Risk Assesment: TAP Runway excursion at Aeroporto Internacional de Belém (SBBE), Brasil

Final report published on May, 30th, 2016.  TAP Runway excursion during 180º turn on runway without turn pad, Aeroporto Internacional de Belém (sbbe), Belém – Brasil, 08th June 2014 at 23:17 UTC. TAP PORTUGAL / AIRBUS A330-200 CS-TOJ.

The A330 was instructed by ATC to taxi for line up on runway 06, using a taxi route via the runway (backtrack) compelling necessarily to perform an 180° turning maneuver, even though it is recognized that, because the airport did not integrate a turning area (turn pad) in the designated runway, the aircraft did not meet the recommended ICAO safety settings. It is considered that the contamination of the runway was also a factor in that the maneuver was compounded by the nose gear skidding, making it impossible to the crew to control the aircraft. The risk was high with the conditions on the day of operation. It would not be at all possible to prevent the event, for the presented conditions since crew flight preparation, instructions from the controller and crew decision making when confronted with the inability to control the maneuver.

a) Why the risk assessment carried out by the operation’s direct parties did not include the operating difficulties encountered in the day of the event?

b) Why were these variables  not identified earlier?

TAP A330
Photo (C) Rui Miguel https://img.planespotters.net/media/photos/original/067000/PlanespottersNet_067155.jpg

Runway excursion during 180º turn, on runway without turn pad. Final report approved by the Director of GPIAA (Álvaro Neves), on the 30th May 2016. 

The Gabinete de Prevenção e Investigação de Acidentes com Aeronaves- GPIAA, Portugal Civil Aviation Safety Investigation Authority became aware, through the notification held by TAP PORTUGAL, in the period established of 72 hours, of an incident occurred at the international airport of Belem (SBBE) on 8th June 2014, involving the runway excursion of the CS-TOJ aircraft during the taxi to later take-off at the threshold of the runway 06.

Having begun talks with the counterpart at the State of occurrence, the Centro de Investigação e Prevenção de Acidentes Aeronáuticos- CENIPA, the Brazilian Aeronautical Accidents Investigation and Prevention Center, was subsequently informed that the initial classification of occurrence had been simple incident, not being provided for the opening of an investigation by the CENIPA counterpart.

After an evaluation carried out on the basis of potential damage identified at an early analysis via photographic information as a result of the maneuver performed on the runway from Belem airport, GPIAA took the responsibility to take the opening of an investigation, classifying the event as an incident in accordance with the recommendations of ICAO Annex 13.

CENIPA was informed of this decision and in accordance with international agreements, representing the State of occurrence appointed an accredited representative to mediate the necessary actions with the airport operator responsible for the infrastructure under the technical research process established by GPIAA. The aircraft operator actively cooperated in technical research and provided expert support in the survey of the evidence throughout the process.

History of the Flight

Initial preparation of flight

The rotation for this flight began with the presentation of the crew in LIS at 06:20 UTC, two days before the incident, to the LIS-MAO flight, taking MAO-BEL flight was performed with the presentation at 17:45 UTC, and BEL-LIS flight departure time scheduled at 22:15 UTC.

On June 08th 2014, the Airbus A-330-200 of TAP, registration CS-TOJ, was preparing to take off from the airport of Belem – Brazil (SBBE) for a scheduled air transport having as a destination Lisbon Airport with 116 passengers and 11 crew members on board. On site the weather was not favorable, the night presented with the sky overcast with very strong showers, visibility for taxing was not the best and the wind was blowing from 060° with about 6 knots of intensity.

Being the first time that the crew was operating in this airport, and due to the specificity of the maneuver of the 180° turn on a runway with 45 m wide, without turning pad, the Commander (CM1) of the flight was contacted by phone by a representative of the operator TAP that provided some information regarding the maneuver. It was also suggested to re-read all the information contained in FCOM and FCTM about the procedure.

The whole flight process documentation was analyzed by both pilots during the flight briefing preparation.

During the flight preparation, the Official Pilot (First Officer – CM2) was assigned to Pilot Flying.

