A B737-500 flight crew experience a heading track deviation when they miss the clearance from ATC fo...

Attributes
ACN	513250
Time
Date	200105
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	intersection : skunk
State Reference	CA
Altitude	msl single value : 16000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-500
Flight Phase	descent : holding
Route In Use	arrival : holding pattern arrival star : big sur
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : atp pilot : multi engine
Experience	flight time last 90 days : 100 flight time total : 5800 flight time type : 3100
ASRS Report	513250
Events
Anomaly	non adherence : clearance other anomaly other other spatial deviation
Resolutory Action	controller : issued new clearance
Supplementary
Problem Areas	Weather Flight Crew Human Performance Cabin Crew Human Performance Airspace Structure ATC Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were en route from burbank, ca, to san francisco, ca, at cruise when we received information from the high altitude center controller (oak) that we could expect holding on the big sur arrival. We were told we would probably be #3 in line to go in. When we switched over to the low altitude controller, we were instructed to hold south of skunk intersection as published, leg lengths at our discretion, at 16000 ft with an efc of XA30Z. We reported and entered the hold appropriately. Dispatch was notified and the passenger were briefed by me as to the nature and length of the hold. We had selected 15 NM legs and allowed the aircraft to continue in the hold in LNAV. At the completion of the first turn, the flight attendant working in the purser position entered the cockpit to ask more about the delay. It was at this time that we received notification by ATC that we were going to be next to go in. We responded with a thank you. The airplane continued on the outbound leg and then started the inbound turn in LNAV. About 90 degrees into the turn, the center controller asked if we were making our inbound turn and we responded with an 'affirmative.' ATC responded by saying that we were to continue flying the outbound heading and that now we should disregard and fly a heading of 270 degrees. The captain and I looked at one another as if to say 'what did we miss?' our best assumption was that, at the point the flight attendant entered the cockpit, we were distraction from the radio call and did not get the entire clearance. Since we acknowledged with a 'thank you' ATC may have assumed we heard the whole clearance. At the same time, it was our responsibility not to be distraction by the flight attendant. This is a perfect example of a minor misstep on each side that could lead to a traffic conflict. We were aware of no traffic at our altitude in the hold, but the error chain can get started with just one slip-up in communication.

Original NASA ASRS Text

Title: A B737-500 FLT CREW EXPERIENCE A HDG TRACK DEV WHEN THEY MISS THE CLRNC FROM ATC FOR A HDG TO LEAVE THE HOLDING PATTERN NEAR MRY, CA.

Narrative: WE WERE ENRTE FROM BURBANK, CA, TO SAN FRANCISCO, CA, AT CRUISE WHEN WE RECEIVED INFO FROM THE HIGH ALT CTR CTLR (OAK) THAT WE COULD EXPECT HOLDING ON THE BIG SUR ARR. WE WERE TOLD WE WOULD PROBABLY BE #3 IN LINE TO GO IN. WHEN WE SWITCHED OVER TO THE LOW ALT CTLR, WE WERE INSTRUCTED TO HOLD S OF SKUNK INTXN AS PUBLISHED, LEG LENGTHS AT OUR DISCRETION, AT 16000 FT WITH AN EFC OF XA30Z. WE RPTED AND ENTERED THE HOLD APPROPRIATELY. DISPATCH WAS NOTIFIED AND THE PAX WERE BRIEFED BY ME AS TO THE NATURE AND LENGTH OF THE HOLD. WE HAD SELECTED 15 NM LEGS AND ALLOWED THE ACFT TO CONTINUE IN THE HOLD IN LNAV. AT THE COMPLETION OF THE FIRST TURN, THE FLT ATTENDANT WORKING IN THE PURSER POS ENTERED THE COCKPIT TO ASK MORE ABOUT THE DELAY. IT WAS AT THIS TIME THAT WE RECEIVED NOTIFICATION BY ATC THAT WE WERE GOING TO BE NEXT TO GO IN. WE RESPONDED WITH A THANK YOU. THE AIRPLANE CONTINUED ON THE OUTBOUND LEG AND THEN STARTED THE INBOUND TURN IN LNAV. ABOUT 90 DEGS INTO THE TURN, THE CTR CTLR ASKED IF WE WERE MAKING OUR INBOUND TURN AND WE RESPONDED WITH AN 'AFFIRMATIVE.' ATC RESPONDED BY SAYING THAT WE WERE TO CONTINUE FLYING THE OUTBOUND HDG AND THAT NOW WE SHOULD DISREGARD AND FLY A HDG OF 270 DEGS. THE CAPT AND I LOOKED AT ONE ANOTHER AS IF TO SAY 'WHAT DID WE MISS?' OUR BEST ASSUMPTION WAS THAT, AT THE POINT THE FLT ATTENDANT ENTERED THE COCKPIT, WE WERE DISTR FROM THE RADIO CALL AND DID NOT GET THE ENTIRE CLRNC. SINCE WE ACKNOWLEDGED WITH A 'THANK YOU' ATC MAY HAVE ASSUMED WE HEARD THE WHOLE CLRNC. AT THE SAME TIME, IT WAS OUR RESPONSIBILITY NOT TO BE DISTR BY THE FLT ATTENDANT. THIS IS A PERFECT EXAMPLE OF A MINOR MISSTEP ON EACH SIDE THAT COULD LEAD TO A TFC CONFLICT. WE WERE AWARE OF NO TFC AT OUR ALT IN THE HOLD, BUT THE ERROR CHAIN CAN GET STARTED WITH JUST ONE SLIP-UP IN COM.

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.

A B737-500 flight crew experience a heading track deviation when they miss the clearance from ATC for a heading to leave the holding pattern near mry, ca.