documentation & examples - srvsop/2017-10... · safety assessments and compatibility studies...

Safety assessments and compatibility studies Documentation & examples

Sebastien Lavina – Airport Operations

[email protected]

[email protected]

October 2017

Contents

• Context

• Short runways

• Narrow runways

• Runway characteristics

• Taxiway characteristics

• Separations

• Holding points

• Visual aids

• Bridges

• Parking stands

October 2017 Safety assessments and compatibility studies 2

Contents

• Context

• Short runways

• Narrow runways



• Separations

• Holding points

• Visual aids

• Bridges

• Parking stands


ICAO Annex 14 introductory note

• Introductory Note.— This Annex contains Standards and Recommended Practices (specifications) that prescribe the physical

characteristics and obstacle limitation surfaces to be provided for at aerodromes, and certain facilities and technical services

normally provided at an aerodrome. It also contains specifications dealing with obstacles outside those limitation surfaces. It is not

intended that these specifications limit or regulate the operation of an aircraft.


EASA

• ADR.OPS.B.090 Use of the aerodrome by higher code letter aircraft

COMMISSION REGULATION (EU) No 139/2014 of 12 February 2014 laying down requirements and administrative procedures

related to aerodromes pursuant to Regulation (EC) No 216/2008 of the European Parliament and of the Council

SUBPART B — AERODROME OPERATIONAL SERVICES, EQUIPMENT AND INSTALLATIONS (ADR.OPS.B)

ADR.OPS.B.090 Use of the aerodrome by higher code letter aircraft

• (a) Except for aircraft emergency situations, an aerodrome operator may, subject to prior approval by the Competent Authority,

permit the use of the aerodrome or parts thereof by aircraft with a higher code letter than the aerodrome design characteristics

specified in the terms of the certificate.

• (b) In showing compliance with point (a), the provisions of ADR.OR.B.040 shall apply.


EASA

Safety assessments


General methodology overview

• Baseline identification

ICAO SARPS

Justification materials

• Hazard analysis

Identification of undesirable events and hazards

Causal analysis

Consequences analysis, severity level

• Risk assessment

• Conclusion

• Publication in Aerodrome Manual

• Factors of consideration: frequency analysis, experience from other airports/authorities


Risk assessment classification

• Type A

Depends on specific aircraft performance and handling qualities

Safety level achieved by suitability between above characteristics and infrastructure

Risk assessment based on aircraft design and certification (with additional simulations as requested)

• Type B

Aircraft behaviour calculated from existing aircraft measurements

Risk assessment based on statistics and accident analyses

Development of generic quantitative risk models

• Type C

Risk assessment study not needed

Geometric argument to calculate infrastructure requirements

No need to wait for certification results of to collect statistics for existing aircraft


Airport 1

• Airfield infrastructure assessed by comparing known characteristics against requirements

• Identification of areas requiring action

• Modelisation of aircraft ground movement

Check pavement width

Object clearances

• Comparison with other airports

• Safety assessment

Operational risk assessment process

Joint panels with ANSP

• Compliance matrix


Item Annex 14

requirement

National CAA

requirement

Compliance

status Evidence

Safety

measures &

comments

Airport 2

• Risk analysis

Identification of risk

Acceptability classification

Causes

Corrective measures

Action on consequence/frequency

Acceptability classification after corrective measures

• Action plan

• Return on experience

• Update of measures as and when required


Frequency

Classification

Very frequent Frequent Occasional Rare Extremely

rare

Catastrophic

Serious

Major

Minor Event

Negligble

Frequency

Classification

Very frequent Frequent Occasional Rare Extremely

rare

Catastrophic

Serious

Major

Minor

Negligble Event

FAA MoS (Modification of Standards) methodology

• Standard being modified

• Standard/requirement

• Proposal

• Explanation: why standard cannot be met

• Discuss viable alternatives

• Statement: why modification would provide acceptable level of safety


https://www.faa.gov/airports/engineering/nla_mos/

Aerodrome code / larger aircraft accommodation

• Aerodrome Reference Code is for design and planning purpose. It is not intended to restrict aircraft operations at an airport



