The Beech 18
I remember in the 1950's seeing, but more importantly hearing, a Twin Engine Piston Aircraft flying into Northolt Airport.
As I was an aircraft spotter anorak at the time I knew it was a Beechcraft 18, Twin Pratt & Whitney Wasp Radial Engines
I have enjoyed doing a considerable amount of research into this classic aircraft
Some Video Clips from YouTube
Aircraft Restoration Company Duxford
A Restoration at Bruntingthorpe UK.
Concerns on the Wing Spar
Beech 18 Pictures
Beechcraft AT-11 & SNB-1 Kansan
Some differences between models of the Beech 18
Beechcraft Heritage Museum Tullahoma TN USA