Narrative:

On the evening before the day of this event, I had called potomac TRACON and informed them that on the next day (may/sat) there would be joint exercises being conducted by both air and surface units of the military civilian branch over the chesapeake bay and within the ADIZ, with at least 2 aircraft involved, which would be flying at levels as low as 500 ft AGL. This seemed to be well understood and accepted. On that next morning, I filed an ADIZ flight plan from fdk to W29 via fme and anp. This was filed over the usual WX briefing system, and I think (but not sure) it was filed with altoona FSS. This flight plan was filed for this aircraft, as is standard for aircraft being flown under civilian military patrols or tasking. This flight was under military order. In the remarks section of my ADIZ flight plan, I asked that it be noted the aircraft would not be landing at W29, but rather would be conducting joint air/surface exercises over this area of the chesapeake bay, within the ADIZ. Again, this seemed to be well understood and accepted. I began my flight from fdk, called potomac TRACON, and received my squawk to enter the TRACON. Traversing the TRACON, as per flight plan was executed without difficulty, staying clear of class B as instructed, and changing frequency to 119.7 as instructed by ATC. Arriving over the chesapeake bay, we began the exercises, continuing to monitor 119.7 as well as guard 121.5, while at the same time communicating with civilian military facilities on FM channels. 2 hours later after takeoff, on 121.5, we monitored a message essentially calling aircraft squawking (our squawk) and informing that that aircraft was in the ADIZ, and to exit immediately by flying east, etc. We called TRACON on 119.7 and they sent us to 126.75. We reported the message we had heard on 121.5 and basically asked what was going on. We discussed the situation, and at first all seemed well, but after a min or two, we were informed that we would need to call ATC upon landing. We were given a new squawk, but then broke off our patrol exercises, flew out of the ADIZ to esn, landed and called the TRACON, only to be informed that that number was not in service. Fortunately, I had baltimore TRACON numbers on my flight sheet, called TRACON and was then told to call ATC's newer number. The whole situation was reviewed, and I was told that since our squawk had disappeared, they thought we had landed or gone out of the area and had assigned our squawk to someone else. Therefore, when we 'resurfaced' (came back up to an altitude where at that range our squawk reappeared on their radar), they had 2 same squawks, which, of course, just wouldn't do. However, at the end of the conversation, it appeared that the matter had been rectified. They asked at least a couple of times if we had landed at any time during our loss of radar contact, and we informed them that absolutely we had not. We then filed a new ADIZ flight plan on the ground at esn, took off, obtained a new ADIZ squawk, reported in to the civilian military controller (activities, baltimore), and resumed participation in the exercises. In retrospect, the incident could probably have been prevented by taking the following actions (although if the remarks on my flight plan had been heeded by ATC, there should have been no difficulty): I could have reported to ATC at the time I was beginning my exercise activities and that I would probably at times be beneath their radar coverage. Also, I could have 'resurfaced' (climbed to where I was again in their radar coverage) and reported in every 15-30 mins or so to be sure they were still aware of my presence. (However, with the frequencys in the ADIZ already being very crowded, such additional xmissions pose some disadvantage. Further, it would have caused some disruption of the exercises.) finally, on filing my original ADIZ flight plan, I could have indicated the duration of flight as 4 or 5 hours (the time it was expected to be the maximum duration of our exercises), though it takes less than 30 mins to get from fdk to W29. This may have kept TRACON from timing out my squawk.

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Original NASA ASRS Text

Title: MIL BE35 PLT HAS A PROB WITH ACFT SQUAWK CODES WITH PCT CTLR WHEN OPERATING IN AND OUT OF THE RADAR COVERAGE AREA SE OF BAL, MD.

