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Runway Identification

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Runway Confusion

Description

Positive Runway Identification is usually described as the unequivocal association of a runway with its correct identity prior to landing on it, prior to taxiing onto it in a fixed wing aircraft, hover taxiing over it in a rotary wing aircraft or entering it as a vehicle driver.

Discussion

Accident and incident reports show that misidentification of runways by pilots - and sometimes by vehicle drivers too - can be a significant factor in both accidents and serious incidents in which a runway collision risk was created. The unintended use or otherwise attempted use of parallel taxiways for both take off and landing has in the past been at least as common as Wrong Runway Use. In extreme cases, large aircraft on public transport flights have been landed on runways that are not even at the right airport. Runway misidentification can result in a runway incursion or a runway overrun and may lead to the use of a taxiway or an incorrect runway for take off or landing. Ultimately a collision with another aircraft, a vehicle or ground obstructions can create the conditions for a fatal accident.

The Take Off Case

A typical take off case involves a departing aircraft lining up on a parallel taxiway after being cleared to do so on the adjacent runway. There are also cases of aircraft lining up on the runway edge lights in the mistaken belief that they were runway centreline lights and, since this error can be difficult for ATC to detect, then making a take off on this false alignment. Such errors usually occur either in restricted visibility or at night. See, for example, A332, Abu Dhabi UAE, 2012, A319, Las Vegas NV USA, 2006, AT72, Dresden Germany, 2002 and B738, Oslo Gardermoen Norway, 2005 which all occurred at night. However,the serious incident A320, Oslo Norway, 2010 occurred when a take off from the same parallel taxiway as the one involved in the 2005 incident was made in daylight in the presence of frozen deposits on the manoeuvring surfaces. Norway was somewhat unusual at that time in mandating the use of surface markings which were contrary to the ICAO Standard usually encountered. This was apparently a state-wide response to the perceived difficulties with standard white markings in the winter period when a 'back to blacktop' policy for removal of frozen deposits is frequently considered to be an impracticable objective. Modification of this policy so that the main international airports (only) in Norway are ICAO-compliant has since been re-considered.

Less often, and usually in the presence of complex airport layouts, a runway parallel or nearly parallel to that authorised is inadvertently used for take off - see for example B732, Seattle WA USA, 2006. If a wrong runway is involved and it is closed or partially closed for Runway Maintenance, then the eventual outcome, if the line up error is undetected, can be a collision with obstructions - see for example B744, Taipei Taiwan, 2000. More often, a take off from a parallel taxiway is (just) successful, albeit with considerably reduced margins of safety which leave no margin for unexpected occurrences during the take off roll - see for example A343, Hong Kong China, 2010 and A343, Anchorage AK USA, 2002.

The Landing Case

The most typical landing case involves a landing on a taxiway parallel to the correct runway, by day or by night. See for example B734, Palembang Indonesia, 2008, B732, London Gatwick UK, 1993 and B739, Akita Japan, 2007. Less often another runway at the same airport is inadvertently used; even less often, an approach - and sometimes even a landing - is made to runway with a similar orientation in the vicinity of the extended centerline of the correct runway, but at a different airport, is used, see for example B733, vicinity Belfast Aldergrove UK, 2006. A few cases where aircraft landed on a runway at the wrong airport have occurred, see for example A320, Ballykelly Northern Ireland UK, 2006.

The Common Feature

Almost all occurrences where the correct runway was not positively identified have been because of complacency in visual acquisition. Such a failure most frequently occurs when a paved surface near to the correct with the same or a similar orientation is selected. However, an exception is the fatal accident which resulted from the use of an incorrect runway for take off in 2006, see CRJ1, Lexington KY USA, 2006.

In most departure cases and almost all landing cases, visual reference is not restricted and there is simply a complete absence of any attempt at positive runway identification. Most documented occurrences have involved multi-crew aircraft, which indicates an additional failure of the effectiveness of cross monitoring by the pilot designated as PM. Incidents involving operations in restricted forward visibility occasionally feature in the take off case, but it appears that the more rigorous procedures and heightened flight crew awareness of the scope for inadvertent error which apply in these circumstanced are generally an effective mitigation against increased risk.

Defences

  • Pre flight briefing should include a review of airport layouts with which one or both pilots are not wholly familiar with.
  • Flight Crew and vehicle drivers should ensure that they maintain progressive position awareness whilst undertaking ground movement. For aircraft taking off, a check for the correct take off position by alignment alone cannot provide assurance that the aircraft is on the correct runway (although of course a check against the correct ILS LLZ display - can).
  • Flight crew should at all times ensure that the cross monitoring by the pilot designated as PM of the actions of the PF is effective, both in respect of detection and response. Similar vigilance and where necessary response should be exercised by supernumerary crew members occupying flight deck seats for take off and landing.
  • If a straight-in precision approach is expected to be flown to or near to DA before the required viusual reference for a landing is obtained, then an extra check that any radio aid frequency being used is tuned and identified as corresponding to that for the correct runway.
  • If an offset ILS, any non precision approach (NPA), a circling approach or an entirely visual approach is being flown, the approach briefing should include discussion of how positive runway identification will be accomplished.
  • Runway Lighting is coloured completely differently to Taxiway Lighting and should provide a normally alert flight crew with an opportunity to distinguish one from the other.
  • Since runway edge lighting is spaced differently to any runway centreline lighting, line up with reference to the edge lighting should be avoidable.
  • If ATC have surface movement radar or more sophisticated equipment to track aircraft ground movements, this can prevent an error in runway identification from having a serious consequence. If time permits or if there is are any indications of position uncertainty in respect of a particular aircraft, especially in restricted forward visibility conditions, then active aircraft ground position monitoring is especially valuable prior to the issue of a take off clearance. A-SMGCS can additionally provide a range of alerts where an aircraft fails to follow its issued clearance or it has been given an inappropriate ATC clearance.
  • The addition of RAAS functionality to ‘standard’ TAWS provides a direct means of confirming that runway identification is correct.

Accidents and Incidents

SKYbrary contains reports on the following events that the use of the wrong active runway:

  • A320, Ballykelly Northern Ireland UK, 2006 (On 29 March 2006, an Eirjet Airbus 320 was operating a scheduled passenger flight from Liverpool to Londonderry Airport in Northern Ireland for Ryanair in daylight. At 8nm from LDY, the operating crew reported that they were having problems with the ILS glideslope on approach to Runway 26. They judged that they were too high to carry out a safe landing from the ILS approach and requested permission from ATC to carry out a visual approach. The aircraft, with the commander as PF, then flew a right hand descending orbit followed by a visual circuit from which it landed. Upon landing, the crew were advised by Londonderry ATC, who had had the aircraft in sight when it called Finals and had then cleared it to land that they had, in fact, landed at Ballykelly airfield, a military helicopter base 5nm to the east-north-east of Londonderry.)

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