The taxi out maneuver was performed by CM1.

The 180° turn on the runway was studied and analyzed before the flight by the crew having become referred to during Take-off briefing, cockpit preparation and taxi-out.

During the transit time of the aircraft in BEL were checked some periods of rain, having this situation and the impact in the area of maneuver, been approached by pilots during the preparation phase of the flight in the cockpit.

The aircraft started to taxi out maneuver at 23:02 UTC in the wet runway conditions, having been instructed to proceed from the stand 06, to line up on the runway 06 via taxiway B, runway 02 and perform taxing on the runway to align runway 06.

While they made the taxing to the runway 02 was given instruction by the ATC to hold the position about 100 m before the runway 06/24 an aircraft was on approach to runway 06.

During taxi “backtrack” on the runway 24 was reviewed once more the procedure of “180° turn on runway”.

Taxi phase on the runway and 180° turn

The CM1 lift the seat before starting the taxi and asks to the CM2 to switch on the landing lights.

During the taxi the pilots remained always in communication, verbalizing actions and coordinating/confirming the values of the parameters recommended in the technical manuals.

When starting the 180° turn to the right, there was a strong noise in the cockpit.

The aircraft runway excursion occurs between the taxiway E and the runway 06.

It was confirmed that the aircraft was out of the runway, having made about 2/3 of the turn, immobilizing on the side of the runway. While turning around to line up for take-off the aircraft went off the paved surface of the runway and came to a stop with all gear on the soft ground.

TAP 1

Immobilization and evacuation

With aircraft grounded, the CM1 informed the ATC of the runway excursion and to close the airport, and also assistance from the ground services and maintenance.

After stopping the aircraft, the CM1 called the Cabin Supervisor (SCC) to the cockpit and informed of what happened.

The CM2 started the APU, after the request of the CM1 and performed the engines shut down, while the CM1 spoke to the passengers.

The SCC informed passengers would disembark with all hand luggage.

The passengers and crew disembarked in an unconventional manner in groups of 4 elements, assisted by the airport authorities of Belem Airport, there has been no injury to any passenger resulting from the event.

Operational documentation

The A330 Flight Crew Operating Manual and Flight Crew Training Manual includes the following procedures for the 180° turn on the runway:

TAP 2

TAP 3

TAP 4

FCOM (PRO-NOR-SOP-10) recommends the following: “Asymmetric thrust should be used during the turn, to maintain a continuous speed (between 5 to 10 kt). Some anticipation is required to ensure that asymmetric thrust is available at the beginning of the turn”.

FCTM (NO-040) recommends similarly: “Asymmetric thrust will be used during the turn. Anticipation is required to ensure that asymmetric thrust is established before the turn is commenced [50% N1 or 1.05 EPR] to maintain a continuous speed of approximately 8 knots throughout the maneuver”.

FCTM (NO-040) recommends the following: “Differential braking is not recommended, to prevent stress on the landing gear assembly. In addition, a braked pivot turn in NOT permitted”.

Airport specific information

The published and in force NOTAM for crews consulting, with information regarding aerodrome conditions, namely, prompted the prohibition of an 180° turn outside the turning pads. It should be mentioned that this information does not provide a correct wording to airport users, given the physical characteristics of the airport presenting only 2 turning pads, one on runway 24 and one on runway 20 it is concluded that the turn on runway 06 is inaccessible to crews.

The information regarding the runway 06/24 closure in case of water accumulation due to the occurrence of moderate to strong rain should be taken into account by crews assessment before start taxiing, where confirmation by the airport operator is clearly required that the runway meets the required safety conditions for authorization of turning maneuver and take-off on the referenced runway.

TAP 5

NOTAM 10475/14: According to information obtained by the internal investigation conducted by Belém ATC it was confirmed that the purpose of published NOTAM was only meant to meet the need to impose on the air traffic obligation to turn in the turning pads to avoid runway asphalt breakdown and not for operational reasons, but its wording was imperfect and incomplete, which raised a number of questions to stakeholders.

