Like in most accidents if not all, the causes of Air Inter Mt St Odile are many , The fact that the ELT did not activate and that the aircraft was not equipped with GPWS did not help but those were not among the causes of the accident. GPWS was not mandatory at the time and it was not as reliable as it is today with lots of false alarms for those who remember . The ergonomic of the button between rate and angle is mentioned as probably one of the causes, the military ATC in place in Strasbourg at the time was another. But read the report in the BEA archives. There is also an interesting book about the rescue operation.