[Spaceships] with wings

[MatthewVilter]

I was designing a transatmospheric shuttle so I looked at "Getting into Space" on page SS37, and now I'm confused.

Look at this: "The spacecraft’s acceleration must also exceed gravity (1G, for Earth), or it must be winged (in atmosphere) or have contragravity lifters."

Does this mean contragravity lifters are only good for unstreamlined craft?

Does this mean I can put 1/3 of an Ion Drive (0.000167 Gs of acceleration) on my winged ship and fly to orbit in (5.6*.045/.000167)~=1509 hours??!!??!!

EDIT: Also, if I use a Ram-Rocket engine how long does it run on atmosphere? Is it assumed that I can use it to get the full delta-V saving from air-speed on page SS37 -AND- use it to burn the fuel needed for the remaining delta-V?