The Crew and Company Information (CCI) published in the route manual had no information about the backtrack maneuver.

The CCI published in self-briefing at the date of occurrence and available in NOTAM contained the following additional information:

TAP 6

A330 manufacturer specific information

The minimum effective runway width required for a U-turn assumes that the procedure provided in the FCOM is applied:

  • Amongst others that no differential braking is used, and that asymmetrical thrust is set at the entry of the 180° turn so as to easily ensure a GS between 5 to 10 kt.
  • The minimum effective width required is 42/46 m with 72° steering angle with asymmetrical thrust and proper FCOM procedure applied.

In the case of an 180° turn on the runway, a specific procedure is provided in SOP. Keep in mind that:

  • You should not let the G/S drop below 8kt during the maneuver in order to avoid stopping.
  • Use differential thrust setting, by adding thrust on outer engines (≅ 50 % N1 or 1.05 EPR).
  • The use of differential braking is not recommended due to gear stress.
  • It is essential to keep minimum GS during the turn in order not to need to increase the thrust too significantly so as not to get stuck. Thus, it is recommended to set the differential thrust before starting the turn.

Finally on wet or contaminated surfaces, more specifically when turning on the runway white or yellow painted markings, tight turns lead to jerky rides of the nose wheel which are noisy and uncomfortable.

Visibility from cockpit from static position

TAP 8 y 9

180˚ Turn on Runway Width

This section gives the minimum line-up distance correction for an 180˚ turn on the runway width.

TAP 10

For this maneuver, the pavement width is considered to be the runway width, which is a frozen

As per the standard operating procedures for the ”180˚ turn on runway” (described in the Flight Crew Operating Manual), the aircraft is initially angled with respect to the runway centerline when starting the 180˚ turn.

The value of this angle depends on the aircraft type and is mentioned in the FCOM.

During the turn, all the clearances must meet the minimum value of 4.5 m (15 ft) for this category of aircraft as recommended in ICAO Annex 14. Where severe weather conditions and resultant lowering of surface friction characteristics prevail, a larger wheel-to-edge clearance of 6 m should be provided where the code letter is E or F.

ANALYSIS

This occurrence involved an Airbus A330 aircraft on June 8th, 2014 at the International Airport of Belém in Pará, Brazil meets the ICAO definition of an incident.

The A330 was instructed by ATC to taxi for line up on runway 06, using a taxi route via the runway (backtrack) compelling necessarily to perform an 180° turning maneuver, even though it is recognized that, because the airport did not integrate a turning area (turn pad) in the designated runway, the aircraft did not meet the recommended ICAO security settings. It is considered that the contamination of the runway was also a factor in that the maneuver was compounded by the nose gear skidding, making it impossible to the crew to control the aircraft. The risk was high with the conditions on the day of operation. It would not be at all possible to prevent the event, for the presented conditions since crew flight preparation, instructions from the controller and crew decision making when confronted with the inability to control the maneuver.

This incident investigation determined to have been no evidence of any technical defects on board the aircraft, airport or air traffic service provider that may be the cause or influence in the incident.

The key areas, during this occurrence, were the following questions:

a) Why the risk assessment carried out by the operation’s direct parties did not include the operating difficulties encountered in the day of the event?

b) Why were these variables  not identified earlier?

The possibility of having guaranteed the extraction of voice data from the CVR equipment installed on board it was performed an analysis of human performance where it was found that the crew coordination before, during and after the event complied with the indicated in CRM parameters allowing the effective use of all human resources in the cockpit, hardware and information available to pilots to ensure the safety and efficiency of flight operations.

However, given the encountered conditions, it is considered that the reduction of human error in this assessment might be defined as an act or omission that led to the deviation of the intentions of the crew or situational requirements, such as organizational policies, regulations and standard operating procedures (SOP) in place for the operation under analysis.

Operational analysis

Flight preparation phase

Because of the risk inherent to the taxi on the runway for line up maneuver and the fact of being at an early stage of the operation, it was given by the operator a few days before the flight a briefing to CM1 about the 180° turn on the runway with the suggestion to re-read all the FCOM and FCTM information about the procedure. The 180° turn on the runway and their specific feature, were analyzed before the flight by the crew and was again raised during the take-off briefing, cockpit preparation and taxi-out.

