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Gulfstream crew squawks 7700 when they meant to squawk 7600 after spending some time off ARTCC frequency.
| Attributes | |
| ACN | 452440 |
| Time | |
| Date | 199910 |
| Day | Fri |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| State Reference | UT |
| Altitude | msl single value : 43000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zlc.artcc |
| Operator | general aviation : corporate |
| Make Model Name | Gulfstream IV |
| Operating Under FAR Part | Part 91 |
| Navigation In Use | other |
| Flight Phase | cruise : level |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : corporate |
| Function | flight crew : captain |
| Qualification | pilot : multi engine pilot : atp |
| Experience | flight time last 90 days : 80 flight time total : 12700 flight time type : 1920 |
| ASRS Report | 452440 |
| Person 2 | |
| Affiliation | company : corporate |
| Function | flight crew : first officer |
| Qualification | pilot : atp pilot : multi engine |
| Experience | flight time last 90 days : 100 flight time total : 4800 flight time type : 400 |
| ASRS Report | 452438 |
| Events | |
| Anomaly | aircraft equipment problem : less severe non adherence : published procedure non adherence : far other anomaly other |
| Independent Detector | other flight crewa |
| Resolutory Action | flight crew : overcame equipment problem |
| Consequence | faa : reviewed incident with flight crew |
| Supplementary | |
| Problem Areas | Flight Crew Human Performance Aircraft |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation |
Narrative:
While cruising at FL430, I apparently miscopied the next ATC assigned frequency. When no one responded to my transmission, I went back (I thought) to the previously assigned frequency. Actually, the previously assigned frequency had been lost. It was lost due to my using the control head for the #1 radio in conjunction with the remote tune (FMS) application with the FMS remote tune having been placed in previous 'deselect' by the last crew. The FMS confusion contributed to the miscom. It took nearly 20 mins to re-establish contact with ATC. After 15 mins of trying various frequencys obtained from various sources and not having any success, I decided that for safety reasons I should squawk 7600 to advise ATC of our situation. I mistakenly squawked 7700. When communication was established with ATC, the controller said that he was receiving our 'emergency' squawk. I looked at the transponder setting and I had indeed tuned 7700. I informed ATC that I had meant to tune in 7600. I was asked if we needed any assistance. I explained that we did not and continued with the flight. The ATC manager informed me the situation was non disruptive. He checked with the controllers and felt certain that no reports would be requested from our flight crew. Very careful reading of the FMS manual revealed that with the FMS automatic tune setup in a certain confign, it could cause the 'last tuned' frequency to appear to have been lost. Also, using both automatic tune and manual tune can cause a similar situation.
Original NASA ASRS Text
Title: GULFSTREAM CREW SQUAWKS 7700 WHEN THEY MEANT TO SQUAWK 7600 AFTER SPENDING SOME TIME OFF ARTCC FREQ.
Narrative: WHILE CRUISING AT FL430, I APPARENTLY MISCOPIED THE NEXT ATC ASSIGNED FREQ. WHEN NO ONE RESPONDED TO MY XMISSION, I WENT BACK (I THOUGHT) TO THE PREVIOUSLY ASSIGNED FREQ. ACTUALLY, THE PREVIOUSLY ASSIGNED FREQ HAD BEEN LOST. IT WAS LOST DUE TO MY USING THE CTL HEAD FOR THE #1 RADIO IN CONJUNCTION WITH THE REMOTE TUNE (FMS) APPLICATION WITH THE FMS REMOTE TUNE HAVING BEEN PLACED IN PREVIOUS 'DESELECT' BY THE LAST CREW. THE FMS CONFUSION CONTRIBUTED TO THE MISCOM. IT TOOK NEARLY 20 MINS TO RE-ESTABLISH CONTACT WITH ATC. AFTER 15 MINS OF TRYING VARIOUS FREQS OBTAINED FROM VARIOUS SOURCES AND NOT HAVING ANY SUCCESS, I DECIDED THAT FOR SAFETY REASONS I SHOULD SQUAWK 7600 TO ADVISE ATC OF OUR SIT. I MISTAKENLY SQUAWKED 7700. WHEN COM WAS ESTABLISHED WITH ATC, THE CTLR SAID THAT HE WAS RECEIVING OUR 'EMER' SQUAWK. I LOOKED AT THE XPONDER SETTING AND I HAD INDEED TUNED 7700. I INFORMED ATC THAT I HAD MEANT TO TUNE IN 7600. I WAS ASKED IF WE NEEDED ANY ASSISTANCE. I EXPLAINED THAT WE DID NOT AND CONTINUED WITH THE FLT. THE ATC MGR INFORMED ME THE SIT WAS NON DISRUPTIVE. HE CHKED WITH THE CTLRS AND FELT CERTAIN THAT NO RPTS WOULD BE REQUESTED FROM OUR FLC. VERY CAREFUL READING OF THE FMS MANUAL REVEALED THAT WITH THE FMS AUTO TUNE SETUP IN A CERTAIN CONFIGN, IT COULD CAUSE THE 'LAST TUNED' FREQ TO APPEAR TO HAVE BEEN LOST. ALSO, USING BOTH AUTO TUNE AND MANUAL TUNE CAN CAUSE A SIMILAR SIT.
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.