Originally Posted by
standardgirl
I had the same problem and believe that my problem had to do with Delta Connection flights. When I tried to book award travel on DL using CI miles, I can almost always get seats on the ATL to whereever segment, but nothing else. The ATL flight is directly operated by Delta (3 digit or fewer flight number) whereas my other segments (even listed in DL with a 4 digit flight number) seem to be operated by one the the "delta connection" flights. After various tries, I just ended up believing that CI miles are only good on DL flights and no one any of the DL connection flight.
It's pretty annoying since the only so-called "delta" that flies to my home airport is by one of those connection...
Chances are the Delta Connection flights are very difficult to come by due to the fact they are usually Regional Jets or smaller. Less overall seats on the plane means way less chance that DL will release sufficient seats to CI. The mainline jets usually have a couple
seats avail to CI and other partners.
Also, if it is a DL codeshare, that would be just impossible.