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Difference between revisions of "Taxiway Collisions"

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|control_caption  = About SKYbrary
 
|control_caption  = About SKYbrary
 
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==Description==
 
==Description==
 
An airport is a complex interface between the air and the ground environments, where  access must be controlled and separation between aircraft or between aircraft and vehicular traffic must be maintained and optimised. While most occurrences on airport aprons and taxiways do not have consequences in terms of loss of life, they are often associated with aircraft damage, delays to passengers and avoidable financial costs.
 
An airport is a complex interface between the air and the ground environments, where  access must be controlled and separation between aircraft or between aircraft and vehicular traffic must be maintained and optimised. While most occurrences on airport aprons and taxiways do not have consequences in terms of loss of life, they are often associated with aircraft damage, delays to passengers and avoidable financial costs.
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*aircraft-aircraft collisions or near collisions - collisions can result from:
 
*aircraft-aircraft collisions or near collisions - collisions can result from:
 
**failure to follow taxiway centreline guidance
 
**failure to follow taxiway centreline guidance
**failure to stop prior to a stop bar
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**failure to stop prior to a [[Stopbars (SKYclip)|stopbar]]
 
**taxiing at speeds unsuited to the conditions or level of congestion
 
**taxiing at speeds unsuited to the conditions or level of congestion
 
**taxiway deviation whilst trying to manoeuvre to "squeeze" past another aircraft. Manoeuvring around an aircraft partially blocking a taxiway (as might be the case if the aircraft was approaching, but not yet at the stop point of, a gate) can lead to collision. If misjudged, this could result in a wingtip striking the tail of the stopped aircraft or it could compromise clearance between obstacles or other aircraft and the wingtip opposite the stopped aircraft
 
**taxiway deviation whilst trying to manoeuvre to "squeeze" past another aircraft. Manoeuvring around an aircraft partially blocking a taxiway (as might be the case if the aircraft was approaching, but not yet at the stop point of, a gate) can lead to collision. If misjudged, this could result in a wingtip striking the tail of the stopped aircraft or it could compromise clearance between obstacles or other aircraft and the wingtip opposite the stopped aircraft
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==Prevention==
 
==Prevention==
 +
Most taxiway accidents and incidents are preventable. This prevention is dependant upon appropriate training and testing, compliance with clearances, published procedures and right-of-way rules, maintaining situational awareness and adapting speed of movement to suit the weather and surface conditions. Some specific accident prevention strategies are as follows:
 +
*Vehicle operators - It is imperative that vehicle operators be properly trained, tested and authorised for ramp and taxiway operations. Driving infractions should be investigated and additional training provided where appropriate. Multiple infractions should be considered grounds for suspension of airside driving privileges. Operators should:
 +
**ensure daily inspection for their vehicle is complete and that beacon/hazard lights are operating when the vehicle is airside
 +
**maintain situational awareness
 +
**operate their vehicle safely and in accordance with all company and airport rules
 +
**obey all "rules of the road" inclusive of speed limits, stop signs and right-of-way guidance
 +
**yield to aircraft at all times
 +
**obtain and read back any ground movement controller clearance prior to entering an area where clearance is required. If clearance is not understood, ASK!
 +
*Tug operators - Tug operators have the additional responsibility of moving aircraft on and off gates as well as positioning aircraft from one location on the airfield to another. In addition to the aforementioned items for vehicle operators, the tug operator must:
 +
**know the size of the aircraft in tow inclusive of the wingspan
 +
**be conversant with the normal taxi routes from one airfield location to another
 +
**understand the stopping distances required for a tug with an aircraft in tow
 +
**comply with all clearances, especially runway crossing clearances
 +
**use wing and tail walkers when manoeuvring in congested areas
 +
*Controllers - The ground controller is responsible for the safe and efficient movement of aircraft and vehicle traffic on the taxiways and aprons. They should:
 +
**provide the appropriate clearance for the requested action
 +
**ensure that the clearance readback is accurate
 +
**to the extent possible, monitor the movement visually, via transponder or by use of [[Multilateration|multilateration equipment]] to ensure clearance compliance
 +
*Pilots - In general, pilots are responsible for the ground movement of an aircraft from the runway to the gate and from the gate to the runway although they may also reposition aircraft from one point on the airfield to another. In all cases they should:
 +
**request, readback and comply with an appropriate clearance
 +
**maintain situational awareness
 +
**taxi at a speed appropriate to the conditions and traffic situation
 +
**maintain the centre of the taxi lane
 +
**be vigilant for taxi lane compromise by another aircraft, vehicle or object
 +
**not assume that vehicles will yield right-of-way
  
