Narrative:

Our purpose was a comprehensive test flight of a new aircraft (medium large transport) following final outfitting on the west coast. We were operating at FL310, under VFR conditions, as a scheduled event within military warning area west 291. We were under VHF continuous 2-WAY communication with the us navy area controller, 'beaver control.' the flight crew consisted of a company manufacturing test pilot, company qualified copilot and 3 reps from the outfitting facility, one of whom (the avionics man) occupied the jumpseat in the cockpit. The test flight began at 15000' with the ultimate intent of working our way gradually up to 45000' in increments as specific flight test objections were met. Although we were operating in continuous voice communications with the controling agency, radar contact had been reported lost early in the flight due to low altitude and distance from their facility. This particular aircraft had been experiencing numerous avionic, electric and other system problems. To complicate matters, the automatic cabin pressurization system was inoperative, which kept the copilot busy trying to maintain some semblance of normality with continuous power changes required by the test profile. At approximately XA00 local, while cruising level at FL310 (our altitude changes were continuously reported to beaver control) we were investigating an electrical system abnormality. At some point in this procedure a power transient apparently tripped our transponder to the standby position. This condition went unnoticed by all 3 cockpit crew members for an estimated 10-15 mins. Meanwhile, southwest air defense command noted a bogie (us) turning on various courses and reportedly penetrating the ADIZ with no transponder. Following their standard procedure, the military first queried ATC who had no knowledge of the bogie. The navy was also contacted and reported that they might have someone in the vicinity of the reported target but were not sure since we were not in radar contact, although we were within our assigned area and approximately 1 + 30 hours into our scheduled 2 hour delay time. By the time the navy could contact us (we responded immediately) asked our position and to 'check our mode C,' and establish positive identify, the air defense command had launched an interceptor aircraft from george AFB. The intercept was terminated as the military aircraft xed the coast outbnd. We were unaware of the launch until approximately 1 hour later when, while conducting the instrument approach phase of the test flight at oxnard, we were asked several questions concerning our mission, home base, pilot's name, etc. Upon landing, I immediately called southwest air defense command to apologize for our error and explain the situation from our side. A combination of cockpit distraction during the investigation of a separate electrical problem and electrical equipment failure contributed to this situation. The medium large transport is an electronically complex and advanced aircraft and is experiencing normal growth problems. The propensity of the transponder to trip during electrical switching will be addressed on an engineering level to resolve the problem, realizing the critical importance of this piece of equipment in today's ATC environment. As a flight crew we should have been more aware of the situation and should have spotted the problem on our own. Fortunately there were no air traffic conflicts.

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Original NASA ASRS Text

Title: CIVILIAN MLG OPERATING IN WARNING AREA INADVERTENTLY PENETRATED THE ADIZ WITH ITS TRANSPONDER INOPERATIVE AND ADC LAUNCHED AN INTERCEPT.

