Originally Posted by
treadigraph
Not sure which Dave's pic illustrates, but the Ambassador was used as a flying test bed for various Tyne, Proteus and Napier Eland engines.
A production turboprop update had been envisaged with various twin and four engined version mooted.
The ubiquitous Dart was also tested whilst at Farnborough the Napier Eland distinguished itself by flying the whole of its flying display using only one engine, the other one being feathered.
NB: Farnborough International rules nowadays do not permit this ever since the Breguet Atlantique crash in 1968 when it had one engine shut down however air show operators in other countries probably may allow it.