 
==Accidents and Incidents==
 
==Accidents and Incidents==
The following accidents and incidents describe collision or near collision between two aircraft, an aircraft and a vehicle or an aircraft and a stationary object.
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The following accidents and incidents involve collision or near collision between two aircraft, an aircraft and a vehicle, or an aircraft and a stationary object.
 
===Aircraft/Aircraft Conflict===
 
===Aircraft/Aircraft Conflict===
 
{{#ask: [[GND::Aircraft / Aircraft conflict]]
 
{{#ask: [[GND::Aircraft / Aircraft conflict]]
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*[http://www.skybrary.aero/bookshelf/books/3524.pdf ACRP Report 148: LED Airfield Lighting System Operation and Maintenance], J. Burns et al., Transportation Research Board (U.S.), 2015
 
*[http://www.skybrary.aero/bookshelf/books/3524.pdf ACRP Report 148: LED Airfield Lighting System Operation and Maintenance], J. Burns et al., Transportation Research Board (U.S.), 2015
  
[[Category:Ground Operations   [[Category:Operational Issues
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[[Category:Ground Operations]]

Latest revision as of 10:02, 28 June 2018

Article Information
Category: Ground Operations Ground Operations
Content source: SKYbrary About SKYbrary
Content control: SKYbrary About SKYbrary

Description

An airport is a complex interface between the air and the ground environments, where access must be controlled and separation between aircraft or between aircraft and vehicular traffic must be maintained and optimised. While most occurrences on airport aprons and taxiways do not have consequences in terms of loss of life, they are often associated with aircraft damage, delays to passengers and avoidable financial costs.

This article examines collisions and near collisions whilst aircraft are on the airport manoeuvring areas inclusive of taxiways and ramp areas. The article On-Gate Collisions provides insight into aircraft collisions occurring whilst on, entering or leaving an assigned gate.

Occurrences

As previously stated, to ensure efficient and safe airport ground operations, separation between aircraft or between aircraft and vehicular traffic must be maintained and optimised. On occasion, however, minimum separation, particularly aircraft/vehicle separation is compromised. Whilst all events do not result in collision with an aircraft, the majority of taxiway occurrences involve vehicle operators deviating from a surface movement controller clearance. These "failure to comply" occurrences most usually involve vehicles:

  • using an incorrect taxiway
  • failing to stop at a taxiway holding point
  • failing to stay on the surface movement control radio frequency or ground frequency as appropriate
  • failing to obtain a clearance before entering an area subject to control.

In all cases, these actions have the potential to put the vehicle in conflict with an aircraft which, in turn, could:

  • lead to collision
  • require aggressive braking by the aircraft which could result in personnel injuries. Cabin crew are especially vulnerable as they might be moving within the cabin preforming pre-departure or post-landing duties


Most of the remaining occurrences are related to one of the following:

