Automatic missed approach and late go-around detection

Job BrJob Brüüggenggen

Safety ManagerSafety Manager

ATC The NetherlandsATC The Netherlands

18th June 20132Automatic Missed Approach and Late go-around detection

Background (2007)•Near mid-air collision at Schiphol between Airbus A318 approaching to RWY18c and Boeing 737 departing from RWY24.

•Airbus A318 made a missed approach and crossed path of the departing B737. Closest distance 460m at same altitude.

TO Clearance KL1027 GA AF3484 GA Undetected

18th June 20133Automatic Missed Approach and Late go-around detection

We can’t be the only one …

18th June 20134Automatic Missed Approach and Late go-around detection

…SPL dependent rwy combinations

18th June 20135Automatic Missed Approach and Late go-around detection

Estimated collision risk 8.5 x 10 -9

Missed approach

2 x 10-3

Inadequate timing

1 x 10-1

No ATC resolution

1 x 10-1

No pilot (TCAS) resolution

8.5 x 10-1No separation

5 x 10-4

18th June 20136Automatic Missed Approach and Late go-around detection

Mitigation measures

1. Restrict use of dependent rwy combinations

2. Change the timing procedure3. Monitor operations4. Training and Safety Culture5. Increase detection probability

18th June 20137Automatic Missed Approach and Late go-around detection

5.1 Increase detection probability

18th June 20138Automatic Missed Approach and Late go-around detection

5.2 track vector on GND radar

18th June 20139Automatic Missed Approach and Late go-around detection

5.3 automatic go-around detection

Landing

Aircraft?

Landing

Aircraft?

Non-nominal

landing

parameters?

Non-nominal

landing

parameters?

Alert!Alert!yes yes

Surveillance

reportdetection

18th June 201310Automatic Missed Approach and Late go-around detection

Preliminary Algorithm

• Preliminary algorithm developed on minimum amount of readily available data (with limited resolution and sample rate):

– Position [x, y]: 1/64 NM– Mode-C altitude: 100 ft– Groundspeed: 1 kts– Tracker sample rate: 1/4.19 (0.24) Hz

• Dataset contains MA/GA plus flights with severe weather landings

18th June 201311Automatic Missed Approach and Late go-around detection

Algorithm Development per phase•High final: deviation from reference path•Low final: persistent pos. ROC•Stable final: path deviation+positive ROC•Flare/Land: altitude•Overshoot: by definition, if not land

18th June 201312Automatic Missed Approach and Late go-around detection

Results (1/3) for 293 MA, 2011

-6 -4 -2 0 2 4 6 8 100

500

1000

1500

2000

2500

3000GA detection performance for all missed approaches 2011

Distance to Threshold [nm]

Hei

ght

[ft]

18th June 201313Automatic Missed Approach and Late go-around detection13

Results (2/3)Number of Detections per Phase (293 cases, 2011)

0

20

40

60

80

100

120

140

1 2 3 4 5

High final Low final Stable final Flare/Land Overshoot

18th June 201314Automatic Missed Approach and Late go-around detection

Results (2/3)Identified Go-around Altitude (293 cases, 2011)

14

0 500 1000 1500 2000 25000

10

20

30

40

50

60

Height of go-around detection [ft]

Num

ber

of c

ases

Go-around detection height, all phases

18th June 201315Automatic Missed Approach and Late go-around detection

Results (3/3)Estimated Detection Delay per Phase

0 10 20 30 400

2

4

6

8

10Phase 1: high final

nr. of

cas

es

10 20 30 40 500

10

20

30

40Phase 2: low final

nr. of

cas

es0 10 20 30

0

10

20

30

40

50Phase 3: stable final

Estimated detection delay [sec]

nr. of

cas

es

0 10 20 300

2

4

6

8Phase 4: flare & land

Estimated detection delay [sec]nr

. of

cas

es

MEAN [SEC] STANDARD DEVIATION [SEC]

Phase 1 20.6 8.1

Phase 2 21.5 6.8

Phase 3 10.7 4.4

Phase 4 16.9 6.3

18th June 201316Automatic Missed Approach and Late go-around detection

Achievable responsiveness

2000 ft

1200 ft

0 1 2 3 4a 4b 5

Intermediate

Approach

High Final

Approach

Low Final

Approach

Stable Final

Approach

500 ft

Flare Landing Run Overshoot

50 ft

22 s22 s 11 s11 s 17 s17 s21 s21 s

False alerts:

- non-stabilised approach

- circling

Options for improvement

-Use 25 ft altitude resolution Mode S

-Use Multilateration data for 1 sec update

6.2 NM / ~2.7 min ~1.9 NM / ~1 min

11 % 32 % 43 % 13 % 0 %Probability of missed approach:

18th June 201317Automatic Missed Approach and Late go-around detection

Complications

1.05 1.1 1.15 1.2 1.25 1.3 1.35

x 105

4.76

4.78

4.8

4.82

4.84

4.86

4.88

4.9

4.92

4.94

4.96

x 105

AMS PAMSPL

OM 06

OM 27

OA L18C

OM 18C

WP L27

AMEGA

Approach 18R, MA 18R identified, approach 24,

circling 22, MA 22, circling 27 all correctly identified.

18th June 201318Automatic Missed Approach and Late go-around detection

Simulator sessions

18th June 201319Automatic Missed Approach and Late go-around detection

Automatic Go around detection: results• Operational concept defined• HMI acceptable• Functionality usable• Implementation before winter operations

2014.

LuchtverkeersleidingNederland

BezoekadresStationsplein ZuidWest 10011117 CV SCHIPHOL

PostadresPostbus 752001117 ZT SCHIPHOL

T +31 (0)20 4062000 F +31 (0)20 6484999

E communications@lvnl.nlW www.lvnl.nl

www.luchtverkeersleider.nl