As the Pentagon and Boeing begin to finally talk about the new KC-46A contract, one question is: where did the winglets go?

Until this week, Boeing widely distributed artist concepts of its NewGen Tanker, based on the 767, with prominent winglets, sparking discussion among onlookers about why they were needed and how much integration would cost.

One characteristic of the KC-46A in newly released images, however, is the conspicuous absence of the winglets. So, about six weeks after winning the $4.4 billion KC-X development contract, the design is now different than that proposed on the company’s website for months.

Boeing opted against revising its so-called NewGen tanker marketing materials in advance of the source selection despite having earlier determined that the winglets would not be needed after conducting design trade studies. “Based on the USAF refueling requirements, the missions were not of sufficient duration nor conducted at altitudes that optimize the benefits derived from winglets,” according to a company statement provided as a response to the winglets issue. “We felt comfortable showing winglets on the NewGen tanker because we were considering them through the trade study. Showing available technology and potential airplane configurations in marketing material is a normal practice in the industry.”

In short, Bill Barksdale, Boeing’s KC-46A spokesman, says the winglets did not “earn their way onto the airplane.” But, they apparently earned their way into concept art renderings and managed to stay there.

Barksdale declines to say when the design decision was made to opt for standard wings. Boeing’s tanker website still features images of the aircraft with winglets. “I don’t think we are ever going to talk about the timing of when we decided to take them off,” he explains.