Description

The risk of collision between aircraft and another aircraft or vehicle which is crossing an active runway may arise through various factors such as airport design, weather, operational pressures or errors by ATCOs or pilots/crews. This checklist supports the identification of the potential threats/hazards so that aircraft operators as well as pilots/crews may be in the best possible position to deal with the risk of runway-crossing-incursions. This risk is an important sub-set of the general risk of Runway Incursion.

Flight Operations Risk Assessment Checklist - Active Runway Crossing

There are various forms and templates available supporting an operational risk assessment  ranging from the use of an empty piece of paper listing and assessing possible threats/hazards up to bowtie  or FRAM-analyses or the use of a sophisticated software solution such as the Flight Operations Risk Assessment System (FORAS). Independent of the methodology used, the following list of risk-factors derived from the Global Action Plan for the Prevention of Runway Incursions (GAPPRI)  can be considered by aircraft operators and pilots/crews when performing their own risk assessment. This assessment should be carried out periodically to ensure the output is modified as circumstances change. Some of these risk factors may be similarly relevant for risk assessment of vehicle driver operation at an aerodrome. 

The risk assessment should consider resonance effects stemming from the interconnection of various risk factors. To enable this the most important advice is to incorporate frontline personnel into the risk-assessment process and to take their advice and experiences from practice seriously so that the risk assessment can reflect reality as accurately as possible.

1. Airport

1.1 Airport identification: Identify and make pilots/crews aware of airports where the ground crossing of an active runway is a possibility, or where intersecting runways or 'closely spaced' parallel runways are simultaneously active. Possible means are preparing a list of all routinely-used airports (including designated alternates) of such airports or highlighting the possibility of potential runway crossings in existing airport briefings. Keep this information under constant review and notify pilots/crews of any changes.

1.2 Event identification: Identify and review information on hotspots as well as on recent incident and accident information regarding runway crossing and incursions at those relevant airports. Consider liaising with the Local Runway Safety Team (LRST)  at those airports as well as with other operators using those airports to gather safety relevant information and possibly exchange risk assessments on runway crossings at those airports. Consider establishing two-way email contact between the Operator and the Local Runway Safety Teams (LRST) at every airport identified as having the potential for active runway crossing during taxi, or which simultaneously operates intersecting or ‘closely spaced’ parallel runways, so as to remain aware of their work and of relevant changes to procedures and facilities (see GAPPRI AO1 and AO2).

1.3 Signage and Lighting: Review and assess current airport signage and lighting available at possible runway crossings or intersections with a special focus on installation and operation of stop bars, low visibility operations (lvo), Autonomous Runway Incursion Warning Systems (ARIWS)  and Runway Status Lights (RWSL). Summarize relevant risk and associated mitigation information in an easy-to-use format for pilots/crews (e.g. include important information in airport briefings). If not already done, ensure pilots/crews are properly trained regarding the correct interpretation of ARIWS/RWSL indications (see GAPPRI AO4 and AO23).

1.4 Other Aircraft traffic: Review flight schedules on those relevant airports to determine if own flights arrive or depart during peak/hub times leading to a possible increase of runway incursion risk. Include relevant risk and mitigation information in pilots/crews airport briefings or operational flight plan applications. 

1.5 Ground vehicle traffic: Identify hotspots or routings where there is an increased likelihood of ground vehicle traffic crossing active runways possibly leading to runway incursions affecting your flight(s), e.g. due to frequently used service roads, work in progress or routine inspection routes. Consider liaising with LRST to identify times or locations of those hotspots as well as to identify possible additional threats stemming from operational pressures (time, efficiency related), poor safety cultures or lack of training and oversight which could tempt vehicle drivers to shortcut routes or procedural compliance.

1.6 Runway use and runway changes: Consider possibilities of scheduled or unscheduled runway changes requiring active runway crossings. This should also include determining standard/preferential runway use by your pilots/crews in daily practice, e.g. requests for specific departure or arrival runway depending on parking position or on preferred departure direction. Making use of available data (e.g. from FDM or Flight Replay applications) might also help to gather information on common parking positions, taxi routings and possible runway crossings, which could be disseminated to your pilots/crews (see GAPPRI AO7).

1.7 Airport design and topography: Assess if there is an increased risk for runway incursions due to airport design and/or topography. Angled taxiways, buildings or specific orography such as uneven runways or terrain nearby may make it harder for pilots/crews to oversee the final approach or relevant parts of the maneuvering area (see GAPPRI AO20).

1.8 Land and Hold Short Operations (LAHSO): Check in your operations manuals whether LAHSO clearances are to be accepted by day, or H24, or not at all. Even if such clearances are not to be accepted, it will still be necessary to establish those airports/runways which use this system so that crews can be made aware of the prospect of getting take off or taxi clearances which may be based upon a LAHSO clearance accepted by other aircraft.

2. Air Traffic Control

2.1 Specific ATC Procedures: Review Aeronautical Information Publication (AIP) of the identified airports for ATC-specific procedures regarding runway crossing and highlight relevant information in pilot/crew airport briefings.