All flight process documentation was analyzed by both pilots during the flight preparation phase, having the NOTAM 10475/14, which refers to the prohibition of executing an 180° turn outside from turning pads on runway 06/24, being interpreted as referring to the landing phase instead of take-off.

Within 4 hours prior to the incident, according to METAR’s analysis, there was a period of heavy rain and three periods of light rain as described in this report, a fact that was repeatedly mentioned by the crew in rotation BEL and moments before the start taxi-out phase.

Taxi phase

It is noticeable in the recorded communications the CM1’s concern to perform the 180° turn on the runway due to weather conditions and the runway grip conditions, which would have made it difficult to taxi when arriving at BEL.

The taxi-out maneuver was performed by the CM1 according to the operator’s FCAP (Flight Crew Airline Policy).

After the pushback maneuver, from stand 06, the taxi clearance was obtained to leave Apron 4 via taxiway B, enter runway 02 and perform backtrack on runway 06, despite the information shown in the NOTAM 10475/14 as indicated in point 1.18 of this report.

In order to improve cockpit visibility to the outside, the CM1 raises his seat height before starting the maneuver and asks the CM2 to turn on the landing light. (The pilots eyes are 5,8 m above the ground, which causes a front view dead angle of 16 m).

180 degree turn maneuver phase

The 180° turn on the runway maneuver was started at 23:26:46, being the aircraft on the right of the runway centerline on heading 250°, following a left turn to heading 221° (approximate angle of divergence of 024° to runway QFU of 245°). The maximum registered taxi speed during this phase of maneuvering was 5 Kt. The brakes were symmetrically applied, 10° on the left, 10° on the right. During the maneuver there was effective and assertive communication among pilots with verbalization of actions and coordination/confirmation of values (heading, thrust, ground speed) recommended in the technical manuals.

TAP 11

23:17:03 – Starting right turn (heading 221°; 31,5% N1; 25,9% N2; 4 kt GS).

23:17:04 With the aircraft approaching the right edge of runway 06, it was initiated the 180° turn with 4 knots of ground speed. The N1 power in engines ENG1/ENG2 was 31.5%/25.9%, beginning to be increased at that moment. Asymmetric brakes application, 18° left side and 7° right side.

23:17:08 The turning angle of 75.0°was achieved. During all the turn, the nose wheel maximum angle in relation to the neutral position was 73.1°. Asymmetric brakes application, 21° left side and 4° right side.

23:17:10 Maximum Engine Pressure Ratio during the turn of 1,06 on the left engine. The N1 power on both engines was 49.5/37.0%. Asymmetric brakes application, 21° left side and 4° right side.

23:17:16 Indicated ground speed of 6 kt and N1 power on both engines of 55.0% and 36.9%, having not been a direct correlation between the power increase and the speed variation compared to the ground speed of point 1, which indicates the start of the skidding. Asymmetric brakes application, 10° left side and 2° right side.

When the nose landing gear wheels reached the threshold marks of runway 06, the noise created by the skidding difficult the communication between both pilots.

23:17:24 It was reached the maximum N1 engine power on both engines, with a value of 59.0%/39.8%. Asymmetric brakes application, 10° left side and 3° right side.

With a high level of noise in the cockpit, the CM1 questions the CM2, which was in a better position to make an assessment of the aircraft position, if in his opinion there would still be further space for the maneuver.

23:17:25 The maximum registered rolling speed during the turn was 13 kt, being reached 1 second before the runway excursion and setting engines power to IDLE (no trust). Asymmetric brakes application, 0° left side and 23° right side.

The CM2 has the perception that it will not be possible to maneuver and warns the CM1, which due to the high noise level will not have heard the warning.

23:17:26 The nose landing gear wheels overrun the runway and engine thrust levers are set to IDLE. Asymmetric brakes application, 0° left side and 43° right side.

