The Wing and Pier F had adapters for a colleague. But it worked out better for both of us to charge our phones from my power pack.

I always assumed the power outlets onboard were able to accept from more than one type, for example North American and Euro plugs. Most airlines I've flown internationally seem to have the same type of outlets allowing this.

I am not sure if cabin crews have spare adapters, but then I always travel with more than one and have lost a few requiring purchase at airports.