2 The University’s Role Member of the ICAO NOSS Study Group Jointly conducted the first two trials of the NOSS methodology with Airservices Australia and Airways New Zealand.
3 NOSS Operating Characteristics Over-the-shoulder observations during normal shiftsJoint Management/Union sponsorshipVoluntary participationDe-identified, confidential, and non-disciplinary data collectionSpecifically designed form for collection of dataTrained and calibrated observersTrusted data collection sitesData cleaning processTargets for safety enhancementFeedback results to the controllers
4 ThreatsThreat: An event or error that occurs outside the influence of the controller, but which requires their attention and management if safety margins are to be maintained.Air Navigation Service Provider (Internal) ThreatsAir Traffic Control – Pilot Interaction ThreatsEnvironmental Threats
5 Threats Threat Categories Air Navigation Service Provider (Internal) ThreatsAirborne ThreatsEnvironmental ThreatsExamplesErrors by other controllersSimilar call signsAdverse weatherUnserviceable equipmentLanguage difficultyAirspace designProceduresA/C flying unassigned headingRestricted AirspaceCoordination issuePilot not responding to callTraffic mixComputer malfunctionOther pilot errorsTurbulence
6 ErrorsError: An observed deviation from organizational expectations or controller intentionsCommunication ErrorsProcedural ErrorsEquipment / Automation ErrorsTraffic Handling Errors
7 Errors Error Categories Communication Procedural Equipment / Computer Traffic HandlingExamplesPhraseologyReadback / HearbackerrorMissed callCoordination errorChecklistBriefing errorAircraft transferFlight progress strip errorDid not check RWY prior to issuing TO clearanceAC label inaccurate infoCommunication system manipulationRadar screen range selectionLate decentIncorrect clearance instructionNo altitude instruction
8 Undesired States Controller Console Setup US’s Traffic State US’s Inaccurate representation of trafficTraffic situation not being monitoredIncomplete handoverTraffic State US’sSeparation not assuredRWY/TXY not verified to be clear for progress
9 NOSS Trial Data NOSS trials LOSA archive 5.7 3.7 2.6 0.6 0.5 88% 63% Threats per observation5.73.7Errors per observation2.6Undesired States per observation0.60.5Percentage of observations with an internal threat88%63%Percentage of observations with pilot/ATC interaction threats87%54%Percentage of observations with environmental (common) threats78%75%
10 Preliminary FindingsGreater threat prevalence of internal and ATC/pilot interactions when compared to LOSAA few pilot – ATC interaction issuesSimilar call signsReadback / phraseology issues
11 Methodological Challenges Will it work in the various ATC environments?Focus on positionsConcernsObservability: A similar number of observable errors are seen in NOSS and LOSALack of proceduralization / standardization: There may be reason to compare organizations with different procedures
12 What’s Next? NOSS & LOSA: What can each add to the other? Reliability and validity studies in conjunction with FAANAV CANADA NOSS area/terminal trialAirservices Australia tower trialFully operational NOSS in 2006? Airservices?