Due to the high level of noise in the cockpit, the CM1 realizes, through non-verbal communication used by the CM2, that there would be no space to perform the maneuver.

23:17:29 The rolling speed of 13 kt started to reduce, with brakes application. Asymmetric brakes application, 1° left side and 41° right side.

23:17:32 The aircraft came to a full stop, with the nose wheel at 67.7° from its neutral position.

Then the crew instructed the ATC to close the airport since it would not be possible to remove the aircraft from the position it was in.

Evaluation of airport characteristics

Runway 06 characteristics

Runway 06 of Belém airport is an asphalt runway with an area of 400 m of grooves before crossing runway 02/20.

It’s a runway that is easily contaminated with water accumulated in the event of heavy or continuous rain.

The aircraft needs at least 42 m radius, without safety margins, to make an 180° turn on the runway.

The runway has a width of 45 m and has no turning pad, which according to Annex 14 of ICAO and the manufacturer’s operating manual (Airbus), does not comply with the safety margin of 4,5 or 6 m, distance in relation between the outside of the tires and the runway edge, as the runway is dry or wet, so it is possible to perform a safe 180° turn, for this type of aircraft (Airbus 330-200).

The aircraft was parked on apron 4 which is served by taxiways C and D for accessing runway 06.

The taxiway C has 18 m width. According to a recommendation of Annex 14 of ICAO, for this aircraft type, the minimum taxiway width should be 23 meters.

TAP 13FIG

Comments to aircraft operator

180° turn on runway without turning pad simulator training

It was found during the investigation that the practice of 180° turn on runways without turning pad is not part of the simulator sessions as well as training actions covering tight turning with the need to adapt the techniques recommended by the manufacturer in these situations.

According to the Flight Crew Airline Policy (FCAP) this maneuver is only executed under the Chief Fleet or Chief Pilot authorization.

As a not regularly performed maneuver, the GPIAA recommends to TAP operator (RS Nº 16/2015) to include on the simulator programs (Recurrent training and checking) the training of the 180° turn on runways without turning pad.

Human factors

Usually, these kinds of incidents, runway excursions, are the result of a chain of events supported by certain conditions and basic causes. The interaction of the people involved plays a special role. During the analysis of this runway excursion during the 180°, one of the key aspects was the interaction between the Air Traffic Controller in the tower position (ground) and the crew members. The other aircraft in the circuit to approach or rolling on the ground are not to have any direct or indirect influence on the occurrence.

An error analysis of the actions of all those involved showed that the crew of the A330 has accepted the instructions of the controller for taxi route to runway 06, not taken into account the NOTAM 10475/14, in which it stated, the prohibition to execute 180 degrees turn on runway 06/24 outside of turning pads. This might be considered a pilot deviation, ie a crew did not adhere to an instruction or have deviated from the prescribed procedure, given the flight commander is sovereign in the actions it takes, may decline and/or change the instructions in accordance with its risk assessment. In addition, the deviation may also be attributed to the controller on duty for the instructions do not take into account the accumulation of water by the occurrence of moderate rain strong on the track 06, despite the information shown in the NOTAM 10475/14.

In order to deduce the appropriate actions to prevent similar future occurrences, the question has to be answered why this error occurred and why was not recognized and/or foreseen by those involved during the time of preparation of this operation.

The GPIAA opinion is that the following aspects of this question arose:

  1. The A330 crew had never experienced an 180° on that runway, under those atmospheric conditions found on the day of the incident. For the crew, the deviation of the compliance mentioned in the NOTAM, may have been induced by the lack of understanding of that the text also applied to the take-off operation, whereas it would be routine in some way this operation to be confronted with this type of instruction, therefore, recognize that there would be a deviation from the standard procedure established. During the pre-flight preparation, this takeoff procedure had been discussed by the crew.
  2. The tower controller formally gave the correct instructions, but should have corrected himself, warning the crew that this maneuver contravened the published in NOTAM, while recognizing that it would be the only one for which the aircraft could take off the runway in use. Even if the taxi route path has been agreed upon beforehand, still in the flight pre-preparation phase.

