First officer reported a track error departing lga citing error in reading cpdlc change of initial h...

Narrative:

Controller pilot datalink communication (cpdlc) instruction was 'cleared to ZZZ aprt LGA5 except turn left heading 360 for rv then as filed'. When I received and acknowledged the clearance; I read it to the captain stating expect turn to 360 instead of except ....' nothing more; the captain read the cpdlc and acknowledged what we briefed. Captain was PF. We were cleared for takeoff from runway 4 and we commented that usually they state 'turn to heading ###'; however; tower frequency was too busy to inquire and in the absence of further instruction we turned to the SID heading of 051 degrees. Once transferred to departure control; he gave us a heading of 360 degrees. A few minutes later; departure control requested to know what heading we were assigned by lga tower; and I stated 'we weren't given a heading but cpdlc stated to expect a heading of 360 degrees.' nothing more was said. Thirty minutes passed; and I decided to reread the cpdlc and noticed my error of reading 'expect' instead of 'except'. No excuses; I was wearing my new glasses and it was light outside; there were no stressors during boarding. I plainly misread the clearance. We read what we think we want to see and perhaps my only recommendation would be: 1. First officer to be more thorough.2. I wish they (clearance) could use different verbiage and 3. Tower could reinforce the change to the standard clearance but I know lga is busy.'

Original NASA ASRS Text

Title: First Officer reported a track error departing LGA citing error in reading CPDLC change of initial heading during predeparture briefing as probable cause.

Narrative: Controller pilot datalink Communication (CPDLC) instruction was 'Cleared to ZZZ APRT LGA5 EXCEPT TURN LEFT HDG 360 FOR RV THEN AS FILED'. When I received and acknowledged the clearance; I read it to the Captain stating EXPECT TURN TO 360 instead of EXCEPT ....' Nothing more; the Captain read the CPDLC and acknowledged what we briefed. Captain was PF. We were cleared for takeoff from Runway 4 and we commented that usually they state 'turn to heading ###'; however; Tower frequency was too busy to inquire and in the absence of further instruction we turned to the SID heading of 051 degrees. Once transferred to Departure Control; he gave us a heading of 360 degrees. A few minutes later; Departure Control requested to know what heading we were assigned by LGA Tower; and I stated 'We weren't given a heading but CPDLC stated to expect a heading of 360 degrees.' Nothing more was said. Thirty minutes passed; and I decided to reread the CPDLC and noticed my error of reading 'Expect' instead of 'Except'. No excuses; I was wearing my new glasses and it was light outside; there were no stressors during boarding. I plainly misread the clearance. We read what we think we want to see and perhaps my only recommendation would be: 1. First Officer to be more thorough.2. I wish they (Clearance) could use different verbiage and 3. Tower could reinforce the change to the standard clearance but I know LGA is BUSY.'

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	1702288
Time
Date	201911
Local Time Of Day	0601-1200
Place
Locale Reference	LGA.Airport
State Reference	NY
Environment
Light	Daylight
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Initial Climb
Route In Use	SID LAGUARDIA FIVE
Flight Plan	IFR
Person 1
Function	First Officer
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Events
Anomaly	Deviation - Procedural Clearance Deviation - Track / Heading All Types

First officer reported a track error departing lga citing error in reading cpdlc change of initial heading during predeparture briefing as probable cause.