Rumour has it that HM isn't that fond of helicopters unlike her Mum, who was.
I've heard the same rumour and took the opportunity last year to ask the DoE if it was true.
He seemed genuinely surprised and said it wasn't. When I said I'd noticed HM didn't often fly in helicopters he agreed that was true but said it was simply because of the nature of her engagements. If there was a need she was happy to do so, but there was rarely a need.
It was an informal chat at a private party, no connection with aviation. I can't think of any reason why he'd be less than frank - particularly as the Duke is famous for being blunt rather than for sugar-coated diplomacy.
Back to the topic -
I wish the couple a long and happy marriage.
Prince William seems to be a thoroughly decent man with many of his mother's wonderful qualities.
FL