One of the best ways to check availability on oneworld airlines (which are partners of American Airlines) is to use the British Airways website. That’s because BA.com shows the most partners online — including Japan Airlines flights that are not available on the other good site for award searches, Qantas.

You find award space on partners that don’t show up on American’s website — like Cathay Pacific, LAN, Iberia, Malaysia Airlines, and more — and then call American to book the space.

Unfortunately the British Airways site is given to ‘break’. It will either not show entire airlines (for awhile US Airways flights didn’t show there but fortunately those show at AA.com!) or will show ‘phantom’ award space, it will appear as though awards are available but in the end the space isn’t bookable and will error out at BA.com (or if you call a partner airline, you’ll be told the space isn’t available).

Mark O. points out that British Airways is showing phantom availability for US Airways routes. They are displaying award space in coach on American Airlines codeshares of US Airways flights.

Here’s what’s available for Boston – New York LaGuardia tomorrow September 25. There is no non-stop coach award space available. There are only connecting options.

The British Airways website correctly shows no space available on the US Airways non-stop flights between these cities. However it is also displaying the same flights as American Airlines codeshares. And it shows those flights as:

• Having coach award space
  
• Having no first class cabin

Both are wrong.

Fortunately American and US Airways space are easily checked elsewhere. AA.com doesn’t show the phantom award availability, and neither does the Qantas site. Clearly it’s a glitch on the British Airways side. And no doubt they’ll fix it, hopefully soon. In the meantime don’t be fooled (and don’t transfer points into British Airways from another program on the anticipation of booking awards on American Airlines codeshares operated by US Airways).