Scary stuff!
I agree 100% that airliners shouldn't be flying NDB approaches anymore. A big hurdle to implementation of GPS approaches at many small regional airports is the high cost of the required consultations needed for regulatory compliance. Here's a link to the BEA investigation page where the full report, currently only available in French, can be downloaded.
Incident to the Boeing B737-800 registered EI-EMK operated by Ryanair on 01/29/2015 when approaching AD Bergerac-Roumanière (24)
Direct link to report pdf