A challenge if you will.

[SkippyBing]

You guys realise that at least in peace time both civil and military aircraft are legally limited to no more than 250 knots IAS below 10,000'?

Anyway, I am not going to be a spoiled sport - what a fun challenge in such a scenic area! Think I will try it in something light, small and agile like the the Douglas A-4 Skyhawk and report back.

Not strictly true, the limit certainly doesn't apply to military aircraft in the UK where it varies by type but is usually around 450 knots over land. I suspect the US and most other countries are the same. For civil aircraft if you're under certain air traffic control services then the limit can be higher if they clear it, I believe for many airliners they're cleared faster as it's safer/more efficient.