The investigators interviewed managers and training personnel and "observed Asiana procedures in a simulator and an exemplar aircraft," according to a NTSB announcement Friday.
Investigators in Korea also combed through records from the airplane involved in the accident.
The NTSB on Friday also announced that a two-day investigative hearing on the crash will be held Dec. 10 and 11 in
The hearing will focus on "pilot awareness in highly automated aircraft, emergency response, and cabin safety," according to the NTSB.
Because of the government shutdown earlier this month, the NTSB said the hearing had been delayed from November to December.
On July 6,
Also included in the NTSB update was an examination of the evacuation slide or raft systems at a manufacturing plant in New Jersey. The Survival Factors Group had also re-examined the wreckage.
Investigators and others also met in Seattle "to examine the recorded flight data and compare it to the expected airplane systems operation."