Flights *into* NYC and WAS seem to be the only places where turning off Ch. 9 due to 'security concerns' is a semi-consistent issue. Of course, I'm sure there are some Captains who don't want it on and I respect that. However, often the switch is simply off and I've found many times that asking nicely gets it turned on.

If it were me, I'd simply ask the F/A or Purser very nicely if I could speak with the Captain (during boarding when the cockpit door is open), without getting into specifics. That request I've only had sort of resisted once (F/A: "I don't know if that's OK, they're busy, let me ask...<checks with cockpit> *sigh* go ahead, be quick...").