Narrative: OUR PURPOSE WAS A COMPREHENSIVE TEST FLT OF A NEW ACFT (MLG) FOLLOWING FINAL OUTFITTING ON THE WEST COAST. WE WERE OPERATING AT FL310, UNDER VFR CONDITIONS, AS A SCHEDULED EVENT WITHIN MIL WARNING AREA W 291. WE WERE UNDER VHF CONTINUOUS 2-WAY COM WITH THE US NAVY AREA CTLR, 'BEAVER CTL.' THE FLT CREW CONSISTED OF A COMPANY MANUFACTURING TEST PLT, COMPANY QUALIFIED COPLT AND 3 REPS FROM THE OUTFITTING FAC, ONE OF WHOM (THE AVIONICS MAN) OCCUPIED THE JUMPSEAT IN THE COCKPIT. THE TEST FLT BEGAN AT 15000' WITH THE ULTIMATE INTENT OF WORKING OUR WAY GRADUALLY UP TO 45000' IN INCREMENTS AS SPECIFIC FLT TEST OBJECTIONS WERE MET. ALTHOUGH WE WERE OPERATING IN CONTINUOUS VOICE COMS WITH THE CTLING AGENCY, RADAR CONTACT HAD BEEN RPTED LOST EARLY IN THE FLT DUE TO LOW ALT AND DISTANCE FROM THEIR FAC. THIS PARTICULAR ACFT HAD BEEN EXPERIENCING NUMEROUS AVIONIC, ELECTRIC AND OTHER SYS PROBS. TO COMPLICATE MATTERS, THE AUTOMATIC CABIN PRESSURIZATION SYS WAS INOP, WHICH KEPT THE COPLT BUSY TRYING TO MAINTAIN SOME SEMBLANCE OF NORMALITY WITH CONTINUOUS PWR CHANGES REQUIRED BY THE TEST PROFILE. AT APPROX XA00 LCL, WHILE CRUISING LEVEL AT FL310 (OUR ALT CHANGES WERE CONTINUOUSLY RPTED TO BEAVER CTL) WE WERE INVESTIGATING AN ELECTRICAL SYS ABNORMALITY. AT SOME POINT IN THIS PROC A PWR TRANSIENT APPARENTLY TRIPPED OUR TRANSPONDER TO THE STANDBY POS. THIS CONDITION WENT UNNOTICED BY ALL 3 COCKPIT CREW MEMBERS FOR AN ESTIMATED 10-15 MINS. MEANWHILE, SW AIR DEFENSE COMMAND NOTED A BOGIE (US) TURNING ON VARIOUS COURSES AND REPORTEDLY PENETRATING THE ADIZ WITH NO TRANSPONDER. FOLLOWING THEIR STANDARD PROC, THE MIL FIRST QUERIED ATC WHO HAD NO KNOWLEDGE OF THE BOGIE. THE NAVY WAS ALSO CONTACTED AND RPTED THAT THEY MIGHT HAVE SOMEONE IN THE VICINITY OF THE RPTED TARGET BUT WERE NOT SURE SINCE WE WERE NOT IN RADAR CONTACT, ALTHOUGH WE WERE WITHIN OUR ASSIGNED AREA AND APPROX 1 + 30 HRS INTO OUR SCHEDULED 2 HR DELAY TIME. BY THE TIME THE NAVY COULD CONTACT US (WE RESPONDED IMMEDIATELY) ASKED OUR POS AND TO 'CHK OUR MODE C,' AND ESTABLISH POSITIVE IDENT, THE AIR DEFENSE COMMAND HAD LAUNCHED AN INTERCEPTOR ACFT FROM GEORGE AFB. THE INTERCEPT WAS TERMINATED AS THE MIL ACFT XED THE COAST OUTBND. WE WERE UNAWARE OF THE LAUNCH UNTIL APPROX 1 HR LATER WHEN, WHILE CONDUCTING THE INSTRUMENT APCH PHASE OF THE TEST FLT AT OXNARD, WE WERE ASKED SEVERAL QUESTIONS CONCERNING OUR MISSION, HOME BASE, PLT'S NAME, ETC. UPON LNDG, I IMMEDIATELY CALLED SW AIR DEFENSE COMMAND TO APOLOGIZE FOR OUR ERROR AND EXPLAIN THE SITUATION FROM OUR SIDE. A COMBINATION OF COCKPIT DISTR DURING THE INVESTIGATION OF A SEPARATE ELECTRICAL PROB AND ELECTRICAL EQUIP FAILURE CONTRIBUTED TO THIS SITUATION. THE MLG IS AN ELECTRONICALLY COMPLEX AND ADVANCED ACFT AND IS EXPERIENCING NORMAL GROWTH PROBS. THE PROPENSITY OF THE TRANSPONDER TO TRIP DURING ELECTRICAL SWITCHING WILL BE ADDRESSED ON AN ENGINEERING LEVEL TO RESOLVE THE PROB, REALIZING THE CRITICAL IMPORTANCE OF THIS PIECE OF EQUIP IN TODAY'S ATC ENVIRONMENT. AS A FLT CREW WE SHOULD HAVE BEEN MORE AWARE OF THE SITUATION AND SHOULD HAVE SPOTTED THE PROB ON OUR OWN. FORTUNATELY THERE WERE NO AIR TFC CONFLICTS.

Data retrieved from NASA's ASRS site as of August 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.