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Air China Flight 129 15.4.2002

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Circling Approach

1. What Is A Circling Approach

2. Its Design Criteria & Mechanics Involved

3. Flight Safety Awareness

4. Pans-Ops & TERPS Differences

5. Jeppesen Approach Chart Explained

This Presentation Is To Discuss:

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What Is A Circling Approach?

• It is a visual flight manoeuvre

• Or an extension of an instrument approach

Basic Assumptions:• Visual with landing runway or approach aids

• At or above MDA unless in a position to land

• If visual is lost, a go-around must be executed

• A climbing turn towards the runway, and to establish on published missed approach track

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When To Do A Circling Approach

• No precision approach aid available

• Unable to design a non-precision approach due to certain constraints:a. Navigational facility out of design tolerance

b. Unable to make a normal descent rate landing due to terrain constraints

c. The only available mean to make a landing on a particular runway

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Visual Manoeuvring Area

The visual manoeuvring area is determined by drawing arcs (Ř) centred on each runway threshold and joining those arcs with tangent lines

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Visual Manoeuvring (Circling Approach) Area

Ř = 2 (r) + straight segmente.g. Cat D Airplane: Ř = 2.34+2.34+0.60 = 5.28nm

Where (r) is the airplane’s turn radius (242kt TAS & 20º AOB)

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Design Criteria (ICAO Pans Ops)

• Aircraft Category (Cat C or Cat D)

• Aircraft Manoeuvre Speed

• Wind Velocity – 25kt throughout the turn

• Bank Angle – Rate 1 Turn or 20º whichever is less

• Airport Elevation – 2000ft amsl

• ISA + 15°

Reference: ICAO Pans-Ops Doc 8168 Volume 1 Chapter 4

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ICAO Pans Ops Design Criteria

Category C D

Manoeuvre Speed (IAS) 180kt 205kt

TAS At 2000ft +

Wind Factor215kt 242kt

Radius Of Turn (r) 1.85nm 2.34nm

Straight Segment 0.50nm 0.60nm

(Ř) 4.20nm 5.28nm

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Visual Manoeuvring (Circling) Area Not Considered For Obstacle Clearance

It is permissible to eliminate from consideration a particular sector where a prominent obstacle exists in the manoeuvring (circling) area outside the final approach and missed approach area (Known as the prohibited area)

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Visual Manoeuvring (Circling) Area

And The Prohibited Area

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Obstacle Clearance & OCA/H (Where MDA is worked out)

CategoryObstacle

Clearance

Lowest OCA/H Above Aerodrome

Elevation

Minimum visibility*

C 394ft 591ft 3700m (2.0nm)

D 394ft 689ft 4600m (2.5nm)

* There are exceptions to the rule. Minimum visibility can be lowered if a localiser or other navigational facilities are available for the inbound tracking

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US TERPS Criteria

Cat C Cat D

Manoeuvring Speed 140kt 165kt

Ř 1.7nm 2.3nm

Minimum Visibility *1-1.5sm

(1600-2400m)

2sm

(3200m)

Minimum H.A.A. 450ft 550ft

Obstacle Clearance 300ft 300ft

* Minimum visibility can be lowered if a localiser orother facility is available for the inbound tracking

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PANS-OPS & TERPS DEFINITIONS

PANS-OPS (ICAO):

Procedures For Air Navigation Services – Flight Operations

TERPS (USA):

Terminal Instrument Approach Procedures

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Visual Manoeuvring Using Standard Track

For Discussion Purpose Only

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The Mathematics Behind

• At Speed 210kt = 3.5nm per minute• Rate 1 turn = 180º per minute• 45º turn will take 15 second to complete• 15+30+15 seconds = 1 min

At 210kt: S = Sine 45º x 3.5 = 0.707 x 3.5 = 2.47nm

• At Speed 180kt = 3nm per minute

At 180kt: S = Sine 45º x 3.0 = 0.707 x 3.0 = 2.12nm

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B747-400 Gear Down Flaps 30 - 150Kt IAS(Groundspeed 165Kt Maximum)

• S = 1.76nm (150kt Groundspeed) or • S = 1.94nm (165kt Groundspeed)

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Approximate Rate Of Descent From MDA To Touch Down

• At 700ft a.a.l. -------- 300-400fpm

• At 1000ft a.a.l. -------- 500-600fpm

• At 1200ft a.a.l. -------- 600-700fpm

CAUTION! Wings Must Be Level By 300ft a.a.l.

