Quote Andrasz:
The problem is/was not their relationship, but the fact that they paired for 85% of their flights. Trust & familiarity inevitably leads to complacency and relaxed monitoring, regardless of relationship. Being paired with a competent stranger is the safest combination, as both sides will be alert to what the other is doing.
I forgot the exact date but about 2-3 years ago an exec jet crashed due to the gust lock still in place. (overran the RWY at high speed, not able to rotate). Some serious CRM issues there like an almost non existent checklist discipline. I think this is an issue with private companies that fly their own bizz jet with a small number (2?) of pilots.
I agree that a non familiar combo tends to have all crew adhere to standard calls and procedures from the start. However there must be numerous cases, the other member tackeld a problem, knowing the other's weak points. I have a very personal recollection about at least one experience.