Anatomy of a Cheap Roundtrip

Until recently, American had a NYC-DUB fare priced at $51 (with $202 in additional fuel surcharges).  While prices have gone up slightly (the base fare is now $151), sub-$500 roundtrips to Europe are nothing to scoff at.

My starting point for any itinerary like this one is to glance at ExpertFlyer.

The fare rules for the OKX7Q5G1 fare include a few interesting snippets:

American tends to use MPM-based routing rules for its international fares; this fare is no different:

/VIA THE ATLANTIC/ MPM 3811
MILEAGE SYSTEM APPLIES BETWEEN ORIGIN AND DESTINATION
 MILEAGE SYSTEM APPLIES ORIGIN TO DESTINATION
       TICKETED POINT DEDUCTION OF 550 MILES APPLIES
       WHEN TRAVEL IS VIA CHI AND/OR DFW AND/OR RDU AND/OR
       MIA
       TICKETED POINT DEDUCTION OF 705 MILES APPLIES
       WHEN TRAVEL IS VIA SUB AREA 21

American directly serves DUB via ORD, but this trip is 4413 miles:

The CHI ticketed point deduction provides an additional 550 miles beyond the 3811 base when we connect in ORD, so routing via O’Hare is permissible.  With a base fare in-hand, we now want to try looking for itineraries that might work:

The “Advanced Routing Codes” have two components:

• “c:aa+” specifies that I want to fly on one or more AA-coded flights.
• “/f bc=o” specifies I want to fly under an O booking code.

Unfortunately, since this fare has been around for about a week, the O inventory on AA metal has largely disappeared:

Rather than fly entirely AA metal, we can try flying to Europe, then connecting to Aer Lingus:

The “c:aa+ c:ei” routing code specifies that I want to fly one or more AA-coded flights then an Aer Lingus-coded flight.  On the inbound leg, I need to reverse the order.  This search yields some prospective dates:

Clicking through on the 18th yields a few options:

Examining the price breakdown, we see that our $151 base fare was applicable.  (The variations in price are due to changes in government-imposed taxes.)

The next tricky part is trying to actually book this itinerary.  Roundtrip quickly stops providing the relevant flights and even Multicity may fail.  Generally, my complex revenue trips (including this one) have been booked by calling.  Even if the phone booking fee could not be waived, spending $25 to book an itinerary substantially cheaper than the “obvious” trips offered on the airlines’ websites may be worth it.