WPR11IA019

NTSB incident investigation · Bombardier CL-600-2B19 · Phoenix, AZ · October 18, 2010

Incident · No injuriesIncident investigationFinal report
Date
October 18, 2010, 14:34 local (21:34 UTC)
Place
Phoenix, AZ
Injuries
53 uninjured
Damage
Minor damage
Phase of flight
Standing
Aircraft
N938SWBombardier CL-600-2B19
Defining event
Standing: Sys/Comp malf/fail (non-power)
Weather
Visual (VMC) · Day
Status
Completed · report October 4, 2012
Report
Approved by Office Director
NTSB office
Western Pacific Region
Parties
SkyWest Airlines, Federal Aviation Administration
Case key
77615

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the incident.

On this page

Probable cause

The overextension of the main cabin door due to difficulty opening the door because the power-assist motor cable was lodged within the main cabin door assembly.

Findings · 1

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The flight crew reported that, at the completion of the flight, the airplane taxied to the arrival gate, and ground personnel attempted to open the airplane's main passenger cabin door. The airplane had been dispatched with the main cabin door's power-assist motor inoperative, which was deferred via company maintenance procedures and the minimum equipment list. Ground personnel were unable to open the door and received assistance from the captain. Initially, the captain was unable to open the door, which was jammed in the closed position. After several attempts, the captain exerted a large force with his shoulder and was able to get the door to open. When the main cabin door was finally opened, it traveled beyond its normal extension limits and hit the pavement. The power-assist motor cable was found lodged within the door assembly.

Factual narrative

On October 18, 2010, about 1425 mountain standard time, a Bombardier, Inc., CL-600-2B19, N938SW, operated by SkyWest Airlines as United Express flight #6522, landed at the Phoenix Sky Harbor International Airport, Phoenix, Arizona (PHX), under the provisions of 14 Code of Federal Regulations Part 121. The scheduled domestic passenger flight taxied to the terminal gate, where the main passenger cabin door (MCD) became jammed shut and would not open. The airplane sustained minor damage to the MCD. There were no injuries to the 2 airline transport pilots, 1 flight attendant, or the 50 passengers. Visual weather conditions prevailed and an instrument flight rules plan was filed for the flight, which originated from Los Angeles International Airport, Los Angeles, California (LAX), about 1241 Pacific daylight time, with an intended destination of Phoenix. The captain reported to a National Transportation Safety Board (NTSB) investigator who was on the flight, that the MCD's power assist motor was inoperative when the flight was dispatched from LAX. He stated that he had been authorized to fly the airplane to PHX with the MCD's deferred maintenance status, and the flight was performed in accordance with SkyWest's minimum equipment list (MEL) procedures. The captain further reported that approaching PHX, he advised his company that ground personnel assistance would be required to open the door. The captain stated that he anticipated the MCD would open freely upon receiving assistance from personnel outside the airplane. A United Airlines employee who marshaled the airplane to the gate stated that after he chalked the nose wheel, the captain signaled him to open the MCD. The marshaller stated that he pulled on the latch to open the door, but it would not open. He followed the procedures he has used on numerous occasions to open this type of airplane door. However, on this occasion, he could not open the door. A captain, who was waiting on the jet bridge to fly the airplane on its next scheduled leg also attempted to open the door and was unsuccessful. This malfunction precluded passengers from immediately exiting the airplane. Shortly after, the incident captain exited the cockpit to assess the problem. The captain tried pushing on the door while personnel outside the airplane were pulling it open and while he was lifting the door handle from the inside. The captain stated "nothing worked." And he then returned to the cockpit and made a public address announcement to the passengers, stating that because of technical problems with the door, there would be a delay exiting the airplane. The captain opened the galley service door on the opposite of the airplane to acquire direct communication with outside ramp personnel. The captain said that his plan was to have the ramp personnel stow the door handle from the outside, and this would allow him to try opening the MCD from the inside. Following this plan, the captain pushed his shoulder against the door andused some exerted force. The door opened and extended beyond its normal limits and rotated downward until it impacted the tarmac. The elapsed time from the airplane arriving at the gate until the MCD was opened was about 10 minutes. The MCD sustained damage to its supporting wheel assembly and power assist motor cable. The cable was found stuck inside the door.

Aircraft

Registration
N938SW
Reported as
Bombardier CL-600-2B19
Category
Airplane
Serial number
7741
Engines
GE CF34 SERIES, 9,140 lbs thrust, turbo fanGE CF34 SERIES, 9,140 lbs thrust, turbo fan
Damage
Minor damage
Flight
Part 121
Operator
SkyWest Airlines, doing business as United Express
Registered owner
Wells Fargo Bank Northwest Na Trustee
Airworthiness certificate
Standard, Transport
Last inspection
Continuous airworthiness · September 13, 2010
Departed
LAX · Los Angeles, CA
Destination
PHX · Phoenix, AZ
Flight plan
IFR
Airport
PHX · Phoenix Sky Harbor Intl.

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
41
Injuries
None
Certificate
Airline transport
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, With waivers/limitations
Last flight review
September 9, 2010
Seat
Left
Flight hours
11,490 total · 4,618 in this make and model
Role
Co-pilot
Age
55
Injuries
None
Certificate
Airline transport
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, With waivers/limitations
Last flight review
July 9, 2010
Seat
Right
Flight hours
8,871 total · 1,574 in this make and model

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
None
Temperature
84 °F, dew point 50 °F
Altimeter
29.82 inHg
Observed at
PHX

Docket · 4

The files NTSB released with the investigation on August 14, 2012, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.2 MB in all.