<< >> NASA ASRS Report 1535917, April 2018

B777 flight crew reported a track deviation occurred when they offset their course to avoid wake turbulence without coordinating with ATC.

Attributes
ACN	1535917
Time
Date	201804
Local Time Of Day	1801-2400
Place
Locale Reference	CZQM.ARTCC
State Reference	NB
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B777 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	Cruise
Flight Plan	IFR
Person 1
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 65 Flight Crew Type 467
Person 2
Function	Captain Pilot Flying
Qualification	Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument
Experience	Flight Crew Last 90 Days 150 Flight Crew Total 19200 Flight Crew Type 1620
Events
Anomaly	Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types

Narrative:

We offset 1 NM because of wake turbulence from aircraft in front and above us on the same airway thinking that it was okay since the airways are defined by several miles on either side. After being queried by moncton ATC...they then said we were 'approved' to slop (strategic lateral offset procedure). That got us thinking that maybe we were wrong and should have sought approval first. I checked with fom and then discovered that slop is not permitted without ATC clearance in domestic controlled airspace.

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Original NASA ASRS Text

Title: B777 flight crew reported a track deviation occurred when they offset their course to avoid wake turbulence without coordinating with ATC.

Narrative: We offset 1 NM because of wake turbulence from aircraft in front and above us on the same airway thinking that it was okay since the airways are defined by several miles on either side. After being queried by Moncton ATC...they then said we were 'approved' to SLOP (Strategic Lateral Offset Procedure). That got us thinking that maybe we were wrong and should have sought approval first. I checked with FOM and then discovered that SLOP is not permitted without ATC clearance in domestic controlled airspace.

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.