Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 148,159 pages of information and 233,681 images on early companies, their products and the people who designed and built them.
Note: This is a sub-section of John William Dunne.
The D.4 took the wing cellule designed for the D.1 and added a gondola beneath it that contained wheeled undercarriage and a 25 hp engine turning two pusher propellers. In this form, the aircraft flew at Blair Atholl in December 1908.