Network Maager omiated by the Europea Commissio EUROCONTROL Operatioal Safety Study: Ladig without ATC clearace Editio 1.0 Editio date: 20/05/2014 Status: Released Issue Iteded for: Geeral Public
DOCUMENT APPROVAL The followig table idetifies all maagemet authorities who have successively approved the preset issue of this documets. Authority Name ad sigature Date Operatioal Safety Coordiator, DNM/NOM/SAF Mr. Tzetomir Blajev 19/05/2014 Head of Safety Uit, DNM, NOM Mr. Atoio Licu 19/05/2014 Head of Network Operatios Maagemet Divisio Mrs. Nicola Cooper 20/05/2014 Director NM Mr. Joe Sultaa 20/05/2014 Operatioal Safety Study Ladig without ATC clearace Editio 1.0 3
DOCUMENT CHANGE RECORD The followig table records the complete history of the successive editios of the preset documet. Editio Number Editio Date Reaso for chage Pages affected 0.1 29/07/2013 Creatio of the Workig Draft All 0.2 07/08/2013 Iteral Review All 0.3 22/08/2013 Iteral Review All 0.4 28/08/2013 Iteral Review All 0.5 05.09/2013 Iteral Review All 0.6 19.09/2013 Iteral Review All 0.7 19.05.2014 Iteral Review All TIT
TABLE OF CONTENTS DOCUMENT APPROVAL 3 DOCUMENT CHANGE RECORD 4 EXECUTIVE SUMMARY 7 CHAPTER 1 - INTRODUCTION 8 1.1 What is the purpose of this documet? 8 1.2 What are the Network Maager Top 5 ATM Operatioal Safety Priorities for 2013 ad 2014? 8 1.3 How did we idetify the Top 5? 9 CHAPTER 2 - THE GENERIC PROCESS: OVERVIEW 10 CHAPTER 3 - GENERIC SCENARIOS 11 3.1 How should geeric operatioal scearios be defied? 12 3.2 Aalytical decostructio of operatioal scearios 12 3.3 Examples of actual ladig without clearace evets 14 CHAPTER 4 - BARRIERS 16 4.1 Barriers as opportuities i some situatios 17 4.2 Two types of barriers 17 4.3 Barriers which may prevet ladig without clearace 18 4.4 Barriers which may mitigate the cosequeces of ladig without clearace 19 CHAPTER 5 - OPERATIONAL CONTEXT 20 5.1 Differet operatioal cotext 21 5.2 Radar coverage 21 5.3 Meteorological coditios 21 5.4 Ruway status 21 5.5 Clearace coditios 21 5.6 Visual surveillace capability from the TWR 22 CHAPTER 6 - ANALYSIS 23 6.1 Aalysis of Prevetio Barriers 24 6.2 Aalysis of Mitigatio Barriers 29 6.3 Prevetio Barrier Matrix 33 6.4 Top 4 Potetial Prevetio Barriers 34 6.5 Mitigatio Barrier Matrix 35 6.6 Top 4 Potetial Mitigatio Barriers 36 CHAPTER 7 - OTHER STUDIES 37 CHAPTER 8 - CONCLUSIONS AND RECOMMENDATIONS 39 APPENDIX A - SAFETY NETS 42 APPENDIX B - REFERENCES 49 Operatioal Safety Study Ladig without ATC clearace Editio 1.0 5
EXECUTIVE SUMMARY The EUROCONTROL Safety Improvemet Sub-Group (SISG), reportig to the EUROCONTROL Safety Team, was tasked to idetify the Top 5 ATM Operatioal Safety Priorities. SISG performed a review durig summer 2012 ad ivolved a series of dedicated workshops with 6 ANSPs, represetig a large part of Europea air traffic. Comprehesive barrier models - Safety Fuctios Maps (SAFMAPs) - were developed ad populated with represetative data from the participatig ANSPs. The icidet data is for high severity (classified as A ad B ) evets, which are o oe side thoroughly ivestigated ad o the other side - highly iformative because the icidet scearios test the majority of the available safety barriers. As a result of the SAFMAP aalysis the Top 5 priority areas were suggested, agreed by SISG ad edorsed by the Safety Team: Risk of operatio without traspoder or with a dysfuctioal oe Ladig without ATC clearace Detectio of occupied ruway Blid spot iefficiet coflict detectio with the closest aircraft Coflict detectio with adjacet sectors This purpose of this report is twofold: To documet the operatioal safety study o oe of the Top 5 Network Maager operatioal safety priorities for 2013 - Ladig without ATC clearace. To serve as a referece for the Network actors i case they udertake operatioal safety aalysis ad improvemet activities for ladig without clearace. The priorities were reviewed by SISG with SAFMAP aalysis of the data for year 2013 ad re-cofirmed as Top 5 priorities for 2014. The methodology employed was as follows: Geerate a set of geeric scearios that could result i a Ladig without Clearace. Cosider what barriers exist that if implemeted ad deployed could prevet a Ladig without Clearace. Cosider what barriers exist that if implemeted ad deployed could mitigate the result of a Ladig without Clearace. Aalysis each geeric sceario agaist the potetial barriers to establish which of these barriers could be effective over the whole rage of scearios. Review a set of actual evets to cofirm that the barriers suggested by the geeric aalysis to validate that the same barriers should be the most effective i the live eviromet. Review other published study data ad coclusios to check upo covergece ad source ew iformatio ad ideas. This report has foud a very high correlatio betwee the geeric aalysis ad the review of real evets. Other studies have provided valuable cofirmatory evidece. The Coclusios detail the Top 4 potetial prevetio barriers ad the Top 4 mitigatio barriers. Combiatios of these barriers will provide eve greater safety gai. There is also evidece that a combiatio of prevetio barriers could be developed as set together. This may iclude low cost techical developmets. Recommedatios are made to Stakeholders, icludig Airport Authorities, Air NavigatioService Providers, Aircraft Operators, Aircraft Maufacturers, Groud Service Operators, Pilots, ATCOs ad vehicle drivers. Most of the recommedatios require represetatives of all parties to work together to obtai the safety beefits that are available. Operatioal Safety Study Ladig without ATC clearace Editio 1.0 7
CHAPTER 1 - INTRODUCTION 1.1 What is the purpose of this documet? This purpose of this report is twofold: To documet the operatioal safety study o oe of the Top 5 Network Maager operatioal safety priorities for 2013 ad 2014 - Ladig without ATC clearace. To serve as a referece for the Network actors i case they udertake operatioal safety aalysis ad improvemet activities for ladig without clearace. 1.2 What are the Network Maager Top 5 ATM Operatioal Safety Priorities for 2013 ad 2014? Risk of operatio without traspoder or with a dysfuctioal oe Ladig without ATC clearace Detectio of occupied ruway Blid spot - iefficiet coflict detectio with the closest aircraft Coflict detectio with adjacet sectors Operatios without traspoder or with a dysfuctioal oe costitute a sigle threat with a potetial of passig through all the existig safety barriers up to see ad avoid. For various reasos, aircraft sometimes lad without ATC clearace resultig i Ruway Icursios that are ofte oly resolved by providece. Some Ruway Icursio icidets could have bee preveted if cotrollers had had better meas to detect that the ruway was occupied at the time of issuig clearace to the ext aircraft to use the ruway. Loss of separatio Blid Spot evets are typically characterised by the cotroller ot detectig a coflict with the closest aircraft. They usually occur after a descet clearace ad i the cotext of a rapidly developig situatio - ofte whe the coflictig aircraft are 1000ft ad 15 m apart. Losses of Separatio i the E-Route eviromet sometimes ivolve iadequate coordiatio of clearace with a adjacet sector. These typically ivolve either a early (premature) trasfer of cotrol to or from the eighbourig sector. 8