• Many aerodromes with reference code 4E accommodating the A380 and B747-8 (code F)

Airport operator to provide justification of the safe operations (and possibly operational procedures to be put in place)

• Many aerodromes with reference code 3C accommodating A320 and B737

Airport operator does not need to file any dossier to the local CAA



• Example: Florence airport, Italy

• Runway length 1,560m

• Aerodrome reference code 3C (length < 1,800m)

• The Aerodrome Manual reports all the characteristics of the runway, its proper aerodrome reference code (3C) and its

representative aircraft (Airbus A319, theoretically a code 4 aircraft (RFL = 1,800m))

• No need for any specific authorization from the Civil Aviation Authority, as the use of the first element (number) is only for airport

design purpose and not for airport operational reasons

• A319 is fully capable of taking-off and landing at Florence airport

• About 65 A319 departures per week at Florence airport


Contents

• Context

• Short runways

• Narrow runways



• Separations

• Holding points

• Visual aids

• Bridges

• Parking stands


0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2,000

0

20

40

60

80

100

120

140

Runway length (TORA)in meters

Average number of A320 flights per week

Airports with A320 family operating on runways shorter than 1,800m

North / South America

Europe

Asia

A320 family operations on short runways

• A320 family aircraft are classified as code 4C according to ICAO Annex 14 (reference field length > 1,800m)

• A320 can also operate on runways shorter than 1,800m, as it is the case in more than 25 airports in the world.


Code 3 limit

(*) Airports with TODA above 1,800m

A320 family operations on short runways

• On short runways: performances can be augmented with special surfaces (wet grooved or PFC (Porous Friction Course))

• Objective is to enhance the runway drainage so that the friction with the aircraft tyres is increased.

• In addition, special aircraft modifications are required to take a performance credit on those runways

• The monitoring of the runway condition is the responsibility of the aerodrome operator

• AIP should state if runway surface pavements qualify for performance credit

• Example in Europe: Florence airport (1,560m)


Contents

• Context

• Short runways

• Narrow runways



• Separations

• Holding points

• Visual aids

• Bridges

• Parking stands


A320 operations on narrow runways

• The nominal runway width for operations of the aircraft is 45 m.

• Operations on runways with a width below 45 m are covered through a specific modification. Only aircraft fitted with the

modification can safely operate on narrow runways.

• The aircraft has been shown to be safely controllable and to be compliant with applicable airworthiness requirements when

operating on runways with a width of 30m or more

• Specific limitations apply:

Operations on narrow runways is not allowed in case of nose wheel steering inoperative,

Operations on narrow runways is not allowed in case of one brake or more inoperative.

Autoland is not allowed.

• The Aircraft Flight Manual (AFM) contains all necessary information on procedures and limitations


A320 operations on narrow runways

• 48 airports with A320 operations on narrow runways - 22 airports with operations on 30m runways


0

50

100

150

200

250

300

350

400

Number of weekly departures

A320 family Operations on narrow runways

Operations on 30m runways

Narrow runway – A330/A340 family

• ICAO Annex 14 recommendation: 45m minimum

• Allowance for some operations on lower runway width requested on a case by case basis

• Airbus guidelines

Autoland Cat3 operations on runway below 45m width not allowed

Operation on 44m wide runways is acceptable

Operation on 43m wide runways is acceptable, provided total runway + paved shoulders width is at least 44m

Operation on 40m to 42m wide runways is acceptable, provided total runway + paved shoulders width is at least 44m. Shoulders

shall be capable of supporting the aeroplane without inducing structural damage.

