B737 crew deviates from shead 4 departure out of las.

Attributes
ACN	719072
Time
Date	200612
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : las.airport
State Reference	NV
Altitude	agl single value : 1000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : l30.tracon
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	climbout : initial
Route In Use	departure sid : shead5
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 131 flight time type : 3600
ASRS Report	719072
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : less severe non adherence : published procedure other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance flight crew : returned to intended or assigned course
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Flight Crew Human Performance

Narrative:

We departed las runway 7L on the shead 4 RNAV departure. All flight plan information in the FMS was verified on the preflight to be correct. The FMS was updated as we took the runway for takeoff. At 400 ft AGL the captain; who was PF; engaged the LNAV. The v-bars commanded a 045 degree heading. The captain kept the airplane on the 075 degree heading and asked me to reselect direct waste which I did. At 1000 ft AGL the captain engaged the autoplt and the FMS commanded the autoplt to turn left. The captain disengaged the autoplt and began his turn back to 075 degrees just as ATC asked why we were turning on a straight out departure. ATC then gave us a heading for direct shead. Even though 'waste' was reselected; we should have verified the correct heading on the departure to the heading in the FMS. I do not know why the FMS; which had all the correct fixes; did not have the correct headings.

Original NASA ASRS Text

Title: B737 CREW DEVIATES FROM SHEAD 4 DEP OUT OF LAS.

Narrative: WE DEPARTED LAS RWY 7L ON THE SHEAD 4 RNAV DEP. ALL FLT PLAN INFO IN THE FMS WAS VERIFIED ON THE PREFLT TO BE CORRECT. THE FMS WAS UPDATED AS WE TOOK THE RWY FOR TKOF. AT 400 FT AGL THE CAPT; WHO WAS PF; ENGAGED THE LNAV. THE V-BARS COMMANDED A 045 DEG HDG. THE CAPT KEPT THE AIRPLANE ON THE 075 DEG HDG AND ASKED ME TO RESELECT DIRECT WASTE WHICH I DID. AT 1000 FT AGL THE CAPT ENGAGED THE AUTOPLT AND THE FMS COMMANDED THE AUTOPLT TO TURN L. THE CAPT DISENGAGED THE AUTOPLT AND BEGAN HIS TURN BACK TO 075 DEGS JUST AS ATC ASKED WHY WE WERE TURNING ON A STRAIGHT OUT DEP. ATC THEN GAVE US A HDG FOR DIRECT SHEAD. EVEN THOUGH 'WASTE' WAS RESELECTED; WE SHOULD HAVE VERIFIED THE CORRECT HDG ON THE DEP TO THE HDG IN THE FMS. I DO NOT KNOW WHY THE FMS; WHICH HAD ALL THE CORRECT FIXES; DID NOT HAVE THE CORRECT HDGS.

Data retrieved from NASA's ASRS site as of January 2009 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.