Expertflyer confused?
 

I return from LHR to DUR on the 13th (next Sunday).

I am on EK4 and then EK775.

Flying in Y, so I am trying hard to upgrade at least one of the sectors with miles. In EF, when I enter depart as LHR and arrive as DUR, EK4 is not shown as one of the flights LHR-DXB (it shows 2 QF flights and EK6) and EK775 shows as full in both Y and J (it is a 2 class flight).

If I enter LHR as depart and DXB as destination, it shows all EK/QF flights LHR-DXB and EK4 has F2 J7 Y9. There is no D available but if there are 7 they should open some soon.

I phoned EK and they claim that EK4 is also full and that there is only F1 A1. This does not correspond with EF.

I'm just confused as to why EK4 does not show as one of the flights for LHR-DUR (as it is the best connection time in DXB too), but it shows when searching LHR-DXB. Also why EF says that there are so many seats available, but EK say that there is nothing at all.

I am still phoning them about every hour trying to get one of those damn D class seats. I've given up on EK775 as even on the website there is nothing available to sell. EK775/776 are always always always full in the holidays because it is the only international flight out of DUR.

You are indeed correct. However, if you change the point of sale to UK the EK4 and EK775 combination shows.

Seems like availability is NIL for LHR-DXB-DUR, F0 AC J0 CC IC OC all of economy is closed.

A particular flight (LHR-DXB) is sold as part of many and multiple possible itineraries.

When you search for a LHR-DXB flight, you are actually looking up a completely different journey than a LHR-DUR flight. In this case, it seems that EK are no longer willing to sell any more seats on EK4 to customers looking to travel to Durban, but they have kept the last few remaining seats on board for customers looking to travel to Dubai.

Although it is the same flight, Emirates doesn't treat it that way. When you bought your ticket to Durban, you weren't charged [cost of London to Dubai] plus [cost of Dubai to Durban] - although this is what you actually end up flying - they maintain completely separate London-Durban prices, and they therefore maintain the fares, flight loads and availabilities for London-Durban separately than the other distinct markest of London to Dubai and Dubai to Durban.

When an airline only has a few seats left on a particular service, it DOES NOT MEAN those seats are available to purchase on EVERY routing that the airline offers.

As regards discrepancies between availability, then assuming that both you and the agent are talking about availability for the exact same market, then the point of sale can also have an impact. It probably doesn't explain your exact example, but as a flight draws closer, an airline may close off, or restrict, sales in certain countries and/or to third parties. It's not unusual that, in the last day or so before a busy flight, Emirates might still sell a seat or two on their own website, but these seats cannot be bought anywhere else.

Thanks for all the explanations.

Does this mean that even if there is D-class available I would not get it? Or if I pay to upgrade to J they will not sell?

Point of sale was not UK. It was South Africa.

Still nothing... Hope to have some luck at the airport at check-in or on board.

I assume that they will sell me an upgrade at the airport if there are seats left?

Slightly off-topic, but in airline booking systems, don't "0" and "c" after a booking class mean the same thing?

If airlines indicate a booking class availability as "c", presumably meaning closed, they can always reopen it later. So why not just stick to "0" to show no availability?

Please pardon my ignorance, but I could never wrap my head around this one.

"c" availability indicates that the waitlist for that fare bucket is also closed as well as there being no space available.
Having C and L (waitlist open) is a holdover from the past and for compatibility with other airlines who are connected to global ticketing and distribution systems but may not for whatever reason provide numerical breakdowns of the availability of seats in each bucket.

Got it. Maybe... :)