David id suggest you assume she was Howland area at 1912Z and look for your error further back along the plot. It could be a simple transcription error. Remember Noonan was probably the best of his day, certainly one of. I understood she had a PNR of 10 hrs from Lae. Critical point ?. Surely something was calculated for a diversion as you lost an engine beyond the critical point you would not make it to destination. It would be common practice as it is today. Nowadays its the depressurized critical point which can be critical on long Etops.