Is this illegal nesting? If so, alternatives?
 

(This has probably been addressed somewhere, but I couldn't find it in the stickies, search is down and it's probably the work of fifteen seconds for a knowledgeable person to answer it.)

I'm considering a DONE5 this summer. I'd leave Boston for Australia in late May, continue on to London, hang out there for a couple of months, go to Africa in August and return home. So far, so good.

Problem is, I can't just hang out in London, or in Europe, for 2+ months.

So I'd like to buy a ticket LHR-BOS-LHR or some such to get me home and back between early June and early August. And I'd like to do it on AA, or as a minimum on a oneWorld airline, for the miles and such.

Can I do this without screwing up the ONE by returning to my point of origin? Does it help to return to a different airport, say, PVD? Or a different country, in this case Canada (Montreal)?

Yes, IMO.

Goodness, if doing part of a xONEx, going home, doing another part, going home, ... etc, were illegal there would be hundreds of us in trouble.

AA's ToC show these three practices as illegal:

* Back to Back Ticketing
* Throwaway Ticketing
* Hidden City/Point Beyond Ticketing

For starters the OWE is not an excursion fare, so that wipes out the first two, and the third is definitely not meant to discourage, much less prohibit, the purchasing of multiple fares as described.

"...I'm considering a DONE5 this summer. I'd leave Boston for Australia in late May, continue on to London, hang out there for a couple of months, go to Africa in August and return home. So far, so good."

I don't think your intended order of continents will work. I will defer to those with more experience, but if NA is your starting point, I don't think you can do NA-SWP-EUR-Africa-NA. Is there any service Africa to North America on OW?

Not directly, but it's my understanding that I can transit Europe (London in this case) en route from Africa to North America if I don't stop over. On this leg I wouldn't expect to.

Yes, you can, but ONLY in this, very limited, case:

38N . C. 2 PERMITTED IN EUROPE TO/FROM/VIA
39N . GHANA/NIGERIA. 1 MUST BE A TRANSIT WITHOUT
40N . STOPOVER BETWEEN GHANA/NIGERIA AND ANOTHER
41N . CONTINENT.

(Deleted as duplicate info.)

Where in Africa
 

Remember that some of Africa is in Europe/Middle East for fares purposes so it depends where you want to go on the continent.

Try route BOS-Australia-SYD-JNB and Africa-Europe home for a 4 continent NA/SWP/Africa/Europe. What about buying a NBO-LHR-BOS return ticket as these could all be day flights if you try and economy with a stop in London might not be too bad a fare to give you all the routes you need.

Do you have to do the continents in that order on those dates?

I have to be in Sydney in late May/early June and in Kenya in mid-August for FT-related events. (My original post has links to their threads for the curious.) Other than that, and a general desire to be home for as much of the time in between as possible, no constraints.

It seemed that a DONE* would let me fly in comfort and earn enough AA Q-points to requalify for EXP for not much more than the two round trips would otherwise cost in economy.

Africa is the sticky part. The problem with the SYD-JNB idea is that I'd nominally be in Africa for two months. Getting home from there is more expensive than from London; the longer trip makes an economy seat less attractive; and with AA not flying that route I can't upgrade, or at least can't upgrade all of it. The restrictions on transiting Europe en route from Africa make it hard to get back, especially since no oneWorld airline (as far as I can tell) can get me to either Ghana or Nigeria from anywhere else on the continent. All the BA and IB flights are to their home countries, none within Africa itself. The African BA affiliates just have local networks within their home areas. Am I missing a basic point?

Thanks for everyone's help!!!!