Extended Crew Damage

So far, I have been applying this rule for multiple crew planes only.
Re-reading the rules on BoB p.21, however, a doubt comes up.
"If the crew has a single member (the pilot), all the hits are, of course, on him"

Does it mean that single seaters are also affected, or that the remaining crew member will get all the hits?

You wouldn't play extended damage on a single seater - what it's saying is, if there's only the pilot left from a crew then he takes all the hits.