  • aircraft-aircraft collisions or near collisions - collisions can result from:
    • failure to follow taxiway centreline guidance
    • failure to stop prior to a stopbar
    • taxiing at speeds unsuited to the conditions or level of congestion
    • taxiway deviation whilst trying to manoeuvre to "squeeze" past another aircraft. Manoeuvring around an aircraft partially blocking a taxiway (as might be the case if the aircraft was approaching, but not yet at the stop point of, a gate) can lead to collision. If misjudged, this could result in a wingtip striking the tail of the stopped aircraft or it could compromise clearance between obstacles or other aircraft and the wingtip opposite the stopped aircraft
    • taxiway configuration - converging taxiways can potentially lead to reduced or compromised clearance, especially where they cross
  • reduced aircraft clearance with ground equipment or obstacles. Reduced clearance accidents or incidents can occur in various ways. These include:
    • inappropriate use of a restricted taxiway - some taxiways are restricted by wingspan. Use by a larger aircraft could compromise obstacle clearance
    • failure to follow taxi lane guidance - deviation from the lane guidance whilst manoeuvring in proximity to light stands, gates or stationary equipment can result in collision
  • jet blast -inappropriate thrust settings or following too closely can result in aircraft damage due to jet blast. Jet blast can also cause unsecured equipment such as Unit Load Devices (ULD) to move and strike other aircraft, equipment or personnel

Prevention

Most taxiway accidents and incidents are preventable. This prevention is dependant upon appropriate training and testing, compliance with clearances, published procedures and right-of-way rules, maintaining situational awareness and adapting speed of movement to suit the weather and surface conditions. Some specific accident prevention strategies are as follows:

  • Vehicle operators - It is imperative that vehicle operators be properly trained, tested and authorised for ramp and taxiway operations. Driving infractions should be investigated and additional training provided where appropriate. Multiple infractions should be considered grounds for suspension of airside driving privileges. Operators should:
    • ensure daily inspection for their vehicle is complete and that beacon/hazard lights are operating when the vehicle is airside
    • maintain situational awareness
    • operate their vehicle safely and in accordance with all company and airport rules
    • obey all "rules of the road" inclusive of speed limits, stop signs and right-of-way guidance
    • yield to aircraft at all times
    • obtain and read back any ground movement controller clearance prior to entering an area where clearance is required. If clearance is not understood, ASK!
  • Tug operators - Tug operators have the additional responsibility of moving aircraft on and off gates as well as positioning aircraft from one location on the airfield to another. In addition to the aforementioned items for vehicle operators, the tug operator must:
    • know the size of the aircraft in tow inclusive of the wingspan
    • be conversant with the normal taxi routes from one airfield location to another
    • understand the stopping distances required for a tug with an aircraft in tow
    • comply with all clearances, especially runway crossing clearances
    • use wing and tail walkers when manoeuvring in congested areas
  • Controllers - The ground controller is responsible for the safe and efficient movement of aircraft and vehicle traffic on the taxiways and aprons. They should:
    • provide the appropriate clearance for the requested action
    • ensure that the clearance readback is accurate
    • to the extent possible, monitor the movement visually, via transponder or by use of multilateration equipment to ensure clearance compliance
  • Pilots - In general, pilots are responsible for the ground movement of an aircraft from the runway to the gate and from the gate to the runway although they may also reposition aircraft from one point on the airfield to another. In all cases they should:
    • request, readback and comply with an appropriate clearance
    • maintain situational awareness
    • taxi at a speed appropriate to the conditions and traffic situation
    • maintain the centre of the taxi lane
    • be vigilant for taxi lane compromise by another aircraft, vehicle or object
    • not assume that vehicles will yield right-of-way

Accidents and Incidents

The following accidents and incidents involve collision or near collision between two aircraft, an aircraft and a vehicle, or an aircraft and a stationary object.

