Narrative:

While being radar vectored for the runway 34 ILS approach at narita international airport, the copilot inadvertently and briefly lost radio communication with tokyo approach control (125.9). After pre- setting tower control frequency (118.2) in the right head of the #1 VHF communication radio, I accidentally switched the head selector from the left side (approach control) to the right side (tower frequency). Both pilots became suspicious when our vector heading took us through the final approach course. When the copilot performed a radio check and tower responded, the error was discovered. Fortunately, we were monitoring 121.5 on the #2 VHF communication radio and heard approach control advising us to come up on a different frequency (125.8). This was the second day where we had flown 'all- nighters' (nrt-gum-nrt) and the fatigue associated with being awake all night contributed to the error. Additionally, from the copilot's seat, it is difficult to see which head is selected on the #1 VHF communication radio due to parallax.

Google
 

Original NASA ASRS Text

Title: TEMPORARY LOSS OF COM FREQ WITH APCH CTLR.

Narrative: WHILE BEING RADAR VECTORED FOR THE RWY 34 ILS APCH AT NARITA INTL ARPT, THE COPLT INADVERTENTLY AND BRIEFLY LOST RADIO COM WITH TOKYO APCH CTL (125.9). AFTER PRE- SETTING TWR CTL FREQ (118.2) IN THE R HEAD OF THE #1 VHF COM RADIO, I ACCIDENTALLY SWITCHED THE HEAD SELECTOR FROM THE L SIDE (APCH CTL) TO THE R SIDE (TWR FREQ). BOTH PLTS BECAME SUSPICIOUS WHEN OUR VECTOR HDG TOOK US THROUGH THE FINAL APCH COURSE. WHEN THE COPLT PERFORMED A RADIO CHK AND TWR RESPONDED, THE ERROR WAS DISCOVERED. FORTUNATELY, WE WERE MONITORING 121.5 ON THE #2 VHF COM RADIO AND HEARD APCH CTL ADVISING US TO COME UP ON A DIFFERENT FREQ (125.8). THIS WAS THE SECOND DAY WHERE WE HAD FLOWN 'ALL- NIGHTERS' (NRT-GUM-NRT) AND THE FATIGUE ASSOCIATED WITH BEING AWAKE ALL NIGHT CONTRIBUTED TO THE ERROR. ADDITIONALLY, FROM THE COPLT'S SEAT, IT IS DIFFICULT TO SEE WHICH HEAD IS SELECTED ON THE #1 VHF COM RADIO DUE TO PARALLAX.

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.