Help advise -- duck eggs with air sac on narrow side - how to position in cradle?

I am impressed with all the assistance everyone contributes - hope you can help me.
My immediate emergency QUESTION below - please ADVISE .........................
I am trying to hatch out some Pekin ducklings. They have been in the incubator for 15 days and all look healthy upon candling.
THE PROBLEM
ALL of the eggs seem to have the air sac on the narrower side.
They have been in the incubator narrow side down for the 15 days but I think I should put them with the air sac on the top -- which would mean narrow side up (opposite of what all websites advise).
One other factor --- the duck eggs are now really pointy or very narrow at one end -- same are hard to tell which is the narrower side.
???????So again my question is should I put them in the incubator cradle with the air sac on the top side?????????
Please help as I am so concerned that these ducklings will develop and then die of suffocation before hatching out.