However, the GPIAA is of the opinion that the inaccuracies in communication have not contributed to the parties involved to understand according to the ICAO recommendations. It was not a single mistake, just minor inaccuracies which added the role of contributing factors. The GPIAA is of the opinion that the confidence with which the crew took over the maneuver, as well as the care accounted for it to be successful, not due to negligence and/or lack of proficiency , but rather the risk assessment performed before the start of operation that does not cautioned the difficulties presented at the aerodrome for the operation with this type of aircraft were developed, with an acceptable calculated risk, enhancing the crews diversion when called upon to take decision to operate under these conditions.

Considering all the established facts during the material collection for the technical investigation process, the GPIAA assumes that the instructions given by the ATC and accepted by the crew as well as the previously outlined plan for the taxiing of this type of aircraft at the Belém airport, have failed to comply with the operating rules approved by the actors involved in this event by the country of occurrence authorities and in strict compliance with the technical assessments made for the implementation of the operation.

The GPIAA is of the opinion that both the crew and the duty controller, the imputed workload was not unusual, and generally unsafe.

But, the analysis clearly showed that in this situation a deviation or an exception to the standard operating situation and/or stipulated is not appropriate and may cause unsafe events. Thus, the GPIAA is of the opinion that the conscious deviation from the sense of procedures for taxi route for the A330 aircraft at the Belém airport, causing exceedances of standards and best operating practices can result in a hazardous situation.

The GPIAA assumes that, the A330 crew has not mentally registered after receiving the clearance instructions, that the tight 180° turn maneuver in a 45 meter contaminated runway was not possible, planning the maneuver according to the data inserted in FCOM, in strict compliance with the aircraft performance.

Superficial human factors analysis of the sequence of events on board the A330, revealed that the crew would have expressed discomfort for executing the maneuver even in the preparation flight phase, where after receiving the taxi instructions (clearance) from the controller is noticeable that the workload in the cockpit intensified, to the detailed preparation of the turning operation which kept the crew in a state of high “stress” due to the current conditions. Presumably, no member of the A330 crew did acknowledge their discomfort to the duty controller, because of a feeling that would be the only ones to taxi on the runway, not having any pressure to expedite, thinking so, they would have more than time so that it would unveil safe according to the prior planning.

Defenses

Defenses are measures to protect a system against the consequences of technical or human failure. The GPIAA is of the opinion that a mechanism that would have prevented this runway excursion by the A330, is the adherence is the adherence of interveners from Belém airport and the operator to Standard Operating Procedures for an operation with this nature (SOP).

The following SOP’s would have been of importance:

1. Adherence to taxi procedures for the runway according to layout

The airport operator and the air traffic service provider should have agreed on an operating protocol for taxi maneuver to the runway in use in accordance with the rules and the available layout – So should have been constituted an SOP. The instruction to the A330 to enter the runway and perform a “backtrack” was a conscious deviation from the procedures of an SOP.

This instruction was given by the fact that the taxiway C did not have the width in accordance with the category of the aircraft, which allow access to the threshold of runway 06, preventing a tight 180° turn. In terms of guidance for the duty controller and the own flight crew, it was accepted that the deviation was validated for the sake of facilitating the operation. The deviation of the good practices of an existing SOP did not occur as an ad hoc situation, but a pre-agreed situation.

2. Signal, marks and technical equipment

At the time, the Belém airport was not equipped with centerline lights or aiding marks to turn at the threshold by the lack of a turning pad on runway 06, or other markings or signs to help prevent runway excursions in 180° turns. The GPIAA is however of the opinion that in this case this marks or signs would have prevented the failure of the maneuver, allowing the crew to better manage the little available slack they had in turning radius, the conditions to which they were subjected on the day of the event.

Monitoring the runway pavement for the accumulation of water and rubber in the threshold area would have allowed a greater tire grip, preventing slippage and consequent excursion.