1.3 How did we idetify the Top 5? The Network Maager idetifies Network safety issues to eable aviatio stakeholders to mitigate existig hazards ad aticipate ew operatioal risks The first step was to defie broad priority areas for further prioritisatio Our ultimate goal is to keep the Network safe ad able to icrease its capacity ad efficiecy. The EUROCONTROL Safety Improvemet Sub-Group (SISG), reportig to the EUROCONTROL Safety Team, was tasked to idetify the Top 5 ATM Operatioal Safety Priorities. I 2012, the SISG followed a structured two-step process of operatioal safety prioritisatio. Firstly SISG idetified a list of priority areas. The agreed list cotais work priority areas addressig operatioal threats, safety precursors or udesired safety outcomes. The list icludes: Airspace Ifrigemet Ruway Icursio Loss of Separatio ATC sector overloads Level Bust Severe Weather Risk Air Groud commuicatios Ruway Excursio The list of agreed priority areas cotais issues that are too broad to be a part of a focussed work program. There was a eed to get more graularity ad select some of the areas for a detailed review. Based o the availability of reliable safety iformatio, two of the risk areas were selected for detailed review: The secod step was a detailed review with SAFMAPS. The priorities were re-cofirmed for 2014 Ruway Icursio ad Loss of Separatio E-Route. The review was performed durig summer 2012 ad ivolved a series of dedicated workshops with 6 ANSPs, represetig a large part of Europea air traffic. Comprehesive barrier models Safety Fuctios Maps (SAFMAPs) - were developed ad populated with represetative data from the participatig ANSPs. The icidet data is for high severity (classified as A ad B ) evets, which are o oe side thoroughly ivestigated ad o the other side highly iformative because the icidet scearios test the majority of the available safety barriers. As a result of the SAFMAP aalysis the Top 5 priority areas were suggested, agreed by SISG ad edorsed by the Safety Team: Risk of operatio without traspoder or with a dysfuctioal oe Ladig without ATC clearace Detectio of occupied ruway Blid spot iefficiet coflict detectio with the closest aircraft Coflict detectio with adjacet sectors The priorities were reviewed by SISG usig the same approach of aalysig the high severity icidet with SAFMAPs. As a result SISG re-cofirmed the Top 5 priorities for 2014. Operatioal Safety Study Ladig without ATC clearace Editio 1.0 9
CHAPTER 2 - THE GENERIC PROCESS: OVERVIEW The figure below provides a overview of the geeric steps i the Operatioal Safety Study BARRIERS SCENARIOS ANALYSIS CONCLUSIONS OPERATIONAL CONTEXT 10
CHAPTER 3 - GENERIC SCENARIOS BARRIERS. Loss of commuicatio. RWY cofusio. Commuicatio misuderstadig. Assumig clearace. Deliberate SCENARIOS ANALYSIS CONCLUSIONS OPERATIONAL CONTEXT Operatioal Safety Study Ladig without ATC clearace Editio 1.0 11
3.1 How should geeric operatioal scearios be defied? Combiatio of top-dow ad bottom-up approaches Geeric operatioal scearios are used to help reduce the complexity of the subsequet aalysis. Sceario defiitio is by story tellig, specific to help assess the effectiveess of the proposed safety barriers ad geeric eough to keep their umber relatively small. The scearios draw upo two sources of iformatio: A systematic aalytical de-costructio of each operatioal sceario ito sub-scearios. This is based o all theoretically possible combiatios of sceario (1) sources, (2) mechaisms ad (3) outcomes. A review of the publicly available iformatio from ivestigatio reports of accidets ad serious icidets ivestigated followig the provisios of ICAO Aex 13 ad cofidetially provided data i respect of less sigificat icidets. 3.2 Aalytical decostructio of operatioal scearios The followig reasos for ladig without clearace were idetified: Sceario Sources A. Loss of commuicatio B. Ruway cofusio C. Commuicatios misuderstadig D. Absece of clearace overlooked by the pilot(s) E. Deliberate The mechaisms as a sceario elemet describe the flight after the sceario sources occurred. I the case of Ladig without clearace it ca happe durig the fial phases of the flight: Sceario Sources Durig Fial approach Durig Ladig Durig go-aroud The review of the sceario mechaisms revealed that they are ot providig ay importat differetiatio of the scearios i terms of risk ad are therefore irrelevat for this operatioal study. The sceario mechaisms were ot retaied further. 2a 3a 3b 1 3c 3d 1. Uoccupied RWY ad o clearace give 2. Uoccupied but a clearace has bee give 3. Occupied RWY 2b. Loss of commuicatio. RWY cofusio. Commuicatio misuderstadig. Absece of clearace overlooked. Deliberate Figure 1: Ladig without clearace scearios 12
The traffic situatio related to the ruway at which a ladig without clearace potetially occurs is illustrated o the figure above ad ca be described by oe of the optios: Sceario Outcome The resultig list of geeric operatioal scearios for aalysis 1. Ruway uoccupied ad o other clearace for its use has bee give 2. Ruway uoccupied ad aother clearace for its use has bee give: a. To cross (aeroplae or vehicle) b. To eter (Aeroplae lie-up or vehicle) 3. Ruway occupied by: a. A previously laded aeroplae b. A aeroplae o take-off roll c. A aeroplae which has rejected its take-off or is doig so d. A vehicle e. A aeroplae lied up for departure A1 Ladig without clearace after loss of commuicatio o a uoccupied ruway whe o other clearace for the ruway has bee give. A2 Ladig without clearace after loss of commuicatio o a uoccupied ruway whe aother clearace for the ruway has bee give. A3 Ladig without clearace after loss of commuicatio o a occupied ruway. B1 Ladig without clearace after ruway cofusio o a uoccupied ruway whe o other clearace for the ruway has bee give. B2 Ladig without clearace after ruway cofusio o a uoccupied ruway whe aother clearace for the ruway has bee give. B3 Ladig without clearace after ruway cofusio o a occupied ruway. C1 Ladig without clearace after commuicatio misuderstadig o a uoccupied ruway whe o other clearace for the ruway has bee give. C2 Ladig without clearace after commuicatio misuderstadig o a uoccupied ruway whe aother clearace for the ruway has bee give. C3 Ladig without clearace after commuicatio misuderstadig o a occupied ruway. D1 Ladig without clearace after the absece of clearace was overlooked o a uoccupied ruway whe o other clearace for the ruway has bee give. D2 Ladig without clearace the absece of clearace was overlooked o a uoccupied ruway whe aother clearace for the ruway has bee give. D3 Ladig without clearace the absece of clearace was overlooked o a occupied ruway. E1 Deliberate ladig without clearace o a uoccupied ruway whe o other clearace for the ruway has bee give. E2 Deliberate ladig without clearace o a uoccupied ruway whe aother clearace for the ruway has bee give. E3 Deliberate ladig without clearace o a occupied ruway. Operatioal Safety Study Ladig without ATC clearace Editio 1.0 13
3.3 Examples of actual ladig without clearace evets Ladig without clearace after loss of commuicatio Ladig without clearace after ruway cofusio Ladig after commuicatio misuderstadig The Private Pilot flyig a sigle egie light aircraft mistued the TWR frequecy whilst strugglig to fly a o-precisio approach i IMC ad assumed that the subsequet lack of cotact was the result of radio failure. The approach was cotiued util the ruway was acquired visually ad a ladig over the top of a apparetly usee twi turbo-prop lied up for departure occurred. A VFR light aircraft o a local flight retured to the airfield havig lost commuicatio. ATC was uaware util the aircraft overflew the ruway wagglig its wigs after which it completed a circuit ad laded. At a airport with two parallel ruways, the oe usually used for ladig havig bee closed for the previous three moths for major maiteace with NOTAM actio i place, a arrivig regioal jet crew makig a visual approach i excellet visibility ad light surface wids asked to use 01R rather tha i the reciprocal i-use directio 19L ad was cleared to lad accordigly with a correct readback. Neither the pilots or the cotroller realised that the aeroplae subsequetly laded o the closed 01L util it had doe so. There were o fixed obstacles o the ruway but the required closed ruway markigs were preset. The crew stated that they had ot oticed these ad attributed their error to eterig the wrog ruway i their FMS. With two aerodromes 3 miles apart, fast jet VFR traffic with a ladig clearace at oe, a military base, uexpectedly tured fials ad laded at the other, a large commercial airport. ATC at the commercial airport observed the error whe the aircraft appeared o fial approach ad esured that the ruway was clear for the potetial ladig. ATC advised the pilot of a xxxx to expect late ladig clearace ad received the read back ladig clearace with the abbreviatio goig uchalleged. The pilot believed that he was cleared to lad ad did so. ATC istructed a pilot of a xxxx to cotiue the approach whe at a rage from touchdow of xxxx. There was o further commuicatio ad the pilot, believig that he must have received a ladig clearace, cotiued to a ladig. ATC were distracted by a operatioal phoe call. 14