Aircraft/Aircraft Conflict

  • B742 / B741, Tenerife Canary Islands Spain, 1977 (On 27 March 1977, a KLM Boeing 747-200 began its low visibility take-off at Tenerife without requesting or receiving take-off clearance and a collision with a Boeing 747-100 backtracking the same runway subsequently occurred. Both aircraft were destroyed by the impact and consequential fire and 583 people died. The Investigation attributed the crash primarily to the actions and inactions of the KLM Captain, who was the Operator's Chief Flying Instructor. Safety Recommendations made emphasised the importance of standard phraseology in all normal radio communications and avoidance of the phrase "take-off" in ATC Departure Clearances.)
  • B738/A321, Prague Czech Republic, 2010 (On 18 June 2010 a Sun Express Boeing 737-800 taxiing for a full length daylight departure from runway 06 at Prague was in collision with an Airbus 321 which was waiting on a link taxiway leading to an intermediate take off position on the same runway. The aircraft sustained damage to their right winglet and left horizontal stabiliser respectively and both needed subsequent repair before being released to service.)
  • DC91 / B722, Detroit MI USA, 1990 (On 3 December 1990 a Douglas DC9-10 flight crew taxiing for departure at Detroit in thick fog got lost and ended up stopped to one side of an active runway where, shortly after reporting their position, their aircraft was hit by a departing Boeing 727-200 and destroyed by the impact and subsequent fire. The Investigation concluded that the DC9 crew had failed to communicate positional uncertainty quickly enough but that their difficulties had been compounded by deficiencies in both the standard of air traffic service and airport surface markings, signage and lighting undetected by safety regulator oversight.)
  • A321 / B734, Barcelona Spain, 2015 (On 25 November 2015, an Airbus A321 taxiing for departure at Barcelona was cleared across an active runway in front of an approaching Boeing 737 with landing clearance on the same runway by a Ground Controller unaware that the runway was active. On reaching the lit stop bar protecting the runway, the crew queried their clearance and were told to hold position. Noting that the event had occurred at the time of a routine twice-daily runway configuration change and two previous very similar events in 2012 and 2014, further safety recommendations on risk management of runway configuration change were made.)
  • DH8C / GALX, Valencia Spain, 2008 (On 11 February 2008, the crew of a DHC8-300 misjudged the sufficient clearance during taxi and collided with a Gulfstream G200 at a taxiway intersection.)
  • A332/A345, Khartoum Sudan, 2010 (On 30 September 2010, an A330-200 was about to take off from Khartoum at night in accordance with its clearance when signalling from a hand-held flashlight and a radio call from another aircraft led to this not taking place. The other (on-stand) aircraft crew had found that they had been hit by the A330 as it had taxied past en route to the runway. The Investigation found that although there was local awareness that taxiway use and the provision of surface markings at Khartoum did not ensure safe clearance between aircraft, this was not being communicated by NOTAM or ATIS.)
  • A319 / UNKN, Stockholm Arlanda Sweden, 2011 (On 5 February 2011, an Airbus A319-100 being operated by Air Berlin on a passenger flight departing Stockholm inadvertently proceeded beyond the given clearance limit for runway 19R and although it subsequently stopped before runway entry had occurred, it was by then closer to high speed departing traffic than it should have been. There was no abrupt stop and none of the 103 occupants were injured.)
  • SH33 / MD83, Paris CDG France, 2000 (On the 25th of May, 2000 a UK-operated Shorts SD330 waiting for take-off at Paris CDG in normal visibility at night on a taxiway angled in the take-off direction due to its primary function as an exit for opposite direction landings was given a conditional line up clearance by a controller who had erroneously assumed without checking that it was at the runway threshold. After an aircraft which had just landed had passed, the SD330 began to line up unaware that an MD83 had just been cleared in French to take off from the full length and a collision occurred.)

