they could easily bore a hole right under the runway some 5cm thick and cause no issue at all, having a poke around for crates.
That would be an entirely pointless exercise. If there was anything like crates with Spitfires
under the runway they will stay there for all eternity, because no government, however friendly, will close the airport and dig up the runway, however much they are worth, even if your snaky drill did find a wooden crate.