Narrative:

The theme of this flight was dealing with shortcuts which continually put us outside of the off-shore limit for our non-eow (extended over water) aircraft. As we were proceeding direct filbe southeast of omn; miami center instructed us to fly heading 120 and expect a reroute. I immediately felt suspicion as this heading was taking us off shore; and but elected to wait and see what the new route was.we were soon cleared direct aybid and the aybid transition of the FRWAY5 arrival; with ATC stating 'make sure to tell your company that this is the route for arrivals into pbi from now on.' we accepted the clearance; and I initially checked the distance off shore of these waypoints by inserting mlb (melbourne; fl airport) between aybid and mimmi and reading the distance between points on the legs page (aybid-mlb-mimmi) the both legs showed less than 50 nm between points; but by a very thin margin showing approximately 49.8 nm from aybid to mlb; and 47 nm from mlb to mimmi. Still concerned with the tight margins; I entered aybid on the enroute chart page of my jeppview app; and noticed that it appeared that the waypoint was over 50 nm according to the range rings. I sent an ACARS message to dispatch telling them of the route and conflicting information; and received a response that 'aybid is too far offshore for non eow aircraft; you need to turn back.'I instructed the new controller of our problem; and requested an immediate turn back towards the coast. Center responded by clearing us directly to mimmi; and to cross mimmi at FL240. This resulted in an approximately 90 degree turn; and I was satisfied that we had avoided violating company policy. I sent a reply to dispatch that 'turning back to pbi now.' and we continued to a normal landing. On discussing the situation with dispatch on the ground; I learned that both aybid and mimmi are more than 50 nm off shore; although the dispatcher could not tell us exactly how far off shore we reached. On discussing the situation with the first officer; he reminded me that we did pass over mimmi when we met the crossing restriction.I still don't know exactly how far offshore we got. When I checked my FMS measurements on the ground; the distances for both aybid and mimmi showed more than 50 nm from mlb; my shore reference. I believe this discrepancy exists because the aircraft was not including its turn anticipation in the distance measurements; which is why the distances were different on the ground vs. In the air. I have also noticed that the jeppesen range rings will not depict a 50 nm ring; although that specific distance is important for our operations.ATC may not understand our eow limitations on this route; combined with either their policies or preference to use the aybid transition. I also believe that I became complacent after I informed ATC of our restriction; and accepted the turn to mimmi; believing this fix was within the envelope; and without independently verifying so. Finally; if this is a repeated issue; a caution note could be added to the 10-7 page to inform pilots to not accept this transition due to eow limitations.

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Original NASA ASRS Text

Title: Air carrier flight crew and Dispatcher reported ATC routed the flight offshore beyond the non-EOW (Extended Over Water) limit.

Narrative: The theme of this flight was dealing with shortcuts which continually put us outside of the off-shore limit for our non-EOW (Extended Over Water) aircraft. As we were proceeding direct FILBE southeast of OMN; Miami center instructed us to fly Heading 120 and expect a reroute. I immediately felt suspicion as this heading was taking us off shore; and but elected to wait and see what the new route was.We were soon cleared direct AYBID and the AYBID transition of the FRWAY5 arrival; with ATC stating 'make sure to tell your company that this is the route for arrivals into PBI from now on.' We accepted the clearance; and I initially checked the distance off shore of these waypoints by inserting MLB (Melbourne; FL airport) between AYBID and MIMMI and reading the distance between points on the legs page (AYBID-MLB-MIMMI) The both legs showed less than 50 nm between points; but by a very thin margin showing approximately 49.8 nm from AYBID to MLB; and 47 nm from MLB to MIMMI. Still concerned with the tight margins; I entered AYBID on the enroute chart page of my Jeppview app; and noticed that it appeared that the waypoint was over 50 nm according to the range rings. I sent an ACARS message to dispatch telling them of the route and conflicting information; and received a response that 'AYBID is too far offshore for non EOW aircraft; you need to turn back.'I instructed the new controller of our problem; and requested an immediate turn back towards the coast. Center responded by clearing us directly to MIMMI; and to cross MIMMI at FL240. This resulted in an approximately 90 degree turn; and I was satisfied that we had avoided violating company policy. I sent a reply to dispatch that 'Turning back to PBI now.' And we continued to a normal landing. On discussing the situation with dispatch on the ground; I learned that both AYBID and MIMMI are more than 50 nm off shore; although the dispatcher could not tell us exactly how far off shore we reached. On discussing the situation with the FO; he reminded me that we did pass over MIMMI when we met the crossing restriction.I still don't know exactly how far offshore we got. When I checked my FMS measurements on the ground; the distances for both AYBID and MIMMI showed more than 50 nm from MLB; my shore reference. I believe this discrepancy exists because the aircraft was not including its turn anticipation in the distance measurements; which is why the distances were different on the ground vs. in the air. I have also noticed that the Jeppesen range rings will not depict a 50 nm ring; although that specific distance is important for our operations.ATC may not understand our EOW limitations on this route; combined with either their policies or preference to use the AYBID transition. I also believe that I became complacent after I informed ATC of our restriction; and accepted the turn to MIMMI; believing this fix was within the envelope; and without independently verifying so. Finally; if this is a repeated issue; a caution note could be added to the 10-7 page to inform pilots to not accept this transition due to EOW limitations.

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.