Aircraft/Vehicle Conflict

  • B737, Gran Canaria Spain, 2016 (On 7 January 2016, a Boeing 737-700 was inadvertently cleared by ATC to take off on a closed runway. The take-off was commenced with a vehicle visible ahead at the runway edge. When ATC realised the situation, a 'stop' instruction was issued and the aircraft did so after travelling approximately 740 metres. Investigation attributed the controller error to "lost situational awareness". It also noted prior pilot and controller awareness that the runway used was closed and that the pilots had, on the basis of the take-off clearance crossed a lit red stop bar to enter the runway without explicit permission.)
  • Vehicle / B752, Dublin Ireland, 2009 (On 29 May 2009, a Boeing 757-200 being operated by UK Airline Thomson Airways on a passenger charter flight from Sharm-el-Sheikh, Egypt to Dublin and having just landed on runway 10 at destination at night in poor visibility overtook a small ride-on grass mower moving along the right hand side of the runway in approximate line with the aircraft’s right hand wing tip. The driver of the mower was unaware of the arriving aircraft until he heard it on the runway behind him. Prior to the landing, ATC had been informed that all grass-cutting equipment previously working on and around the runway had cleared it.)
  • B763, Luton UK, 2005 (On 16 February 2005, at Luton Airport, a Boeing B767-300 collided with the tug pulling it forward when the shear pin of the unserviceable tow bar being used to pull the aircraft broke. The aircraft ran onto the tug when the ground crew stopped the tug suddenly. As result of the collision with the tug the aircraft fuselage and landing gear was damaged.)
  • A320, London Heathrow UK, 2006 (On 26 June 2006, after an uneventful pre-flight pushback of a British Airways Airbus A320-200 at London Heathrow Airport, the aircraft started moving under its own power and, shortly afterwards, collided with the tractor that had just performed the pushback, damaging both the right engine and the tractor.)
  • B738, London Stansted UK, 2008 (On 13 November 2008, a Boeing 737-800 with an unserviceable APU was being operated by Ryanair on a passenger flight at night was in collision with a tug after a cross-bleed engine start procedure was initiated prior to the completion of a complex aircraft pushback in rain. As the power was increased on the No 1 engine in preparation for the No 2 engine start, the resulting increase in thrust was greater than the counter-force provided by the tug and the aircraft started to move forwards. The towbar attachment failed and subsequently the aircraft’s No 1 engine impacted the side of the tug, prior to the aircraft brakes being applied.)
  • A320, Dublin Ireland, 2017 (On 27 September 2017, an Airbus A320 being manoeuvred off the departure gate at Dublin by tug was being pulled forward when the tow bar shear pin broke and the tug driver lost control. The tug then collided with the right engine causing significant damage. The tug driver and assisting ground crew were not injured. The Investigation concluded that although the shear pin failure was not attributable to any particular cause, the relative severity of the outcome was probably increased by the wet surface, a forward slope on the ramp and fact that an engine start was in progress.)
  • E190 / Vehicle, Paris CDG France, 2014 (On 19 April 2014, an Embraer 190 collided with the tug which was attempting to begin a pull forward after departure pushback which, exceptionally for the terminal concerned, was prohibited for the gate involved. As a result, severe damage was caused to the lower fuselage. The Investigation found that the relevant instructions were properly documented but ignored when apron services requested a 'push-pull' to minimise departure delay for an adjacent aircraft. Previous similar events had occurred on the same gate and it was suspected that a lack of appreciation of the reasons why the manoeuvre used was prohibited may have been relevant.)
  • A343, Frankfurt Germany, 2008 (On 21 August 2008, an Airbus A340-300 being operated by an undisclosed operator by a German-licensed flight crew on a scheduled passenger flight from Teheran to Frankfurt collided with a stationary bus with only the driver on board whilst approaching the allocated parking gate in normal daylight visibility. The No 4 engine impacted the bus roof as shown in the photograph below reproduced from the official report. None of the occupants of either the aircraft or the bus were injured.)

