You gus are right, now I recall that the early/summer LH flight from IAD used to be on the Airbus, and was the first flight to have the new C out of IAD. Then they started using the 747 on the route, but originally when it was a seasonal flight it used to be on Airbus.

As I checked all the other dates that week 416 will be operated by a 747, except for the 25.

Thanks everyone.