 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Aircraft type demonstrates a radio communication problem because of auditory interference. Flight crew changes frequency without clearance.
| Attributes | |
| ACN | 208756 |
| Time | |
| Date | 199204 |
| Day | Fri |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : rsw |
| State Reference | FL |
| Altitude | msl bound lower : 1000 msl bound upper : 1000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tower : rsw tower : tyr |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Navigation In Use | Other Other |
| Flight Phase | descent : approach |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 100 flight time total : 4000 flight time type : 100 |
| ASRS Report | 208756 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : flight engineer |
| Experience | flight time last 90 days : 90 flight time total : 8000 flight time type : 300 |
| ASRS Report | 208757 |
| Events | |
| Anomaly | aircraft equipment problem : less severe non adherence other |
| Independent Detector | other flight crewa |
| Resolutory Action | other |
| Consequence | faa : reviewed incident with flight crew |
| Supplementary | |
| Primary Problem | Aircraft |
| Air Traffic Incident | other |
Narrative:
Was on a VOR/DME approach to airport. Switched tower after directed by approach. Tower frequency is 120.0. The tower cleared us to land, but 120.0 was very broken and garbled. This always happens on the medium large transport model on 120.0 or frequencys ending in '.0.' tower became very unreadable so in interest of safety and communications, we switched to ground control, 121.9, to reestablish communication. At this time we were 500 ft AGL preparing to land. Ground control came back and seemed upset that we switched without permission or telling them. I have been to this airport before and have had to use ground control to takeoff and land. This has been a problem in our medium large transport model for yrs and nothing has been done about the tower frequencys or the aircraft. Supplemental information from acn 208757: the 'point 0' frequency hum is a known medium large transport model communications problem. This problem should be rectified as soon as possible. Either the FAA should not use it or they should compel the manufacturers to correct the problem. Callback conversation with reporter revealed the following: reporter said his air carrier was working on a fix and had also issued a bulletin to all pilots about this interference problem on communication frequency 120.0 MHZ. Rsw tower is familiar with the problem because, in the past, if a pilot complained about the problem, the tower asked if they were flying that particular model medium large transport. He is not sure if the reported incident was due to the fix not being installed yet or if an installed fix failed to work. Coincidentally, the reporter has a personal small aircraft and has the same problem with 120.0. He said a LORAN installation on his aircraft interferes with his receiver. A callback to the captain disclosed there is no history of this problem with the older model aircraft but that when they were converted to the new advanced electronics, the problem arose. He specified that the problem has happened on 118.0, 120.0, and 123.0 MHZ.
Original NASA ASRS Text
Title: ACFT TYPE DEMONSTRATES A RADIO COM PROBLEM BECAUSE OF AUDITORY INTERFERENCE. FLC CHANGES FREQ WITHOUT CLRNC.
Narrative: WAS ON A VOR/DME APCH TO ARPT. SWITCHED TWR AFTER DIRECTED BY APCH. TWR FREQ IS 120.0. THE TWR CLRED US TO LAND, BUT 120.0 WAS VERY BROKEN AND GARBLED. THIS ALWAYS HAPPENS ON THE MLG MODEL ON 120.0 OR FREQS ENDING IN '.0.' TWR BECAME VERY UNREADABLE SO IN INTEREST OF SAFETY AND COMS, WE SWITCHED TO GND CTL, 121.9, TO REESTABLISH COM. AT THIS TIME WE WERE 500 FT AGL PREPARING TO LAND. GND CTL CAME BACK AND SEEMED UPSET THAT WE SWITCHED WITHOUT PERMISSION OR TELLING THEM. I HAVE BEEN TO THIS ARPT BEFORE AND HAVE HAD TO USE GND CTL TO TKOF AND LAND. THIS HAS BEEN A PROBLEM IN OUR MLG MODEL FOR YRS AND NOTHING HAS BEEN DONE ABOUT THE TWR FREQS OR THE ACFT. SUPPLEMENTAL INFORMATION FROM ACN 208757: THE 'POINT 0' FREQ HUM IS A KNOWN MLG MODEL COMS PROBLEM. THIS PROBLEM SHOULD BE RECTIFIED AS SOON AS POSSIBLE. EITHER THE FAA SHOULD NOT USE IT OR THEY SHOULD COMPEL THE MANUFACTURERS TO CORRECT THE PROBLEM. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: RPTR SAID HIS ACR WAS WORKING ON A FIX AND HAD ALSO ISSUED A BULLETIN TO ALL PLTS ABOUT THIS INTERFERENCE PROBLEM ON COM FREQ 120.0 MHZ. RSW TWR IS FAMILIAR WITH THE PROBLEM BECAUSE, IN THE PAST, IF A PLT COMPLAINED ABOUT THE PROBLEM, THE TWR ASKED IF THEY WERE FLYING THAT PARTICULAR MODEL MLG. HE IS NOT SURE IF THE RPTED INCIDENT WAS DUE TO THE FIX NOT BEING INSTALLED YET OR IF AN INSTALLED FIX FAILED TO WORK. COINCIDENTALLY, THE RPTR HAS A PERSONAL SMA AND HAS THE SAME PROBLEM WITH 120.0. HE SAID A LORAN INSTALLATION ON HIS ACFT INTERFERES WITH HIS RECEIVER. A CALLBACK TO THE CAPT DISCLOSED THERE IS NO HISTORY OF THIS PROBLEM WITH THE OLDER MODEL ACFT BUT THAT WHEN THEY WERE CONVERTED TO THE NEW ADVANCED ELECTRONICS, THE PROBLEM AROSE. HE SPECIFIED THAT THE PROBLEM HAS HAPPENED ON 118.0, 120.0, AND 123.0 MHZ.
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.