A340: recommended total width 45m (runway + paved shoulders) to minimize FOD risk

Does not apply on partially cleared snow runways

• Operational approval shall be given by the local authority

• Absolute minimum; any relevant safety parameters shall also be accounted for (RESA, lighting, runway profile…)

• In service: A330 operations at Port-au-Prince Airport (Haiti)

43m wide runway


Contents

• Context

• Short runways

• Narrow runways



• Separations

• Holding points

• Visual aids

• Bridges

• Parking stands


Runway width

• Main hazard: lateral excursion

• Causal analysis

Human factors (crew, maintenance…)

Aircraft (powerplant, landing gear, engines, systems…)

Weather and surface conditions

• Consequence analysis

Major to catastrophic

• Risk assessment

Strongly depends on aircraft performance and handling qualities

Considerations: final approach speed, flight handling qualities, landing incidence/attitude and cockpit visibility, thrust reversers,

certification process


Runway shoulders

• A380 @ Manchester

Stabilized grass shoulder extending to the limit of the cleared and graded strip

Trials to assess the ability of the shoulder to support a fire tender

RFFS response to aircraft stopped on runway is not dependent upon using the grass areas


Existing natural soil is

strong enough to support a

rescue vehicle (30t here)

45 m runway

7.5 m shoulder

Clean grass with no loose gravels: no

risk of FOD ingestion or jet blast issue

Runway shoulders – Frankfurt airport


Frankfurt Main Airport

07L/25R; evidence regarding

- the condition, load-bearing capacity, and resistance to

erosion and ingestion proc-esses of the shoulder areas

Runway shoulders - Singapore

• Chemical-soil stabilization

• Evaluation criteria

Ability to meet airport operational restrictions

Construction speed

Shoulder pavement design

Environmental impact

Cost effectiveness

• Lessons learnt

Comprehensive project planning

Comprehensive methodology evaluation

Minimizing disruptions

Sample testing for quality assurance


Tests on the occasional load bearing of shoulders


With a Geotextile fabric between the Subgrade and the aggregate

Type 3

6 cm BBME

20 cm GRH

Subgrade (infinite)

Type 2bis

6 cm BBA

20 cm GRH

subgrade (infinite)

Full size testing: 5 Structures tested.

Type 1

6 cm BBA

20 cm GLSR

30 cm of Treated soil

subgrade (infinite)

Type 1 bis

6 cm BBA

20 cm GLSR

Subgrade

(infinite)

Type 2

6 cm BBA

20 cm GRH

30 cm of Treated soil

subgrade (infinite)

BBA : Aeronautical Bituminous Concrete (0/10 class 2)

The selected critical bogie was the A380 WLG at 26.7

and 28.6 tons/wheels (bogie towed by a truck)

Trials Conditions simulated worst operational conditions:

•Subgrade bearing strength very poor (CBR of 2 and 3)

•Taxiing very slow (3-4 km/h)

It allows us to draw conclusions for operational Conditions

and to recommend to airport construction manager validated structures.

BBME : High Modulus Bituminous Concrete (0/10)

GLSR: Special Roadway Hydraulic binder aggregate (0/14)

GRH: humidify reconstituted crushed aggregate (0/20)

Conclusion on the occasional load bearing of shoulders


Runway shoulders – risk assessment

• Hazard identification

Shoulder erosion, engine ingestion

Difficulties for ARFF vehicles to intervene

Aircraft damage after incursion on shoulder

• Causal analysis

Powerplant

Shoulder width and cohesion

Runway centerline deviations

• Consequences analysis

FOD: major

ARFF delay: major to catastrophic

• Risk assessment

Geometric argument

Jet blast contours

Comparison with other aircraft types


Runway shoulders – A380 matrix


R = Runway +

Shoulder Width

Soil Type between

R and 75m Potential Issue

Operational

procedure

required by the

Airline

Operational

procedure

required by the

Airport

75m ≤ R N/A None None None

58m ≤ R < 75m

Stabilized

(without loose gravel) None None None

Unstabilized

(with loose gravel) Jet blast None

Runway inspection

and sweeping

required after take off

R < 58m

Stabilized

(without loose gravel)

