Risk reduction for docking of aircraft

The Uniform platform was expanded from 5 to 9 parking spaces by Schiphol and its partners in order to create more parking spots for wide body aircraft.

The evaluation established that this has reduced the number of tows from and to Schiphol-Oost, leading to less crossings of the Aalsmeerbaan (18L/36R) Runway and the Schiphol-Oostbaan (04/22) Runway.

Co-ordination between the runway controller and tower assistant is an explicit part of new employee training. Furthermore, co-ordination is included in annually-recurring training as well. This reduces the likelihood of runway incursions. The evaluation established that these modifications are implemented and used correctly.

Schiphol and its partners improved the names of specific taxiways. With this revised nomenclature the consistency of the taxiway system has been improved. This reduces the likelihood of errors and misunderstandings due to similar/confusing naming conventions.

Evaluation showed that the revision was correctly implemented and nomenclature is now consistent and thus safer than before.

A missed approach is a standard procedure. An aircraft can come into conflict with departing air traffic when it must execute a missed approach while a converging departure runway is in use. Air Traffic Control the Netherlands (LVNL) and its partners have been investigating how they can further increase the safety of this procedure. 

Timing appears to be an effective measure to reduce the risk of converging approach and take-off operations. By ensuring there is adequate time between these operations we can further decrease the risk of conflicts occurring. 

It was decided to implement timing for all converging runways, taking into account the geometry for each of the converging runway combinations. Air Traffic Control the Netherlands (LVNL) developed  dedicated training for the runway controllers focusing both on conflict prevention and resolution.

Evaluation showed that the share of approaches in the critical area has reduced significantly.  The associated risk has been substantially reduced but was not fully mitigated. Measure is closed, with additional internal follow-up by LVNL and actions by partner airlines to improve pilot response on takeoff roll initiation. 

Schiphol and its partners introduce a fixed connection to the fuel system at the Delta and Echo buffer, which reduces the number of movements of tank trucks to these positions. This is likely to reduce the risk of on-ground safety occurrences. The evaluation established that this system is in place and used for all refuelling at the Delta and Echo buffer. Tank truck movements to these positions are thus no longer necessary.

The European Union is improving the use of European airspace under the project name ‘Single European Sky ATM Research’, or ‘SESAR’. As part of this project, approaches based on satellite technology (RNAV) are implemented at Schiphol. This allows aircraft to carry out an RNP Approach which involves using three-dimensional GPS navigation on the approach to a runway. As of 7 November 2019, an RNAV approach is possible for four runways at Schiphol. The navigation technology makes flight paths for approaching aircraft more predictable, which will reduce the likelihood of any in-flight safety incidents.

The TMA is the airspace controlled above and around the airport by air traffic control. By taking this measure, we will utilise a standard method to enable the desired flight profiles. In this way, we will increase the predictability of the flight paths of approaching aircraft, and reduce the complexity of the airspace.

The evaluation concluded that the measure is implemented and has simplified, standardized, and formalized operation. The expected safety improvements have been realized.

Schiphol and its partners have developed and published a website that pushback drivers can easily consult for the standard procedures for pushback. This will reduce the risk of safety incidents during pushback manoeuvres. The first evaluation showed that more could be achieved from this measure by providing a device for each pushback driver on which they can consult the current pushback procedure. Evaluation of this measure showed more could be achieved with this new website.
This measure has now been fully implemented and has been evaluated twice, based on which, improvements have been proposed and will be implemented. Data shows a security improvement since the implementation of the website.

Air Traffic Control the Netherlands (LVNL) has successfully introduced electronic flight progress strips for air traffic controller workers. This digital system reduces the workload for air traffic controllers. In addition, this electronic method enables extra safety nets to be created. An evaluation of this measure established that the digital strips have been properly implemented and are being used.

During adverse weather conditions, like thunderstorms and storm, or (heavy) fog, all ground handlers need a clear procedure. Schiphol and its partners have implemented a standard procedure that increased the predictability and uniformity of ground handling operations in order to reduce the likelihood of on-ground safety occurrences.

The evaluation of this measure showed that a standardized procedure for heavy wind and storm is in place. This addition to regulate ground handling activities during wind gusts in the handbook provides clarity and uniformity.

Air Traffic Control the Netherlands (LVNL) is now using a ‘runway occupied’ strip in their procedures in both Tower Centre and Tower West whenever a runway is occupied by a bird control or another vehicle. This working procedure was introduced to prevent runway incursions. The evaluation established that the ‘runway occupied’ strip functions adequately and has helped to reduce runway incursions.

Schiphol and its partners have applied additional guidance lines at the G/H-pier area to the Bravo taxiway. This will enable narrow-body aircraft to pass each other safely when taxiing from and to the G/H-pier. This reduces complexity and reduces the likelihood of on-ground safety occurrences. The evaluation established that the double guidance lines are in place and used when possible and beneficial (about 90% of the time). This resulted in less congestion on the taxiways and at the G-H pier area, and less workload for ground control.

Schiphol and its partners have applied additional guidance lines at the G/H-pier area to the Alfa taxiway. This will enable narrow-body aircraft to pass each other safely while taxiing from and to the G/H-pier. This reduces complexity and reduces the likelihood of on-ground safety occurrences. The evaluation established that the double guidance lines are in place and used when possible and beneficial (about 90% of the time). This resulted in less congestion on the taxiways and at the G-H pier area, and less workload for ground control.

During the day, there used to be one or two ground controllers in Tower Centre and one in Tower West near runway 18R/36L (Polderbaan). Air Traffic Control the Netherlands (LVNL) has added a third ground traffic controller to the crew at the Central Control Tower, depending on air traffic volumes. This reduces the workload of ground controllers and the likelihood of runway incursions and on-ground safety incidents. 

