Friday, May 28, 2010

2006 Mid-Air Collision Brazil - Part 2

Boeing 737-8EH
Photo Credit: Boeing Image
1,514 words

I ended Part 1 of this post with the question: Why did this collision happen?

The Brazilian Air Force Accident report quoted the contributing factors as:

5.2.1.1.2. N600XL
Relatively to the crew of the N600XL, the following active failures were identified: lack of an adequate planning of the flight, and insufficient knowledge of the flight plan prepared by the Embraer operator; non-execution of a briefing prior to departure; unintentional change of the transponder setting, failure in prioritizing attention; failure in perceiving that the transponder was not transmitting; delay in recognizing the problem of communication with the air traffic control unit; and non-compliance with the procedures prescribed for communications failure.


a) Training – a contributor
(Participation of the received training process, due to a qualitative or quantitative deficiency, for not providing the trainee with full knowledge and other technical skills required for the performance of the activity).



b) Air traffic control – a contributor
(Participation of the air traffic service provider, on account of inadequate service provision).
The authorization to maintain flight level FL370 was given to the crew of the N600XL, as the result of a clearance transmitted in an incorrect manner. The vertical navigation conducted by the crew ended up being different from the one prescribed in the flight plan that was filed and activated, on account of the instruction incorrectly transmitted that led the N600XL crew to maintain flight level FL370.


c) Cockpit coordination – a contributor
(Error resulting from an inadequate utilization of the human resources for the operation of the aircraft, on account of an ineffective distribution and management of the tasks affecting each crew member, failure or confusion in the interpersonal communication or relationship, inobservance of operational rules).
The attention of both pilots of the N600XL focused on solving the question relative to the performance of the aircraft for the operation in Manaus, as they had learned of a NOTAM limiting the length of the runway of that airport. This hindered the routine of monitoring the evolution of the flight, because both pilots got busy with the same subject, creating the environment in which the interruption of the Transponder transmission was not perceived.


d) Judgment – a contributor
(Error committed by the pilot, resulting of an inadequate assessment of certain aspects of the operation, despite his being qualified for that operation)
The pilots judged that they would be able to conduct the flight even with their little adjustment as a crew and with their little knowledge of the aircraft systems, mainly the fuel system and the calculations of the weight and balance. They believed they could hasten the departure, resulting that they had just a short time to verify the flight plan and other documents, such as the NOTAM informing about the reduction of the runway length available at Manaus airport.

The PIC left the cockpit and stayed away 16 minutes, not considering the consequences of overburdening the SIC.

e) Planning – a contributor
(Pilot error, resulting of inadequate preparation for the flight, or part of the flight)
The planning of the flight was inadequate. Before the departure, there was not a monitoring of the elaboration of the flight plan that was being prepared by the Embraer employee, not allowing the pilots to have a previous knowledge of the proposed route and flight levels, although, in accordance with the Excelaire Manual of Operations, the PIC had to open and close the flight plan at the nearest FAA FSS or ATC office.


f) Oversight – a contributor
(participation of third parties, not belonging to the crew, on account of lack of adequate supervision of the planning or execution of the operation, at administrative, technical or operational levels)
The oversight conducted by the operator for the flight proposed was inadequate. The composition of the crew, with two pilots that had never flown together before, to receive, in a foreign country, an airplane in which they had little experience, with air traffic rules different from those with which they were used to operate, favored the lack of a good adjustment between the pilots, along with the already mentioned difficulties of cockpit coordination.

g) Little flight experience in the airplane – Undetermined
(Pilot error, resulting from little experience in the aviation activity, in the aircraft, or, specifically, in the circumstances of the operation)
The CVR indicated that, shortly before the moment of silence and the moment at which the Transponder discontinued the transmission, the PIC was looking at the fuel page of the MFD, and solved a doubt about fuel management with the SIC. It is possible that the PIC may have continued to look at other pages of the MFD and, possibly, to pages of the RMU.
The little experience of the PIC in this aircraft possibly made him look for information about the fuel consumed on the RMU fuel page, and, when leaving from this page and pushing the pertinent buttons, he unintentionally changed the setting of the Transponder from TA/RA to STANDBY, thus interrupting the altitude information of the mode C;
The insufficient adaptation of the crew with this type of aircraft and with the DISPLAYS of the respective avionics may have contributed to the unintentional selection of the STANDBY mode and to the subsequent lack of perception of the Transponder/TCAS status.

See Part 3 in my next post.


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