I am led to believe that my grandfather, Harold David Dall was a senior design engineer (possibly chief design engineer) for Vickers Armstrong circa 1916. His speciality was diesel engine design and at one time was working on possible diesel power for aircraft. While this does seem unlikely based on weight problems, it may well have been so at that time.
I would like any information that could clarify the period at VA.
As he died in 1943 , most races of him and his history do not exist. However he did have a diesel injection related patent in his name in the 1920s but this related to marine power 5000hp+