CONCLUSIONS

From the available evidence, the following findings are made in relation to the runway excursion at Belém Airport, Brazil (SBBE), on June 8th, 2014; and should not be read as apportioning blame or liability of any organization or private individual

Findings

  1. The aircraft was involved in a passenger transport flight;
  2. The aircraft’s Airworthiness Review Certificate of aircraft was valid and all scheduled maintenance actions were performed in accordance with the maintenance program and Aircraft Maintenance Manual;
  3. The Aircraft Technical Log Book had no record of limitation or restriction for a normal operation of the aircraft;
  4. The aircraft was loaded within the limits;
  5. The crew was duly certified, trained and qualified for the flight in accordance with current regulations. Both crew members had no restrictions or limitations on the operation;
  6. There was no evidence of physiological factors affecting the performance of the flight crew;
  7. The runway 06/24 has a width of 45 meters;
  8. The A330-200 airplane requires a minimum of 42 meters, without safety margin, to perform an 180° on the runway in accordance with the FCOM operating manual of TAP operator;
  9. According to the recommendation of Annex 14 of ICAO and the Aircraft Characteristics – Airport and Maintenance Planning of AIRBUS manufacturer, 180° turns in a given runway must maintain a safety margin of 4,5 m between the wheels and the runway edges;
  10. Runway 06 has no turning pad;
  11. Runway 06/24 has no centreline lights;
  12. The runway was wet according to the investigation via CVR;
  13. NOTAM 10475/14 refers to the prohibition of carrying out the 180° turn on runway maneuver out of turning pads on runway 06/24.
  14. ATC taxi instructions did not take into account the water accumulation by the occurrence of moderate to strong rain on the runway 06, despite the information shown in the NOTAM 10475/14 as indicated in paragraph 1.18.2 of this report.
  15. The prohibition of 180° turn outside from turning pads maneuver was established in NOTAM and CCI published in self-briefing, at the date of occurrence.
  16. The Commander has a long experience in the operation of flights to Brazil, this was his first flight to the Belém airport.
  17. The Commander said that he interpreted the NOTAM (DO NOT PERFORM THE RETURN OUTSIDE TURN-AROUND AREA) as referring to the landing phase and not take-off.
  18. The 180° turn maneuver was executed on the threshold of runway 06, in the area of lower grip, on top of threshold markings and at night.

Causes

Based on DFDR analysis, the runway excursion that occurred during the 180° turn was the result of two main factors combination:

  • Mismanagement of maneuvering speed during the turn.

The 180° turn began without established asymmetrical power and at a low speed (4 kt).

During the turn, there was an excessive increase in the power of both engines, with left engine reaching 59% N1 and the right engine 39.8% N1, with a consequent increase in aircraft speed up to 13 kt.

  • Inappropriate brakes application during the turn.

Contributing factors

  • Being the NOTAM 10475/14 published to the Belém airport, which prohibits 180° turns out of turning pads maneuvers, despite the constraint is not operational, the ATC should not have instructed the flight commander to backtrack via runway 06.
  • The commander knowing the existence of this NOTAM and the company’s CCS, should not have complied with the instructions given by the ATC. Being the first time that he was operating at this airport, with contaminated runway (wet), at night, in a runway without centerline lights, without external references, being the maximum margin of error within about 3 meters.
  • In the TAP Operator Flight Crew Operation Manual (FCOM) was published 42 meters turning radius without safety margin to make an 180° turn on the runway, but according to the recommendations of Annex 14 of ICAO and the AIRBUS manufacturer there must be a safety distance of 4.5 meters to each side between the outer main gear wheel and the edge of the pavement.
  • The maneuver was performed at night and the runway has no centerline lights and, being the pilots eyes 5.8 m above the ground, causes a front dead angle of about 16 m.

SAFETY RECOMMENDATIONS

Implemented measures after the accident

1. TAP

After the incident the TAP operator made a new Operational Risk Assessment, now with 23 mitigation measures (the first ORA had 10 mitigation measures) where it implements the following measures to increase safety in Belém airport:

  • Define a minimum experience/criteria for the assignment of Commanders;
  • The operating area defined a maximum taxi speed of 5 kt to reduce the potential for skidding to be used as reference in ground operations;
  • Consider Airport Cat B for “unusual characteristics or performance limitations”;
  • Do not consider take-off/landing with items that reduce the aircraft’s directional control or braking capacity;
  • Reinforcement of the 180° turn outside from turning pads prohibition faced the hypothesis to date, of dubious interpretation observed the occurrence in question;
  • Taxi in APRON 3, TWY C and D should be assisted by Follow Me;
  • Do not use reduced engine taxi.

