Update of aircraft crash rates used by HSE in assessing ...Military combat and jet trainers: all...
Transcript of Update of aircraft crash rates used by HSE in assessing ...Military combat and jet trainers: all...
Update of aircraft crash rates used by HSE
in assessing hazards from chemical, process
and other major hazard installations
Prepared by the Health and Safety Executive
RR1140 Research Report
© Crown copyright 2019
Prepared 2017 First published 2019
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The Health and Safety Executive (HSE) provides advice on land use planning in the vicinity of major accident hazard
sites and major accident hazard pipelines. As part of this process, HSE publish a guidance document, Failure Rate and
Event Data, which contains failure rates for pieces of equipment found in major hazard chemical and process sites. The guidance document also contains information on
event data such as aircraft crash and flooding, which are used when assessing the risks from such major hazard sites.
An event such as an aircraft crash could lead to a release of a hazardous substance that could potentially harm people.
Th e aircraft crash rates were previously updated in 2009 using data up to 2006. This report updates the crash rates u sing data from 1990 to 2013. The methodology used to calculate the crash rates is also detailed. Uncertainty levels p rovide upper and lower bounds to the calculated crash rates to account for the uncertainty in the data that is used to derive the crash rates.
This report and the work it describes were funded by the Health and
Safety Executive (HSE). Its contents, including any opinions and/or
conclusions expressed, are those of the authors alone and do not
necessarily reflect HSE policy.
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Update Lorem ipsu of aircraftm d croash rates lor sit aused bmet y HSE in
assessing
consectetuer adipiscing
hazards from chemical elit, proce ss
and other major hazard installations
Zoe Chaplin Hea lth and Safety Executive Harpur Hill Buxton Derbyshire SK17 9JN
Acknowledgements
The author gratefully acknowledges the assistance received from Graham French of the Civil Aviation Authority (CAA), who provided data used in this report.
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KEY MESSAGES
The Health and Safety Executive (HSE) provides advice on land use planning in the vicinity of major
accident hazard sites and major accident hazard pipelines. As part of this process, potential external
events are considered that could damage the site or pipeline. One of these events is aircraft crashes.
If an aircraft crash occurs, the equipment on the site can be damaged leading to a release of the
hazardous substance and potentially harming people. Information on aircraft crash rates was
previously updated in 2009 to use data up to 2006.
HSE have updated the aircraft crash rates currently used to incorporate data up to 2013.
The methodology used to calculate the crash rates had been reviewed and modified previously. Both
the current and revised methodologies have been detailed and the revised methodology was used
to update the crash rates.
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EXECUTIVE SUMMARY
HSE provides advice on Land Use Planning (LUP) in the vicinity of major accident hazard sites and major accident hazard pipelines. As part of this process, HSE publish a guide to failure rates for vessels and pipework for use in LUP cases (hereafter referred to as Failure Rate and Event Data1). As part of this guide, external hazards are identified that may also need to be taken into consideration when assessing the hazards from chemical and process sites. One of these events is aircraft crashes. The aircraft crash rates and methodology reported in Failure Rate and Event Data were last updated in 2009 using data up to 2006.
This report is aimed at risk assessment modelling specialists for major accident hazard sites.
The available methodologies on calculating aircraft crash rates were reviewed in 2015 and some of the crash rates were recalculated using data from 1990 to 2013. It was decided that Failure Rate and Event Data should be modified to incorporate the more recent information. In addition, further information has been obtained to update the crash rates that were not considered as part of the recent review.
The crash rates are separated into two categories: background and airfield related. The background rates apply at distances greater than 5 miles from any airfield and relate to the cruising stages of flight. The airfield related crash rates apply within 5 miles of the airfield and are associated with the take-off and landing stages of flight.
The background crash rates and airfield related crash rates have been updated for five categories of aircraft. A 95% confidence interval has been included as part of the calculations to provide an indication of the level of uncertainty surrounding the data. The revised background crash rates are given in Table 1. Table 2 reports the revised airfield related crash rates.
Table 1 Calculated background crash rates (× 10-6 km-2 yr-1) for the period 1990 to 2013 for Great Britain.
Aircraft type Mean Lower confidence limit Upper confidence limit
Light aircraft 18.5 15.1 22.4
Small transport aircraft 2.2 1.1 3.8
Large transport aircraft 0.7 0.2 1.9
Helicopters 10.3 7.8 13.4
Military combat aircraft 6.7 4.7 9.2
Total 38.4 28.9 50.7
1 HSE (2012). Failure rate and event data for use within risk assessments (28/06/2012).
http://www.hse.gov.uk/landuseplanning/failure-rates.pdf
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Table 2 Airfield related crash rates (× 10-6 per movement) for the period 1990 to 2013 for Great Britain
Aircraft type Mean Lower confidence limit Upper confidence limit
Light aircraft 2.5 2.1 2.9
Small transport aircraft 3.8 2.5 5.5
Large transport aircraft 0.08 0.02 0.24
Civil helicopters 2.4 1.6 3.5
Military combat aircraft 3.5 2.5 4.8
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CONTENTS KEY M ESSAGES……………………………………………………………………. 5
EXECUTIVE S UMMARY 6 …………………………………………………………….
1 INTRODUCTION ............................................................................................. 9
2 METHODOLOGY .......................................................................................... 10 2.1 Current Methodology ..................................................................................... 10 2.2 Revised Methodology .................................................................................... 11
3 REVISED CRASH RATES ............................................................................ 12 3.1 Background crash rate................................................................................... 12 3.2 Airfield related crash rate............................................................................... 12
3.2.1 Small and Large Transport Aircraft ..................................................................................13
3.2.2 Light Aircraft ....................................................................................................................13
3.2.3 Helicopters .......................................................................................................................18
3.2.4 Military Combat Aircraft ..................................................................................................20
3.2.5 Summary of crash rates ...................................................................................................20
4 CONCLUSIONS ............................................................................................ 21
5 APPENDIX A: BACKGROUND RATE DATA............................................... 22
6 APPENDIX B: AIRFIELD RELATED RATE DATA....................................... 33
7 REFERENCES .............................................................................................. 47
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1 INTRODUCTION
The Health and Safety Executive (HSE) publish a guide to failure rates for vessels and pipework for use in Land Use Planning (LUP) cases [1] (hereafter referred to as Failure Rate and Event Data). As part of this guide, external hazards are identified that may need to be taken into consideration when assessing the hazards from chemical, process and nuclear sites. The external hazards include lightning, flooding and aircraft crash.
Aircraft have the potential to crash onto a site, causing significant damage. As part of an LUP assessment, it is therefore necessary to consider the aircraft crash rate. The aircraft crash rates and methodology reported in Failure Rate and Event Data were last updated in 2009 using data up to 2006.
The crash rates are separated into two categories: background and airfield related. In both cases, crash rates are calculated for different types of aircraft (e.g. large transport, small transport, helicopters etc.). The background crash rates apply outside of a 5 mile radius of any airfield and relate to the cruising stage of flight. The airfield related crash rates apply within 5 miles of the airfield and are associated with the take-off and landing phases of flight.
In 2015, HSE reviewed the available methodologies on calculating aircraft crash rates as part of another project [2]. The background crash rates were also recalculated using data from 1990 to 2013, together with the airfield related crash rates for large transport aircraft. H SE therefore decided that Failure Rate and Event Data should be modified to incorporate the more recent information. In addition, the remaining airfield related crash rates that had not been considered as part of the earlier project should be updated.
The remainder of the report is structured as follows:
Section 2 provides an overview of the current methodology and details the revised methodology;
Section 3 details the calculations required to update the crash rates; and
Section 4 concludes the report.