Narrative: ON THE EVENING BEFORE THE DAY OF THIS EVENT, I HAD CALLED POTOMAC TRACON AND INFORMED THEM THAT ON THE NEXT DAY (MAY/SAT) THERE WOULD BE JOINT EXERCISES BEING CONDUCTED BY BOTH AIR AND SURFACE UNITS OF THE MIL CIVILIAN BRANCH OVER THE CHESAPEAKE BAY AND WITHIN THE ADIZ, WITH AT LEAST 2 ACFT INVOLVED, WHICH WOULD BE FLYING AT LEVELS AS LOW AS 500 FT AGL. THIS SEEMED TO BE WELL UNDERSTOOD AND ACCEPTED. ON THAT NEXT MORNING, I FILED AN ADIZ FLT PLAN FROM FDK TO W29 VIA FME AND ANP. THIS WAS FILED OVER THE USUAL WX BRIEFING SYS, AND I THINK (BUT NOT SURE) IT WAS FILED WITH ALTOONA FSS. THIS FLT PLAN WAS FILED FOR THIS ACFT, AS IS STANDARD FOR ACFT BEING FLOWN UNDER CIVILIAN MIL PATROLS OR TASKING. THIS FLT WAS UNDER MIL ORDER. IN THE REMARKS SECTION OF MY ADIZ FLT PLAN, I ASKED THAT IT BE NOTED THE ACFT WOULD NOT BE LNDG AT W29, BUT RATHER WOULD BE CONDUCTING JOINT AIR/SURFACE EXERCISES OVER THIS AREA OF THE CHESAPEAKE BAY, WITHIN THE ADIZ. AGAIN, THIS SEEMED TO BE WELL UNDERSTOOD AND ACCEPTED. I BEGAN MY FLT FROM FDK, CALLED POTOMAC TRACON, AND RECEIVED MY SQUAWK TO ENTER THE TRACON. TRAVERSING THE TRACON, AS PER FLT PLAN WAS EXECUTED WITHOUT DIFFICULTY, STAYING CLR OF CLASS B AS INSTRUCTED, AND CHANGING FREQ TO 119.7 AS INSTRUCTED BY ATC. ARRIVING OVER THE CHESAPEAKE BAY, WE BEGAN THE EXERCISES, CONTINUING TO MONITOR 119.7 AS WELL AS GUARD 121.5, WHILE AT THE SAME TIME COMMUNICATING WITH CIVILIAN MIL FACILITIES ON FM CHANNELS. 2 HRS LATER AFTER TKOF, ON 121.5, WE MONITORED A MESSAGE ESSENTIALLY CALLING ACFT SQUAWKING (OUR SQUAWK) AND INFORMING THAT THAT ACFT WAS IN THE ADIZ, AND TO EXIT IMMEDIATELY BY FLYING E, ETC. WE CALLED TRACON ON 119.7 AND THEY SENT US TO 126.75. WE RPTED THE MESSAGE WE HAD HEARD ON 121.5 AND BASICALLY ASKED WHAT WAS GOING ON. WE DISCUSSED THE SIT, AND AT FIRST ALL SEEMED WELL, BUT AFTER A MIN OR TWO, WE WERE INFORMED THAT WE WOULD NEED TO CALL ATC UPON LNDG. WE WERE GIVEN A NEW SQUAWK, BUT THEN BROKE OFF OUR PATROL EXERCISES, FLEW OUT OF THE ADIZ TO ESN, LANDED AND CALLED THE TRACON, ONLY TO BE INFORMED THAT THAT NUMBER WAS NOT IN SVC. FORTUNATELY, I HAD BALTIMORE TRACON NUMBERS ON MY FLT SHEET, CALLED TRACON AND WAS THEN TOLD TO CALL ATC'S NEWER NUMBER. THE WHOLE SIT WAS REVIEWED, AND I WAS TOLD THAT SINCE OUR SQUAWK HAD DISAPPEARED, THEY THOUGHT WE HAD LANDED OR GONE OUT OF THE AREA AND HAD ASSIGNED OUR SQUAWK TO SOMEONE ELSE. THEREFORE, WHEN WE 'RESURFACED' (CAME BACK UP TO AN ALT WHERE AT THAT RANGE OUR SQUAWK REAPPEARED ON THEIR RADAR), THEY HAD 2 SAME SQUAWKS, WHICH, OF COURSE, JUST WOULDN'T DO. HOWEVER, AT THE END OF THE CONVERSATION, IT APPEARED THAT THE MATTER HAD BEEN RECTIFIED. THEY ASKED AT LEAST A COUPLE OF TIMES IF WE HAD LANDED AT ANY TIME DURING OUR LOSS OF RADAR CONTACT, AND WE INFORMED THEM THAT ABSOLUTELY WE HAD NOT. WE THEN FILED A NEW ADIZ FLT PLAN ON THE GND AT ESN, TOOK OFF, OBTAINED A NEW ADIZ SQUAWK, RPTED IN TO THE CIVILIAN MIL CTLR (ACTIVITIES, BALTIMORE), AND RESUMED PARTICIPATION IN THE EXERCISES. IN RETROSPECT, THE INCIDENT COULD PROBABLY HAVE BEEN PREVENTED BY TAKING THE FOLLOWING ACTIONS (ALTHOUGH IF THE REMARKS ON MY FLT PLAN HAD BEEN HEEDED BY ATC, THERE SHOULD HAVE BEEN NO DIFFICULTY): I COULD HAVE RPTED TO ATC AT THE TIME I WAS BEGINNING MY EXERCISE ACTIVITIES AND THAT I WOULD PROBABLY AT TIMES BE BENEATH THEIR RADAR COVERAGE. ALSO, I COULD HAVE 'RESURFACED' (CLBED TO WHERE I WAS AGAIN IN THEIR RADAR COVERAGE) AND RPTED IN EVERY 15-30 MINS OR SO TO BE SURE THEY WERE STILL AWARE OF MY PRESENCE. (HOWEVER, WITH THE FREQS IN THE ADIZ ALREADY BEING VERY CROWDED, SUCH ADDITIONAL XMISSIONS POSE SOME DISADVANTAGE. FURTHER, IT WOULD HAVE CAUSED SOME DISRUPTION OF THE EXERCISES.) FINALLY, ON FILING MY ORIGINAL ADIZ FLT PLAN, I COULD HAVE INDICATED THE DURATION OF FLT AS 4 OR 5 HRS (THE TIME IT WAS EXPECTED TO BE THE MAX DURATION OF OUR EXERCISES), THOUGH IT TAKES LESS THAN 30 MINS TO GET FROM FDK TO W29. THIS MAY HAVE KEPT TRACON FROM TIMING OUT MY SQUAWK.

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.