I recently checked in at NRT for a CX flight to HKG as part of a 16 segment AONE4 trip. I was informed that there had been a same day change of equipment from a 3 class 747 to a 2 class 777 and that I would have to travel in business class. Naturally I was a little disappointed but I figured that there wasn't much that I could do about it as I needed to get to Hong Kong that day and there were no later flights with a first class cabin. The CX ground staff were extremely apologetic (this was Japan after all) and said that they could offer me a refund for the difference between first and business class. Interesting, I thought, how are they going to do that with an AONE4 ticket? As I thought about it seemed that this would be quite a complicated calculation and that it might reveal some interesting insights into how revenue is aportioned to the airlines on these tickets. I was also aware that if I had chosen a 2 class flight for this segment, it would have had no effect on the price of the ticket.

What they did next was a complete surprise - because I was handed an envelope containing 140,000 Yen (about 1,500 USD)! They explained that this was the difference between the point-to-point F class and J class fares from NRT to HKG plus some compensation for my inconvenience (about 200 USD). 1,500 USD is about one sixth of the amount that I paid for the entire AONE4 ticket (9,000 USD). As it is about 1,800 miles from NRT to HKG and my complete itinerary covered about 56,000 miles, I figured that this particular segment would account for a mere 1/30 of the cost of the ticket - or about 300 USD. But CX were handing me five times that amount of money and were still flying me, relatively comfortably to Hong Kong without delay!

My main conclusion from this experience is that CX were very nice to me! In fact, they were remarkably generous. There is no published procedure, as far as I am aware, for calculating a fare difference on an AONE4 ticket for an involuntary downgrade from A class to D class. Indeed, if I had chosen to travel on a 2 class flight with my AONE4 ticket then I wouldn't have received any refund whatsoever. It seems that it all came down to who decided which class of service I would be using. But I have absolutely no complaints about the speedy, efficient and courteous way that CX dealt with the situation. What do other FF'ers think? Have any of you had similar experiences with CX or other ONEWORLD carriers?

According to gcm NRT-BKK is 1,842 miles
So you were compensated JPY76 for each mile

For how many miles would you have to be involuntarily downgraded to get back the full cost of your AONE4?

Wow, unbelievable.
I have experienced last minutes F->C downgrade on that NRt->HKG route a few times.
But, I have never gotten compensation.

Well, either CX at Narita made a mistake - which seems quite unlikley given that I was clearly booked in A class and had an AONE4 ticket - and they thought I had an F ticket, or else they have had a change of policy? Maybe somebody has made a legal challenge about involuntary downgrades, regardless of ticketing type, and they are just playing safe. Or, am I missing something here - could there be another explanation??

There's no grounds for a legal challenge as they tell you upfront in the XONEX fare rules that downgrades can happen and that you are not entitled to compensation.

I wonder if you are referring to this clause:

I think this means that when you book an AONEx, and F is not offered on a particular segment, then you can "voluntarily" downgrade to J or Y, but there is no adjustment of the AONEx fare.

OP's case is a bit different: he was involuntarily downgraded on day of flight (perhaps due to IRROPS) and therefore was entitled to some sort of compensation (though it seems remarkably generous!) I think others have reported receiving compensation in similar cases.

Unfortunately I have fallen between both cases, as I booked four segments in F on CX, but they canceled F service on those routes after I booked, but weeks or months before the date of flight. It's annoying, but no compensation due.

Happy Travels.

Good customer service still exists

Very cool, love that above and beyond attitude that CX has.

I have been in the OPs situation (3 yrs ago). AONEx ticket, ticketed & confirmed in A class HKG-BKK. CX subbed a 330 for the run and, of course, no F class. CX HKG were very blunt in saying to take it up with the issuing agent (CX BKK) for any refund. Needless to say, CX BKK cited the "downgrade on booking" rule and would not entertain the my "invol downgrade after ticketing" argument.

I gave up as it was only a short flight.

Was this on the day of the flight? I was in a similar situation at HKG for a flight to PVG on an AONE4 and was given ~HK$1300 for the downgrade.

Of course when a sub occurs prior to the day of the flight and is scheduled I weren't given any refunds (but there is the option of rescheduling).

Yes it was. OP siad "I recently checked in at NRT for a CX flight to HKG as part of a 16 segment AONE4 trip. I was informed that there had been a same day change of equipment from a 3 class 747 to a 2 class 777 and that I would have to travel in business class."

I say it was an act of generosity on CX'x part!

No I wasn't asking the OP, I was asking og where no compensation was given.

I think the word "available" covers them for equipemnjt changes made after booking.

CX is frequently more generous in this area then they need to be. I've got no problem with that, of course.

This is one of the reasons CX is my favorite OW carrier. They really understand customer service, especially in the premium cabin. I flew HKG-AKL one time when the video system wasn't working. It was a night flight so I was sleeping anyway. But on board, they gave me a $100.00 certificate for the duty free shop, and I got a nice pair of sunglasses.
I just thought that was classy.

WOW, I love CX more and more now,
I had 2 segment flight with them and credited my miles to Asiamiles,
a month later I receive an envelop from Marco Polo Club with a Gold card and a welcome letter ! how generous, now I fly more and more with them ....