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2 METHODOLOGY
Aircraft crash rates enable an assessment to be made of the hazard that an aircraft crash poses to a piece of infrastructure e.g. a chemical site, a nuclear plant etc. The methodology to calculate aircraft crash rates therefore needs to consider different types of aircraft as the hazards posed by them will vary e.g. a small aircraft is likely to cause less damage than a large passenger aircraft. The methodology must also be applicable to all sites located in Great Britain. This includes sites that are within 5 miles of an airport where airport specific crash rates are used, sites that are further away where a background crash rate will apply, and sites that have a significant number of military aircraft flying over them.
The details of the current methodology are given in Section 2.1 and the revised methodology is described in Section 2.2.
2.1 CURRENT METHODOLOGY
The methodology used in Failure Rate and Event Data is that of Byrne [3]. The methodology involves calculating background crash rates for different classes of aircraft across the UK. The background rates apply in areas that are at least 5 miles away from an airfield. The aircraft categories are:
Light aircraft: fixed wing aircraft of less than 2.3 te maximum take-off weight authorised (MTWA). It includes military light aircraft used for training that are less than 2.3 te MTWA;
Helicopters: all civil and military helicopters;
Small transport aircraft: fixed wing aircraft in the MTWA range of 2.3 te to 20.0 te, including civil and transport military aircraft;
Large transport aircraft: any other civil or military fixed wing aircraft not covered in the other categories; and
Military combat and jet trainers: all military fixed wing aircraft with MTWA up to 40 te to 50 te capable of aerobatic style flying.
Two areas of the UK are designated as being in high crash concentration zones for military aircraft. These are areas where low-level flying occurs. The crash rate applicable from military aircraft is adjusted if the site being assessed is within one of these zones. If the site is within a 50 km transition zone from a high crash concentration zone, then additional analysis is undertaken to adjust the military aircraft background crash rate.
Airfield specific crash rates apply if a site is within 5 miles of an airfield. In this case, crash rates have been derived per take-off and landing for each of the five aircraft categories. The rates calculated are assumed to apply for all airfields within the UK. The crash rates for each aircraft category are multiplied by the number of movements of that category of aircraft at the airfield in a typical year to derive a crash rate specific to an airfield. The likelihood that an aircraft will crash on a site as a result of a take-off or landing failure depends on the direction of the site from the airfield and the directions of the runways. A method is available to derive the frequency with which a unit ground area at a specified position relative to the runway would suffer an impact.
Beyond the 5 mile limit of an airfield, the background crash rates are assumed to apply.
Flight paths are also considered as part of the methodology. This allows particular airways to be considered when calculating the likelihood of a crash on a specific site.
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A worked example has been given in Failure Rate and Event Data, including assumptions about the type of vessel failure that could occur, depending on the type of aircraft involved and the distance from the vessel.
2.2 REVISED METHODOLOGY
The crash rates within Failure Rate and Event Data [1] used data on aircraft incidents up to 2006 and relied on the Byrne methodology report [3] from 1997. The methodology has been reviewed [2] and data from 1990 to 2013 has been used to update crash rates, where possible.
The main change to the use of the Byrne methodology has been to include levels of uncertainty around the calculated crash rates. It has been assumed that the background crash rates may be represented as a Poisson process [4] with rate parameter λ (i.e. the number of background crashes per year for a chosen area). The maximum likelihood method [5] has been used to estimate the value of λ and the chi-squared distribution [6] has been used to calculate 95% confidence intervals.
In the subsequent tables in this section, the calculated crash rate is given together with the lower and upper confidence interval limits. The calculated crash rate is based upon the data available and the lower and upper confidence limits give the 95% confidence interval range. In simple terms, the calculated value of the crash rate is the one based directly on the data and can be thought of as the “mean” value (this value is referred to as the mean subsequently in this report), whilst the confidence interval provides an upper and lower bound on the true value of the crash rate, i.e. it is a measure of the uncertainty in the process and can be thought of as limits on the true value of the crash rate.
For the airfield related crash rates, a Poisson process has again been used with the maximum likelihood method used to calculate the airfield related crash rate per flight movement. The chi-squared distribution has been used to calculate 95% confidence intervals. The flight path data has not been updated since that reported by Byrne [3] in 2007 due to the levels of uncertainty involved in the calculations and the lack of easily available data. The general trends in the data appear to indicate that aircraft reliability is improving. The use of the data from Byrne for the flight paths can therefore be considered as cautious.
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3 REVISED CRASH RATES
3.1 BACKGROUND CRASH RATE
The data and calculations for the background crash rate were updated for the Airports Commission [2] using the years 1990 to 2013. The incidents used in the calculations are reproduced in Appendix A. The calculated crash rates for Great Britain are given in Table 3 and are taken from the Airports Commission report.
Table 3 Calculated background crash rates (× 10-6 km-2 yr-1) for Great Britain for the period 1990 to 2013
Aircraft type Mean Lower confidence limit Upper confidence limit
Light aircraft 18.5 15.1 22.4
Small transport aircraft 2.2 1.1 3.8
Large transport aircraft 0.7 0.2 1.9
Helicopters 10.3 7.8 13.4
Military combat aircraft 6.7 4.7 9.2
Total 38.4 28.9 50.7
To understand the data in Table 3, the value of 2.2 × 10-6 km-2 yr-1 is the mean value calculated for the small transport aircraft crash rate for Great Britain i.e. the value calculated using the maximum likelihood method and based directly on the data. The value of 1.1 × 10-6 km-2 yr -1 is the lower end of the confidence interval and the value of 3.8 × 10-6 km-2 yr-1 is the upper end of the confidence interval.
The crash rates in Table 3 indicate that, across Great Britain as a whole, the total likelihood of a crash occurring is 38.4 × 10-6 km-2 yr-1, using the mean estimate.
In Failure Rate and Event Data [1], two areas of Great Britain were identified as being high crash concentration zones for military aircraft. This was based on data from 1996 to 2006. If the full set of data from 1990 to 2013 is considered, there appears to be a downward trend in the number of incidents. Only four incidents have occurred since 2004, of which none occurred in the previously identified high crash concentration zones.
When all 37 incidents are considered, there is a significant level of scatter in the locations. Whilst it may be possible to draw boxes around some of the incidents in some areas of the country, these will cover significant areas of the country and this could be considered a somewhat arbitrary approach that would be based on judgement rather than any specific criteria. It is therefore proposed that high crash concentration zones for military aircraft are no longer considered and the general background rate is applied to the whole country.
3.2 AIRFIELD RELATED CRASH RATE
The airfield related crash rate for small and large transport aircraft were calculated previously for the Airports Commission [2]. Crash rates were not calculated for the light aircraft, helicopter and military aircraft categories, however. These need to be calculated to allow crash rates associated with a specific airfield to be derived.
The number of movements for each category of aircraft per year from all airfields in Great Britain is required to calculate the crash rates,. The Civil Aviation Authority (CAA) records movements from
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‘reporting’ airports. These are airports that are above a threshold in terms of the numbers of passengers or quantity of freight being transported.
For the small and large transport aircraft categories, this information is sufficient, as there are only a small number, if any, of small and large transport flights that occur at smaller airports.
For light aircraft and helicopters, however, there are a large number of small airfields from which flights occur and which do not report to the CAA. There are not many flights in these categories that do either take-off or land at the larger airports and so another source of information is required.
3.2.1 Small and Large Transport Aircraft
The airfield related crash rates for small and large transport aircraft have been taken from the Airports Commission report [2] and are shown in Table 13.
Table 4 Airfield related crash rates (× 10-6 per movement) for Great Britain
Aircraft type Mean Lower confidence limit Upper confidence limit
Small transport aircraft 3.8 2.5 5.5
Large transport aircraft 0.08 0.02 0.24
The results in Table 13 indicate that the airfield related crash rate for large transport aircraft is two orders of magnitude lower than that for small transport aircraft.
