Top 5 ATM Operational Safety Priorities

Top 5 ATM Operational Safety Priorities

Landing Without Clearance

BLAJEV TzvetomirOperational Safety Coordinator, EUROCONTROL

Captain Ed PooleyThe Air Safety Consultancy

In Brief:

The process to determine the priorities - SAFMAPs

What are the Top 5?

Operational safety study example: Landing without clearance

In Brief:


What are the Top 5 ?

Operational safety study example: Landing without Clearance

How to prioritise

Counting numbers versus understanding mechanisms

Single point of view versus a common picture

Learning from negative versus learning from both negative and

positive

How did we get it?

We studied two risk areas:

(1) Runway incursion (2) Loss of separation en-route

Workshops with 6 ANSPS during Summer 2012

Reviewing severity A and B incidents for 2011

Mapping the incidents on SAFMAPs (Safety Functions Maps) –

3 hierarchical levels were developed

SAFMAP Level 0 – Runway Collision

RUNWAY INCURSION

UNRESOLVED BY ATC RUNWAY CONFLICT

UNRESOLVED BY ATC AND PILOT/DRIVER RUNWAY CONFLICT

RUNWAY CONFLICT

Preventing incorrect presence into RWY protected area

Preventing incorrect RWY presence to turn into RWY conflict

ATC RWY Conflict Resolution

Pilot/Driver RWY Conflict Resolution

Providence

SAFMAP Level 1

No incorrect presence of take-off

aircraft

Taxi pilot/driver adequate

communication

No confusion that there is a

clearance

Correct vacation

Taxi pilot/driver adequate positional

awareness

No incorrect presence of landing

aircraft

No incorrect

presence of person

ATC prevents incorrect presence


RUNWAY INCURSION

ATCO detects the conflict

Sufficient time and effective ATC decision

Adequate Communication

Crew/driver/person initiates action on time

The avoidance action is correctly implemented and

collision is avoided


Opportunity for physical collision avoidance

The conflict is detectable by the pilot / driver

The conflict is detected by the pilot/ driver





PROVIDENCE

Preventing ATC causing

incorrect entry

Pilot/driver detecting that RWY entry will be incorrect

Opportunity to prevent the conflict before or with

intended RWY use clearance ATCO prevents conflict after detecting it before or with intended RWY use clearance

RUNWAY CONFLICT

Crew/driver prevents conflict after detecting it before or with intended RWY use clearance



RUNWAY CONFLICTCrew/driver prevents conflict after detecting it before or with intended RWY use clearance

Incident trajectories on the SAFMAP

No incorrect presence

of take-off aircraft


communication


clearance

Correct vacation


awareness

No incorrect presence

of landing aircraft

No incorrect

presence of person



RUNWAY INCURSION















PROVIDENCE


incorrect entry


Incident trajectory example 1


aircraft


communication


clearance

Correct vacation


awareness


aircraft

No incorrect

presence of person



RUNWAY INCURSION















PROVIDENCE


incorrect entry





• A vehicle entered RWY for maintenance work without clearance after confusion of the position

• ATCO detected the incorrect entry with the red stop bar crossing alarm at the time of issuing clearance for a take-off aircraft

• ATCO immediately cancel the take-off clearance



aircraft


communication


clearance

Correct vacation


awareness


aircraft

No incorrect

presence of person



RUNWAY INCURSION















PROVIDENCE


incorrect entry





• During high workload, wet RWY, many Arrivals, more time than usual to vacate the RWY

• ATCO focussing on the one vacating the outer RWY, tired at the and of the day

• Clear an a/c to cross (after landing) after already given TOF clearance to another a/c

• No stop bars used - only for low visibility procedures

• After identifying the conflict ATCO instructed the crossing to expedite



aircraft


communication


clearance

Correct vacation


awareness


aircraft

No incorrect

presence of person



RUNWAY INCURSION















PROVIDENCE


incorrect entry





• Landing aircraft mistuned frequency of the TWR and decided to follow the loss of communication landing procedure in VMC

• Take-off aircraft on the RWY already but no opportunity for take-off or for vacating the RWY

• The landing aircraft failed to see that RWY is occupied and landed on top of the a/c at the threshold

In Brief:


What are the Top 5?


Top 5: (1) Risk of operations without transponder or with dysfunctional one

A single threat often removing all the barriers up to ‘see and avoid’;

No ATC awareness;

No STCA;

No TCAS/ACAS.

Top 5: (2) Landing without clearance

For numerous reasons, aircraft sometimes land without ATC clearance;

This results in runway incursions that are often only resolved through ‘providence’.

Top 5: (3) Detection of Occupied Runway

Good share of the severe Runway Incursion incidents could have been prevented;

Need for the controllers to detect that the runway was occupied at the time of giving a clearance for the next aircraft to use it.