Ladig without clearace after the absece of clearace was overlooked Deliberate ladig without clearace The pilot of a xxxx was asked whe the aeroplae was at 10 m fial to cotiue the approach ad call back at 4m fial for ladig clearace. The aeroplae cotiued ad laded without clearace just after a ispectio vehicle had cleared the ruway. The pilot of a xxxx asked whe the aeroplae was o fial approach to reduce speed ad chage to the frequecy of TWR. There was o read back of the frequecy ad at 1 m the pilot asked APP if there was a clearace to lad. The pilot of a xxxx did ot chage the frequecy to TWR after readig back the istructio to do so. The TWR cotroller did ot try to call the aircraft util after it had laded ad observed that he had t bee aware of the aircraft ivolved because of a busy situatio with other traffic. After the first cotact with the TWR the crew of a xxxxx was istructed to cotiue approach ad to expect to be called back. After ladig without clearace, the crew commeted that ladig clearaces at this airport are a problem because they are ofte give a log way out whe there are 2/3 precedig aeroplaes so that the absece of the promised call back with clearace was easily missed whe it is rare to issue ladig clearaces o short fial. The pilot of a xxxx was chaged frequecy to TWR but remaied o the APP frequecy laded ad asked for a taxi route. TWR did t otice that it was t o frequecy ad observed that APP is permitted to keep aeroplaes o its frequecy ad issue a ladig clearace. A xxxxx cotacted TWR while it was No 2 i the approach sequece ad was istructed to reduce to miimum approach speed ad cotiue. The TWR cotroller the forgot about the aeroplae. It was oted that the cotroller had marked the correspodig strip at the time of the first cotact with the aeroplae as if it had already bee cleared to lad. A xxxx was give a speed reductio, wid iformatio ad a istructio to cotiue the approach. The cotroller the forgot the lack of clearace ad the frequecy was so busy that the crew was uable to trasmit. They cotiued the approach ad laded without clearace. A light aeroplae lost positioal awareess, saw what was cosidered to be a coveiet airport ad proceeded to joi the circuit ad complete a approach ad ladig without radio cotact. The TWR cotroller saw the aeroplae whe it was dowwid ad istructed aother aeroplae makig a approach i the opposite Operatioal Safety Study Ladig without ATC clearace Editio 1.0 15
CHAPTER 4 - BARRIERS. Prevetig Ladig without clearace. Mitigatig the effects of ladig without clearace BARRIERS SCENARIOS ANALYSIS CONCLUSIONS OPERATIONAL CONTEXT 16
4.1 Barriers as opportuities i some situatios Opportuity versus resposibility The Barriers icluded i this risk aalysis have bee idetified as possible ways that Ladig without Clearace could be preveted or the cosequeces mitigated. Their iclusio does ot imply that they relevat to all situatios ad either does it imply that their adoptio by aircraft operators or ANSPs as a group would ecessarily be appropriate. It may be possible to idetify more potetially useful barriers tha are icluded here. 4.2 Two types of barriers A barrier model I order to defie the barrier there is a eed first to defie the geeric barrier groups for reducig the risk of ladig without clearace evets. The figure below represets a geeralised SAFMAP for Ladig without clearace. This geeralised SAFMAP is derived from the Level 0 Ruway Collisio SAFMAP ad is the most geeric barrier model for prevetig ruway collisio because of situatios of ladig without clearace. Providece Ruway coflict uresolved by ATC ad pilot/driver MITIGATION BARRIERS Pilot/Driver RWY Coflict Resolutio Ruway coflict uresolved by ATC ATC RWY Coflict Resolutio Ruway coflict Prevetig ladig without clearace to tur ito RWY coflict Ruway icursio PREVENTION BARRIERS ATC RWY Coflict Resolutio Figure 2: Geeralised SAFMAP for Ladig without clearace Operatioal Safety Study Ladig without ATC clearace Editio 1.0 17
There are two sets of barriers which ca reduce the risk associated with ladig without clearace. These barriers are foud i both aircraft operatio ad air traffic cotrol ad have bee idetified from both a wide literature search ad from cosultatio. These are: Balacig prevetig ad mitigatig the risk associated with ladig without clearace Barriers to prevet the occurrece of ladig without clearace. These barriers are specific for the ladig without clearace type of ruway icursio. Barriers to mitigate the cosequeces of ladig without clearace. These barriers are geeral to ruway collisio avoidace, but their effectiveess for ladig without clearace scearios is explicitly reviewed i Chapter 6 of this report. 4.3 Barriers which may prevet ladig without clearace Barriers prevetig ladig without clearace PB1 Trigger for pilots to check ladig clearace - SOP to select the ladig/taxi lights o oly whe clearace to lad is received. PB2 Trigger for pilots to check ladig clearace iclusio of a item i the ladig check-list. PB3 Trigger for pilots to check ladig clearace - SOP to do so at a existig fixed poit i a approach such as at a height-defied stabilisatio gate. PB4 Esure that pilots ca revert to the previous radio frequecy by itroducig a SOP which requires that two way cotact be established o each ew frequecy before the pre-select frequecy is chaged from the previous frequecy to a aticipated subsequet oe. PB5 The provisio of a automatic alert to the pilot whe a ruway is occupied such as the visual alertig provided by the Fial Approach Ruway Occupacy Sigal (FAROS) system (see Appedix). PB6 Robust procedures to esure that the correct ruway ad/or ruway approach procedure are etered ito aircraft o-board systems that require this ad that the correct approach procedure is displayed to both pilots. PB7 Pilot positive visual idetificatio of the correct ruway except i Cat 2/3 coditios. PB8 Sigs ad markigs to clearly idicate closed ruway. PB9 Other meas for cotrollers to alert pilot to the absece (or existece) of a ladig clearace such as the availability of a selectable visual alert illumiated close to touchdow. PB10 The availability of a effective cotroller memory aid to auciate whether ladig clearaces have bee issued or ot. PB11 System supported ATCO detectio of aircraft about to lad without clearace or o the wrog ruway with oe, for example, ASMGCS ad RIMCAS (see Appedix). PB12 Cotroller visual detectio of a aircraft about to lad without clearace. PB13 Cotroller visual detectio of a aircraft about to lad o a ruway other tha the oe for which clearace has bee give. PB14 A specific go-aroud policy i case of pilot awareess of o ladig clearace which is effectively moitored for compliace. 18
4.4 Barriers which may mitigate the cosequeces of ladig without clearace Barriers mitigatig the effects of ladig without clearace MB1 Cotroller prevets coflict after detectig the risk of it visually before, durig or after the issue of a potetially coflictig ruway access clearace ad before eterig the ruway. MB2 Cotroller prevets coflict after detectig it with system support before, durig or after the issue of a potetially coflictig ruway access clearace ad before eterig the ruway. MB3 Flight crew/vehicle driver prevet coflict after detectig the risk of it from radio traffic or visual moitorig before, durig or after receivig a ruway access clearace ad before eterig the ruway. MB4 Flight crew/vehicle driver prevet coflict after detectig the risk of it with system support such as the RWSL system compoets Ruway Etrace Lights (REL) s ad Take-off Hold Lights (THLs) before or after receivig a ruway access or movemet clearace ad before eterig the ruway (see Appedix). MB5 Cotroller ruway coflict resolutio after detectig the risk visually. MB6 Cotroller ruway coflict resolutio after detectig the risk with the help of surveillace systems. MB7 Cotroller ruway coflict resolutio after detectio the risk by a safety et alert such as RIMCAS. MB8 Flight crew/vehicle driver ruway coflict resolutio after detectig the risk visually. MB9 Flight crew/vehicle driver ruway coflict resolutio after detectig the risk based o R/T traffic moitorig. MB10 Flight crew/vehicle driver ruway coflict resolutio after detectig the risk with system support. Operatioal Safety Study Ladig without ATC clearace Editio 1.0 19
CHAPTER 5 - OPERATIONAL CONTEXT BARRIERS SCENARIOS ANALYSIS CONCLUSIONS OPERATIONAL CONTEXT. Approach guided/ot guided by radar VMC/IMC RWY: Active, Iactive, Closed Ladig clearace coditios Lie of sight 20
