An additional case that I know about, the Tenerife airport disaster: http://en.wikipedia.org/wiki/Tenerife_airport_disaster

Quoting:

  Speculation regarding other contributing factors includes:
    The flight engineer's apparent hesitation to challenge Van Zanten
    further, possibly because Captain Van Zanten was not only senior in rank,
    but also one of the most able and experienced pilots working for the airline.

  As a consequence of the accident, sweeping changes were made to
  international airline regulations and to aircraft... Hierarchical
  relations among crew members were played down. More emphasis was
  placed on team decision-making by mutual agreement.