>In the back of my mind I seem to recall that an accident in the states ,was it Washington? lead to the change on the Boeing 737 from epr to n1.<
Seat1APlease, not quite the full story.
In the wake of the Washington accident, the operator I was flying for required us to compute N1 as well as EPR for take-off and write both on the bug card. The N1 was a "gross error" check but EPR remained the parameter for setting take off thrust. I believe this procedure was adopted by all the UK airlines operating the B 737- 200 by advice from the CAA.