5.1 Differet operatioal cotext The local operatioal cotext with relevace for the preset study are idetified as follows: The operatioal cotext that may affect the efficiecy of barriers Availability of radar guidace for the approach Meteorological coditios ad time of the day Ruway status Clearace coditios Visual surveillace capability from the Tower 5.2 Radar coverage The level of ATC radar coverage may differ Radar guided approaches affect likelihood for detectig a aircraft boud for ladig ad the existig situatio of loss of commuicatio whe the traspoder Mode A is set to squawk 7600. 5.3 Meteorological coditios The i-flight visibility ad time of the day be such as to allow pilots to: Possibility of detectig potetial threats i good time Recogise potetial threats i good time. Prevet the recogitio of potetial threats i good time. The surface visibility/cloud base ad time of the day be such as to allow cotroller: Recogise potetial threats i good time. Prevet the recogitio of potetial threats i good time. 5.4 Ruway status Ruways ca be i use or ot for traffic purposes ad there may or may ot be obstructios The ruway status that ca ifluece the efficiecy of barriers for the differet scearios are: Active Ruway Iactive Ruway Closed Ruway 5.5 Clearace coditios Variatio i local procedures ad practices for deliverig a ladig clearace The way ladig clearace is delivered at differet airports may vary, icludig whether or ot: Multiple ladig clearaces are used. Coditioal ladig clearaces are issued. There are specified miimum distaces from the ruway threshold (or laded/departig traffic) by which a ladig clearace must be issued. Operatioal Safety Study Ladig without ATC clearace Editio 1.0 21
5.6 Visual surveillace capability from the TWR Physical visibility The view (direct or usig CCTV) of the relevat part of the aerodrome ad its viciity from The ATC Tower may be restricted by: The locatio, height, desig, equipmet of the tower. The airport layout or obstructios The temporary presece of aircraft or vehicles. 22
CHAPTER 5 - ANALYSIS BARRIERS SCENARIOS ANALYSIS CONCLUSIONS OPERATIONAL CONTEXT Operatioal Safety Study Ladig without ATC clearace Editio 1.0 23
6.1 Aalysis of Prevetio Barriers Table 1: Aalysis of Prevetio Barrier Efficiecy PB1-PB7 1 PREVENTION BARRIERS: OPERATIONAL SCENARIOS: PB1: SOP for turig the ladig/taxi lights o whe clearace to lad is received. PB2: A item i the ladig checklist to check. PB3: SOP for a check call at a give approach poit/height. PB4: Pilot SOP to revert to the previous sector frequecy PB5: Automatic alert to the pilot for occupied ruway. PB6: Pilot procedures: correct ruway i the systems ad correct approach charts. PB7: Pilot visual idetificatio of the correct RWY. A1: LwC after loss of comm/o a uoccupied ruway whe o other clearace for the ruway has bee give. The barrier ca support prevetio of cases iitiated by mistuig the radio chael if recogised. A2: LwC without clearace after loss of comm/o a uoccupied ruway whe aother clearace for the ruway has bee give. The barrier ca support prevetio of cases iitiated by mistuig the radio chael if recogised. A3: LwC after loss of comm. o a occupied ruway. The barrier ca support prevetio of cases iitiated by mistuig the radio chael if recogised. B1: LwC after ruway cofusio o a uoccupied ruway whe o other clearace for the ruway has bee give. B2: LwC after ruway cofusio o a uoccupied ruway whe aother clearace for the ruway has bee give. B3: LwC after ruway cofusio o a occupied ruway. The barrier ca support prevetio of cases where the ruway is correctly idetified but there is cofusio about the clearace received. The barrier ca support prevetio of cases where the ruway is correctly idetified but there is cofusio about the clearace received. The barrier ca support prevetio of cases where the ruway is correctly idetified but there is cofusio about the clearace received. The barrier ca support prevetio of cases where the ruway is correctly idetified but there is cofusio about the clearace received. The barrier ca support prevetio of cases where the ruway is correctly idetified but there is cofusio about the clearace received. The barrier ca support prevetio of cases where the ruway is correctly idetified but there is cofusio about the clearace received. The barrier ca support prevetio of cases where the ruway is correctly idetified but there is cofusio about the clearace received. The barrier ca support prevetio of cases where the ruway is correctly idetified but there is cofusio about the clearace received. The barrier ca support prevetio of cases where the ruway is correctly idetified but there is cofusio about the clearace received. Depeds o the iflight visibility Depeds o the iflight visibility Depeds o the iflight visibility 1 Note: Red shadig defies either a iefficiet barrier or barrier that is ot iteded for the operatioal sceario, yellow shadig defies barrier that is partially effective or partially efficiet for the operatioal sceario or efficiet uder certai coditios, ad gree shadig defies barrier that is effective ad efficiet for the operatioal sceario. 24
PREVENTION BARRIERS: OPERATIONAL SCENARIOS: PB1: SOP for turig the ladig/taxi lights o whe clearace to lad is received. PB2: A item i the ladig checklist to check. PB3: SOP for a check call at a give approach poit/height. PB4: Pilot SOP to revert to the previous sector frequecy PB5: Automatic alert to the pilot for occupied ruway. PB6: Pilot procedures: correct ruway i the systems ad correct approach charts. PB7: Pilot visual idetificatio of the correct RWY. C1: LwC after commuicatio misuderstadig o a uoccupied ruway whe o other clearace for the ruway has bee give. C2: LwC after commuicatio misuderstadig o a uoccupied ruway whe aother clearace for the ruway has bee give. C3: LwC after loss of comm. o a occupied ruway. D1: LwC after the absece of clearace was overlooked o a uoccupied ruway whe o other clearace for the ruway has bee give. D2: LwC after the absece of clearace was overlooked o a uoccupied ruway whe aother clearace for the ruway has bee give. D3: LwC after the absece of clearace was overlooked o a occupied ruway. This barrier depeds o a passive, rather tha actively euciated, trigger. This barrier depeds o a passive, rather tha actively euciated, trigger. This barrier depeds o a passive, rather tha actively euciated, trigger. Active trigger but effectiveess depeds o the timig of ladig check-list completio. Active trigger but effectiveess depeds o the timig of ladig check-list completio. Active trigger but effectiveess depeds o the timig of ladig check-list completio. Active trigger - guarateed prompt Operatioal Safety Study Ladig without ATC clearace Editio 1.0 25
PREVENTION BARRIERS: OPERATIONAL SCENARIOS: PB1: SOP for turig the ladig/taxi lights o whe clearace to lad is received. PB2: A item i the ladig checklist to check. PB3: SOP for a check call at a give approach poit/height. PB4: Pilot SOP to revert to the previous sector frequecy PB5: Automatic alert to the pilot for occupied ruway. PB6: Pilot procedures: correct ruway i the systems ad correct approach charts. PB7: Pilot visual idetificatio of the correct RWY. E1: Deliberate LwC o a uoccupied ruway whe o other clearace for the ruway has bee give. E2: Deliberate LwC o a uoccupied ruway whe aother clearace for the ruway has bee give. E3: Deliberate LwC o a occupied ruway. Table 2: Aalysis of Prevetio Barrier Efficiecy PB8-PB14 PREVENTION BARRIERS: OPERATIONAL SCENARIOS: PB8: Sigs ad markigs to clearly idicate closed RWYs. PB9: Other alert to the pilot via ATC for lack of ladig clearace e.g. -visual alerts. PB10: ATCO memory aid for issued ladig clearaces. PB11: System supported ATCO detectio of ladig aircraft or of potetial coflict for the ladig aircraft PB12: ATCO visual detectio of ladig a/c. PB13: ATCO visual detectio of ladig a/c o correct/ icorrect RWY. PB14: Go-aroud policy coditios i case of o ladig clearace. A1: LwC after loss of commuicatio o a uoccupied ruway whe o other clearace for the ruway has bee give. effectiveess of ATC would ormally permit ladig. Pilots expected to follow loss of comms procedures. A2: LwC after loss of commuicatio o a uoccupied ruway whe aother clearace for the ruway has bee give. effectiveess of Pilots expected to follow loss of comms procedures. A3: LwC after loss of commuicatio o a occupied ruway. effectiveess of Pilots expected to follow loss of comms procedures. 26