Foreign object

ingestion

Apply specific 58m

take-off procedure None

Unstabilized

(with loose gravel)

Foreign object

ingestion + jet

blast

Apply specific 58m

take-off procedure

Runway inspection

and sweeping

required after take-off

Shoulder

Shoulder

Soil

Runway R 45 m

minimum 75 m

Soil

Runway strip - Definition


Runway strip objectives:

• Reduce the risk of damage to aircraft running off a runway;

• Protect aircraft flying over it during take-off or landing operations

Runway strip requirements

• Width:

• 150m on each side of the RWY centreline for code 3 or 4 runways

(ICAO Annex 14, §3.4.3)

• Graded portion: 75m on each side of the RWY centreline for code 3 or

4 runways to protect runway veer-off (ICAO Annex 14, §3.4.8)

• Transverse slope on graded portion: 2.5% for code 3 or 4 runway (ICAO

Annex 14, §3.4.15)

Runway strip

• What to do if the runway strip available is not wide enough?


RWY

Obstacle

Sea

RWY

Minimum recommended width

instrument runways (150m)

Minimum recommended width

non-instrument runways (75m)

Runway strip - example

• Limitation due to geographical constraints: Special Condition required to authority


75m 75m

Rwy strip

• Airport X – Methodology

Elements/arguments on physical and topographical limitations

Need for efficient drainage (pit – culvert)

Geometrical demonstration (obstacles below runway or taxiway altitude -> wing well over obstacle in case of deviation)

Risk analysis, frequency, deviation statistics


RESA – Runway end Safety Area - Definition


Minimum

150m

RESA (Runway End Safety Area)

• RESA required as per ICAO Annex 14 or equivalent regulation (EASA CS-ADR, RBAC-154, etc)

• What to do if there is no space to build a RESA?


San Sebastian Airport (Source, Google Earth, © Europa Technologies)

No space for a RESA – Option 1: Expand over the sea:

• Steel pillars (to mitigate environmental impact / river streams modifications) or landfill


RESA

Part built on

pillars

Tokyo Haneda airport – runway 05 threshold

No space for a RESA – Option 2: implement an arrestor bed (EMAS)

• What is EMAS?

EMAS (Engineered Material Arresting System) standard developed by FAA

in the 1990s. => allows to reduce RESA length

Composed of crushable material that would stop an aircraft overrunning the

runway. Depth of the EMAS increases with distance from runway.

When the aircraft reaches the arrestor bed, the material interface with the tire

provide a resistive force, which quickly decelerates the aircraft

Aircraft entry speed usually ~70 kt

• EMAS already installed at many airports since 1996

Equipping 100+ runways (JFK, MAD, BOS, ORD, TSA…)

Length reduced down to 60 m at certain airports (Boston, runway 04L end)

Already stopped safely 10+ aircraft overrun

• Airbus working in cooperation with EMAS manufacturers to provide aircraft

characteristics to be used for design

• Provision of an arresting system should be published in the AIP

October 2017

Safety assessments and compatibility studies

38

Boston Logan airport – runway 04L end

No space for a RESA – Option 3: Reduced Declared distance

• No space to expand or implement an arrestor bed

• Chosen solution was to reduce the declared distances

• Declared distances:

Initial 1,754m

New TORA 1,590m, new LDA 1,427m

• New pavement marking: like a displaced threshold (arrows)

Prevents runway undershoot (displaced threshold)

Reduced take-off length in the direction of the take-off

• High impact on operations

A319 and equivalent: max payload 62 pax instead of 144 pax

Potential solution through PFC / improved grooving surface.

