public safety zones facc, 30 november 2009 ference van ham
TRANSCRIPT
Public Safety Zones
FACC, 30 November 2009
Ference van Ham
Introduction - Helios
• Since its creation in 1996, Helios has grown from its roots in air traffic management to become Europe’s leading independent management and technology air transport consultancy. During this time, we have worked with government bodies and agencies, regulators, service providers, manufacturing industry and investors.
• Our success has been recognised through two Queen’s Awards for Enterprise (in 2004 and 2009)
• Based on the AeroPark in Farnborough since 2007
Introduction – Ference van Ham
• Joined Helios 5 years ago, now senior consultant in the Operations team. Before Helios worked for the Dutch National Aerospace Laboratory (NLR) in Amsterdam for over 5 years.
• Project manager on a wide variety of projects including safety, validation, cost-benefit analysis.
• Some relevant project experience:
• Quality of Life in Airport Regions – an international programme set up by a number of European airport regions, in which Helios supported West Sussex County Council
• Second opinion on CDAs at Amsterdam Airport Schiphol – assessment of the feasibility of introducing CDAs at Schiphol airport, commissioned by the Dutch MoT on request from residents
Purpose of the presentation
• Request: “a ‘layman’s level’ presentation covering the main aspects of the subject”
• This presentation will discuss…• …why Public Safety Zones are considered necessary
• …how they are established° Which metrics?° Which boundary values?° How shape and size are determined
Inputs:
DfT Circular 1/2002 Control of development in Airport Public Safety Zones
NATS R&D Report 9636 Third party risk near Airports and Public Safety Zone policy
Number of fatal accidents(source: Aviation Safety Network)
0
50
100
150
200
250
300
1984-1988 1989-1993 1994-1998 1999-2003 2004-2008
Why do we need Public Safety Zones – some safety statistics
• Despite growing air traffic, the number accidents is decreasing
Why do we need Public Safety Zones – some safety statistics
• Despite growing air traffic, the number accidents is decreasing
• Risk is relatively high during landing and take-off
• Margins of error are smaller
• Aircraft are operating closer to their limits
Why do we need Public Safety Zones – some safety statistics
• Despite growing air traffic, the number accidents is decreasing
• Risk is relatively high during landing and take-off
• Margins of error are smaller
• Aircraft are operating closer to their limits
• Third party fatalities on the ground are rare
Total number of third party fatalities in ECAC 1980 – 2003: 62Average number of third party fatalities per year: 3Largest number of third party fatalities in a single accident: 43
So is it dangerous to live near an airport?
What is considered dangerous?
In recognition of both positives and negatives, development near airports is typically restricted but not prohibited
Risk associated with various aspects of daily life:
According to the Royal Society for the Prevention of Accidents……over 2,500 people were killed in road accidents in the UK in 2008…almost 4,000 people die of accidents in the home every year
According to the UK Health and Safety Executive, in 2008/2009……180 people were killed in work related accidents…94 members of the public were killed in work related accidents…the UK is relatively safe compared to the European average
According to the US National Weather Service, an estimated 70 people were killed by lightning in the US in 2008
YES – there is a risk associated with airport operations
NO – the risk is not excessive compared to other activities
What is a Public Safety Zone?