3.2.2 Light Aircraft
The number of light aircraft movements per year are required to calculate the light aircraft airfield related crash rate,. This information is not readily available, however, as small airfields are not required to provide movement data to the CAA. Instead, the number of movements has to be estimated using a number of other sources of data.
The General Aviation Small Aerodrome Research Study (GASAR) [7] assessed information obtained from questionnaires sent to a number of aerodromes in England, a large number of which are not ‘reporting’ sites for the C!! (i.e. they are not contained within the C!! data). From this, the G!S!R study was able to estimate that there were 4,347,000 General Aviation (GA) movements in England in 2002. GA movements are assumed to cover all aeroplane and helicopter flights other than those by major airlines or the Armed Forces.
The answers in the questionnaires also allowed a break-down to be made of the aircraft types at all airports in England. This is shown in Table 5. The GASAR study was concerned with GA movements and excludes aircraft owned by the major airlines.
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Table 5 Percentage of registered aircraft types at all airports in England from the GASAR [7] study
Aircraft category % of total number of registered aircraft
Helicopters 7
Jets 1
Single-Engined Piston 55
Multi-Engined Piston 6
Gliders 16
Microlight 13
Airship/Balloons 0
Others 2
Total 100
Table 5 shows that 61% of the aircraft fall into the light aircraft category, if it is assumed that all single- and multi-engined piston aircraft can be classified as light aircraft. In the GASAR study, single-engined piston aircraft were defined as being either over or under 750 kg whilst multi-engined piston aircraft were defined as being under or over 5,700 kg. These separate definitions were not used in the breakdown of registered aircraft by aircraft type, however, meaning that it is not possible to determine what proportion of the aircraft are below the 2,300 kg limit used as the light aircraft definition in this work. It may be assumed, however, that the majority of the single-engined piston aircraft will be below this weight.
The multi-engined piston aircraft are generally larger than the single-engined piston aircraft, but they make up a much lower percentage of the overall number of registered aircraft. Given the level of uncertainty surrounding the overall calculations, assuming a value of 55% of all GA movements for the number of light aircraft movements is not unreasonable. This leads to a total of approximately 2,400,000 light aircraft movements in England in 2002 that fall under the General Aviation category.
The CAA table of aircraft movements for 2002 [8] has been examined to estimate the number of movements in Scotland and Wales,. The proportion of Aero-club and private movements occurring in England, Scotland, Wales and Northern Ireland has been calculated and assumed to be representative of the proportion of light aircraft movements in each of the individual countries.
The number of Aero-club and private movements by country is shown in Table 6, together with the percentage of the total movements by country. Northern Ireland is shown as it is included in the CAA data and has a small effect on the final percentages, but Northern Ireland is not included in the analyses contained in this report, which concentrates on the crash rates in Great Britain.
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Table 6 Number of Aero-club and Private movements by country
Country No. of movements Percentage (%)
England 747,867 86.6
Scotland 64,325 7.5
Wales 39,017 4.5
Northern Ireland 11,929 1.4
Using these percentages and applying them to the 2,400,000 movements in England, implies a total number of light aircraft movements in Great Britain in 2002 of approximately 2,730,000 (i.e. not including Northern Ireland).
The number of movements for light aircraft for each year from 1990 to 2013 is required to calculate the aircraft crash likelihood. The CAA provided HSL with a spreadsheet containing the number of movements for each aircraft type from all the reporting airports (excluding Northern Ireland and the Channel Islands) for the years 1990 to 2013. The maximum take-off weight (MTOW) of the aircraft was included in the data, allowing the information to be split according to the aircraft categories used in this analysis. Table 7 lists the number of movements that fell into the light aircraft category by year.
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Table 7 Number of light aircraft movements by year from the reporting airports
Year Number of movements
1990 789
1991 911
1992 1150
1993 981
1994 197
1995 225
1996 42
1997 10
1998 5
1999 25
2000 7
2001 30
2002 5
2003 6
2004 3
2005 2
2006 0
2007 0
2008 0
2009 0
2010 0
2011 0
2012 1
2013 0
Total 4389
Table 7 shows that the number of light aircraft movements from the reporting airports increased until 1992, then decreased rapidly. Since 2002, there have been a negligible number of light aircraft movements. The number of movements in all the years is small compared to the total number of movements in this aircraft category across Great Britain as a whole. This means that it is difficult to deduce year-on-year changes in the number of movements from this data as there is a high level of uncertainty associated with the data.
An alternative method to assess the number of light aircraft movements is to use the Aero-club and private movements for a representative set of airports as reported by the CAA in Table 3.1 of the UK Airport Statistics [9]. Although the data in Table 7 indicates that the majority of these flights do not fall under the light aircraft category, the trends seen are considered to offer a reasonable representation of the trends in overall light aircraft movements, given the lack of any other available data.
The airports used for the analysis were Biggin Hill, Blackpool, Bournemouth, Dundee, Gloucester, Lydd and Shoreham as these have historically had a higher proportion of smaller aircraft flying from
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these airports. Table 8 shows the percentage of Aero-club and private movements for each year when compared to 2002, together with the final calculated number of light aircraft movements. The previously calculated value of 2,730,000 movements for 2002 has been used as the baseline figure.
Table 8 Calculated light aircraft movement data
Year Percentage of 2002 Aero-club and private movements (%)
No. of light aircraft movements
1990 101.0 2,757,438
1991 80.8 2,206,133
1992 73.6 2,010,169
1993 83.1 2,268,420
1994 100.4 2,741,650
1995 115.4 3,149,752
1996 112.9 3,081,898
1997 114.9 3,136,504
1998 118.0 3,220,539
1999 112.7 3,076,540
2000 108.9 2,972,803
2001 112.5 3,071,368
2002 100.0 2,730,000
2003 110.0 3,004,348
2004 102.4 2,795,028
2005 102.1 2,788,450
2006 95.4 2,604,808
2007 88.1 2,405,617
2008 81.4 2,222,986
2009 80.4 2,194,946
2010 67.6 1,844,816
2011 68.7 1,875,959
2012 65.1 1,776,700
2013 63.2 1,725,089
Total - 61,661,959
Table 8 shows that the final total number of light aircraft movements for the period 1990 to 2013 is 61,661,959. Given the uncertainties and assumptions used, the value of 6 2,000,000 has been used in the subsequent calculations.
The total number of crashes between 1990 and 2013 are required to calculate the likelihood of a light aircraft airfield related crash. The recorded crashes are detailed in Table 21 in Appendix B and the total number of crashes is 152. The calculated crash rate, including the 95% confidence interval values, is shown in Tabl e 9.
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Table 9 Calculated light aircraft airfield related crash rates
Rate Crash rate (× 10 -6
) per movement
Mean rate 2.5
Lower confidence limit 2.1
Upper confidence limit 2.9
Table 9 shows that the mean airfield related crash rate for light aircraft is 2.5 × 10-6 per movement.
3.2.3 Helicopters
To calculate the airfield related crash rate for helicopters, the number of helicopter movements for the time period 1990 to 2013 is required. As in the case for light aircraft, the CAA only outlines information from ‘reporting’ airports, which does not cover a large number of sites where helicopters take off and land.
Four sources of information have been used to derive the helicopter movements:
“Public transport air taxi operations (a) for year 2002” published by the C!! [10];
“Aircraft movements 2002” published by the C!! [8];
“Passengers and air transport movements split by fixed wing and rotary wing aircraft 2002” published by the CAA [11]; and
The “General Aviation Small Aerodrome Research Study (GASAR)” published by UCL [7].
The first source [10] provides the breakdown by aircraft type of the air taxi stage flights in 2002 and has been used to derive a percentage of air taxi flights that were performed by helicopter. The calculated value is 74.8%.