• Implemented in August 2017


04

22

New threshold 22

New threshold 04

No space for a RESA – Option 2: Example of arrestor bed creation

• Arrestor bed at a French airport (Saint-Denis-La Réunion)

• Justification dossier to be provided if necessary by the airport to the civil aviation authority (specification on design solution: aircraft

type considered, capability of the material to sustain the deceleration)


Runway End Safety Areas

• Possible solutions

extension over water

threshold displacement


Contents

• Context

• Short runways

• Narrow runways



• Separations

• Holding points

• Visual aids

• Bridges

• Parking stands


Taxiway width – straight section



Lateral excursion

• Causal analysis

Mechanical failure

Surface conditions

Loss of visual guidance

Pilot precision and attention


Theoritically major

In-service events: extremely low rate

• Risk assessment

Low dependency on aircraft type

Pilot attention and precision: aircraft behaviour deduced from measurements

Geometric argument (visibility from cockpit)

Taxiway deviation statistics

Note: cameras (when available) for assistance only

Taxiway width – curved section


• Similation tools for checks

• Mitigation measures

Oversteering

Taxiway width – Safety analysis

• Airport Z

Calculation of edge margin

Shoulders

Lighting, markings

Long-term plan for widening (during usual maintenance programme)

Experience of other airports / CAAs, experience of previous operations at the airport (same or similar aircraft)


Taxiway shoulders



Shoulder erosion, engine ingestion

Aircraft damage after incursion

• Causal analysis

Powerplant

Shoulder width and cohesion

Taxiway veer-off


Erosion, ingestion: minor

If undetected and followed by engine failure at takeoff: potentially major

• Risk assessment

Geometric argument (visibility from cockpit)

Comparison with other aircraft

Jet blast contours

Taxiway deviations

Taxiway shoulders – A380 matrix


T = Taxiway

Width + Shoulder

Soil Type between

T and 54m Potential Issue Recommended Taxi Procedure

Airport Operations

Recommendations

54m(1) ≤ T N/A None Normal None

36m ≤

T

< 60m

Stabilized

(without loose gravel

or sand)

None Normal None

Unstabilized

(with loose gravel or

sand)

Jet blast

from outer engines

Keep outer engines at idle (or shut

down) and put additional thrust on

inner engines if necessary

Taxiway inspection and

cleaning may be needed

(especially in turns)

T < 36m

Or

T is contaminated

N/A

Foreign object ingestion

by inner engines & jet

blast from all engines

Keep inner engines at idle (or shut

down) and smoothy put additional

thrust on outer engines if

necessary

Taxiway inspection and

cleaning may be needed

(especially in turns)

Shoulder

Shoulder

Soil

T 23m

60m(1)

Soil

Taxiway Caution: Given changing conditions

at some airports, pilots shall monitor

the paved surface for the presence

of loose gravel and modify thrust

procedures accordingly

Contents

• Context

• Short runways

• Narrow runways



• Separations

• Holding points

• Visual aids

• Bridges

• Parking stands


Runway to taxiway separation



Collision between an aircraft (in flight or veering off the runway) and an object (fixed or mobile)

• Causal analysis

Human factors

Weather conditions

Aircraft (wingspan, mechanical failure)

Airport layout

Obstacle density


Aircraft in flight: catastrophic; in service: no known case

Aircraft veering off: potentially catastrophic

In-service events: extremely low rate

• Risk assessment

Aircraft performance and handling qualities

Geometric argument

Balked landing simulations

Veer-off statistics / database

Runway to taxiway separation – FAA initial operational standards (A380)


Runway Use Separation Restriction

Departure 400 ft (120 m) No

Arrival

More than ¾-statute mile approach visibility minima 400 ft (120 m) No

Cat I 400 ft (120 m)

No more than one A380 maybe on the first 3,000 ft (915 m) of the parallel taxiway from the threshold

500 ft (150 m) No

Cat II/III 400 ft (120 m)

No A380 maybe on the first 4,000 ft (1,220m) of the parallel taxiway from the threshold

500 ft (150 m) No more than one A380 maybe on the first 3,000 ft (915 m) of the parallel taxiway from the threshold

