AA seems to be somewhat trapped as the retrofitting takes longer than expected (they were among the last to "jump onto the train") due to high demand !
So, they are forced to send some - not yet "upgraded" - 757īs over the pond.
Other than the inaccuracy that AA still has non-winglet 757s, which was pointed out above, it's also wrong to say that AA was among the last to order winglets.
See
http://www.aviationpartnersboeing.co...nyhistory.html
Here are a few dates:
2004
■April 26th: Continental Airlines becomes the first U.S. Major to order Blended Winglets when they place an order for both 757-200 and 737-NG Blended Winglets.
2006
■March 29th: American Airlines orders 76 additional shipsets of 737-800 Blended Winglets.
■May 1st: 1000th shipset of Blended Winglets is installed on an American Airlines 757-200.
■May 26th: Northwest Airlines orders 757-200 Blended Winglets.
■July 19th: American Airlines orders 104 additional shipsets of 757-200 Blended Winglets.
■October 12th: US Airways orders 757-200 Blended Winglets.
2007
■March 22nd: United Airlines orders 757-200 Blended Winglets.
■March 28th: With order from American Airlines for 47 shipsets, APB formally launches certification program for 767-300ER Blended Winglets.
■May 17th: Delta Air Lines orders 737-800 retrofit; 737-700 in-production; and 757-200 Blended Winglets.
■June 8th: Delta Air Lines orders 767-300ER Blended Winglets.
So, while AA wasn't the launch customer for the 752 (CO was - since CO used COPA as a test case in 2002 for 738 winglets, they were more familiar with it), AA quickly got on board, and wqas 3 months ahead of US, 8 months ahead of UA & 10 months ahead of DL. And, AA was the launch customer for the 763 winglet model.