Short Final: Ludicrous Speed

This past September I overheard this:

King Air 12345: "Potomac, King Air 12345, do you still need us to hold back to 190 knots?"

Approach: "King Air 345, yes I do. There's a Pilatus about 50 miles ahead of you, same altitude, and we need to maintain separation while I hand you off to the next sector. You'd have to go really fast to get ahead of him before the hand‑off."

King Air 12345: "Potomac, King Air 345 could push it up to 238 knots. Would that work?"

There was a pause while the controller digested this option.

Approach: "King Air, 345 that works. Turn 10 degrees right and speed your discretion."

King Air 12345: "Roger, Potomac, King Air 345 cleared ‘ludicrous speed!'"