nope, I think he might mean the WACO glider which you drop on Sicily in from Breakthrough. Altough those of u who didn't buy it wouldn't know about that...
It's in (with /maintt as the moddir in Project Settings): addon>vehicle>CG4Aglider*
Spearhead SDK is compatible with Breakthrough but I couldn't get any of the of the Breakthrough textures to work properly. When I compiled my maps the BT textures shranka and rotated back to their default setting despite me having set them up nicely in Radiant. I couldn't fix this and none of the replies to my posts here could help either.