I think some similar restriction was placed on him after he flew the Richard Noble inspired ARV Super 2 two seat aircraft built on the IOW.
![[Linked Image]](https://upload.wikimedia.org/wikipedia/commons/thumb/2/2b/ARV_prototype.jpg/440px-ARV_prototype.jpg)
Probably just as well as the Hewland three cylinder two stroke engine had a propensity for oiling plugs leading to a swift return to the airfield.