Westland 30 problems
The main problem was that it was badly underpowered using RR gem 60 engines which had to be replaced after only a few hours usage. For every 2*C above ISA you had to throw a pax overboard. It was always under rotored and if the series 300 with with T700 engines and 5 bladed rotor had actually been continued it would have been been a 150 kt useful payload machine. Having been involved in trying to sell this aircraft worldwide I can tell you it was not easy!