Captain reported turning too early contrary to the amended departure procedure.

Attributes
ACN	1709808
Time
Date	201912
Local Time Of Day	0601-1200
Place
Locale Reference	EWR.Airport
State Reference	NJ
Aircraft 1
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	Initial Climb
Route In Use	SID NEWARK FOUR
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument
Events
Anomaly	Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types

Narrative:

Original ATC clearance was the newark four (EWR4) departure off of runway 4L. The EWR4 calls for a left turn to 060 at 500 feet; then at 4DME ieza a left turn to 290. The clearance was amended via cpdlc before pushback to fly runway heading until 4DME ieza then left turn to 290. The change was briefed at the gate and again prior to takeoff. Heading 290 was preselected in the flight control panel. After takeoff; at 500 feet; I asked for heading select. I initiated a turn to 290 between 500 and 1000 feet instead of waiting until 4 DME ieza. ATC questioned our heading then said we were supposed to wait until 4 DME for the turn. A heading of 310 was issued.

Original NASA ASRS Text

Title: Captain reported turning too early contrary to the amended departure procedure.

Narrative: Original ATC clearance was the NEWARK FOUR (EWR4) departure off of runway 4L. The EWR4 calls for a left turn to 060 at 500 feet; then at 4DME IEZA a left turn to 290. The clearance was amended via CPDLC before pushback to fly runway heading until 4DME IEZA then left turn to 290. The change was briefed at the gate and again prior to takeoff. Heading 290 was preselected in the Flight Control Panel. After takeoff; at 500 feet; I asked for heading select. I initiated a turn to 290 between 500 and 1000 feet instead of waiting until 4 DME IEZA. ATC questioned our heading then said we were supposed to wait until 4 DME for the turn. A heading of 310 was issued.

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.