2.INFRAERO/Belém

The airport operator INFRAERO/Belém has implemented the following measures after the incident:

  • The Emergency Response Plan and the Disabled Aircraft Removal Plan were properly reviewed and forwarded to the Brazilian Civil Aviation Authority (ANAC);
  • A follow me procedure for TAP air operator departure operations has been established as well as an operating agreement has been signed between the INFRAERO/Belém and TAP;
  • Revitalization of the markings of the runway 06/24 was performed;
  • Grooving3 of the runway 06/24 was implemented;
  • The vertical signaling services were maintained in the movement area of the SBBE airport;
  • The construction project in runway 06/24 and taxiways was amplified, including the construction of a turning pad on threshold 06, with the implementation of the planned work for 2017.

Safety recommendations

In the context of the investigation, seven safety recommendations were issued.

According to the provisions of Annex 13 of the ICAO, all safety recommendations listed in this report are intended for the supervisory authority of the competent state, which has to decide on the extent to which these recommendations are to be implemented. Nonetheless, any agency, establishment or individual is invited to strive to improve aviation safety in the spirit of the safety recommendations pronounced.

In the Decree on the Investigation of Aircraft Accidents and Serious Incidents (GPIAA), the Portuguese legislation D.L. 318/99 provides for the following regulation regarding implementation: Article 27º Safety recommendations.

SR Nº 06/2016 To TAP

Include in the simulator programs (recurrent training and checking) training in 180° turns without turning pads.

SR Nº 07/2016 To TAP

Include in the FCOM the turning radius distances with the safety levels recommended by Annex 14 of ICAO and the AIRBUS manufacturer.

SR Nº 08/2016 To INFRAERO

Integrate on its expansion plan as soon as possible the construction of a turning pad, in runway 06’s threshold at Belém International Airport, according to the recommendations of Annex 14 of ICAO, to increase the operation safety levels with Airbus A330-200 aircraft.

SR Nº 09/2016 To INFRAERO

Integrate on its SMS program a verification plan for friction macro texture measurements and as well as rubber removal of runways 06/24 and 20/02 from Belém International Airport (SBBE) and to publish the measurement reports as required by resolution Nº 236, of 5th June 2012, issued by ANAC Brazil.

SR Nº 10/2016 To Departamento do Controle do Espaço Aéreo-DECEA

Update, including more information on AIP Brazil, on the physical characteristics of the aerodrome, namely, width, type and pavement strength of taxiways B/C/D/E/G/H/J/K, of the Belém International Airport (SBBE).

SR Nº 11/2016 To ANAC Portugal and ANAC Brasil

The supervision of the correct interpretation and implementation of the recommendations contained in this report to ensure the effectiveness and improving the operator’s safety should be activated by ANAC Portugal and Brazil under an agreement.

SR Nº 12/2016 To ANAC Brazil

In cooperation with DECEA, responsible for air navigation and air traffic control service providers, the airport operator INFRAERO/Brazil, and users of Belém International Airport, should conduct a comprehensive analysis of operating procedures and take all necessary steps to find appropriate measures to reduce complexity and systemic risks.

Excerpted from Final Report of Incident with Airbus A330, registration CS-TOJ, 08th jun 2014, at International Belem Airport – Brazil published 2016-06-08. http://www.gpiaa.gov.pt/ Final Report of Incident with Airbus A330, registration CS-TOJ, 08th jun 2014, at International Belem Airport – Brazil

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Posts in this blog:

Human Factors in Aviation

Accidents/Incidents investigation

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12 thoughts on “Risk Assesment: TAP Runway excursion at Aeroporto Internacional de Belém (SBBE), Brasil

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