• Department for Transport Circular 1/2002: ‘Public Safety Zones are areas of land at the ends of the runways at the busiest airports, within which development is restricted in order to control the number of people on the ground at risk of death or injury in the event of an aircraft accident on take-off or landing’
How is a PSZ defined - metrics
• Individual risk
• the chance that an individual at a particular location will be harmed by an incident
• Societal risk
• the chance of a number of people being harmed by a single incident
• Cost benefit
• a balance between the benefits of reducing risk and the costs of taking the relevant measures
How is a PSZ defined - metrics
• Individual risk
• the chance that an individual at a particular location will be harmed by an incident
• Societal risk
• the chance of a number of people being harmed by a single incident
• Cost benefit
• a balance between the benefits of reducing risk and the costs of taking the relevant measures
Constrained cost benefit: implementing measures to reduce intolerable risk, without regard for cost; implementing additional measures only if benefits outweigh costs
How the boundary values have been established
Decreasingrisk
Unacceptableregion
Broadlyacceptable
region
Tolerabilityregion
Risks cannot be justified save inextraordinary circumstances
Risk is tolerable if cost of risk reduction exceeds benefits
10-4
10-6
How the boundary values have been established
Decreasingrisk
Unacceptableregion
Broadlyacceptable
region
Tolerabilityregion
Risks cannot be justified save inextraordinary circumstances
10-4
10-6
10-5
Benefits of risk reduction generally outweigh costs
Costs of risk reduction generally outweigh benefits
How is a PSZ defined – metrics to contours
• Two levels of risk are considered:
• 1:10,000 individual risk is the maximum risk the public should be exposed to
° DfT Circular 1/2002 ‘The Secretary of State regards the maximum tolerable level of individual third party risk of being killed as a result of an aircraft accident as 1 in 10,000 per year.’
• 1:100,000 individual risk forms the outer boundary for PSZ policy
• These levels form the basis for PSZ policy
1:100,000 contour
1:10,000 contour
How is a PSZ defined - models
• Three major contributors• the probability of a crash
occurring near a given airport (crash frequency)
• the distribution of such crashes with respect to location (crash location)
• the size of the crash area and the proportion of people likely to be killed within this area (crash consequence)
• Models are required to determine these three contributors
How often will an aircraft crash occur, and if an aircraft crashes, where will it crash and what will be the impact?
Contributor 1: Crash frequency
• The crash frequency for a particular airport depends on:
• The types of aircraft flying into the airport
• The number of movements at the airport – per type of aircraft
• Crash frequency is determined in an empirical way rather than a deterministic way
Use of historical data
• Issues with historical data• Needs to be representative of the type of operation being
modelled: ideally, we want crash rates at UK airports per aircraft type for all types…
• …but there is insufficient data for this approach
• Compromises suggested:° ’First world’ data only
° Aircraft groups created
All aircraft
Jet
Turboprop
Piston
Western
Eastern
Executive
Class I
Class II+
Western airline
Other
Pre-1970
Post-1970
Contributor 2: Crash location
• Two aspects of probability of crash location are required:
• longitudinal distribution – crashes are more likely to occur closer to runway
• lateral distribution – crashes are more likely to occur closer to extended runway centreline
• Models aim to fit a mathematical distribution function to historical data
• Statistically relevant data is even more limited
• Need for information on where an aircraft crashed adds a further dimension to the required information
• Crash reports do no always include all required information
Longitudinal
Lateral
Contributor 3: Crash consequence
• Two factors are of importance:
• The size of the area affected
• The probability of people within that area being killed
• ‘The consequences of an aircraft accident depend upon a large number of factors including size of aircraft, impact velocity, impact angle, whether or not the aircraft breaks up on impact, the amount of fuel on board, whether a fire occurs (and the extent of the fire), the terrain at the crash site etc.’
• Different models provide significantly different results
Why would a PSZ change - inputs
• It is Government policy that PSZs should be updated approximately every seven years to ensure that the data underpinning the contours are reliable
• Inputs change:
• Number of movements
° Runway use
• Aircraft mix
• Airport layout
Note: inputs should always be taken at some point in future, not current figures!
Why would a PSZ change - models
• It is clear from the description of the three contributors to PSZ definition that many factors are assumed or based on limited statistical evidence
• Models may be updated (or new models may be developed!) to reflect the latest knowledge and understanding of relevant parameters
• Changes in understanding
• Changes in statistical basis
• …
What is the policy applied to a PSZ
• DfT Circular 1/2002
• Objective is to restrict development in specific areas, with the aim of not increasing and, over time, decreasing the number of people living, working or congregating in these areas
• Over time, removing all residential and commercial properties in the 1 in 10,000 zone
• ‘General presumption’ that there will be no new or replacement development in the 1 in 100,000 zone
° With certain exceptions
