Narrative:The Cessna 650 Citation VII corporate jet took off from the Congonhas Airport in São Paulo, Brazil to Brasília in the morning and was scheduled to return at the end of the same day. This flight was intended to transport executives from the company that owned the aircraft.
During preparations for the return leg to Congonhas Airport, the primary pitch trim system failed. As a consequence the autopilot could not be used. According to Brazilian Regulations the aircraft was not allowed to depart in this state, however the flight crew elected to depart.
The flight took off on the flight back to Congonhas Airport at 18:39. During the initial climb, the secondary pitch trim system was activated. At 18:53, some 14 minutes after takeoff, the flight crew attempted to engage the autopilot and the primary pitch trim system was switched on again. It was not possible to engage the autopilot and the secondary pitch trim system was again activated.
As the aircraft was climbing through FL340, the flight crew requested to continue to FL410. This was authorised.
At 19:03 the crew again switched to the primary pitch trim system. The horizontal stabilizer then moved to a nose-down position and the warning clacker sounded in the cockpit. The aircraft had reached a highest altitude of 36800 feet and from that moment on it entered a rapid descent. The crew switched back to the secondary pitch trim system but failed to perform the 'Pitch Trim Runaway or Failure' emergency procedure.
Control could not be regained and the aircraft impacted a farm field near Guarda-Mor, Brazil. All four aboard were killed.
Probable Cause:
Contributing factors.
- Control skills - undetermined.
It is possible that, after inadvertent movement of the horizontal stabilizer, the crewmembers did not operate on the control switches of the secondary pitch trim system, since no other warning sound (Clacker) was recorded on the CVR recordings.
The action prevised in the emergency procedures Pitch Trim Runaway or Failure, item 3, regarding trimming of the aircraft through the secondary system, possibly, was not performed.
The performance of the crew may have been restricted only to the elevator control on the aircraft controls or to the control of the stabilizer associated with the primary trimming mode.
- Attitude - undetermined.
The decision to make the flight without the proper functioning of the primary pitch trim and autopilot system may have been the result of the pilot's self-confidence because of the successful previous flight under similar operating conditions.
Considering the hypothesis that the updated Shutdown Checklist, which should incorporate the Stabilizer Trim Backdrive Monitor - TEST, was not performed after the pre-crash flight, one could consider that there was a lack of adhesion to the aircraft operating procedures.
Such an attitude could be associated with the pilot's self-confidence about the aircraft's operating routine, whose acquired experience could have given him the habit of ignoring some of the procedures deemed less important during the flight completion phase.
- Crew Resource Management - a contributor
Throughout the flight, there was an absence of verbalization and communication of the actions on the checklist.
Similarly, in the face of the emergency situation of the horizontal stabilizer (Pitch Trim Runaway or Failure), no statements were identified regarding the actions required to manage this situation among the crew.
These characteristics denote inefficiency in the use of human resources available for the aircraft operation.
- Training - undetermined.
It is possible that the absence of a periodic training in simulator, especially the emergency Pitch Trim Runway or Failure, has affected the performance of the crew, as far as the CVR did not record statements related to the actions required by the abnormal condition experienced.
- Organizational culture - undetermined.
The operator did not usually properly fill out the PT-WQH flight logbook. This condition evidenced the existence of informal rules regarding the monitoring of the operational conditions of the aircraft. In this context, it is possible that the history of failures related to the pitch trim system has not been registered.
- Piloting judgment - undetermined.
Moments prior to takeoff, it was recorded in the CVR speeches related to the flight without the autopilot, possibly related to a failure or inoperativeness of the primary pitch trim system.
The takeoff with a possible failure in the pitch trim system of the aircraft, showed an inadequate assessment of the risks involved in the operation under those conditions.
- Aircraft maintenance - undetermined.
It was not possible to establish a link between the maintenance services performed on the aircraft in September 2015 and the events that resulted in the accident occurred on 10NOV2015.
However, it was not ruled out that an incomplete crash survey was carried out in the pitch trim system of the aircraft, due to the lack of detail of the service orders.
- Decision-making process - a contributor.
The sounds related to the test positions of the Rotary Test Switch have not been recorded in the CVR recording, so it is possible to conclude that the Warning Systems - Check item of the Cockpit Preparation Checklist has not been performed.
The decision to perform the flight without the complete execution of all items of the Cockpit Preparation Checklist, prevented the correct verification of the primary longitudinal Trim system of the aircraft and reflected an inadequate judgment about the risks involved in that operation.
- Interpersonal relationship - undetermined.
According to the CVR data, there was a possible rush of the crew to take-off, even though it was verified that the aircraft's pitch trim system did not work properly.
It was not possible to determine if this rush was motivated by passengers pressure or self-imposed by the pilot.
- Support systems - undetermined.
It is possible that the Pilots' Abbreviated Checklist - NORMAL PROCEDURES, aboard the aircraft, was outdated, without the incorporation of the Stabilizer Trim Backdrive Monitor - TEST procedure in the Shutdown Checklist.
The possible completion of Shutdown Checklist with outdated procedures would have hampered the manufacturer's suggested verification for identification of abnormalities in the aircraft's pitch trim system.
- Managerial oversight - undetermined.
The records and control of the operational check flights, both by the maintenance shop and by the operator, prevised in documentation issued by the manufacturer (SB650-27-53 and ASL650-55-04) were not performed in an adequate manner, indicating possible weaknesses in the supervision of the maintenance activities.
Accident investigation:
|
Investigating agency: | CENIPA Brazil |
Status: | Investigation completed |
Duration: | 3 years and 5 months | Accident number: | A-149/CENIPA/2015 | Download report: | Final report
|
|
Classification:
Loss of control
Sources:
»
em.com.br
Follow-up / safety actions
CENIPA issued 4 Safety Recommendations
Issued: 08-APR-2019 | To: ANAC | A-149/CENIPA/2015 - 01 |
Act with TAM Executive Aviation and Air Taxi S.A, so that the maintenance organization implements improvements in the control processes and test flight records (operational verification flights) required after the maintenance actions. |
Issued: 08-APR-2019 | To: ANAC | A-149/CENIPA/2015 - 02 |
Act with Banco Bradesco S.A, so that the operator improves the processes related to the logbook records, especially regarding the execution of test flights (operational verification flights). |
Issued: 08-APR-2019 | To: ANAC | A-149/CENIPA/2015 - 03 |
Act with the Cessna Aircraft Company to revise the AFM of aircraft model 650, so that changes in operational procedures introduced through Temporary Changes can also be incorporated into their condensed checklists (Pilots\' Abbreviated Checklist). |
Issued: 08-APR-2019 | To: ANAC | A-149/CENIPA/2015 - 04 |
Verify with the primary certifier of the aircraft, the Federal Aviation Administration (FAA), the need to revise the aircraft model 650-certification documents, regarding the use of the secondary pitch trim system under the horizontal stabilizer trim runaway conditions. |
Show all...
Photos
accident date:
10-11-2015type: Cessna 650 Citation VII
registration: PT-WQH
accident date:
10-11-2015type: Cessna 650 Citation VII
registration: PT-WQH
Video, social media
Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does
not display the exact flight path.
Distance from Brasília-Presidente Juscelino Kubitschek International Airport, DF to São Paulo-Congonhas Airport, SP as the crow flies is 870 km (544 miles).
Accident location: Approximate; accuracy within a few kilometers.
This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.