2.2 ATC quality: Question your pilots/crews, other aircraft operators or the LRST of that airport for their experience with that airport regarding ATC-related risk factors such as  single frequency-operation, use of non-English language, use of angled taxiways for runway crossings, non-availability of A-SMGCS, a tendency of ATCOs for issuing complex, early, conditional or challenging clearances or frequently using minimum separation only thereby putting time pressure on pilots/crews, e.g. during runway crossing or for immediate departures. Consider liaising with the LRST to address those risk factors and possible mitigations in advance before operating to that aerodrome.

3. Pilot/Crew

3.1 TEM-Briefings: Check if your briefing policies are Threat and Error Management (TEM)-based and specifically contain a requirement that enable your pilots/crews to identify and brief active runways which may be crossed during taxiing for departure, or after landing, or during take off or landing. Check if these policies also include discussion and application of possible runway incursion risk factors and associated mitigation strategies (see GAPPRI AO8). Additionally, your briefing-SOP or TEM-chart (whichever is applicable) should contain at least the following items regarding active runway crossing:

• The requirement to ascertain any taxiing hotspots and airfield WIP (Work in Progress) and consider its effects on intended and potential own and other aircraft or ground vehicle movement,
• The requirement to highlight, discuss and mitigate the existence and probable use of angled taxiways possibly limiting pilots/crews lookout for other traffic during runway crossing (see GAPPRI AO20)
• The requirement to confirm, if feasible, the existence and operation of illuminated stop bars at all relevant runway entry points by use of up-to-date charts, relevant NOTAM or airport briefing sheets (see GAPPRI AO7)
• The requirement to brief specifics regarding taxiway and runway holding positions, e.g. regarding the existence of ARIWS/RWSL, the application of LAHSO or special considerations during reduced or low visibility operation (LVO) such as differing holding positions.
• The requirement to highlight and discuss the threat of receiving conditional clearance for runway crossing (see GAAPRI AO28).

3.2 SOPs: Check if your operations manuals contain at least the following SOP regarding active runway crossing:

• The requirement that all pilots within a crew always positively and continuously monitor aircraft position, especially during reduced or low visibility operation.
• The requirement that pilots/crews monitor ATC throughout the taxi phase, especially for possible conflicts. Any doubts must be resolved immediately (see GAPRRI AO24)
• The requirement to record/verbalize a received clearance to ensure shared understanding among pilots/crew of the cleared taxi-route and clearance limit (see GAPPRI AO13)
• The requirement that aerodrome charts must always be displayed on the flight deck during taxi (see GAPPRI AO10)
• The application of the Sterile Flight deck policy during ground operation, too. (AO11)
• The requirement that, if at least one pilot is in doubt of their position on the aerodrome surface, the aircraft must be stopped immediately, and ATC must be contacted (see GAPPRI AO12)
• Pilot monitoring (PM) responsibility for monitoring and confirming aircraft ground position at all times and immediately alerting the pilot flying (PF) of any uncertainties and, if necessary, effectively intervene (see GAPPRI AO14/16)
• The requirement to receive an explicit clearance to cross a runway, regardless of runway status (active/inactive) (see GAPPRI AO24). The SOP should include a means (memory aid) for the PF and PM to visually indicate, crosscheck and verify receipt of any ATC clearance to cross a runway (see GAPPRI AO25).
• The requirement not to cross illuminated stop bars in any case and to challenge ATC even if a crossing clearance was received (see GAPPRI AO22)
• The requirement to make optimum use of Traffic Collision and Avoidance System (TCAS) or equivalent equipment (e.g. ATSAW, ADS-B) to increase pilots/crews traffic awareness before entering or crossing a runway (see GAPPRI AO19).
• The requirement for a positive visual check (in one or both directions as appropriate) before crossing an active runway considering especially possible threats related to conditional clearances (e.g. paint mismatching aircraft callsign, low sun angels, aerodrome layout, see GAPPRI AO28).
• The requirement to make optimum use of Electronic Flight Bag (EFB) solutions to increase position and traffic awareness (e.g. use of Airport Moving Maps (AMM), highlighting expected or cleared taxi-route, verbalizing warnings issued by the relevant chart application).

3.3. Pilot/Crew Training: Check if your pilot/crew training programs cover the specific risks regarding runway crossing. Emphasis should be on pilots/crews using standard RT (see GAPPRI AO5/6), AWIRS awareness (“Red means stop”, see GAPPRI AO 23) and PM-intervention (see GAPPRI AO16). If you are operating aircraft for which it is not possible to taxi the aircraft from both pilot stations (e.g. due to restrictions by design (no tiller for the RHS-pilot) or from your operating procedures) consider specific intervention trainings, including physically taking away control or braking by the PM, ensuring pilots in the PM-role feel free to actively intervene independent of rank, age or experience.

Final Assessment and Mitigation

Working through the listed risk factors should provide you with an initial risk picture which helps you not only to better categorize the relevant airports but also to detect possible improvements necessary in your operations manuals, airport briefings or trainings. However, and irrespective of the outcome of your risk assessment it is advisable to continuously and actively include your pilots/crews as the relevant front-line staff into the risk assessment process. Operational Learning Reviews, shop talks or similar front-line focused means may help to gain valuable insights and inputs from their experience at the relevant airports and adapt the risk assessment and mitigations as necessary.

Accidents and Incidents

Further Reading

• Runway Safety - Use of Stop Bars 24H
• A Pilot's Guide to Runway Safety: Airservices Australia, 6th edition, June 2015.
• The Functional Resonance Accident Model