Air carrier captain reported a misunderstanding between the captain and first officer whether to fly...

Narrative:

SETZR1 RNAV departure was assigned during pushback. We briefed and ran departure plan checklist and I thought the bases were covered. There was a clue during taxi; that the first officer thought LNAV was required for takeoff. But I didn't engage him for his reasoning; we just set up for an hgs takeoff at my request. Sat tower simply cleared us for departure on runway 04. No additional instructions; as I recall.on departure I was flying runway heading as I expected. The first officer asked me if I wanted LNAV to proceed to the first fix (vauhn) and I said no; just runway heading. He said we were supposed to go direct and I said 'are you sure?' he said 'yes!' so; I said ok; and we engaged LNAV and started the turn. Then he checked in with sat departure. They were polite as there were no traffic conflicts. They reminded us that we were supposed to maintain runway heading; (or an assigned heading; per the SID) for our clearance.in retrospect I should have asked my first officer to go ahead and contact departure control in order to verify our clearance. (Let ATC be the tie-breaker.)

Original NASA ASRS Text

Title: Air carrier Captain reported a misunderstanding between the Captain and First Officer whether to fly runway heading or comply with the RNAV Departure procedures which resulted in heading deviation.

Narrative: SETZR1 RNAV Departure was assigned during pushback. We briefed and ran Departure Plan Checklist and I thought the bases were covered. There was a clue during taxi; that the First Officer thought LNAV was required for takeoff. But I didn't engage him for his reasoning; we just set up for an HGS takeoff at my request. SAT Tower simply cleared us for departure on Runway 04. No additional instructions; as I recall.On departure I was flying Runway Heading as I expected. The First Officer asked me if I wanted LNAV to proceed to the first fix (VAUHN) and I said no; just runway heading. He said we were supposed to go direct and I said 'Are you sure?' He said 'YES!' So; I said ok; and we engaged LNAV and started the turn. Then he checked in with SAT Departure. They were polite as there were no traffic conflicts. They reminded us that we were supposed to maintain runway heading; (or an assigned heading; per the SID) for our clearance.In retrospect I should have asked my First Officer to go ahead and contact Departure Control in order to verify our clearance. (Let ATC be the tie-breaker.)

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.

Attributes
ACN	1327374
Time
Date	201601
Local Time Of Day	0001-0600
Place
Locale Reference	SAT.Airport
State Reference	TX
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Large Transport
Operating Under FAR Part	Part 121
Flight Phase	Takeoff
Route In Use	SID SETZR1
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 201
Events
Anomaly	Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types

Air carrier captain reported a misunderstanding between the captain and first officer whether to fly runway heading or comply with the RNAV departure procedures which resulted in heading deviation.