Top 5: (4) “Blind Spot”

Conflict was not detected with the closest aircraft;

After descending clearance;

Rapidly developing situation – often 1000ft and 15 Nm between the conflicting a/c.

Top 5: (5) Conflict detection with adjacent sectors

Involve “inadequate coordination” of clearance with an adjacent sector;

These typically involve either an early (premature) transfer of control to or from the neighbouring sector.

In Brief:


What are the Top 5 ?


Top 5 Safety Priorities 19

Operational Safety Study

Provide additional insights on causal/contributory factors

Suggest actions to reduce or eliminate risk factors

Identify industry ‘best’ practice and lessons learned

Inform development of SKYbrary material


The Generic Study Process

CONCLUSIONSCONCLUSIONSANALYSISANALYSISSCENARIOSSCENARIOS

BARRIERSBARRIERS

OPERATIONALCONTEXT

OPERATIONALCONTEXT




BARRIERSBARRIERS

OPERATIONALCONTEXT

OPERATIONALCONTEXT


Example Conflict Scenarios (1)Active RWY

2a

2b3e3d3c3b3a

1. Unoccupied RWY and no clearance given

2. Unoccupied but a clearance has been given

3. Occupied RWY

A. Loss of communication

B. RWY confusion

C. Communication misunderstanding

D. Absence of clearance overlooked

E. Deliberate

LANDING WITHOUT CLEARANCE

1



CONCLUSIONSCONCLUSIONSANALYSISANALYSIS

BARRIERSBARRIERS

OPERATIONALCONTEXT

OPERATIONALCONTEXT

SCENARIOSSCENARIOS


Barriers

RUNWAY INCURSION

RUNWAY CONFLICT UNRESOLVED BY ATC

RUNWAY CONFLICTUNRESOLVED BY ATC AND PILOT/DRIVER

Preventing landing without clearance situations

Preventing landing without clearance to turn into RWY conflict

ATC RWY Conflict Resolution

Pilot/Driver RWY Conflict Resolution

Providence

RUNWAY CONFLICT

PREVENTION BARRIERS

MITIGATION BARRIERS


RUNWAY INCURSION















PROVIDENCE



RUNWAY CONFLICT

Crew/driver prevents conflict after detecting it before or with intended RWY use clearance

Mitigation Barriers



CONCLUSIONSCONCLUSIONSANALYSISANALYSIS

BARRIERSBARRIERS

OPERATIONALCONTEXT

OPERATIONALCONTEXT

SCENARIOSSCENARIOS


Operational Context (1)

Availability of radar guidance for the approach Meteorological conditions and time of the day Runway status Clearance conditions Visual surveillance capability from the Tower




BARRIERSBARRIERS

OPERATIONALCONTEXT

OPERATIONALCONTEXT


OPERATIONAL SCENARIOS v BARRIER EFFECTIVENESS

All Scenarios formulated are not equally prevalent! And:

All Prevention Barriers (PB) are not equal in their relevance to the various scenarios

All Mitigation Barriers (MB) are not equal in their relevance to the various scenarios

But In both cases there are some clear indications of best “value-added” in responding to the risk of LwC

Assign each ‘PB’ and each ‘MB’ to the defined scenarios as fully effective, partially effective or ineffective/not intended to address – traffic light system:


PREVENTION 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


MITIGATION BARRIER MATRIX

MB1 MB2 MB3 MB4 MB5 MB6 MB7 MB8 MB9 MB10

A1

A2

A3

B1

B2

B3

C1

C2

C3

D1

D2

D3

E1

E2

E3


RANKING OF PREVENTION BARRIER EFFECTIVENESS

Arbitrary weighting of Green: Yellow at 3:1 (use of 2:1 would make little relative difference)

Best Ranked Prevention Barriers (score range 3-31):

PB 5 an automated (probably visual), alerting of pilots to an occupied runway and thus the (probable) absence of a landing clearance

PB9 a controller-activated (probably visual) alerting of pilots to the absence of a landing clearance.

Best/Worst Coverage of Prevention Barriers by Scenario:

Best - ‘D’ (pilot unaware)

Intermediate - ‘B’ (runway confusion); ‘C’ (comms confusion); ‘A’ (loss of comms)

Worst - ‘E’ (deliberate act)


RANKING OF MITIGATION BARRIER EFFECTIVENESS

Same Arbitrary weighting of Green: Yellow at 3:1 (again use of 2:1 would make little relative difference)

Best Ranked Mitigation Barriers (score range 20-33 plus one outlier at 3):

MB 2 - controller intervention prompted by an automatic alert with or without prior issue of a conflicting clearance.