The evaluation of the introduction of a third ground traffic controller showed that it indeed led to a reduction of the ground controller workload and did not introduce unacceptable safety risks.

Air Traffic Control the Netherlands has redesigned work stations in the Tower. This allows air traffic controllers to work at positions that have the most favourable view over their areas of control, thereby reducing the likelihood of safety occurrences in the air and on the ground. It is established that the redesign of work stations in the Control Tower is implemented.

Schiphol and Air Traffic Control the Netherlands (LVNL) have created an unambiguous traffic flow to and from the Kilo platform at Schiphol East. This is effectuated by introducing a one-way traffic system and a safer routing for entering and leaving the Kilo platform. The evaluation established that this measure has helped to decrease runway incursions at this location.

Schiphol and Air Traffic Control the Netherlands (LVNL) have applied standard practices for taxiing and towing on the Alfa and Bravo taxiways by introducing a one-way traffic system. The driving direction on the Alfa runway is now clockwise and the Bravo runway is anticlockwise. These standard routes will improve predictability of taxiing and towing movements, in order to reduce the likelihood of on-ground safety occurrences. The evaluation established that the standard routing is used, except where circumstances require another solution, e.g., during construction work. The objective of improving the predictability is met.

Aircraft following the routing to the beginning of runway 18L (Aalsmeerbaan) pass intersection N2/E6. At that point, the traffic crosses runway 09 (Buitenveldertbaan). 

Schiphol and its partners constructed a runway stop bar in order to prevent aircraft that erroneously turn right from taxiing via the Buitenveldertbaan runway towards departing traffic. This will reduce the risk of runway incursions.  

The results of the 2024 evaluation showed that the stop bar is correctly implemented and that the stop bar measure is effective in reducing the identified risks. 

ISMS partners jointly investigated a safety incident in 2018, which happened between a towed aircraft and a marshaller in the field. As a result, Schiphol and its partners have already taken a number of further measures, such as tightening up the procedure, to reduce the risks of marshalled towing. The tow drivers are trained and qualified for the new 2021 standard. The manual has been changed with a clear instruction for tow drivers on the operational procedure. We have also reduced the need to marshal towing movements, thus reducing the risk of safety incidents with marshalled tows.

Evaluation has shown that marshalled tows hardly occur anymore. Implemented actions have made sure that the risks of both a collision between a marshaller and a tow and a runway incursion with a marshalled tow are almost eliminated. 

In 2016, an Embraer departed from the edge of the Kaagbaan (runway 24). Directly after the incident, Schiphol extended the taxiway centre line marking towards the runway centre line. The Dutch Safety Board (DSB) published a report in November 2018 about this incident, which included recommendations. As a result of this report, ISMS partners have changed the markings and guidance lines to reduce the risks associated with misaligned takeoffs. This measure was evaluated in 2023, which showed that all underlying actions were correctly implemented and effective. No more comparable incidents have taken place since.

Link to DSB report

Bron: Report ‘Misaligned take off’ by OVV

ISMS partners jointly investigated a runway incursion in which an aircraft was cleared to enter the Zwanenburgbaan (Runway 18C), while another aircraft had permission to depart to the south. The study brought a number of measures to light which may further reduce the risk of incorrect line-ups. For example, the sight lines from the Control Tower may be improved. We have also conducted further research into the ways of working and operational procedures when taking-off from the Zwanenburgbaan Runway (18C).

The initial proposals for potential risk reducing actions indicated four areas to be investigated as improvements in these areas might bring safety benefits. Result of the evaluation is that these investigations have indeed been executed and led to several operational risk reducing measures.

On February 15 and July 9, 2019, two aircraft had a collision during a pushback manoeuvre. ISMS partners jointly investigated these pushback accidents.
The task force has implemented four measures which prevent pushback accidents. The long pushback procedure was refined and the responsibilities of the ground controllers and the pushback drivers were clarified. There are fixed pushback and release points on taxiway Alpha and for non-standard pushback clearances. This measure was evaluated in 2024, which showed that all underlying actions were correctly implemented and effective.

 The Uniform platform was expanded from 5 to 9 parking spaces by Schiphol and its partners. Three additional parking spaces have been created for wide body aircraft. This reduces bottlenecks in parking spot allocation and relieves gate planning, which thereby reduces the risk of on-ground safety incidents. In addition, aircraft will be serviced at the total of 12 parking spots. That means they will cross the Aalsmeerbaan Runway (18L/36R) less frequently, thereby reducing the risk of runway incursions. 

Air Traffic Control the Netherlands (LVNL) has created an extra safety net so that air traffic controllers receive a digital warning if they want to use a runway that is not currently in use. An additional warning will follow if the air traffic controller then gives permission to take off or land on that runway. These warnings prevent planes from taking off or landing on runways that are not in use. This measure was evaluated in 2023, which showed that it was correctly implemented and effective.

On 6 September 2019 an aircraft attempted to take off from a taxiway instead of the Zwanenburg Runway. A number of measures to prevent this from occurring again were immediately implemented. For example, the standard night taxi route has been changed and the location has been identified as a hotspot where pilots and air traffic controllers are required to be extra alert. The markings that guide pilots towards the runway have also been made clearer and new lightings at runway entries, Runway Guard Lights, have been implemented. Lastly, awareness programs for flight crew and ground controllers are launched.

This measure was evaluated in 2023, which showed that all underlying actions were correctly implemented and effective. No more comparable incidents have taken place since.

The G-buffer is increasingly used for handling aircraft. In the spring of 2024, the remote buffer positions G73, G76 and G79 were renewed. Part of this renewal was the introduction of a fixed connection to the fuel system. This means that tankers no longer have to drive to these buffer positions. This is likely to reduce the risk of on-ground safety occurrences.