The Dash 8 vs. the Localizer.
I've had a number of occasions where Dash 8's have passed through the localizer while vectoring them in for an LLZ/DME approach.
We usually set them up with a 30 degree angle to the LLZ, giving the 1NM of straight flying before the LLZ, to intercept 2NM before the descent begins on the procedure.
That seems to work pretty well, and has never caused any problems in the past, and doesn't now with other types. But a few years back one of the carriers aquired new Dash 8-200, and since then, it's not unusual to have them fly straight through the LLZ, and us intervene to turn them back on.
Is there something in the operation of a Dash 8, that makes it tricky when intercepting a LLZ?