Date: 201705
Local time of day: 0601-1200
Location: EIDW.Airport, FO
Flight conditions: VMC
Light: Dawn
Aircraft: Large Transport; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
ATC / advisory: Center EISN
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Confusion; Workload
Second reporter function: Captain; Pilot Flying
Anomaly: ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Chart Or Publication; Human Factors; Procedure
Primary problem: Human Factors

Narrative: We were cleared direct to OLAPO for the OLAPO1L Arrival. Near OLAPO; Dublin Approach issued the clearance 'direct to KERAV to hold'; which was about 55 miles away. The OLAPO1L arrival chart (10-2F) depicts '209 degree Inbound Course with Right Hand Turns.' When we initially asked for clarification on whether to execute non-published holding or hold as published; Dublin Approach responded 'Hold with Right Hand Turns.' This led to multiple inquiries by both the Non-flying Pilot (FO) and the Flying Pilot (Captain) for Dublin Approach to clarify whether she wanted us to establish non-published holding on our inbound course of 109 degrees or to fly the published holding pattern. Dublin Approach's reply continued to be 'enter holding with a right hand turn.' Finally; the NFP asked 'Do you want us to hold as published or do you want us to hold on a non-published 109 inbound course right hand turn?' She simply stated 'The latter.' At this point; the Captain; FO; and IRO felt that we had received confirmation to execute a non-published holding pattern even though the controller never used the terms 'non-published' or 'published'. The Captain had the IRO look up the holding speeds and leg distances for Ireland. Passing KERAV; I called 'entering holding and requested an expected clearance time.' The controller responded initially 'One round' and amended it to 'two rounds of holding.' On the initial outbound leg of the hold; the controller asked when we were we were going to start our turn north. When we tried to explain that we understood her instructions to establish non-published holding; she responded 'There is confusion all around.' At that point; we were given a radio frequency change to another Dublin Approach Controller. He initially gave us direct to GIRAS followed by vectors to the Final Approach Course. The remainder of the flight was uneventful. In retrospect; the best course of action would have been to refuse holding and ask for vectors unless we could get a verbal confirmation of either 'published' or 'non-published' holding. There was no conflict with any traffic at any time.


Second narrative: [Report narrative contained no additional information.]


Synopsis: Air carrier flight crew reported confusion due to improper instructions about holding on the EIDW OLAPO 1L Arrival approaching the KERAV.