There was definitely a back up CAT A helipad procedure for the A model in the UK. I think it relied on two rad alt calls, one at 80' and one at 120'. Single pilot required special rad alt lights.
If my aged memory from 20 odd years ago serves me correctly, 80' was straight forward and down, between 80 and 120 was a nose down and nose up manoeuvre to get back to the helipad and 120' and over was a continued take off. The weights were very restrictive, around 9000-9400lbs in the UK climate. The profile required 1 hour's training and a supplementary check ride to be checked out.
I was one of the few who was checked out for a limited number of departures during some unusual operations.