The total number of Air taxi movements for 2002 for Great Britain was obtained from the CAA data [8] (noting that the movements associated with Northern Ireland were deducted from the total reported in the CAA table). This showed that there were 67,810 Air taxi movements in GB in 2002. Using the 74.8% obtained previously for the number of these flights performed by helicopter gives a value of 50,707 movements.
The third source [11] gives the number of air transport movements (as reported in Table 3.1 of the Airport Statistics [8]), minus the number of Air taxi movements, by fixed and rotary wing. There were 58,922 rotary wing movements in GB in 2002 that were not associated with Air taxis.
GASAR data [7] was used to calculate the number of helicopter flights associated with general aviation (GA) i.e. not associated with major airlines or the armed forces. From the GASAR data, as seen in Table 5 in Section 3.2.2, 7% of the GA flights were assumed to be by helicopters. The total number of GA flights in 2002 was 4,347,000, meaning that 304,290 were by helicopter. This data covers England only. Percentages of flights by country have been derived earlier in the report, using Aero-club and private data, as shown in Table 6. These percentages have been assumed to apply to helicopters as well, d ue to a lack of any other available data. This means that there were 346,455 GA helicopter movements in GB in 2002.
If the three calculated helicopter movements for 2002 are added together, the total number of movements is 456,084. Given the uncertainty involved in the calculations, a value of 456,000 has been used subsequently.
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To derive the number of movements by helicopter for each year from 1990 to 2013, Table 19 of the CAA Airport Statistics [9] for each year has been interrogated to obtain the number of rotary wing air transport movements (i.e. excluding Air taxis and general aviation). The percentage change from 2002 has been calculated and then applied to the total number of helicopter movements for 2002, i.e. 456,000. Table 10 reports the percentage of the 2002 rotary wing air transport movements for each year, the calculated number of helicopter movements for each year, and the total number of movements for the period 1990 to 2013. Data was unavailable for the years 1997 to 1999. For these years, the mean number of movements for the years 1994 to 1996 and 2000 to 2002 has been used.
Table 10 Calculated helicopter movement data
Year Percentage of 2002 rotary wing air transport movements (%)
No. of helicopter movements
1990 127.1 579,360
1991 128.6 586,264
1992 123.0 560,988
1993 120.3 548,381
1994 91.1 415,494
1995 99.9 455,721
1996 110.6 504,392
1997 99.7 454,824
1998 99.7 454,824
1999 99.7 454,824
2000 95.1 433,820
2001 101.6 463,515
2002 100.0 456,000
2003 91.7 418,071
2004 90.6 413,257
2005 100.2 456,727
2006 111.8 509,949
2007 119.9 546,880
2008 119.2 543,699
2009 118.7 541,091
2010 108.2 493,488
2011 113.3 516,868
2012 114.5 522,146
2013 130.6 595,705
Total - 11,926,286
The calculated total number of helicopter movements from Table 10 has been rounded to 12 million in the airport related crash rate calculations.
The final crash rate, including 95% confidence interval values, have been calculated using the total number of 29 crashes between 1990 and 2013 as reported in Table 22 in Appendix B. The helicopter airfield related crash rate is given in Table 11.
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Table 11 Calculated helicopter airfield related crash rates
Rate Crash rate (× 10 -6
) per movement
Mean rate 2.4
Lower confidence limit 1.6
Upper confidence limit 3.5
3.2.4 Military Combat Aircraft
The airfield related crash rate for military combat aircraft was calculated previously using data up to, and including, 2006 and was reported at the 50% confidence level. The report is not in the public domain, but a copy of the report has been made available to the project team. The number of military aircraft movements required to calculate the crash rate was not readily available and had to be derived using a complex method utilising worldwide data for UK military aircraft. Consequently, worldwide incident data was also required in the calculations.
No additional information has become available since the 2006 report. The report contains the necessary information to calculate the mean crash rate and the 95% confidence interval for the crash rate. This allows rates to be calculated that are consistent with the other aircraft crash rates calculated, but using the data available up to 2006 only. It is proposed that these rates are calculated using the information contained in the confidential report, noting that the crash rates are likely to be cautious as more crashes are likely to occur at unfamiliar sites, some of which may be in war zones. The crash rates are given in Table 12.
Table 12 Military combat aircraft airfield related crash rates
Rate Crash rate (× 10 -6
) per movement
Mean rate 3.5
Lower confidence limit 2.5
Upper confidence limit 4.8
3.2.5 Summary of crash rates
The final airfield related crash rates for the five aircraft categories are given in Table 13, together with the lower and upper confidence limits.
Table 13 Airfield related crash rates (× 10-6 per movement) for Great Britain
Aircraft type Mean Lower confidence limit Upper confidence limit
Light aircraft 2.5 2.1 2.9
Small transport aircraft 3.8 2.5 5.5
Large transport aircraft 0.08 0.02 0.24
Helicopters 2.4 1.6 3.5
Military combat aircraft 3.5 2.5 4.8
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4 CONCLUSIONS
The crash rates reported in HSE’s Failure Rate and Event Data [1] have been reviewed and updated to use data for the years 1990 to 2013, with the exception of the military combat aircraft airfield related crash rate which is based on information for the years 1990 to 2006 due to insufficient data being available after 2006. The methodology has been modified to include the use of confidence intervals, allowing for the uncertainty surrounding the data.
The revised background crash rates are given in Table 14 for the background crash rates and in Table 15 for the airfield related crash rates.
Table 14 Calculated background c rash rates (× 10-6 km-2 yr-1) for Great Britain for the period 1990 to 2013
Aircraft type Mean Lower confidence limit Upper confidence limit
Light aircraft 18.5 15.1 22.4
Small transport aircraft 2.2 1.1 3.8
Large transport aircraft 0.7 0.2 1.9
Helicopters 10.3 7.8 13.4
Military combat aircraft 6.7 4.7 9.2
Total 38.4 28.9 50.7
Table 15 Airfield related crash rates (× 10-6 per movement) for Great Britain
Aircraft type Mean Lower confidence limit Upper confidence limit
Light aircraft 2.5 2.1 2.9
Small transport aircraft 3.8 2.5 5.5
Large transport aircraft 0.08 0.02 0.24
Helicopters 2.4 1.6 3.5
Military combat aircraft 3.5 2.5 4.8
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5 APPENDIX A: BACKGROUND RATE DATA
This appendix contains tables of the crash data used in the analysis of the background crash rate. The locations of the incidents in these tables use the distance units (e.g. nautical miles, miles, kilometres, etc.) as recorded in the data. An aircraft crash is defined as an uncontrolled landing or mid-air break-up leading to serious damage to the aircraft and/or at least one fatality.