Aircraft/Object Conflict

  • B722, Cotonou Benin, 2003 (On 25 December 2003, a Boeing 727-200 being operated by UTA (Guinea) on a scheduled passenger flight from Cotonou to Beirut with a planned stopover at Kufra, Libya, failed to get properly airborne in day VMC from the 2400 metre departure runway and hit a small building 2.45 metres high situated on the extended centreline 118 metres beyond the end of the runway. The right main landing gear broke off and ripped off a part of the trailing edge flaps on the right wing. The airplane then banked slightly to the right and crashed onto the beach where it broke into several pieces and ended up in the sea where the depth of water varied between three and ten metres. Of the estimated 163 occupants, 141 were killed and the remainder seriously injured.)
  • A320, Lisbon Portugal, 2015 (On 19 May 2015, an Airbus A319 crew attempted to taxi into a nose-in parking position at Lisbon despite the fact that the APIS, although switched on, was clearly malfunctioning whilst not displaying an unequivocal ‘STOP’. The aircraft continued 6 metres past the applicable apron ground marking by which time it had hit the airbridge. The marshaller in attendance to oversee the arrival did not signal the aircraft or manually select the APIS ‘STOP’ instruction. The APIS had failed to detect the dark-liveried aircraft and the non-display of a steady ‘STOP’ indication was independently attributed to a pre-existing system fault.)
  • B744, Johannesburg South Africa, 2013 (On 22 December 2013, a Boeing 747-400 taxiing for departure at Johannesburg at night with an augmented crew failed to follow its correctly-acknowledged taxi clearance and one wing hit a building resulting in substantial damage to both aircraft and building and a significant fuel leak. The aircraft occupants were all uninjured but four people in the building sustained minor injuries. The accident was attributed to crew error both in respect of an inadequate briefing and failure to monitor aircraft position using available charts and visual reference. Some minor contributory factors relating to the provision of airport lighting and signage were noted.)
  • B738, Surat India, 2014 (On 6 November 2014, a Boeing 737-800 taking off at night from Surat hit an object as it was approaching 80 knots and the take-off was immediately rejected. On return to the gate substantial damage was found to the left engine and a runway inspection found one dead buffalo and another live one. The runway was reopened after removal of the carcass but the live buffalo was not removed and was seen again by the runway the following day. The Investigation found a history of inadequate perimeter fencing and inadequate runway inspection practices at the airport.)
  • DH8D, Hubli India, 2015 (On 8 March 2015, directional control of a Bombardier DHC 8-400 which had just completed a normal approach and landing was lost and the aircraft departed the side of the runway following the collapse of both the left main and nose landing gear assemblies. The Investigation found that after being allowed to drift to the side of the runway without corrective action, the previously airworthy aircraft had hit a non-frangible edge light and the left main gear and then the nose landing gear had collapsed with a complete loss of directional control. The aircraft had then exited the side of the runway sustaining further damage.)
  • B734, Aberdeen UK, 2005 (Significant damage was caused to the tailplane and elevator of a Boeing 737-400 after the pavement beneath them broke up when take off thrust was applied for a standing start from the full length of the runway at Aberdeen. Although in this case neither outcome applied, the Investigation noted that control difficulties consequent upon such damage could lead to an overrun following a high speed rejected takeoff or to compromised flight path control airborne. Safety Recommendations on appropriate regulatory guidance for marking and construction of blast pads and on aircraft performance, rolling take offs and lead-on line marking were made.)
  • B74S, Stockholm Arlanda Sweden, 1996 (On 14 June 1996, a Boeing 747SP being operated by Air China on a scheduled passenger flight from Beijing to Stockholm was arriving on the designated parking gate at destination in normal daylight visibility when it collided with the airbridge. None of the 130 occupants of the aircraft suffered any injury but the aircraft was “substantially damaged” and the airbridge was “damaged”.)
  • B772, Singapore, 2013 (On 19 December 2013, the left engine of a Boeing 777-200 taxiing onto its assigned parking gate after arrival at Singapore ingested an empty cargo container resulting in damage to the engine which was serious enough to require its subsequent removal and replacement. The Investigation found that the aircraft docking guidance system had been in use despite the presence of the ingested container and other obstructions within the clearly marked 'equipment restraint area' of the gate involved. The corresponding ground handling procedures were found to be deficient as were those for ensuring general ramp awareness of a 'live' gate.)

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