1.   All five previous fatal crashes of this type of plane occurred overseas, and all were caused by human error.

2.   City officials said they did not know how much experience the pilot had or whether he had been involved in any previous crashes.

3.   In previous crashes, infighting between the U.S. agencies investigating the incident has contributed to a welter of conflicting stories about the cause.

4.   In some previous crashes, information stored in on-board computer chips yielded valuable data about the condition of the aircraft in the seconds before impact.

5.   In some previous crashes, information stored in on-board computer chips yielded valuable data about the condition of the aircraft in the seconds before the impact.

6.   The plane and the airline were covered by the safety measures imposed after previous crashes involving icing and propeller problems.

7.   The sense of discouragement stems from the knowledge, investigators said, that they have scoured the seabed more thoroughly than in any previous crash.

8.   The script had played out in previous crashes involving other airlines.

9.   They have solved previous crashes with much less.

10.   Five crewmen died in the previous crashes.