Air carrier widebody transport starting extended overwater operation returned due VHF communication problems. PIC set wrong transponder code, using 7500 instead of 7600.

Home

Browse by month

Random

Latest

About

Contact

Attributes
ACN	120385
Time
Date	198908
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : anc
State Reference	AK
Altitude	msl bound lower : 0 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zan tracon : anc
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 4 Turbojet Eng
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 150 flight time total : 9500 flight time type : 2000
ASRS Report	120385
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical non adherence : far other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	none taken : unable other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

On climb out from anc, vhr's worked intermittently. We contacted maintenance and proceeded to bethel, final destination yakota AFB, japan. Lost all communications, tried HF's. Able to receive, not able to transmit. Captain elected to return to anc under VFR conditions. He directed second officer, F/east, to prepare to dump fuel and directed me to keep trying on the radios and punch in coordinates for the iws to get us back to anc. The captain selected mistakenly 7500 on the squawk instead of 7600. We turned back for anc and descended to 15000'. Return to anc was normal with the radios working occasionally, or with carrier only. ATC's mention of the word 'trip' alerted us finally to the fact that we had 7500 for a squawk.

Original NASA ASRS Text

Title: ACR WDB STARTING EXTENDED OVERWATER OPERATION RETURNED DUE VHF COM PROBLEMS. PIC SET WRONG TRANSPONDER CODE, USING 7500 INSTEAD OF 7600.

Narrative: ON CLBOUT FROM ANC, VHR'S WORKED INTERMITTENTLY. WE CONTACTED MAINT AND PROCEEDED TO BETHEL, FINAL DEST YAKOTA AFB, JAPAN. LOST ALL COMS, TRIED HF'S. ABLE TO RECEIVE, NOT ABLE TO XMIT. CAPT ELECTED TO RETURN TO ANC UNDER VFR CONDITIONS. HE DIRECTED S/O, F/E, TO PREPARE TO DUMP FUEL AND DIRECTED ME TO KEEP TRYING ON THE RADIOS AND PUNCH IN COORDINATES FOR THE IWS TO GET US BACK TO ANC. THE CAPT SELECTED MISTAKENLY 7500 ON THE SQUAWK INSTEAD OF 7600. WE TURNED BACK FOR ANC AND DSNDED TO 15000'. RETURN TO ANC WAS NORMAL WITH THE RADIOS WORKING OCCASIONALLY, OR WITH CARRIER ONLY. ATC'S MENTION OF THE WORD 'TRIP' ALERTED US FINALLY TO THE FACT THAT WE HAD 7500 FOR A SQUAWK.

Data retrieved from NASA's ASRS site as of August 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.