Temporary loss of communication frequency with approach controller.

Attributes
ACN	247883
Time
Date	199308
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : nrt
State Reference	FO
Altitude	msl bound lower : 4000 msl bound upper : 4000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : nrt tower : oko
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 4 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	enroute : on vectors enroute airway : nrt
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 6000 flight time type : 1500
ASRS Report	247883
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 22000
ASRS Report	248077
Events
Anomaly	non adherence : clearance other anomaly other other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : became reoriented flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

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.

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.