Thunderstorm activity involved with en route WX/ B767 requests and obtains amended clearance route a...

Attributes
ACN	351267
Time
Date	199610
Day	Sun
Local Time Of Day	0001 To 0600
Place
Locale Reference	atc facility : cma
State Reference	FO
Altitude	msl bound lower : 33000 msl bound upper : 37000
Environment
Light	Night
Aircraft 1
Controlling Facilities	artcc : svzm
Operator	common carrier : air carrier
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude cruise other cruise other
Route In Use	enroute : atlantic enroute : other oceanic
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	351267
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	inflight encounter : weather non adherence : clearance non adherence : far other anomaly other
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation other

Narrative:

Maiquetia control. Location: UL304 sbound after canaima (cma) position sbound on UL304 and approaching isani position we requested and received a clearance to deviate 20 NM left of crs for WX. After deviation was begun we were asked our estimate for isani. We gave mqi AB40 from the FMC for isani. Based on this estimate mqi gave us a clearance to climb to FL370 from FL330. After level off and still deviating in heading select, we noticed the estimated we had given for isani was wrong. Isani was not the active waypoint. We calculated a new estimate AB33. Distance GS. We advised mqi of new estimate and they told us to make a 360 degree turn to the left so as to arrive at isani at our original estimate. When abeam isani, deviation WX, we made 360 degree to left and out of turn went direct to isani position. Our estimate for isani was now AB48. We updated our estimate with mqi and they said ok. We crossed isani at AB48 and proceeded routine for balance of flight. Isani position was given to flight support lima on HF. We also reported our 360 degree turn and the delay from same crossing isani. Deviation distraction did not help to pick up fact that route data on screen was incorrect while I was in heading select. Mqi was hard to reach on VHF and some communication relays were necessary in all this clearance revision.

Original NASA ASRS Text

Title: TSTM ACTIVITY INVOLVED WITH ENRTE WX/ B767 REQUESTS AND OBTAINS AMENDED CLRNC RTE ALT CHANGE BASED UPON AN ERRONEOUS ESTIMATE FOR THE NEXT POS.

Narrative: MAIQUETIA CTL. LOCATION: UL304 SBOUND AFTER CANAIMA (CMA) POS SBOUND ON UL304 AND APCHING ISANI POS WE REQUESTED AND RECEIVED A CLRNC TO DEVIATE 20 NM L OF CRS FOR WX. AFTER DEV WAS BEGUN WE WERE ASKED OUR ESTIMATE FOR ISANI. WE GAVE MQI AB40 FROM THE FMC FOR ISANI. BASED ON THIS ESTIMATE MQI GAVE US A CLRNC TO CLB TO FL370 FROM FL330. AFTER LEVEL OFF AND STILL DEVIATING IN HEADING SELECT, WE NOTICED THE ESTIMATED WE HAD GIVEN FOR ISANI WAS WRONG. ISANI WAS NOT THE ACTIVE WAYPOINT. WE CALCULATED A NEW ESTIMATE AB33. DISTANCE GS. WE ADVISED MQI OF NEW ESTIMATE AND THEY TOLD US TO MAKE A 360 DEG TURN TO THE L SO AS TO ARRIVE AT ISANI AT OUR ORIGINAL ESTIMATE. WHEN ABEAM ISANI, DEV WX, WE MADE 360 DEG TO L AND OUT OF TURN WENT DIRECT TO ISANI POS. OUR ESTIMATE FOR ISANI WAS NOW AB48. WE UPDATED OUR ESTIMATE WITH MQI AND THEY SAID OK. WE CROSSED ISANI AT AB48 AND PROCEEDED ROUTINE FOR BAL OF FLT. ISANI POS WAS GIVEN TO FLT SUPPORT LIMA ON HF. WE ALSO RPTED OUR 360 DEG TURN AND THE DELAY FROM SAME XING ISANI. DEV DISTR DID NOT HELP TO PICK UP FACT THAT RTE DATA ON SCREEN WAS INCORRECT WHILE I WAS IN HEADING SELECT. MQI WAS HARD TO REACH ON VHF AND SOME COM RELAYS WERE NECESSARY IN ALL THIS CLRNC REVISION.

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.

Thunderstorm activity involved with en route WX/ B767 requests and obtains amended clearance route altitude change based upon an erroneous estimate for the next position.