As almost every week, 30 minutes searching dictionaries and thinking about the very one or two, in this case two, viz:
27a. Fertilizer plants appearing in a number of TV shows about hydrogen (8). I have - SH - RIES. The only word I can get that fits is Ashuries, but it surely can't be that (other than ash fertilizer) can it?
5d. Web's turned up a light helmet. I have SA - ET. I also can't find a suitable word that fits the bill (so to speak).
I know I'll kick myself as so often, but grateful for answers.