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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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A320 pilot complains there is no squelch disable switch in the VHF radio system.
| Attributes | |
| ACN | 473720 |
| Time | |
| Date | 200005 |
| Day | Fri |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| State Reference | ND |
| Altitude | msl single value : 37000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zlc.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | A320 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | other |
| Flight Phase | cruise : level |
| Route In Use | enroute airway : j36.airway |
| Flight Plan | IFR |
| Aircraft 2 | |
| Controlling Facilities | artcc : zlc.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | Commercial Fixed Wing |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise : level |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : multi engine |
| Experience | flight time last 90 days : 120 flight time total : 11000 flight time type : 3500 |
| ASRS Report | 443720 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : instrument pilot : multi engine pilot : commercial |
| Events | |
| Anomaly | aircraft equipment problem : less severe non adherence : published procedure non adherence : clearance other anomaly other |
| Independent Detector | other flight crewa |
| Resolutory Action | other |
| Supplementary | |
| Problem Areas | Flight Crew Human Performance Aircraft |
| Primary Problem | Flight Crew Human Performance |
Narrative:
We were talking to ZLC on 126.85 after about 20-30 mins we noticed that we could hear other aircraft xmissions but could not hear ZLC's calls. We asked an air carrier flight to get us another frequency. We checked in on ZMP and had no other problems. The A320 has no squelch disable capabilities so if the ground station gets near the maximum range they will cut out, a squelch disable would allow us to hear a very weak radio. Usually it's not a problem unless you are a long distance from the ATC transmitter when they call. Callback conversation with reporter revealed the following information: reporter has just upgraded from the early model DC9 that did have this switch that he found useful. He admits that he had flown well outside of the coverage of ZMP and may have missed a frequency change.
Original NASA ASRS Text
Title: A320 PLT COMPLAINS THERE IS NO SQUELCH DISABLE SWITCH IN THE VHF RADIO SYS.
Narrative: WE WERE TALKING TO ZLC ON 126.85 AFTER ABOUT 20-30 MINS WE NOTICED THAT WE COULD HEAR OTHER ACFT XMISSIONS BUT COULD NOT HEAR ZLC'S CALLS. WE ASKED AN ACR FLT TO GET US ANOTHER FREQ. WE CHECKED IN ON ZMP AND HAD NO OTHER PROBS. THE A320 HAS NO SQUELCH DISABLE CAPABILITIES SO IF THE GND STATION GETS NEAR THE MAX RANGE THEY WILL CUT OUT, A SQUELCH DISABLE WOULD ALLOW US TO HEAR A VERY WEAK RADIO. USUALLY IT'S NOT A PROB UNLESS YOU ARE A LONG DISTANCE FROM THE ATC XMITTER WHEN THEY CALL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR HAS JUST UPGRADED FROM THE EARLY MODEL DC9 THAT DID HAVE THIS SWITCH THAT HE FOUND USEFUL. HE ADMITS THAT HE HAD FLOWN WELL OUTSIDE OF THE COVERAGE OF ZMP AND MAY HAVE MISSED A FREQ CHANGE.
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.