PREVENTION BARRIERS: OPERATIONAL SCENARIOS: PB8: Sigs ad markigs to clearly idicate closed RWYs. PB9: Other alert to the pilot via ATC for lack of ladig clearace e.g. -visual alerts. PB10: ATCO memory aid for issued ladig clearaces. PB11: System supported ATCO detectio of ladig aircraft or of potetial coflict for the ladig aircraft PB12: ATCO visual detectio of ladig a/c. PB13: ATCO visual detectio of ladig a/c o correct/ icorrect RWY. PB14: Go-aroud policy coditios i case of o ladig clearace. B1: LwC after ruway cofusio o a uoccupied ruway whe o other clearace for the ruway has bee give. effectiveess of ATC would ormally permit ladig. This barrier depeds o o clearace beig give for ay ruway. effectiveess of effectiveess of This barrier depeds o o clearace beig give for ay ruway. B2: LwC after ruway cofusio o a uoccupied ruway whe aother clearace for the ruway has bee give. effectiveess of ATC would ormally permit ladig This barrier depeds o o clearace beig give for ay ruway. effectiveess of This barrier depeds upo good visibility. This barrier depeds o o clearace beig give for ay ruway. B3: LwC after ruway cofusio o a occupied ruway. effectiveess of This barrier depeds o o clearace beig give for ay ruway. effectiveess of effectiveess of This barrier depeds o o clearace beig give for ay ruway. C1: LwC after commuicatio misuderstadig o a uoccupied ruway whe o other clearace for the ruway has bee give. effectiveess of ATC would ormally permit ladig. effectiveess of effectiveess of This barrier depeds o o clearace beig give for ay ruway. C2: LwC after commuicatio misuderstadig o a uoccupied ruway whe aother clearace for the ruway has bee give. This barrier depeds upo good visibility. effectiveess of effectiveess of C3: LwC after commuicatio misuderstadig o a occupied ruway. effectiveess of effectiveess of effectiveess of Operatioal Safety Study Ladig without ATC clearace Editio 1.0 27
PREVENTION BARRIERS: OPERATIONAL SCENARIOS: PB8: Sigs ad markigs to clearly idicate closed RWYs. PB9: Other alert to the pilot via ATC for lack of ladig clearace e.g. -visual alerts. PB10: ATCO memory aid for issued ladig clearaces. PB11: System supported ATCO detectio of ladig aircraft or of potetial coflict for the ladig aircraft PB12: ATCO visual detectio of ladig a/c. PB13: ATCO visual detectio of ladig a/c o correct/ icorrect RWY. PB14: Go-aroud policy coditios i case of o ladig clearace. D1: LwC after the absece of clearace was overlooked o a uoccupied ruway whe o other clearace for the ruway has bee give. effectiveess of effectiveess of effectiveess of D2: LwC after the absece of clearace was overlooked o a uoccupied ruway whe aother clearace for the ruway has bee give. effectiveess of ATC would ormally permit ladig effectiveess of effectiveess of D3: LwC after the absece of clearace was overlooked o a occupied ruway. effectiveess of effectiveess of effectiveess of E1: Deliberate LwC o a uoccupied ruway whe o other clearace for the ruway has bee give. effectiveess of This barrier depeds upo detail of techical fix. E2: Deliberate LwC o a uoccupied ruway whe aother clearace for the ruway has bee give. effectiveess of This barrier depeds upo detail of techical fix. E3: Deliberate LwC o a occupied ruway. effectiveess of This barrier depeds upo detail of techical fix. 28
6.2 Aalysis of Mitigatio Barriers Table 3: Aalysis of Mitigatio Barrier Efficiecy MB1-MB5 2 MITIGATION BARRIERS: OPERATIONAL SCENARIOS: MB1: ATCO prevets coflict after detectig it visually before or with a iteded RWY etry clearace. MB2: ATCO prevets coflict after detectig it with system support before or with a iteded RWY etry clearace. MB3: Crew/driver prevets coflict after detectig it, based o traffic moitorig, before or with a iteded RWY etry clearace. MB4: Crew/driver prevets coflict after detectig it with system support before or with a iteded RWY etry clearace. MB5: ATCO RWY coflict resolutio after detectig it visually. A1: LwC after loss of commuicatio o a uoccupied ruway whe o other clearace for the ruway has bee give No Coflict No Coflict No Coflict A2: LwC after loss of commuicatio o a uoccupied ruway whe aother clearace for the ruway has bee give. A3: LwC after loss of commuicatio o a occupied ruway. No commuicatios ad limited visual observatio of the ladig traffic No commuicatios ad limited visual observatio of the ladig traffic Resolutio via other party Resolutio via other party B1: LwC after ruway cofusio o a uoccupied ruway whe o other clearace for the ruway has bee give. B2: LwC after ruway cofusio o a uoccupied ruway whe aother clearace for the ruway has bee give. may reduce the effectiveess of this No Coflict No Coflict No Coflict may reduce the effectiveess of this B3: LwC after ruway cofusio o a occupied ruway. may reduce the effectiveess of this may reduce the effectiveess of this C1: LwC after commuicatio misuderstadig o a uoccupied ruway whe o other clearace for the ruway has bee give. may reduce the effectiveess of this No Coflict No Coflict No Coflict C2: LwC after commuicatio misuderstadig o a uoccupied ruway whe aother clearace for the ruway has bee give. C3: LwC after commuicatio misuderstadig o a occupied ruway. may reduce the effectiveess of this may reduce the effectiveess of this may reduce the effectiveess of this may reduce the effectiveess of this 2 Note: Additioally to the already defies shadigs, grey shadig defies a barrier that is ot challeged by the sceario. Operatioal Safety Study Ladig without ATC clearace Editio 1.0 29
MITIGATION BARRIERS: OPERATIONAL SCENARIOS: MB1: ATCO prevets coflict after detectig it visually before or with a iteded RWY etry clearace. MB2: ATCO prevets coflict after detectig it with system support before or with a iteded RWY etry clearace. MB3: Crew/driver prevets coflict after detectig it, based o traffic moitorig, before or with a iteded RWY etry clearace. MB4: Crew/driver prevets coflict after detectig it with system support before or with a iteded RWY etry clearace. MB5: ATCO RWY coflict resolutio after detectig it visually. D1: LwC after the absece of clearace was overlooked o a uoccupied ruway whe o other clearace for the ruway has bee give. may reduce the effectiveess of this No Coflict No Coflict No Coflict D2: LwC after the absece of clearace was overlooked o a uoccupied ruway whe aother clearace for the ruway has bee give. D3: LwC after the absece of clearace was overlooked o a occupied ruway. may reduce the effectiveess of this may reduce the effectiveess of this may reduce the effectiveess of this may reduce the effectiveess of this E1: Deliberate LwC o a uoccupied ruway whe o other clearace for the ruway has bee give. may reduce the effectiveess of this This barrier depeds upo reaso for deliberate act judgemetal or o-coformace No Coflict No Coflict No Coflict E2: Deliberate LwC o a uoccupied ruway whe aother clearace for the ruway has bee give. This barrier depeds upo reaso for deliberate act judgemetal or o-coformace may reduce the effectiveess of this E3: Deliberate LwC o a occupied ruway. This barrier depeds upo reaso for deliberate act judgemetal or o-coformace may reduce the effectiveess of this 30
Table 4: Aalysis of Mitigatio Barrier Efficiecy MB6-MB10 MITIGATION BARRIERS: OPERATIONAL SCENARIOS: MB6: ATCO RWY coflict resolutio after detectig it with the help of surveillace. MB7: ATCO RWY coflict resolutio after detectig it with safety et. MB8: Pilot/Driver RWY coflict resolutio after detectig it visually. MB9: Pilot/Driver RWY coflict resolutio after detectig it based o R/T traffic moitorig. MB10: Pilot/Driver RWY coflict resolutio after detectig it with system support. A1: LwC after loss of commuicatio o a uoccupied ruway whe o other clearace for the ruway has bee give No Coflict No Coflict No Coflict No Coflict No Coflict A2: LwC after loss of commuicatio o a uoccupied ruway whe aother clearace for the ruway has bee give. Depeds upo time ad actios available to resolve. Depeds upo time ad actios available to resolve. may reduce the effectiveess of this Resolutio via other party A3: LwC after loss of commuicatio o a occupied ruway. Depeds upo time ad actios available to resolve. Depeds upo time ad actios available to resolve. may reduce the effectiveess of this B1: LwC after ruway cofusio o a uoccupied ruway whe o other clearace for the ruway has bee give. No Coflict No Coflict No Coflict No Coflict No Coflict B2: LwC after ruway cofusio o a uoccupied ruway whe aother clearace for the ruway has bee give. Depeds upo time ad actios available to resolve. Depeds upo time ad actios available to resolve. may reduce the effectiveess of this B3: LwC after ruway cofusio o a occupied ruway. Depeds upo time ad actios available to resolve. Depeds upo time ad actios available to resolve. may reduce the effectiveess of this C1: LwC after commuicatio misuderstadig o a uoccupied ruway whe o other clearace for the ruway has bee give. No Coflict No Coflict No Coflict No Coflict No Coflict C2: LwC after commuicatio misuderstadig o a uoccupied ruway whe aother clearace for the ruway has bee give. Depeds upo time ad actios available to resolve. Depeds upo time ad actios available to resolve. may reduce the effectiveess of this C3: LwC after commuicatio misuderstadig o a occupied ruway. Depeds upo time ad actios available to resolve. Depeds upo time ad actios available to resolve. may reduce the effectiveess of this Operatioal Safety Study Ladig without ATC clearace Editio 1.0 31
