BOAC,
The post of mine that you refer to was merely an attempt to explain to you and rudderrudderrat that you were misunderstanding Clandestino's cryptic remark about trigonometry, and taking seriously his reference to "no swivelling pitots". It was not a statement of my own opinion, merely an attempt to help you understand his point in his absence (for which, predictably, he has offered me not a word of thanks).
It's well known that Clandestino's style of response sometimes invites irritable misunderstanding by the passing objects of his contempt, myself included. Did my polite, but non-didactic, explanation go over your head? Should I have tried the long version?
(Ah, I see OG has done a far better job!)