Table 16 Light aircraft background crashes, 1990 to 2013
Year (number
of crashes)
England Scotland Wales
1990 (5) 24.03.90 3 miles east of Mere
03.05.90 Chadlington
19.05.90 M25, Reigate1
19.05.90 M25, Reigate1
20.11.90 Dunbar Common, near Edinburgh
1991 (5) 18.04.91 Stanmore Common
19.05.91 Aldermaston
20.05.91 Near Lancaster
17.08.91 Ashampstead
15.05.91 Llangollen
1992 (7) 13.02.92 Skiddaw
15.02.92 M25/A13 near Thorrock
07.04.92 Consett
15.07.92 Forest of Bowland
09.12.92 8 miles west of Luton
03.04.92 Loch Muick
22.08.92 Isle of Jura
1993 (4) 21.03.93 Near Shrivenham
20.07.93 Shadoxhurst
18.03.93 3 miles south-west of Maybole
15.09.93 South-west of Sanquhar
1994 (6) 08.01.94 Wrekin
17.01.94 Thirlmere
20.01.94 Near Bloxwich
20.03.94 Near Wellesbourne Mountford
09.10.94 5 miles south-west of Binbrook
20.11.94 3 miles north of Worthing
1995 (3) 04.03.95 Near Malden, Essex
21.03.95 Knottingkey, Yorkshire
13.10.95 Sileay Ruy, Isle of Man*
22
Year (number
of crashes)
England Scotland Wales
1996 (7) 05.05.96 Near Westcott
06.06.96 Pebworth, Near Evesham
15.06.96 Buxton
22.07.96 Tockington Park Farm, Near Almondsbury, Bristol
25.09.96 2 nautical miles west of Southport Pier
26.10.96 Dover VOR
16.10.96 18 nautical miles north-west of Perth
1997 (3) 27.11.97 1.8 miles north-west of Shobdon Airport, Herefordshire
06.05.97 3 nautical miles north of Cumbernauld Aerodrome
21.12.97 Near Ben House, Gatehouse of Fleet, Galloway
1998 (3) 26.07.98 Bentworth, Hampshire
20.10.98 Mow Cop House, Staffordshire
23.05.98 Tryfan, North Wales
1999 (7) 21.01.99 300 metres from western edge of Mattersey, Nottinghamshire
29.04.99 Near Selby, Yorkshire
04.07.99 Near Easingwold, Yorkshire
09.05.99 2 kilometres south of Cromarty, Black Isle, Highlands
12.02.99 Berwyn Mountain, mid Wales
02.08.99 Moel Hebog mountain, Near Beddlegert, North Wales
29.08.99 Sarn, Near Newtown, Powys
2000 (5) 15.05.00 Hambledon Hill, 15 miles north of Leeds Bradford Airport
16.07.00 Near Upper Cumberworth, West Yorkshire
30.11.00 Fortingall, Perthshire
13.12.00 En route Inverness to Benbecula
11.09.00 20 miles north of Swansea
2001 (6) 24.02.01 Near Sharpthorne, West Sussex
12.05.01 Osea Island, Essex
23.06.01 Nash, Shropshire
22.07.01 Near Lichfield, Hampshire
15.08.01 Halesworth, Suffolk
25.01.01 10 nautical miles south of Braemar, Grampian
23
Year (number
of crashes)
England Scotland Wales
2002 (4) 27.02.02 Hannington, Hampshire
25.08.02 Devils Chair, Stiperstones, Shropshire
01.04.02 2 miles west of Cwmbran
18.05.02 12 nautical miles west of Brecon VOR
2003 (2) 05.01.03 2 miles north-east of Towcester, Northamptonshire
13.04.03 Clitheroe, Lancashire
2004 (4) 13.03.04 Hotham, South Cave, Humberside
27.06.04 Beacon Village, Near Honiton, Devon
04.07.04 offshore, in Liverpool Bay, 2 nautical miles north of Wallasey
22.10.04 37 miles northwest of Inverness
2005 (7) 25.05.05 Near Pottersbury, 6 miles north-west of Milton Keynes
15.06.05 Near Woltonunder-Edge, Gloucestershire
18.08.05 Remenham (Berkshire)
17.11.05 Near Bugbrooke, Northamptonshire
18.12.05 Moreton in Marsh, Gloucestershire
19.05.05 Approximately 20 miles north of Dundee
04.09.05 Irish Sea, 5 nautical miles north-west of Stumble Head, Pembrokeshire
2006 (3) 16.07.06 Hoxne, Suffolk
25.08.06 Near Bramley, South Yorkshire
11.09.06 Near Bethesda, Gwynedd
2007 (4) 03.02.07 Sea close to Blackpool beach
16.12.07 Near Rugely, Staffordshire
2
09.04.07 9 nautical miles south of Oban
01.06.07 Near Magar, Gwent
2008 (3) 13.02.08 Rutland Water, Near Empingham, Leicestershire
23.02.08 Farthing Common, Kent
05.04.08 Cairn Gorm, the Cairngorms
24
Year (number
of crashes)
England Scotland Wales
2009 (5) 02.01.09 Colwich Junction, near Little Haywood, Staffordshire
10.04.09 Near Steep, Petersfield, Hampshire
14.06.09 Near Drayton, Oxfordshire
08.07.09 Bishop Norton, Lincolnshire
11.02.09 Near Porthcawl
2010 (4) 19.06.10 Castleford, West Yorkshire
10.07.10 Near Rotherfield Peppard, Oxfordshire
04.09.10 Near Ryde, Isle of Wight
26.11.10 Brecon Beacons
2011 (3) 21.03.11 Ingleborough, North Yorkshire
28.04.11 Near Malden, Essex
15.05.11 Near Witchampton, Dorset
2012 (1) 16.08.12 Near Bruera, Cheshire
2013 (1) 30.09.13 Near Bristol
Total (102)
73 16 13
*Isle of Man has been included as a British Crown Dependency 1Mid-air collision, counted as two separate impacts as ground impacts are different
2This was a crash involving a light aircraft and a small transport aircraft. A corresponding entry has been made
in Table 18
25
Table 17 Helicopter background crashes, 1990 to 2013 (military crashes in italics); only years with crashes shown
Year (number
of crashes)
England Scotland Wales
1990 (3) 28.03.90 1 mile west of Chinnor
24.01.90 Giffnock 12.02.90 10 kilometres north-west of Valley
1991 (1) 08.09.91 Welford-on-Avon
1992 (4) 23.02.92 Royton
28.03.92 Coalport
29.05.92 Near Latimer
14.08.92 Crowthorne
1993 (5) 23.06.93 Near Kendal
20.07.93 Stanford Training Area
11.12.93 Near Wimborne
12.08.93
20.11.93
Llyn Padarn Lake
Near Brecon
1994 (3) 02.06.94
07.12.94
Mull of Kintyre
Ballachulish
22.05.94 Colwyn Bay
1995 (2) 07.04.95 Yarcombe, Somerset
05.10.95 Wye Valley, Chepstow
1996 (3) 23.04.96 1 nautical mile south of Portesham, Dorset
19.10.96 Near Cauldron Lowe, Staffordshire
22.10.96 Middlewich, Cheshire
1997 (3) 16.03.97 Gravesend near Albury, Heartfordshire
11.08.97 Adjacent to M6 motorway at Nether Kellet, Near Lancaster
14.11.97 Cocking, Near Chichester
1998 (3) 19.04.98 900 metres south-west of Gumley
26.07.98 Near Rochester Airport
01.08.98 Near Six Mile Bottom, Cambridgeshire
26
Year (number
of crashes)
England Scotland Wales
1999 (1) 18.05.99 Tilton-on-Hill, east of Leicester
2000 (6) 01.02.00 2 nautical miles east of Chorley, Lancashire
08.03.00 Near Twyford, Berkshire
21.08.00 Dartford Marshes, Kent
23.08.00 Streatley, Berkshire
27.10.00 Inner sound between Island of Rona and Applecross
21.04.00 Coryton Drive, Cardiff
2001 (1) 16.11.01 Brunton
2002 (3) 13.07.02 Hampton Magna, Warwickshire
19.10.02 Wooferton, Shropshire
17.02.02 Near Muirkirk, East Ayrshire
2003 (4) 17.01.03 Cudham, Kent
10.04.03 Brightling, Sussex
02.12.03 Hurstbourne Tarrant, Near Andover
30.07.03 Carlenrig, Teviothead, Near Hawick
2004 (1) 11.11.04 Cophams Hill Farm, Bishopton, Warwickshire
2005 (1) 23.02.05 Salisbury Plain Training
2007 (4) 01.05.07 Near Thornhaugh, Peterborough
03.08.07 Near Kendal, Cumbria
08.08.07 Near Catterick, Yorkshire
15.09.07 Lanark
2008 (3) 26.01.08 Harrogate, North Yorkshire
28.05.08 Kingscott Valley, Devon
01.11.08 Winchcombe, Gloucestershire
2009 (2) 22.09.09 Near Stalmine, Lancashire
15.11.09 Macclesfield, Cheshire
2011 (1) 08.03.11 Keswick, Cumbria
27
Year (number
of crashes)
England Scotland Wales
2012 (1) 06.01.12 Near Ely, Cambridgeshire
2013 (2) 16.01.13 Near Vauxhall Bridge, London
29.11.13 Glasgow
Total (57)
35 (44) 6 (8) 3 (5)
28
Table 18 Small transport background crashes, 1990 to 2013; only years with crashes shown
Year
(number of
crashes)
England Scotland Wales
1993 (3) 13.01.93 Sellafield
11.06.93 Peak District, Broomhead Moor
15.08.93 Near Guildford, Surrey
1995 (1) 24.05.95 6 miles north-east of Leeds/Bradford International Airport
1998 (2) 28.11.98 Owlacombe Cross, Near Bickington, Devon (foreign registered)
24.12.98 1 nautical mile from the coast near Bradwell-on-Sea
1999 (1) 01.08.99 Woolaston, Gloucestershire
2000 (2) 18.08.00 Eastbourne, East Sussex
09.12.00 4 nautical miles north-west of Louth, Lincolnshire
2003 (1) 01.06.03 Borth, North Wales
2007 (1) 16.12.07 Near Rugeley, Staffordshire
1
2010 (1) 15.01.10 Bladon, Oxfordshire
Total (12)
11 0 1
Note: It is known that five of the six crashes that occurred between 1998 and 2003 involved privately owned ex-military jets (Hawker Hunter, two Jet Provosts, a Strikemaster and an Aero Vodochody Delfin). 1This incident was a crash involving a light aircraft and a small transport aircraft. A corresponding entry has been
made in Table 16.