Runway to taxiway separation

• Airport A

Geometric calculation of margin

Restriction of operations on parallel taxiway


Runway to taxiway separation – weather conditions


Taxiway to taxiway separation – AACG process



Collision between two aircraft

• Causal analysis

Human factors

Weather conditions




Potentially major

• Risk assessment

Based on statistics or accident analyses


Cockpit visibility

Proper guidance for night or LVP operations

Taxiway to taxiway separation – MoS process



Group VI taxiway centerline to taxiway centerline separation


324ft

• Proposal

Varies between 298 and 276ft


Proximity of runway

Relocation impact on parking stands or adjacent facilities


No other viable alternatives


No simultaneous A380 operations

Taxiway deviation statistics, low probably of occurence

Taxiway to taxiway separation

• FAA operational standards for A380

• Airport 1

Long-term realignment planned

Restriction of use of parallel taxiway, or wingspan size limitation

Follow-me vehicle

Sequential taxiway centerline lighting during LVP


Separation Restriction – Taxiway Use

237 ft (72.2 m)

Aircraft with wingspan up to 118 ft (34 m) on the adjacent taxiway

267 - 276 ft (81.5 - 84 m)


280.5 ft (85.5 m)


298 ft (91 m)


Taxiway-taxilane to object separation – AACG process



Collision between an aircraft and an object (fixed or mobile)

• Causal analysis

Human factors

Weather conditions




Potentially major

• Risk assessment


Cockpit visibility

Proper guidance for night or LVP operations

Possibility of reduced margins for height-limited objects

Taxiway-taxilane to object separation – MoS process (A380)



Group VI taxiway centerline to fixed or moveable object (FOMO)


193ft

• Proposal

Varies between 146 and 170ft


Impact of relocation (loss of stands, reduced separation elsewhere, infringement of boundaries…)


No other viable alternatives


• FAA operational standards Separation Restriction

146 ft (44.5 m)

No speed restriction

In presence of vehicle service road, height must be limited to 14 ft (4.3 m)

Taxiway to object separation

• Airport W

Specific marking to get sufficient clearance

• Airport Y

Reduced speed during taxi

Displaced centerline

AIP publication for pilots’ information

Cameras if available

Limitation of height of vehicles on service road

Follow-me vehicles


Contents

• Context

• Short runways

• Narrow runways



• Separations

• Holding points

• Visual aids

• Bridges

• Parking stands


Holding points

• Airport 1

Infringement of protection areas

No departing aircraft rolling. No landing aircraft within 3nm from touchdown

• Airport 2

Geometric demonstration

ICAO Circular 301 (OFZ)


Contents

• Context

• Short runways

• Narrow runways



• Separations

• Holding points

• Visual aids

• Bridges

• Parking stands


Visual aids



Jet blast damage

• Causal analysis

Powerplant

Elevated edge lights strength

Aircraft rotation angle at takeoff

Runway deviation factors


Potentially major (if undetected before takeoff and followed by engine ingestion and tire bursting risks)

• Risk assessment

Geometric argument

Engine positions

Jet blast contours

Aircraft rotation angle

Contents

• Context

• Short runways

• Narrow runways



• Separations

• Holding points

• Visual aids

• Bridges

• Parking stands


Taxiway bridge



Veeroff and aircraft falling from the bridge

Evacuation slides falling past the edge

Difficulties for fire fighting intervention

Blast under the bridge

• Causal analysis

Same as taxiway width causes

Bridge width

Evacuation slides configuration

Aircraft (wingspan, engine position and span)


Major to catastrophic depending on the event

In service: no cases reported

• Risk assessment

Geometric argument

Engine positions

Jet blast contours

Firemen practices

Contents

• Context

• Short runways

• Narrow runways



• Separations

• Holding points

• Visual aids

• Bridges

• Parking stands


Parking stands

• Possibility of reduced distance with appropriate measures

• E.g. lighting, marshaller

• Downgrading of adjacent stands

• MARS stands


Thank you

documentation & examples - srvsop/2017-10... · safety assessments and compatibility studies...

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