Narrative:

The managed navigation altam 6 departure off of runway 12 in sjc doesn't duplicate the commercial charts. The way I interpret the navigation display, a right turn is required in managed navigation at the 4000 ft conditional waypoint. We flew the departure in managed navigation backed up with raw data to see what would happen. We appeared to fly through the oak 129 degree radial, but using the raw data was difficult to interpret and trust because of the large needle fluctuations. The aircraft finally made a l-hand turn, but not until passing 8000 ft instead of 4000 ft. The 4000 ft conditional waypoint was west of our position when we started the left turn. Very strange, and not the way the commercial charts read the procedure. Additionally, the navigation display appeared different on the ground than in the air, and the secondary flight plan was something different as well. Callback conversation with reporter revealed the following information: this A320 captain said that he has recently xferred from the B747-400 so he is used to using the FMC and the special FMC charts. However, when he looked at the A320's FMC chart for the altam 6 departure, he noted that it indicated a right turn versus the regular chart's left turn at 4000 ft. The reporter said that he has complained to his company about the accuracy of the FMC charts for the A320 as well as their poor depictions, but he has not received any effective corrections to the charts. This departure he decided to allow the aircraft to follow the FMC guidance while following with raw data information. He said that he wanted to see how far off the computer flight guidance plan was and report this to the chief pilot. After takeoff the aircraft tracked to the east of the oak 129 degree radial and then finally started its left turn out of 8000 ft instead of 4000 ft. The departure controller was curious as to their route deviation and not satisfied with his explanation. The reporter asked about variations in the oak VOR's course readings and the departure controller said that a number of flts had mentioned this. The captain said that he felt safe allowing the aircraft to follow the FMGC because he could see the hills and knew that he had adequate clearance from terrain. The captain reported his findings to his chief pilot, the A320 program director, and to the training department at his airline and they allegedly thanked him and are investigating the chart problem.

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Original NASA ASRS Text

Title: AN ACR A320 FLC NOTED THAT THE FMC'S SID CHART WAS DIFFERENT FROM THE COMMERCIAL CHART. LATER THEY NOTICED THAT THE FMC DEPICTION CHANGED AFTER THEY BECAME AIRBORNE. THE ACTUAL TRACK FLOWN BY THE FMGC DIFFERED FROM THE COMMERCIAL CHART AND FROM THE CTLR'S EXPECTATIONS. ALSO THE OAK VOR'S COURSE INDICATIONS VARIED BY AS MUCH AS 2 DEGS EITHER SIDE OF CTRLINE.

Narrative: THE MANAGED NAV ALTAM 6 DEP OFF OF RWY 12 IN SJC DOESN'T DUPLICATE THE COMMERCIAL CHARTS. THE WAY I INTERPRET THE NAV DISPLAY, A R TURN IS REQUIRED IN MANAGED NAV AT THE 4000 FT CONDITIONAL WAYPOINT. WE FLEW THE DEP IN MANAGED NAV BACKED UP WITH RAW DATA TO SEE WHAT WOULD HAPPEN. WE APPEARED TO FLY THROUGH THE OAK 129 DEG RADIAL, BUT USING THE RAW DATA WAS DIFFICULT TO INTERPRET AND TRUST BECAUSE OF THE LARGE NEEDLE FLUCTUATIONS. THE ACFT FINALLY MADE A L-HAND TURN, BUT NOT UNTIL PASSING 8000 FT INSTEAD OF 4000 FT. THE 4000 FT CONDITIONAL WAYPOINT WAS W OF OUR POS WHEN WE STARTED THE L TURN. VERY STRANGE, AND NOT THE WAY THE COMMERCIAL CHARTS READ THE PROC. ADDITIONALLY, THE NAV DISPLAY APPEARED DIFFERENT ON THE GND THAN IN THE AIR, AND THE SECONDARY FLT PLAN WAS SOMETHING DIFFERENT AS WELL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THIS A320 CAPT SAID THAT HE HAS RECENTLY XFERRED FROM THE B747-400 SO HE IS USED TO USING THE FMC AND THE SPECIAL FMC CHARTS. HOWEVER, WHEN HE LOOKED AT THE A320'S FMC CHART FOR THE ALTAM 6 DEP, HE NOTED THAT IT INDICATED A R TURN VERSUS THE REGULAR CHART'S L TURN AT 4000 FT. THE RPTR SAID THAT HE HAS COMPLAINED TO HIS COMPANY ABOUT THE ACCURACY OF THE FMC CHARTS FOR THE A320 AS WELL AS THEIR POOR DEPICTIONS, BUT HE HAS NOT RECEIVED ANY EFFECTIVE CORRECTIONS TO THE CHARTS. THIS DEP HE DECIDED TO ALLOW THE ACFT TO FOLLOW THE FMC GUIDANCE WHILE FOLLOWING WITH RAW DATA INFO. HE SAID THAT HE WANTED TO SEE HOW FAR OFF THE COMPUTER FLT GUIDANCE PLAN WAS AND RPT THIS TO THE CHIEF PLT. AFTER TKOF THE ACFT TRACKED TO THE E OF THE OAK 129 DEG RADIAL AND THEN FINALLY STARTED ITS L TURN OUT OF 8000 FT INSTEAD OF 4000 FT. THE DEP CTLR WAS CURIOUS AS TO THEIR RTE DEV AND NOT SATISFIED WITH HIS EXPLANATION. THE RPTR ASKED ABOUT VARIATIONS IN THE OAK VOR'S COURSE READINGS AND THE DEP CTLR SAID THAT A NUMBER OF FLTS HAD MENTIONED THIS. THE CAPT SAID THAT HE FELT SAFE ALLOWING THE ACFT TO FOLLOW THE FMGC BECAUSE HE COULD SEE THE HILLS AND KNEW THAT HE HAD ADEQUATE CLRNC FROM TERRAIN. THE CAPT RPTED HIS FINDINGS TO HIS CHIEF PLT, THE A320 PROGRAM DIRECTOR, AND TO THE TRAINING DEPT AT HIS AIRLINE AND THEY ALLEGEDLY THANKED HIM AND ARE INVESTIGATING THE CHART PROB.

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.