A300 captain departing las is given a shortcut to ceasr on the COWBY5 which required a 120 degree he...

Attributes
ACN	1253211
Time
Date	201504
Local Time Of Day	1801-2400
Place
Locale Reference	LAS.Airport
State Reference	NV
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Make Model Name	A300
Operating Under FAR Part	Part 121
Flight Phase	Climb
Route In Use	Direct SID COWBY5
Flight Plan	IFR
Component
Aircraft Component	FMS/FMC
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 60 Flight Crew Total 15000 Flight Crew Type 5000
Events
Anomaly	Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types

Narrative:

On climbout from las on the COWBY5 I coupled auto pilot at 1200 ft AGL and on the way from fixix to roppr we were given direct ceasr and resume SID; about 5 miles prior to ceasr the line being drawn on the navigation display seemed like it was going to turn early but with about a 120 degree left turn I thought it could be acceptable. It started to turn at 3 miles prior and almost immediately ATC questioned where we were going. I disconnected navigation and went to heading mode and turned back toward ceasr. This happened to me 4 months ago (report filed) and as in this case we did not receive any indication from the FMS of being off course; which leads me to believe that the flight director believed it was on course. In my opinion this aircraft should not be used on RNAV departures without an overhaul to the software.

Original NASA ASRS Text

Title: A300 Captain departing LAS is given a shortcut to CEASR on the COWBY5 which required a 120 degree heading change over CEASR. The FMGC leads this turn by three miles causing ATC to question the crew as to where they are going.

Narrative: On climbout from LAS on the COWBY5 I coupled Auto Pilot at 1200 FT AGL and on the way from FIXIX to ROPPR we were given direct CEASR and resume SID; about 5 miles prior to CEASR the line being drawn on the NAV display seemed like it was going to turn early but with about a 120 degree left turn I thought it could be acceptable. It started to turn at 3 miles prior and almost immediately ATC questioned where we were going. I disconnected NAV and went to heading mode and turned back toward CEASR. This happened to me 4 months ago (Report filed) and as in this case we did not receive any indication from the FMS of being off course; which leads me to believe that the flight director believed it was on course. In my opinion this aircraft should not be used on RNAV departures without an overhaul to the software.

Data retrieved from NASA's ASRS site 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.

A300 captain departing las is given a shortcut to ceasr on the COWBY5 which required a 120 degree heading change over ceasr. The FMGC leads this turn by three miles causing ATC to question the crew as to where they are going.