jayteet
As the only protagonist I know who's driven both double deckers (admittedly not from the top deck!) and the fine old Wessex, the bus loses out every time.
John E's memory is good for those figures, and I seem to remember a rotor span of 56ft and a height of 14ft 6in just like a Routemaster. The HU5 had an overload to 14000lbs with a running take off and when it went out of service wuth the RN a basic of pushing 10000lbs, hence a very limited usefulness.
The missiles were SS11 (A Tank) and AS12 (A Ship). Both wire guided, so no heroics as the aimer had to steer the sight with one hand and the missile with the other. The bunting and lobbing was done with the 2" RPs. Not strictly necessary but fun anyway.
Lu Z, it's a twin turbine S58 remember, not the S61 which became the Sea King. Got a good video of one of them doing a little more than the 30deg limit of bank too.