A stuck main cabin door on a SkyWest Airlines CRJ200 in Phoenix in October drew the attention of a National Transportation Safety Board official who happened to be on board.
A preliminary report on the 18 October incident reveals that it took 10min for the pilots and ground personnel to get the jammed door opened after the flight from Los Angeles landed.
SkyWest flight 6522 (N938SW) had three crew and 50 passengers on board, including an NTSB investigator from the agency's Los Angeles field office, who launched an investigation as soon as the door was opened.
The incident is not the first time the NTSB has observed such problems in Phoenix. In June 2007, the same investigator was on board a Mesa Airlines CRJ200 with 50 passengers and three crew inbound from Los Angeles when its main cabin door would not open.
In the follow-up to that event, the NTSB learned that there had been 823 incidents of jammed or difficult to open main cabin doors reported in Canadian service difficulty reports for the CRJ family aircraft since 1995.
US Federal Aviation Administration service difficulty reports contained 58 similar problems for the aircraft family since 1994. Mesa had recorded 14 occasions of door trouble with the particular aircraft over the previous 18 months.
As a result of the latest incident, the NTSB says SkyWest's door maintenance procedures and "related deferral processes" are being evaluated. The captain told the investigator at the scene that the flight had been dispatched from Los Angeles with an inoperative power assist motor for the door.
According to the NTSB, the captain had said that he had been authorised to fly the aircraft to Phoenix with the door's deferred maintenance status, and that the flight was performed in accordance with SkyWest's minimum equipment list procedures.
"The captain further indicated that approaching [Phoenix], he advised his company that ground personnel assistance would be required to open the door," the report says, and adds that the captain had said that he anticipated the door "would open freely upon receiving assistance from personnel outside the airplane".
External crews were not able to open the door, however, despite trying procedures "used on numerous occasions to open this type of airplane door", says the NTSB.
Ultimately, the captain was able to open the door from the inside by pushing his shoulder again the door using what he described as "excessive force", the report says.
Once freed, the NTSB says the door "opened and extended beyond its normal limits", rotating downward until hitting the tarmac.
The aircraft was removed from service for repairs.