MITIGATION BARRIERS: OPERATIONAL SCENARIOS: MB6: ATCO RWY coflict resolutio after detectig it with the help of surveillace. MB7: ATCO RWY coflict resolutio after detectig it with safety et. MB8: Pilot/Driver RWY coflict resolutio after detectig it visually. MB9: Pilot/Driver RWY coflict resolutio after detectig it based o R/T traffic moitorig. MB10: Pilot/Driver RWY coflict resolutio after detectig it with system support. D1: LwC after the absece of clearace was overlooked o a uoccupied ruway whe o other clearace for the ruway has bee give. No Coflict No Coflict No Coflict No Coflict No Coflict D2: LwC after the absece of clearace was overlooked o a uoccupied ruway whe aother clearace for the ruway has bee give. Depeds upo time ad actios available to resolve. Depeds upo time ad actios available to resolve. may reduce the effectiveess of this Depeds o a system that recogises ruway occupacy without authorisatio D3: LwC after the absece of clearace was overlooked o a occupied ruway. Depeds upo time ad actios available to resolve. Depeds upo time ad actios available to resolve. may reduce the effectiveess of this E1: Deliberate LwC o a uoccupied ruway whe o other clearace for the ruway has bee give. No Coflict No Coflict No Coflict No Coflict No Coflict E2: Deliberate LwC o a uoccupied ruway whe aother clearace for the ruway has bee give. Depeds upo time ad actios available to resolve. Depeds upo time ad actios available to resolve. may reduce the effectiveess of this E3: Deliberate LwC o a occupied ruway. may reduce the effectiveess of this 32
6.3 Prevetio Barrier Matrix Table 5: Prevetio Barrier Matrix PB1 PB2 PB3 PB4 PB5 PB6 PB7 PB8 PB9 PB10 PB11 PB12 PB13 PB14 A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D2 D3 E1 E2 E3 Operatioal Safety Study Ladig without ATC clearace Editio 1.0 33
6.4 Top 4 Potetial Prevetio Barriers PB5 has the highest umber of Gree (always) resposes; however PB9 has the highest combied Gree/Yellow (always/sometimes) rate. PB9 Other alert to the pilot via ATC for lack of ladig clearace e.g. selectio of visual alert. PB5 Automatic alert to the pilot for occupied ruway (for example visual alert i the case of Fial Approach Ruway Status Sigal type of Ruway Status Lights. PB11 System supported ATCO detectio of ladig aircraft or of potetial coflict for the ladig aircraft (for example ASMGCS ad RIMCAS). PB10 ATCO memory aid for issued (ot issued) ladig clearaces (strips, flight data). 34
6.5 Mitigatio Barrier Matrix Table 6: Mitigatio Barrier Matrix PB1 PB2 PB3 PB4 PB5 PB6 PB7 PB8 PB9 PB10 A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D2 D3 E1 E2 E3 Operatioal Safety Study Ladig without ATC clearace Editio 1.0 35
6.6 Top 4 Potetial Mitigatio Barriers MB2 has the highest rate, followed by MB10. MB2 ATCO prevets coflict after detectig it with system support before or with a iteded RWY etry clearace. MB10 Flight crew/vehicle driver ruway coflict resolutio after detectig the risk with system support. This is i fact a airbore safety et to help flight crew i idetificatio ad resolutio of ruway coflicts. MB3 Crew/driver prevets coflict after detectig it, based o traffic moitorig (listeig to R/T or visually), before or with a iteded RWY etry clearace. This barrier relatively weak but is selected to be part of the top 4 mitigatio barriers because of the double opportuity for coflict detectio visual ad listeig to the R/T. MB8 Pilot/Driver RWY coflict resolutio after detectig it visually. This barrier is relatively weak but is selected to be part of the top 4 mitigatio barriers because of the limited delay (o eed of a ATC-crew commuicatio loop) for crew actio i case of coflict detectio. 36
CHAPTER 7 - OTHER STUDIES 7.1 MIT Licol Laboratory FAA occurrece data documets a total of 1369 ruway icursios i the USA betwee 1997 ad 2000. A average of oe ruway icursio every day. MIT Licol Laboratory carried out a study of the 167 most high risk evets (defied as a actual miss distace of less tha 100 feet at speeds likely to cause major damage ad loss of life). Approximately 20% of evets were deemed to be ot time-critical whereby ATC has sufficiet time to effect a resolutio. 80% of evets however were time-critical with resolutio best dealt with i the pilot domai. A comprehesive review of icursio geometries revealed that the combied use of ruway etrace lights ad takeoff hold lights i a ruway status light system would provide a warig to oe or both of the affected pilots i about 65% of the cases studied. Status lights i cojuctio with ATC based systems would address about 85% of all icursios. 7.2 AENA A recet study by AENA To lad or ot to lad reviewed a total of 66 evets globally betwee 2007 ad 2012 i.e. a average of 11 per year. The study foud that Commuicatio was the pricipal groupig of cotributory factors. 15 evets (23%) there was o hadover of the aircraft from Approach to Tower 13 evets (20%) the aircraft failed to establish cotact with Tower 12 evets (18%) ivolved misuderstadigs i phraseology. 5 evets (8%) ivolved miss-selectio of the frequecy 16 15 14 12 13 12 10 8 8 8 6 4 2 6 5 5 4 2 6 2 0 No hadover APP-TWR A/C failed to establish cotact Phraseology-related Late clearace/plaig RT cogestio A/C did ot respod o 121.500 Wrog freq. Selectio Laded o the twy or wrog rwy Crew decided to lad based o expectatios Crew decided to lad due to WX issues Crew decided to lad agaist TWR istructios A/C first called TWR o the ruway Operatioal Safety Study Ladig without ATC clearace Editio 1.0 37
It was oted that the failure to trasfer a aircraft from Approach Cotrol to Aerodrome Cotrol opes a wide widow of opportuity for other factors to itervee, with egative safety cosequeces. O may occasios the aircraft did ot call Tower, eve if correctly istructed to do so. Attetioal issues ad crew task workload were maily idetified as well as the fact that there is o specific ladig clearace cofirmatio bullet built ito pre-ladig checklists. 7.3 NASA heryl L. Chappell, NASA Aviatio Safety Reportig System, published a study i 1994 Lessos Leared from Ladigs without a Clearace There are a great umber of reports ito NASA s Aviatio Safety Reportig System (ASRS) that idetify pilots failure to obtai clearaces prior to ladig. A small umber (37) of ASRS reports of ladigs without clearaces were looked at i depth ad revealed some patters. Not o tower frequecy. Of the 34 reports metioig the frequecy pilots were o whe they laded, 74% of them were o Approach frequecy ad oly 24% were o tower. Of the 8 reporters who did chage to Tower frequecy, 5 made iitial cotact with the tower but did ot receive ladig clearace. Lack of clearace discovered too late. 62% of the pilots did fially otice they had ot received a clearace, albeit too late. They geerally detected their error either while they were still o the ruway (7) or as they were turig off the ruway ad chagig to groud frequecy (10). This latter fidig suggests that if there is a fixed poit i cockpit procedures where pilots cosistetly chage frequecies, they may be more likely to remember to do so. High workload. 95% of the 37 reporters stated that their workload was high durig approach. They felt that the may other thigs goig o cotributed to their ot gettig ladig clearace. The reporters sources of workload were varied. Some pilots were i a traiig situatio, some were busy due to weather coditios. Forgettig to call tower at the marker (approximately 4 DME). A patter i the 37 reports was the likelihood of a pilots forgettig to cotact the tower if they were told to do so too far i advace. 9 reporters idicated they were told to cotact the tower at the marker, sometimes as far as 20 miles out. 7 of these ever switched to tower frequecy. 38