“Eye-Ball” All The Way From Base Turn Until Line-Up With The Extended Landing Runway Centreline – Watch

The PAPI To Maintain The Appropriate Slope Angle

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How To Determine Fac & Radius Of Turn

1. Acceleration towards the centre of the turn (ac) = V2/r

2. W = mg or m = W/g

3. Fac = mV2/r = W.V2/gr = W.tan(b)

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Determining Radius Of Turn

Approach speed = 150 knots (TAS)

r = (150 x 0.514)2 / 9.81 x tan 20º

= 5944 m/s / 9.81 x 0.364 m/s2

= 5944 m/s / 3.57 m/s2

= 1665 m = 1.665 km

= 1.665 km / 1.854 km

= 0.9 nm r = 0.8 nm if AOB = 22.5º

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Determine The AOB Of Rate 1 Turn

V = TAS (m/s)

g = 9.81 m/s2

tan(b) = AOB

r = radius of turn (m)

t = s/°.

If the amount of time it takes to fly a 360° circle is 360t; then t will represent the time it takes to turn 1°

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To Determine Angle Of Bank Of Rate 1 Turn Using A Simple Rule Of Thumb

10% Of Groundspeed + 7 = AOB

KTAS Bank Using Equation

Bank Using Rule of Thumb

50 7.8º 12º

100 15.5º 17º

150 22.5º 22º

180 26.5º 25º

260 35.7º 33º

320 41.5º 39º

475 52.7º 55º

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Forget About The Mathematics

• Just Set ND to 5nm Scale

• Ensure Airplane Symbol Stays Within

2nm From Runway

• Fly No Lower Than MDA

• No Faster Than Approach Speed

• You will be safe from obstacles in

the manoeuvring area

--- Rule Of Thumb ---

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Various Visual Entries

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Missed Approach Go-Around

IMPORTANT!

If lost visual during circling, it is imperative that the pilot flying must initiate a climbing turn towards the

runway until established on the published missed approach track

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Should a go-around be necessary after breakoff from the instrument approach, the missed approach procedure associated with that instrument approach should be used.

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Executing A Missed Approach

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Some Airports For Discussion

1. Penang – Pans-Ops

2. Tabriz – Pans-Ops

3. Fukuoka – TERPS

4. Kimhae – TERPS

5. Kathmandu – ?

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Main Differences BetweenPans Ops & TERPS Charts

Pans Ops Chart

1. The phrase “Pans Ops” is printed at the bottom left corner

2. Manoeuvre speeds:

Cat C a/c: 185kt

Cat D a/c: 205kt

TERPS Chart

1. It does not have “TERPS” printed anywhere (Before 2004)

2. Manoeuvre speeds:

Cat C a/c: 140kt

Cat D a/c: 165kt

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Pans-Ops Vs TERPS

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Pans-Ops Chart Legends

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TERPS Chart Legends

TERPS Margin notation appeared on charts printed after 21 Nov 2003

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Pans-Ops Or TERPS?

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IAP Design Indicators

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Fukuoka Airport

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Pusan (Kimhae) Airport

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Revised Chart

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Which Sector Is Prohibited To Circling?

Caution!

Circling Prohibited In Sector Inbound From 070º-200º Clockwise From Threshold Runway 04.

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Penang Airport

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Kathmandu Airport

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Tabriz – VOR DME 1

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The End

This Presentation Is Prepared By:This Presentation Is Prepared By: Capt Eddie Foo S NCapt Eddie Foo S N

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Updated On 3Updated On 3rdrd May 2005 May 2005

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Unlucky!

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Air China Flight 129

You Are Advised To Read & Digest The KAIB’s (Korean Aviation-Accident Investigation Branch) Official Report On Air China Flight 129’s Tragic “Circling To Crash”.

There Are Many Invaluable Lessons To Be Learned; As Well As The Safety Recommendations Proposed/Adopted.