Loss of traffic separation and communication frequency when a B757 flight crew changes to the incorr...

Attributes
ACN	510130
Time
Date	200105
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zfw.artcc
State Reference	TX
Altitude	msl single value : 39000
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
ASRS Report	510130
Events
Anomaly	conflict : airborne less severe inflight encounter : turbulence non adherence : far non adherence : company policies non adherence : clearance
Resolutory Action	controller : issued advisory none taken : detected after the fact
Consequence	faa : investigated faa : reviewed incident with flight crew faa : assigned or threatened penalties
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance Weather
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were switched to frequency of 134.02 and completed check-in. After approximately 10 mins, we requested lower for chop. ATC informed us that we were on houston approach and return to previous frequency. We then noticed that we were on 134.00. We reset frequency to 134.02 and called ATC. They replied that they attempted multiple calls and that our lost communication had caused a conflict and would be reported. After 1 or 2 attempts, ATC should have attempted a SELCAL. At FL390 a conflict should have been avoided by moving the other aircraft. The NORDO aircraft has no way of knowing he is on the wrong frequency. There was constant chatter on 134.00 so we never realized it was the wrong frequency. For review: we don't know how or when the frequency was changed. We are quite sure that we checked in, but we may have actually checked in with iah approach who was very busy. Had we listened to the radio closer, we would have heard other aircraft calling iah approach rather than ZFW.

Original NASA ASRS Text

Title: LOSS OF TFC SEPARATION AND COM FREQ WHEN A B757 FLT CREW CHANGES TO THE INCORRECT FREQ.

Narrative: WE WERE SWITCHED TO FREQ OF 134.02 AND COMPLETED CHK-IN. AFTER APPROX 10 MINS, WE REQUESTED LOWER FOR CHOP. ATC INFORMED US THAT WE WERE ON HOUSTON APCH AND RETURN TO PREVIOUS FREQ. WE THEN NOTICED THAT WE WERE ON 134.00. WE RESET FREQ TO 134.02 AND CALLED ATC. THEY REPLIED THAT THEY ATTEMPTED MULTIPLE CALLS AND THAT OUR LOST COM HAD CAUSED A CONFLICT AND WOULD BE RPTED. AFTER 1 OR 2 ATTEMPTS, ATC SHOULD HAVE ATTEMPTED A SELCAL. AT FL390 A CONFLICT SHOULD HAVE BEEN AVOIDED BY MOVING THE OTHER ACFT. THE NORDO ACFT HAS NO WAY OF KNOWING HE IS ON THE WRONG FREQ. THERE WAS CONSTANT CHATTER ON 134.00 SO WE NEVER REALIZED IT WAS THE WRONG FREQ. FOR REVIEW: WE DON'T KNOW HOW OR WHEN THE FREQ WAS CHANGED. WE ARE QUITE SURE THAT WE CHKED IN, BUT WE MAY HAVE ACTUALLY CHKED IN WITH IAH APCH WHO WAS VERY BUSY. HAD WE LISTENED TO THE RADIO CLOSER, WE WOULD HAVE HEARD OTHER ACFT CALLING IAH APCH RATHER THAN ZFW.

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.

Loss of traffic separation and communication frequency when a B757 flight crew changes to the incorrect frequency.