CHAPTER 8 - CONCLUSIONS AND RECOMMENDATIONS BARRIERS SCENARIOS ANALYSIS CONCLUSIONS OPERATIONAL CONTEXT Operatioal Safety Study Ladig without ATC clearace Editio 1.0 39
Coclusio 1 Coclusio 2 Coclusio 3 Recommedatio 1 This study has idetified the four potetial prevetio barriers ad the fourm potetial mitigatio barriers that could, if implemeted ad applied, achieve the highest safety gai. The three exteral studies refereced i this paper all support the advacemet of the Top 4 barriers idetified. They also however suggest that safety gais could be achieved by further refiemet ad developmet of some other barriers; otably barriers that would reduce the occurrece of pilots that are ot i commuicatio with Aerodrome Cotrol. Prevetio Barrier PB9: Alert to pilot via ATC for lack of ladig clearace. ATC could have a maually selectable warig tool. This, combied with a SOP to go aroud o observig the alert, could be a effective ad low cost It is recommeded that Europea Stakeholders joitly perform Feasibility ad Optios studies to optimise the prevetative barrier - Alert to pilot via ATC for lack of ladig clearace. Prevetio Barrier PB5: Automatic alert to the pilot for occupied ruway (for example visual alert i the case of Fial Approach Ruway Status Sigal type of Ruway Status Lights system). Coclusio 4 Recommedatio 2 This barrier will ot prevet the relatively beig ladig without clearace evet, where there is o immediate coflictig traffic. The study by Licol however suggests that up to 65% of serious evets could be preveted by the implemetatio of such a system. The FAA is sposorig the deploymet of the FAROS system i the USA. It is recommeded that Europea stakeholders moitor the implemetatio ad effectiveess of the FAROS system i the USA to iform their safety improvemet plas. Prevetio Barrier PB11: System supported ATCO detectio of ladig aircraft or of potetial coflict for the ladig aircraft (for example ASMGCS ad RIMCAS). Coclusio 5 These systems have the potetial to assist i the prevetio of majority Ladig without Clearace evets. They are however depedet upo ATCO participatio. The ATCO has to be alert to the system warig, correctly assimilate the iformatio ad take corrective actio, all withi a short time spa. The MIT Licol Laboratory study suggests that a combiatio of Ruway Status Lightig ad System supported ATCO detectio could prevet up to 85% of ruway icursios. Prevetio Barrier PB10: SATCO memory aid for issued (ot issued) ladig clearaces (strips, flight data). Coclusio 6 The AENA study suggests that ieffective ATC ad iteral hadovers betwee Approach cotrol ad Aerodrome cotrol was a factor i 34% of evets. The NASA study suggests that this rate of occurrece is eve higher. Therefore there is evidece that stregtheig the effectiveess of the ATC barrier could uderpi a safety gai. 40
Recommedatio 3 Coclusio 7 Recommedatio 4 Coclusio 8 Coclusio 9 Recommedatio 5 Coclusio 10 ANSPs should share idustry best practice i the maagemet of trasfer of commuicatio ad the maagemet of flight data displays ad memory aids. Mitigatio Barrier MB2: ATCO prevets coflict after detectig it with system support (e.g. ASMGCS) before or with a iteded RWY etry clearace. This appears to be a very strog Mitigatio barrier as the ATCO has the iformatio available to prevet the ruway coflictio. It does however have the same depedecies upo the same as PB11, but kicks i later i the evet chai. ANSPs should accelerate their ruway safety ets implemetatio plas i the cases where they are cosidered ecoomically viable. Mitigatio Barrier MB10: Flight crew/vehicle driver ruway coflict resolutio after detectig the risk with system support. This is i fact a airbore safety et to help flight crew i idetificatio ad resolutio of ruway coflict. This barrier depeds o the aircraft equipage. Mitigatio Barrier MB3: Crew/driver prevets coflict after detectig it, based o traffic moitorig (listeig to R/T or visually), before or with a iteded RWY etry clearace. This barrier has depedecies cocerig correct R/T commuicatio, good visibility ad good airside awareess traiig. Airport operatios stakeholders review Airside driver traiig to esure that istructio is give o proactive safety procedures aroud active ruways, which could iclude the sharig of past evet examples. Mitigatio Barrier MB8: Pilot/Driver RWY coflict resolutio after detectig it visually. This barrier is depedet upo good visibility. This mitigatio barrier is also addressed by the previous recommedatio. Operatioal Safety Study Ladig without ATC clearace Editio 1.0 41
APPENDIX A - SAFETY NETS 1. Fial Approach Ruway Occupacy Sigal (FAROS) 2. Ruway Status Lights (RWSL) 3. Advaced Surface Movemet Guidace & Cotrol System (ASMGCS) 4. Ruway Awareess ad Advisory System (RAAS) 5. Ehaced Visio System (EVS) 1. Fial Approach Ruway Occupacy Sigal (FAROS) Fial Approach Ruway Occupacy Sigal (FAROS) is a FAA-sposored cocept, which is ow beig deployed for operatioal evaluatio i the USA. It works by providig a visual sigal to aircraft o fial approach to lad that the ruway ahead is occupied by aother aircraft or a vehicle. This is doe by adaptig the PAPI or VASI system to alter from steady lights to flashig mode whilst the idetified hazard remais. Exterally, the PAPI or VASI system is ualtered ad cotiues to fuctio ormally i its primary role as a agle of approach awareess idicator whether or ot a FAROS iput has temporarily caused the flashig mode to activate. The iput sigal to the FAROS visual sigal is provided automatically by the embedded iductive loops which are istalled at all ruway etry ad exit poits ad which are able to detect trasitig traffic by the disturbace of the loop magetic field which it causes. The FAROS system is provided to ehace pilot awareess oly. It does ot substitute for, or iterfere with, existig ATC authority or flight crew procedures, ad activatio does ot affect the validity of a existig ATC Ladig Clearace. I may cases, it may be activated o short fials as aother aircraft departs from the same ruway or a aircraft or vehicle cross it i accordace with their ATC clearaces. 2. Ruway Status Lights (RWSL) As developed ad deployed at major airports i the USA, a RWSL system is a fully automatic advisory safety system which provides direct alerts to both vehicles ad pilots idepedetly of the ormal traffic cotrol system operated by ATC. Early versios of the system had two elemets, Ruway Etrace Lights (RELs) ad Take-Off Hold lights (THLs). Ruway Itersectio Lights (RHLs) were subsequetly added ad ow the itetio is to itegrate the three RWSL elemets with the Fial Approach Ruway Occupacy Sigal (FAROS) system. A graphic of showig a typical applicatio of the three baselie; elemets of the system is show below. I summary, the priciples are that: RELs war that it is usafe to eter/cross a ruway THLs war that it is usafe to take off from a ruway RILs war that it is usafe to cross a ruway itersectio 42
Diagram prepared by MIT Licol Laboratory It is importat to ote that activatio of RWSL compoets is completely idepedet of ATC clearaces ad their activatio as a backup safety et agaist huma error bears o relatio to the presece or absece of a ATC clearace. However, whe RWSL idicatios cotradict clearaces, pilots ad vehicle drivers are expected to prioritize respose to the status lights. Coversely, the absece of RWSL idicatios does ot equate to a ATC clearace to proceed. It is routie to see these idicatios cyclig betwee illumiated ad extiguished as the relative dispositio of traffic chages. Ruway Etrace Lights (RELs) RELs are istalled at taxiway/ruway itersectios to provide a idicatio whe it is usafe to eter the ruway. The first light i the patter is istalled 2 feet prior to the ruway holdig poit markig. They cotiue to a peultimate light pair at 2 feet before the ruway edge markig with the last light the sited 2 feet before the ruway cetrelie lights. Illumiated RELs as see from above Operatioal Safety Study Ladig without ATC clearace Editio 1.0 43
Pilot view of illumiated RELs Take Off Hold Lights (THLs) THLs are used at the ruway departure area ad provide a idicatio to pilots ad vehicle drivers that the ruway is usafe for takeoff. They cosist of red uidirectioal lights istalled i two logitudial rows of 16 lights each aliged with ad offset either side of the ruway cetrelie lightig. Take off Hold Lights from above 44
