Re: It's Dr Who
"As far as I can recall ACC never had FTL travel in any of his stories"
You do not recall correctly. He didn't dwell on it -- he didn't have anyone try to justify the travel in-story -- but he certainly had characters moving from point A to point A+many light years.
His best stories were all either on Earth or within the Solar system though, so that may have contributed to your not recalling this.