Booking D Fares (Search not working for me)
 

Does anyone know how to book "D" business class fares, transatlantic, on-line?

I've never found a way to force a D fare. I start with Business "With Restrictions" and sometimes I get lucky and it returns D fare. If that doesn't work, book something and then call Res and have them use that record to refine the search.

Took a few tries but when all was said and done, it works. Thanks.

Which meant that either you ended up selecting flights where "I" inventory was zeroed out or selecting dates/routes where there were no valid "I" fares (e.g., not meeting adv. purch. or min stay requirements). That's the only way to "force" AA.com to price a D fare. As mentioned above, the alternative is to put the "Discounted Business Class" ticket that prices in "I" on hold and call AA.com web services to have them fix it.

What I found was that the D fares usually showed up further down the list and that in most markets for May and June they are pretty outrageous.

Many discounted D/Z/I (business class) fares are a 50 day advance notice so may not appear if your dates are within 50 days.

Isn't Z an F award?

D/Z/I are all discounted business class inventory with various carriers, not just AA. Sorry for any confusion I may have caused.

Trivia
 

Z is Star Alliance's equivalent to oneworld's I. D maps to D, while oneworld's J maps to Star's C.

Your post is as misleading as it is confusing. Yes, D/Z/I are discounted Business Class, but you make it seem like they're equivalent. Let me take you to school:

Deeply Discounted
Z = UA/Star Alliance
I = AA/One World
Z = CO/Sky Team
**Usually 50 day AP requirement
**Usually non refundable
**Not upgradeable

Discounted
D = UA/Star Alliance
D = AA/One World
D = CO/Sky Team
**Usually no or short AP requirement
**Usually refundable, sometimes small penalty
**Upgradeable

Full Fare
C = UA/Star Alliance
J = AA/One World
J = CO/Sky Team
**Typically no AP requirement
**Typically refundable flexible
**Upgradeable

I is also deeply discounted BC on DL w/ the same 50 day AP requirement.