Pilot view of Take-off Hold Lights Ruway Itersectio Lights (RILs) RILs are the third compoet of the RWSL system. They are used where oe ruway itersects aother ad provide a idicatio to pilots ad vehicle drivers that there is high speed traffic o the itersectig ruway ad that it is usafe for to eter or cross. They cosist of red uidirectioal lights istalled i a double logitudial row aliged with ad offset to either side of the ruway cetrelie lightig i the same maer as ad usig the same light fixtures as THLs. Pilot view of Ruway Itersectio Lights Operatioal Safety Study Ladig without ATC clearace Editio 1.0 45
3. Advaced Surface Movemet Guidace & Cotrol System (ASMGCS) A-SMGCS is a system providig routig, guidace ad surveillace for the cotrol of aircraft ad vehicles i order to maitai the declared surface movemet rate uder all weather coditios withi the aerodrome visibility operatioal level (AVOL) while maitaiig the required level of safety. (ICAO Doc 9830: Advaced Surface Movemet Guidace ad Cotrol Systems (A-SMGCS) Maual) A-SMGCS is a modular system cosistig of differet fuctioalities to support the safe, orderly ad expeditious movemet of aircraft ad vehicles o aerodromes uder all circumstaces with respect to traffic desity ad complexity of aerodrome layout, takig ito accout the demaded capacity uder various visibility coditios. A-SMGCS is more tha just a set of systems, it also icludes complemetary procedures ad at the lower levels of implemetatio aims to deliver improved situatioal awareess to cotrollers. Higher levels of implemetatio deliver safety ets, coflict detectio ad resolutio as well as plaig ad guidace iformatio for pilots ad cotrollers. Implemetatio of A-SMGCS defies 4 levels: A-SMGCS Level 1 (improved Surveillace) makes use of improved surveillace ad procedures, coverig the maoeuvrig area for groud vehicles ad the movemet area for aircraft. The procedures cocer idetificatio ad the issuace of ATC istructios ad clearaces. The cotrollers are give traffic positio ad idetity iformatio which is a importat step forward from the traditioal Surface Movemet Radar (SMR) image. A-SMGCS Level 2 (Surveillace + Safety Nets) adds safety ets which protect ruways ad desigated areas ad the associated procedures. Appropriate alerts are geerated for the cotrollers i case of coflicts betwee all vehicles o ruways ad the icursio of aircraft oto desigated restricted areas. 46
A-SMGCS Level 3 (Coflict Detectio) ivolves the detectio of all coflicts o the movemet area as well as improved guidace ad plaig for use by cotrollers. A-SMGCS Level 4 (Coflict Resolutio, Automatic Plaig & Guidace) provides resolutios for all coflicts ad automatic plaig ad automatic guidace for the pilots as well as the cotrollers. 4. Ruway Awareess ad Advisory System (RAAS) The Ruway Awareess ad Advisory System (RAAS) is oe of a umber of related software ehacemets available o later-model Ehaced Groud Proximity Warig Systems. RAAS is desiged to improve flight crew situatioal awareess, thereby reducig the risks of ruway icursio, ruway cofusio ad ruway excursios. Ruway Awareess ad Advisory System uses airport data stored i the EGPWS database, coupled with GPS ad other oboard sesors, to moitor the movemet of a aircraft aroud the airport. It provides visual/aural auciatios at critical poits, such as «Approachig Ruway 09 Left ad cofirmatio whe a aircraft is lied up o the ruway prior to takeoff: for example, «O Ruway 09 Right, 2,450 metres remaiig.» I a sceario where a crew iadvertetly lies up o a parallel taxiway ad commeces a take-off, a aural alert O Taxiway, O Taxiway is provided if the aircraft speed exceeds 40 kts. O approach ad after touchdow, the system cotiues to aouce the distace to go util the ed of the ruway is reached. Advisories/cautios are geerated based upo the curret aircraft positio whe compared to the locatio of the airport ruways, which are stored withi the EGPWS Ruway Database. RAAS provides the flight crew with five routie advisories. Three of these auciatios will be heard by the crew i ormal operatios, providig icreased positio awareess relative to the ruway durig taxi ad flight operatios. They are iteded to reduce the risk of a ruway icursio. The two remaiig routie advisories provide iformatio about the aircraft locatio alog the ruway, ad are iteded to reduce the risk of overrus. These advisories are: Approachig Ruway - (I Air advisory provides the crew with awareess of which ruway the aircraft is lied up with o approach. Approachig Ruway - O-Groud advisory provides the flight crew with awareess of approximate ruway edge beig approached by the aircraft durig taxi operatios. O Ruway advisory provides the crew with awareess of which ruway the aircraft is lied-up with. Distace Remaiig advisories ehace crew awareess of aircraft alog-track positio relative to the ruway ed. Ruway Ed advisory is iteded to improve flight crew awareess of the positio of the aircraft relative to the ruway ed durig low visibility coditios. I additio, RAAS provides the flight crew with several o-routie advisories/cautios. These auciatios are desiged to ehace safety ad situatioal awareess i specific situatios ot routiely ecoutered durig ormal aircraft operatios. Some of the RAAS advisories iclude distace iformatio. The uit of measure used for distace ca be cofigured to be either metres or feet. Approachig Short Ruway - I-Air advisory provides the crew with awareess of which ruway the aircraft is liedup with, ad that the ruway legth available may be margial for ormal ladig operatios. If desired, a additioal cautio auciatio ca be eabled which provides the crew with awareess that the issue has ot bee resolved whe the aircraft is o fial approach. Isufficiet Ruway Legth - O-Groud Advisory provides the crew with awareess of which ruway the aircraft is lied-up with, ad that the ruway legth available for takeoff is less tha the defied miimum takeoff ruway Operatioal Safety Study Ladig without ATC clearace Editio 1.0 47
legth. If desired, a additioal cautio auciatio ca be eabled which provides the crew with awareess that the issue has ot bee resolved whe the aircraft is o the fial stage of takeoff. Exteded Holdig o Ruway advisory provides crew awareess of a exteded holdig period o the ruway. Taxiway Take-Off advisory ehaces crew awareess of excessive taxi speeds or a iadvertet take-off o a taxiway. If desired, this fuctio ca provide a cautio auciatio i lieu of a advisory auciatio. Distace Remaiig advisories provides the flight crew with positio awareess durig a Rejected Take Off (RTO). Taxiway Ladig alert provides the crew with awareess that the aircraft is ot lied up with a ruway at low altitudes. Each RAAS fuctio is idepedetly eabled based o a customer specificatio ad whe eabled, the RAAS fuctios operate automatically without ay actio required from the flight crew. I additio to the aural auciatios provided, visual auciatios ca be activated i the form of cautio idicatios if the auciatios are cosidered cautios. Visual text auciatios ca also be cofigured to be overlaid o the terrai display for a period of time whe the coditio is etered. 5. Ehaced Visio System (EVS) Ehaced Visio is a techology which icorporates iformatio from aircraft based sesors (e.g., ear-ifrared cameras, millimeter wave radar) to provide visio i limited visibility eviromets. EVS II systems use a IR camera mouted i the aircraft s ose to project a raster image o the Heads-Up Display (HUD). The IR image o the HUD is coformal to the outside scee, meaig that objects detected by the IR camera are the same size ad aliged with objects outside the aircraft. Thus i poor visibility the pilot is able to view the IR camera image ad is able to seamlessly ad easily trasitio to the outside world as the aircraft gets closer to the ruway. The advatage of EVS is that safety i early all phases of flight are ehaced, especially durig approach ad ladig i limited visibility. A pilot o a stabilized approach is able to recogize the ruway eviromet (lights, ruway markigs, etc.) earlier i preparatio for touchdow. Obstacles such as terrai, structures, ad vehicles or other aircraft o the ruway that might ot otherwise be see are clearly visible o the IR image. 48
APPENDIX B - REFERENCES 1. Eggert, Howes, Kuffer, Wilhelmse, ad Berays Operatioal Evaluatio of Ruway Status Lights. Licol Laboratory Joural (2006) 2. Barba A.M.(2013) To Lad or ot to Lad. AENA 3. Chappell, S. L. (1994). Prevetig ladigs without clearace. Callback. Moffett Field, CA: Natioal Aeroautics ad Space Admiistratio. Operatioal Safety Study Ladig without ATC clearace Editio 1.0 49