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A B757 flight crew loses contact with ZOB controller when their VHF automatic switches from center frequency to an off frequency selection near yqo, ontario.
| Attributes | |
| ACN | 464560 |
| Time | |
| Date | 200002 |
| Day | Sun |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| State Reference | ON |
| Altitude | msl bound lower : 24000 msl bound upper : 28000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zob.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | B757 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | other |
| Flight Phase | cruise : enroute altitude change |
| Route In Use | arrival star : ns |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : cfi pilot : commercial pilot : flight engineer pilot : instrument pilot : multi engine |
| Experience | flight time last 90 days : 180 flight time total : 11000 flight time type : 4500 |
| ASRS Report | 464560 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : multi engine pilot : instrument pilot : commercial |
| Events | |
| Anomaly | aircraft equipment problem : less severe non adherence : company policies non adherence : far non adherence : published procedure other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : acars other controllera |
| Resolutory Action | flight crew : overcame equipment problem other |
| Consequence | other other |
| Supplementary | |
| Problem Areas | ATC Human Performance Flight Crew Human Performance Aircraft |
| Primary Problem | Aircraft |
| Air Traffic Incident | Pilot Deviation |
Narrative:
Assigned descent from FL280 to FL240. Acknowledged such to ZOB on 132.77. Had been on 132.77 prior to descent clearance. While in descent to FL240, received ACARS message from dispatch to call ZOB on another frequency. Upon inspection of left radio (head) frequency showed 132.72. By just bumping contact head, frequency flipped back to 132.77. We had not touched the frequency selector and assume the loss of ATC contact was caused by the radio frequency control head self-changing between 132.77 and 132.72. This self-switching was observed by both pilots.
Original NASA ASRS Text
Title: A B757 FLC LOSES CONTACT WITH ZOB CTLR WHEN THEIR VHF AUTO SWITCHES FROM CTR FREQ TO AN OFF FREQ SELECTION NEAR YQO, ONTARIO.
Narrative: ASSIGNED DSCNT FROM FL280 TO FL240. ACKNOWLEDGED SUCH TO ZOB ON 132.77. HAD BEEN ON 132.77 PRIOR TO DSCNT CLRNC. WHILE IN DSCNT TO FL240, RECEIVED ACARS MESSAGE FROM DISPATCH TO CALL ZOB ON ANOTHER FREQ. UPON INSPECTION OF L RADIO (HEAD) FREQ SHOWED 132.72. BY JUST BUMPING CONTACT HEAD, FREQ FLIPPED BACK TO 132.77. WE HAD NOT TOUCHED THE FREQ SELECTOR AND ASSUME THE LOSS OF ATC CONTACT WAS CAUSED BY THE RADIO FREQ CTL HEAD SELF-CHANGING BTWN 132.77 AND 132.72. THIS SELF-SWITCHING WAS OBSERVED BY BOTH PLTS.
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.