Hi there,
On page 4.7 of the HPL book the second to last dot point states that heavy rain on a window will make objects look less distacint and further away than they really are.
But on page 5.5, the Bob Tait HPL book states again that heavy rain causes a refraction making objects look closer? I am bit confused as to which is the correct answer.
Thanks in advance.
The statement on Page 4.7 is referring to rain causing the outline of an object to be less distinct and therefore giving the impression of being further away. It is not so much the rain on the windscreen, it is the rain reducing the transparency of the atmosphere between you and the object. Perhaps I should reword that point to make it clearer. Thanks for the comment.
The statement on page 5.5 is referring to a BUILD-UP of water on the windscreen acting like a lens. Most unlikely in a VFR aircraft which should not be flying in heavy rain. It applies especially to large aircraft when windscreen wipers are unable to cope with the build-up of water on the windscreen. I will reword both of those statements.
Thanks for you feed-back.