29
Table 19 Large transport background crashes, 1990 to 2013; only years with crashes shown
Year (number
of crashes)
England Scotland Wales
1990 (1) 30.04.90 30 feet below summit of Maodel, Isle of Harris
1993 (1) 27.05.93 8 nautical miles north-west of Blair Atholl
1994 (1) 25.02.94 Near Uttoxeter
Total (3) 1 2 0
30
Table 20 Military aircraft background crashes, 1990 to 2013; only years with crashes shown
Year (number
of crashes)
England Scotland Wales
1990 (5) 09.01.90 Near Hexham, Northumberland
05.02.90 The Wash
10.04.90 North Dorchester, Dorset
02.05.90 Wells-next-the-sea, Norfolk
06.02.90 Capel-y-Ffyn, Powys
1991 (3) 25.09.91 Near Great Driffield, Yorkshire
10.05.91 Chepstow, Monmouthshire
29.08.91 Near Llanidloes, Powys
1992 (1) 02.04.92 Barton Hartshorn, Buckinghamshire
1993 (2) 28.06.93 Heckington, Lincolnshire
21.10.93 Near Barnard Castle, County Durham
1994 (2) 14.01.94 Aston Somerville, Worcestershire
01.09.94 Killin, Stirling
1996 (5) 10.02.96 Conningsby, Lincolnshire
1
10.02.96 Conningsby, Lincolnshire
1
23.02.96 6 nautical miles south of Taunton, Somerset
13.05.96 4 nautical miles west of Driffield, Yorkshire
28.09.96 Blackpool, Lancashire
1997 (1) 03.06.97 3 nautical miles south-west of Castle Douglas, Dumfries and Galloway
1998 (1) 18.12.98 2.5 nautical miles west of Staindrop, County Durham
31
Year (number
of crashes)
England Scotland Wales
1999 (6) 21.01.99 Everton, near Retford, Nottinghamshire
09.07.99 22.5 nautical miles east-north-east of Cottesmore, Rutland
14.10.99 1.5 nautical miles south-east of Kirkheaton, West Yorkshire
22.10.99 10 nautical miles south of Penrith, Cumbria
14.07.99 7 nautical miles east of Coldstream, Berwickshire
17.11.99 1 nautical mile east of Torness, East Lothian
2000 (2) 18.10.00 Lowick, Northumberland
27.10.00 5 nautical miles north-east of Dumfries
2001 (2) 26.03.01 Ben McDui, Cairngorms
1
26.03.01 Ben McDui, Cairngorms
1
2002 (1) 17.05.02 Humber Estuary, Near Brough
2003 (1) 23.07.03 5 miles north-west of Pickering, North Yorkshire
2004 (1) 29.06.04 10 miles southwest of Boscombe Down, Wiltshire
2009 (1) 02.07.09 Glen Kinglass, Argyll
2011 (2) 20.08.11 River Stour, Southampton
27.01.11 Off Stornoway
2012 (1) 03.07.12 Moray Firth
Total (37)
24 10 3
1Mid-air collision, counted as two separate impacts as ground impacts are different
32
6 APPENDIX B: AIRFIELD RELATED RATE DATA
Data used in the calculation of the airfield related crash rates are listed in the subsequent tables.
Table 21 Light aircraft airfield related crashes, 1990 to 2013
Year (number
of crashes)
England Scotland Wales
1990 (5) 18.03.90 Rattlesden, Suffolk
07.07.90 Cranfield, Bedfordshire
20.10.90 Near East Midlands Airport
05.04.90 On approach to
Glasgow Airport
27.05.90 Stoneykirk, Scotland
1991 (5) 10.03.91 Near Chilgrove, West Sussex
31.03.91 Coventry, West Midlands
11.04.91 North Weald
06.07.91 Winterbourne, Near Bristol
16.12.91 Chichester, West Sussex
1992 (3) 12.07.92 Oxford Airport
04.10.92 Sheepwash, Devon
06.12.92 Near Wycombe, Buckinghamshire
1993 (2) 03.10.93 Near Bridport, Devon
15.11.93 Near Biggin Hill, Kent
1994 (2) 01.08.94 Parham, Suffolk
26.12.94 Near Stapleford, Essex
1995 (4) 16.06.95 Dunkeswell Airfield, Near Honiton, Devon
09.07.95 Bakers Farm, Near Corby, Northamptonshire
20.07.95 Stourhead Gardens, Mere, Wiltshire
05.05.95 Newmill Farm, Dolphinton, Lanarks
33
Year (number
of crashes)
England Scotland Wales
1996 (8) 02.03.96 Shoreham Airport
04.05.96 Old Warden Airfield, Bedfordshire
31.05.96 Lydd Airport
31.07.96 Canterbury Airfield
26.08.96 Near Barton Airfield, Manchester
21.11.96 Near Compton Abbas Airfield, Dorset
23.11.96 Denham, Middlesex
30.10.96 Cardiff
1997 (7) 06.03.97 3.5 miles northeast of Southend Airport
09.03.97 1 mile north-east of Biggin Hill Airfield, Kent
25.07.97 Meppershall Airfield, Bedfordshire
03.08.97 Near Shobdon Airfield, Herefordshire
08.08.97 Brunton Airfield, Northumberland
29.09.97 North Weald Airfield, Essex
20.08.97 Cardiff Airport
1998 (3) 17.05.98 Andrewsfield, Essex
09.08.98 Swanton Morley Airfield, Norfolk
15.08.98 Woburn Abbey, Bedfordshire
34
Year (number
of crashes)
England Scotland Wales
1999 (10)
04.02.99 Turweston Aerodrome, Northamptonshire
28.03.99 Newnham, Hertfordshire
03.07.99 Bembridge Airport, Isle of Wight
17.07.99 East Mersea, Colchester, Essex
29.08.99 Husbands Bosworth Airfield, Leicestershire
18.09.99 Luton Airport, Bedfordshire
26.09.99 Charity Farm Airstrip, Baxterley, Warwickshire
06.10.99 Near Moneweden, Suffolk
14.11.99 Belle Vue, Barnstaple, Devon
18.12.99 Bournemouth International Airport, Dorset
35
Year (number
of crashes)
England Scotland Wales
2000 (8) 04.03.00 RAF Cosford, Shropshire
24.03.00 Upwood Airfield, Cambridgeshire
19.04.00 2 nautical miles north of North Weald Airfield
1
19.04.00 2 nautical miles north of North Weald Airfield
1
12.05.00 Dunstable Downs Airfield, Bedfordshire
01.06.00 Rowley Mile Course, Newmarket, Suffolk
03.12.00 Warren Farm, Lambourne, Berkshire
30.12.00 Compton Abbas Airfield, Wiltshire
2001 (11)
14.02.01 Davidstow Airfield, Cornwall
27.04.01 Sherburn Airfield, Yorkshire
11.05.01 Full Sutton Airfield, Pocklington, Yorkshire
12.05.01 Leicester Airport
19.06.01 Near Southampton Airport
23.06.01 RAF St Mawgan, Cornwall
11.08.01 1 nautical mile north of Crompton Abbas Airfield, Dorset
02.09.01 Near Popham Airfield, Hampshire
14.09.01 Aston Down Airfield, Gloucestershire
28.12.01 Goodwood Aerodrome, West Sussex
18.05.01 Withbybush Airfield, Pembrokeshire
36
Year (number
of crashes)
England Scotland Wales
2002 (5) 16.07.02 White Waltham Airfield, Berkshire.
