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Most taxiway accidents and incidents are preventable.
  
 
==Accidents and Incidents==
 
==Accidents and Incidents==

Revision as of 13:34, 30 May 2018

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

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.

Aircraft/Aircraft Conflict

  • B733 / DH8D, Fort McMurray Canada, 2014 (On 4 August 2014, a Boeing 737-300 making a day visual approach at Fort McMurray after receiving an ILS/DME clearance lined up on a recently-constructed parallel taxiway and its crew were only alerted to their error shortly before touchdown by the crew of a DHC8-400 which was taxiing along the same taxiway in the opposite direction. This resulted in a go around being commenced from 46 feet agl. The Investigation noted that both pilots had been looking out during the final stages of the approach and had ignored important SOPs including that for a mandatory go around from an unstable approach.)
  • 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.)
  • B738 / B738, Toronto Canada, 2018 (On 5 January 2018, an out of service Boeing 737-800 was pushed back at night into collision with an in-service Boeing 737-800 waiting on the taxiway for a marshaller to arrive and direct it onto the adjacent terminal gate. The first aircraft’s tail collided with the second aircraft’s right wing and a fire started. The evacuation of the second aircraft was delayed by non-availability of cabin emergency lighting. The Investigation attributed the collision to failure of the apron controller and pushback crew to follow documented procedures or take reasonable care to ensure that it was safe to begin the pushback.)
  • 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.)
  • B732, vicinity Washington National DC USA, 1982 (On 13 January 1982, an Air Florida Boeing 737-200 took off in daylight from runway 36 at Washington National in moderate snow but then stalled before hitting a bridge and vehicles and continuing into the river below after just one minute of flight killing most of the occupants and some people on the ground. The accident was attributed entirely to a combination of the actions and inactions of the crew in relation to the prevailing adverse weather conditions and, crucially, to the failure to select engine anti ice on which led to over reading of actual engine thrust.)
  • 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.)
  • 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.)

Aircraft/Vehicle Conflict

  • ATP, Jersey Channel Islands, 1998 (On 9 May 1998, a British Regional Airlines ATP was being pushed back for departure at Jersey in daylight whilst the engines were being started when an excessive engine power setting applied by the flight crew led to the failure of the towbar connection and then to one of the aircraft's carbon fibre propellers striking the tug. A non standard emergency evacuation followed. All aircraft occupants and ground crew were uninjured.)
  • 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.)
  • 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.)
  • B744, Paris CDG France, 2003 (On 18 January 2003, a Boeing 747-400F being operated by Singapore Airlines Cargo on a scheduled cargo flight from Paris CDG to Dubai taxied for departure in darkness and fog with visibility less than 100 metres in places and the right wing was in collision with a stationary and unoccupied ground de/anti icing vehicle without the awareness of either the flight crew or anybody else at the time. Significant damage occurred to the de icing vehicle and the aircraft was slightly damaged. The vehicle damage was not discovered until almost two hours later and the aircraft involved was not identified until it arrived in Dubai where the damage was observed and the authorities at Paris CDG advised.)
  • 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.)
  • Vehicle / E190 / E121, Jersey Channel Islands, 2010 (On 1 June 2010, an Airport RFFS bird scaring vehicle entered the active runway at Jersey in LVP without clearance and remained there for approximately three minutes until ATC became aware. The subsequent Investigation found that the incursion had fortuitously occurred just after an ERJ 190 had landed and had been terminated just as another aircraft had commenced a go around after failure to acquire the prescribed visual reference required to continue to a landing. The context for the failure of the vehicle driver to follow existing procedures was found to be their inadequacy and appropriate changes were implemented.)
  • 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.)
  • 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.)
  • 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.)
  • A124, Zaragoza Spain, 2010 (On 20 April 2010, the left wing of an Antonov Design Bureau An124-100 which was taxiing in to park after a night landing at Zaragoza under marshalling guidance was in collision with two successive lighting towers on the apron. Both towers and the left wingtip of the aircraft were damaged. The subsequent investigation attributed the collision to allocation of an unsuitable stand and lack of appropriate guidance markings.)
  • B738, Barcelona Spain, 2015 (On 12 December 2015, whilst a Boeing 737-800 was beginning disembarkation of passengers via an air bridge which had just been attached on arrival at Barcelona, the bridge malfunctioned, raising the aircraft nose gear approximately 2 metres off the ground. The door attached to the bridge then failed and the aircraft dropped abruptly. Prompt cabin crew intervention prevented all but two minor injuries. The Investigation found that the occurrence had been made possible by the failure to recognise new functional risks created by a programme of partial renovation being carried out on the air bridges at the Terminal involved.)
  • AT72, Shannon Ireland, 2014 (On 26 February 2014, an ATR 72-202 which had been substituted for the ATR42 which usually operated a series of night cargo flights was being marshalled out of its parking position with a new flight crew on board when the left wing was in collision with the structure of an adjacent hangar. The Investigation found that the aircraft type had not been changed on the applicable flight plan and ATC were consequently unaware that the aircraft had previously been parked in a position only approved for the use by the usual smaller aircraft type.)
  • RJ85, Helsinki Finland 2010 (On 12 June 2010, a requested 22R runway inspection at Helsinki in normal daylight visibility carried out after a severe engine failure during the take off roll had led an Avro RJ85 being operated by Finnish Airline Blue1 on a scheduled passenger flight to Copenhagen to reject that take off at high speed. This inspection had not detected significant debris deposited on the runway during the sudden and severe engine failure. Two passenger aircraft, one being operated by Finnair to Dubrovnik, Croatia and the other being operated by Swedish airline TUIfly Nordic to Rhodes, Greece then departed the same runway before a re-inspection disclosed the debris and it was removed. Neither of the aircraft which used the runway prior to debris removal were subsequently found to have suffered any damage but both were advised of the situation en route.)
  • 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.)
  • 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.)

Related Articles

Further Reading

[[Category:Ground Operations [[Category:Operational Issues