MB 4 - pilot/driver action prompted by an automatic (probably visual) alert.

MB3 – pilot/driver action promoted by proactive monitoring of traffic visually or on the radio

Best/Worst Coverage of Mitigation Barriers by Scenario:

Best - ‘B’ (runway confusion)

Intermediate - ‘A’ (loss of comms); ‘C’ (comms confusion); ‘D’ (unaware)

Worst - ‘E’ (deliberate act)

VALIDATION OF BARRIER EFFECTIVENESS

Identifies the barriers that could have prevented or mitigated an actual event had they been

Available and Used

×Is not an analysis of what actually happened since the test events were not prevented.


SCENARIO ‘A’ (LOSS OF COMMS)

Non-precision approach by private business flight by aircraft owner. Mistuned TWR in IMC and when no contact possible assumed radio failure and did not revert to APP. Broke cloud at 1.5nm and continued land over a Q400 lined up for departure at the threshold without seeing it.Three effective Prevention Barriers:

PB4, PB5, PB9 These include the top two ranked barriers

Two effective Mitigation Barriers: MB2, MB4 These include two of the three top ranked barriers


SCENARIO ‘B’ (RUNWAY CONFUSION)

Two parallel runways, one closed long term for nearly- completed reconstruction. In VMC, ATC approved an inbound CRJ crew request to land in the reciprocal direction to that in use. The aircraft was then landed on the closed runway without encountering obstacles - ATC only noticed as the aircraft was about to touch down. The crew said they were used to programming the FMS for the runway they actually used and failed to appreciate or correct their error even when flying a

visual approach. Seven effective Prevention Barriers:

PB5, PB6, PB7, PB8, PB9, PB11, PB13 These include the top two ranked barriers

Two effective Mitigation Barriers: MB3, MB8 These include the one of the top three ranked barriers


SCENARIO ‘C’ (COMMS CONFUSION)

ATC instructed pilot to “continue approach” to which the pilot readback was “continue”. ATC made no further attempt to communicate to the aircraft and it was landed in the belief that

clearance had been given. Five effective Prevention Barriers:

PB5, PB9, PB10, PB11, PB12 These include the top two ranked barriers

Six effective Mitigation Barriers: MB2, MB3, MB4, MB5, MB6, MB8 These include the top three ranked barriers


SCENARIO ‘D’ (PILOT UNAWARE)

On initial contact with TWR, the aircraft was instructed to continue advised to expect to be called back. After landing without clearance in the belief that it had been received, the pilot, who was familiar with the airport involved, observed that landing clearance there was usually given a long way out and the absence of the promised call back with clearance was easily missed. Nine effective Prevention Barriers:

PB1, PB2, PB3, PB5, PB9, PB10, PB11, PB12, PB14 These include the top two ranked barriers

Nine effective Mitigation Barriers: MB1, MB2, MB3, MB4, MB5, MB6, MB7, MB8, MB10 These include the top three ranked barriers


SCENARIO ‘E’ (DELIBERATE ACT)

An en-route light aircraft lost positional awareness in VMC and, unequipped with GPS, saw what was considered to be a convenient airport, and made a downwind join in the opposite circuit direction to that in use and continued onto finals and landed without radio contact. TWR saw the aeroplane when it was downwind and instructed another aircraft approaching from the opposite in-use direction to make a go around.Two effective Prevention Barriers:

PB5, PB9 These are the top two ranked barriers

Effective Mitigation Barriers: MB1, MB2, MB3, MB4, MB5, MB6, MB7, MB8, MB10 These include the top three ranked barriers





BARRIERSBARRIERS

OPERATIONALCONTEXT

OPERATIONALCONTEXT

SOME CONCLUSIONS (1)

The study has identified the best performing potential prevention and mitigation barriers. Some barriers are likely to be more cost effective than others.

Other studies referenced in the Paper are supportive of these findings but also advocate looking at barriers which would directly reduce the prevalence of pilots not being on the TWR frequency as the landing runway is approached.

Combinations of the most effective barriers are likely to make an impressive impact on LwC prevalence and mitigation.


SOME CONCLUSIONS (2)

The top two ranked Prevention Barriers, PB5 and PB9, were applicable in all five scenario examples.

The top three ranked Mitigation Barriers, MB2, MB3, & MB4 were all applicable in Scenarios C (Comms confusion), ‘D’ (Pilot unaware) and ‘E’ (Deliberate Act) and at least one was applicable in the other two scenarios - ‘A’ (Loss of Comms) and ‘B’ (runway confusion.

An outstanding PB5 solution, ‘FAROS’ as currently being deployed in the USA, was estimated prior to this implementation as likely to prevent 65% of runway conflicts – some of which are LwC!



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Top 5 ATM Operational Safety Priorities