21.07.02 White Waltham Airfield, Berkshire
22.08.02 Otherton Airfield, Staffordshire
03.11.02 Withycombe Farm, Oxfordshire
05.05.02 Strathallan Airfield, Perthshire
2003 (7) 15.02.03 Bowland Forest Gliding Club, Near Preston, Lancashire
29.03.03 Humberside International Airport
07.04.03 In a field close to Sandtoft Airfield, Humberside
31.05.03 Coventry Airfield
01.08.03 Horton Wood, Near Marlow, Buckinghamshire
06.12.03 Oxford Airport (Kidlington)
01.08.03 2 miles south-west of Hawarden Airport, Clywd
2004 (8) 01.02.04 Crowland Airfield, Lincolnshire
29.02.04 West Chiltington, West Sussex
30.03.04 Near Laneshaw Bridge, Colne, Lancashire
02.05.04 Bridge Farm, Acle, Norfolk
25.05.04 Popham Airfield, Hampshire
04.07.04 Lundy Island, North Devon
28.08.04 Bournemouth International Airport, Dorset
14.10.04 Wadswick Airstrip, Near Corsham, Wiltshire
37
Year (number
of crashes)
England Scotland Wales
2005 (10)
08.02.05 Near Hormonden, Kent
25.03.05 Kinderton Lodge Farm, Middlewich, Cheshire
25.03.05 Kemble Airfield, Gloucestershire
30.04.05 Naish Farm, Clapton in Gordano, Bristol
02.05.05 Private airstrip, Near Keal Cotes, Lincolnshire
08.07.05 White Waltham Airfield, Berkshire
09.07.05 Milfield Airfield, Northumberland
07.08.05 Bracklesham Bay, West Sussex
22.10.05 Near Biggin Hill Airport, Kent
30.08.05 Rhigos, South Wales
2006 (7) 29.06.06 Near Thirkleby Hall, Thirkleby, North Yorkshire
19.07.06 Eastwood Park, Southend-on-Sea, Essex
22.07.06 Bournemouth Airport, Dorset
30.07.06 Popham Airfield, Hampshire.
05.08.06 Denham Green, Buckinghamshire
06.08.06 North Coates Airfield, Lincolnshire
25.09.06 Delamere, Near Chester, Cheshire
38
Year (number
of crashes)
England Scotland Wales
2007 (12)
03.02.07 Blackpool, Lancashire
17.04.07 Near Nantwich, Cheshire
08.07.07 Clutton Hill Farm Strip, Bristol
29.07.07 Near Lechlade, Gloucestershire
05.08.07 0.5 nautical miles south-west of Sandown Airport, Isle of Wight
08.08.07 0.5 miles east of Leicester Airport
27.08.07 Near Stapleford Aerodrome, Essex
28.08.07 Near Exeter, Devon
16.09.07 Shotteswell, Near Banbury, Oxfordshire
06.10.07 Anwick, Lincolnshire
19.12.07 4 nautical miles south of Oxford Airport (Kidington)
01.06.07 Gwent, South Wales
2008 (4) 11.04.08 Highclere, Hampshire
23.07.08 City Airport Manchester, Barton, Eccles
26.07.08 Near Farthing Corner (Stoneacre Farm) Airfield, Kent
29.10.08 Seething Airfield, Norfolk
39
Year (number
of crashes)
England Scotland Wales
2009 (6) 20.02.09 Wombleton Airfield, Harome, North Yorkshire
21.02.09 Fenland Airfield, Near Spalding, Lincolnshire
27.06.09 Great Oakley Airfield, Near Harwich, Essex
19.09.09 Bicester Airfield, Oxfordshire
20.09.09 Tangley, Hampshire
26.09.09 Humberside Airport, North Lincolnshire
2010 (3) 09.05.10 Northweald Airfield, Essex
09.05.10 Old Buckenham Airfield, Norfolk
28.11.10 Near Redland Airfield, Swindon, Wiltshire
2011 (9) 05.05.11 Private airstrip 19 nautical miles south-east of Penrith, Cumbria
26.06.11 North Coates Airfield, Lincolnshire
04.07.11 Shoreham Airport, West Sussex
1
04.07.11 Shoreham Airport, West Sussex
1
29.07.11 Eccles, Greater Manchester
02.09.11 Peterborough Sibson Airfield, Cambridgeshire
19.11.11 Henstridge Airfield, Somerset
18.12.11 Leicester Airport1
18.12.11 Leicester Airport 1
40
Year (number
of crashes)
England Scotland Wales
2012 (7) 02.01.12 Stapleford Airport, Essex
10.01.12 Salisbury, Wiltshire
25.03.12 Godney Moor Airfield, Somerset
01.07.12 Old Warden Aerodrome, Bedfordshire
09.09.12 Private airstrip 4 nautical miles south-west of Bath
15.09.12 South of Popham Airfield, Hampshire
18.01.12 Near Welshpool Airport, Powys
2013 (6) 10.07.13 Abbots Bromley Airfield, Staffordshire
17.08.13 Felthorpe Airfield, Norfolk
21.08.13 Airstrip at Common Farm, Wymeswold, Leicestershire
24.10.13 Denham Aerodrome, Buckinghamshire
15.12.13 Netherthorpe Airfield, Nottinghamshire
19.5.13 Caernarfon Airport, Gwynedd
Total (152)
137 4 8
1Mid-air collision, counted as two separate impacts as ground impacts are different
41
Table 22 Helicopter airfield related crashes, 1990 to 2013; only years with crashes shown
Year (number
of crashes)
England Scotland Wales
1990 (3) 27.06.90 Near Rocester, Staffordshire
13.07.90 Stanley, County Durham
31.08.90 Felsted, Essex
1991 (1) 10.03.91 Halifax, West Yorkshire
1996 (1) 16.12.96 Near Ledbury, Hereford
1997 (2) 16.01.97 Near Redhill, Surrey
13.07.97 Glamis Castle, Near Forfar
1998 (4) 28.01.98 1 nautical mile west of Souldern Manor, Oxfordshire
09.03.98 Amport, Andover, Hampshire
26.07.98 Near Rochester Airport, Kent
10.10.98 Sulby, Near Welford, Northamptonshire
2000 (2) 16.04.00 Carlisle Airport, Cumbria
02.12.00 Biggin, North Yorkshire
2002 (1) 24.05.02 Brough of Birsay, Orkney
2003 (2) 29.06.03 Shipham Airfield, Near Dereham, Norfolk
19.07.03 Knockholt, Sevenoaks, Kent
2004 (2) 03.03.04 1 mile east of Bournemouth Airport, Dorset
19.09.04 Kentallen, Near Oban
2005 (3) 08.05.05 Ockington Farm Strip, Near Dymock, Gloucestershire
15.03.05 7.7 nautical miles west-north-west of Campbeltown Airport, Argyll
21.12.05 3 nautical miles north east of Coupar Angus, Tayside
2006 (1) 01.06.06 Colliford Lake, Bodmin Moor, Cornwall
42
Year (number
of crashes)
England Scotland Wales
2007 (1) 12.06.07 Near Codnor, Derbyshire
2008 (1) 28.07.08 Near Peacehaven, East Sussex
2010 (2) 24.05.10 Poundsgate, Devon
01.06.10 Loch Long, Near Arrochar
2012 (2) 14.08.12 Leicester Airport 16.01.12 Lake Vyrnwy, Powys
2013 (1) 19.06.13 Private landing site, Near Oxford
Total (29)
22 6 1
43
Table 23 Small transport airfield related crashes, 1990 to 2013;
only years with crashes shown
Year (number
of crashes)
England Scotland Wales
1991 (2) 19.05.91 Brimpton Airfield, Near Aldermaston, Berkshire
30.06.91 Audley End, Essex
1992 (2) 27.06.92 Woodford, Manchester
