Caa/jaa/easa Inspectors- Salaries/conditions

[Evinrude]

I am wondering how much does a CAA pilot inspector/check airman makes a year. What are the qualifications required to become one? Do they line fly with large operators such as BA?
The reason I am asking is that I seemed to recall that France had line pilots at Air France doing line check/inspection on other companies such as Corsair on behalf of the DGAC. Is it the same way in the UK?
Thanks

[J.L. Seagull]

I believe a CAA FOI earns around 125K, plus Company Car. No flight or duty pay, but they do line flying with major airlines as well as minor, long and short haul. They don't actually work for said airlines though, and only fly every once in a while.
Qualifications: Heavy Jet experience, Management experience, Training Captain experience. I think selection is by recommendation, although there are occasionally adverts in Flight as well.