I don't know all the in's and out's but I think the terms are probably similar to the old HSBC PSL in that it needs to be secured on a UK property and that the loan, added onto any existing secured loans must not exceed 60% of the valuation. On that basis I imagine it is a stirling loan as the course fees are in stirling.
However, how many people are actually succesful in obtaining 50k+ loans for flight training at the moment would be interesting to know.
Certainly tends to restrict the APP course to those with financialy sound parents (I wish I had that much equity in my house!)