06.10.92 Prestwick, South Ayrshire
1995 (3) 13.03.95 Near Andover, Hampshire
24.05.95 Near Leeds Bradford Airport
11.08.95 Fyfield, Near Andover, Hampshire
1996 (4) 14.07.96 Duxford Airfield, Cambridgeshire
21.07.96 Near Barton Airfield, Manchester
01.09.96 Crosland Moor Airfield, Huddersfield
19.05.96 Griesta, Near Lerwick
1998 (1) 05.06.98 Dunsfold Airfield, Surrey
1999 (1) 03.09.99 Near Glasgow Airport
2000 (3) 08.04.00 Goodwood Airfield, Chichester, West Sussex
14.06.00 Mersey Estuary, Near Liverpool Airport
23.12.00 Near Blackbushe Airport, Hampshire
2001 (3) 02.06.01 Biggin Hill Airfield, Kent
03.06.01 Biggin Hill Airfield, Kent
06.06.01 About 1 nautical mile east of Isle of Man Airport
*
44
Year (number
of crashes)
England Scotland Wales
2002 (3) 04.01.02 Birmingham International Airport
02.06.02 Duxford Airfield, Cambridgeshire
24.12.02 Aberdeen Airport
2006 (2) 05.08.06 Derham Green, Buckinghamshire
06.09.06 Duxford Airfield, Cambridgeshire
2008 (2) 30.03.08 Romsey Close, Farnborough, Kent
17.08.08 Near Coventry Airport
2011 (1) 10.07.11 Near Duxford Aerodrome, Cambridgeshire
Total (27)
24 3 0
* Isle of Man has been included as a British Crown Dependency
Table 24 Large transport airfield related crashes, 1990 to 2013;
only years with crashes shown
Year England
1994 21.12.94 Coventry
1999 22.12.99 Near Stanstead
2008 17.01.08 Heathrow
45
Table 25 Number of movements and accidents for small and large transport aircraft for all major Great British airports, 1990 to 2013
Year Small transport Large transport
Number of movements Number of accidents Number of movements Number of accidents
1990 433,073 0 1,008,799 0
1991 448,331 2 959,437 0
1992 491,146 2 1,022,750 0
1993 375,547 0 953,800 0
1994 371,117 0 914,213 1
1995 382,031 3 974,702 0
1996 400,651 4 987,406 0
1997 344,525 0 1,049,038 0
1998 336,401 1 1,111,094 0
1999 323,119 1 1,203,737 1
2000 317,489 3 1,283,816 0
2001 305,282 3 1,395,012 0
2002 305,607 3 1,482,379 0
2003 324,214 0 1,552,876 0
2004 307,411 0 1,609,350 0
2005 279,958 3 1,636,419 0
2006 269,197 2 1,711,681 0
2007 288,890 0 1,800,839 0
2008 293,717 2 1,915,802 1
2009 309,379 0 1,946,788 0
2010 280,795 0 1,997,535 0
2011 264,147 1 1,959,003 0
2012 249,258 0 1,783,611 0
2013 226,036 0 1,688,761 0
Total 7,184,749 27 36,185,856 3
46
7 REFERENCES
1.
HSE (2012). Failure rate and event data for use within risk assessments (28/06/2012). http://www.hse.gov.uk/landuseplanning/failure-rates.pdf (accessed July 2015).
2. Chaplin Z (2015). Module 14. Operational efficiency: Ground risk analysis. MSU/2015/08. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/437269/o perational-efficiency-ground-risk-analysis.pdf (accessed July 2015).
3. Byrne JP (1997). The calculation of aircraft crash risk in the UK. AEA Technology, HSE Contract Research Report CRR 150/1997. http://www.hse.gov.uk/research/crr_pdf/1997/crr97150.pdf (accessed February 2017).
4. Ross S (2000). Introduction to probability models. Academic Press.
5. Hazewinkel M (2001). Encyclopedia of Mathematics. Springer.
6. Ulm K (1990). A simple method to calculate the confidence interval of a standardized mortality ratio. American Journal of Epidemiology, vol. 131 (2), pp 373-375.
7. UCL (2004). General Aviation Small Aerodrome Research Study (GASAR). https://web.archive.org/web/20061007122800/http://www.gaac.co.uk/gasar/GASAR_Natio nalPilotSurvey.pdf (accessed September 2015).
8. CAA (2003). Table 3.1. Aircraft movements 2002. http://www.caa.co.uk/Data-andanalysis/UK-aviation-market/Airports/Datasets/UK-Airport-data/Airport-data-1990onwards/ (accessed February 2017).
9. CAA. UK Airport Statistics. http://www.caa.co.uk/Data-and-analysis/UK-aviationmarket/Airports/Datasets/UK-Airport-data/Airport-data-1990-onwards/ (accessed February 2017).
10. CAA (2003). Table 1.13 Public transport air taxi operations (a) for year 2002. http://www.caa.co.uk/Data-and-analysis/UK-aviation-market/Airports/Datasets/UK-Airportdata/Airport-data-1990-onwards/ (accessed February 2017).
11. CAA (2003). Table 19. Passengers and air transport movements split by fixed wing and rotary wing aircraft 2002. http://www.caa.co.uk/Data-and-analysis/UK-aviationmarket/Airports/Datasets/UK-Airport-data/Airport-data-1990-onwards/ (accessed February 2017).
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4
Published by the Health & Safety Executive 12/19
5
Update of aircraft crash rates used by HSE
in assessing hazards from chemical, process
and other major hazard installations
The Health and Safety Executive (HSE) provides advice on land use planning in the vicinity of major accident hazard sites and major accident hazard pipelines. As part of this process, HSE publish a guidance document, Failure Rate and Event Data, which contains failure rates for pieces of equipment found in major hazard chemical and process sites. The guidance document also contains information on event data such as aircraft crash and flooding, which are used when assessing the risks from such major hazard sites. An event such as an aircraft crash could lead to a release of a hazardous substance that could potentially harm people.
The aircraft crash rates were previously updated in 2009 using data up to 2006. This report updates the crash rates using data from 1990 to 2013. The methodology used to calculate the crash rates is also detailed. Uncertainty levels provide upper and lower bounds to the calculated crash rates to account for the uncertainty in the data that is used to derive the crash rates.
This report and the work it describes were funded by the Health and Safety Executive (HSE). Its contents, including any opinions and/or conclusions expressed, are those of the authors alone and do not necessarily reflect HSE policy.
RR1140
www.hse.gov.uk