Flew in to Londonderry a few times and I have to say, I'm surprised someone hasn't put down in ballykelly by mistake before now.
The approach onto runway 26 is almost perfectly aligned with the old runway at ballykelly.....albeit ballykelly is about 5 miles from the 26 threshold. To add to the confusion Ballykelly sometimes has its runway lights on.
I can imagine that a NDB approach in marginal conditions could easily end up with a crew unfamiliar with the area mis-identifying Ballykelly.