in class C without xponders and operating above 10000 ft MSL without xponders. Probable causes were: 1) I can't ever recall having a dual transponder failure. 2) trying to accomplish as much of the checks as possible (at a safe altitude). 3) because of #1 above, not being up-to-date on these 2 far sections. I'm now well versed in these pertinent sections.

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Original NASA ASRS Text

Title: ACFT EQUIP PROB DUAL XPONDER FAILURE.

Narrative: HAD A POP-UP TEST FLT WITH AN INTL CUSTOMER IN A CE525. WE WERE TO RUN THROUGH INFLT SYS CHK WHICH REQUIRED IFR CLRNC TO FL310, INTO THE BOOTHILL 1 AREA (ICT 235 DEG RADIAL, ICT 210 DEG RADIAL OUT TO 125 DME). AFTER TKOF, DEP COULD NOT RECEIVE XPONDER. RECYCLED. STILL NO REPLY. CHANGED TO #2 XPONDER. NO REPLY. DEP ASKED FOR INTENTIONS. STATED WE WOULD WORK W OF ICT ABOUT 25 NM AT 14500 FT VFR. ICT AGREED. WE ENDED ABOUT 35 NM W DURING MANEUVERING AT 14500 FT. ICT TERMINATED HANDLING. APPROX 5 MINS LATER, STARTED DSCNT INTO ICT AND ESTABLISHED CONTACT WITH APCH. DID A 30 DEG R TURN FOR RADAR IDENT. RECOVERED VISUALLY. PROBS TO THIS FLT WERE INADVERTENT VIOLATION OF FAR 91.130 AND 91.215, OPERATING IN CLASS C WITHOUT XPONDERS AND OPERATING ABOVE 10000 FT MSL WITHOUT XPONDERS. PROBABLE CAUSES WERE: 1) I CAN'T EVER RECALL HAVING A DUAL XPONDER FAILURE. 2) TRYING TO ACCOMPLISH AS MUCH OF THE CHKS AS POSSIBLE (AT A SAFE ALT). 3) BECAUSE OF #1 ABOVE, NOT BEING UP-TO-DATE ON THESE 2 FAR SECTIONS. I'M NOW WELL VERSED IN THESE PERTINENT SECTIONS.

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.