Pass. Facility Charges, also known as XF taxes, are levied by airports in the USA similar to Canadian AIF's, but only $4.50 ($3 at some airports such as CLT) on each originating or connecting Px flying from that airport. By US Law, frequent-flyer award tickets are exempt from these taxes, but Aeroplan charges them for some reason. For example, I just booked a one-way nonstop SFO--PIT on UA on short notice. Using AC miles, I paid $2.50 TSA tax (XY) + $4.50 XF. If I had used UA miles, price was $2.50 XY + $75 Short Notice Fee, which was the greater of 2 evils. Likewise, AC will charge ~$17 (?) tax each way on flights from USA to Caribbean or Europe, which other airlines do not. It's been like this for years! Gee, hasn't the US IRS notified Aeroplan that some of the taxes they are collecting, do not apply & should be refunded to Pxx?