The research programme capitalised on the most recent advances in electrical machine technologies, thermal modelling, design optimisation and manufacturing processes to realise and evaluate a full-scale helicopter electric tail rotor (ETR) motor that is engineered for flight-critical operation and is representative of an aircraft installation.

A direct drive ETR solution was optimised against the objectives of a peak output power of 3kW per kg of installed active mass making it weight-competitive with current mechanical technology, and was a fault-tolerant design specified to an integrity target of 10 to the -9 failures per flight hour, whilst offering demonstrable performance and whole-life cost benefits.