20 research outputs found
The development of a more risk-sensitive and flexible airport safety area strategy: Part II. Accident location analysis and airport risk assessment case studies
This two-part paper presents the development of an improved airport risk assessment
methodology aimed at assessing risks related to aircraft accidents at and in the
vicinity of airports and managing Airport Safety Areas (ASAs) as a risk mitigation
measure. The improved methodology is more quantitative, risk-sensitive, flexible
and transparent than standard risk assessment approaches. As such, it contributes to
the implementation of Safety Management Systems at airports, as stipulated by the
International Civil Aviation Organisation.
The second part of the paper presents the analysis of accident locations, including the
plotting of Complementary Cumulative Probability Distributions for the relevant
accident types. These were then used in conjunction with the improved accident
frequency models to produce Complementary Cumulative Frequency Distributions
that could be used to assess risks related to specific runways and determine Airport
Safety Area (ASA) dimensions necessary to meet a quantitative target level of safety.
The approach not only takes into account risk factors previously ignored by standard
risk assessments but also considers the operational and traffic characteristics of the
runway concerned. The use of the improved risk assessment technique and risk
management strategy using ASAs was also demonstrated in two case studies based on
New York LaGuardia Airport and Boca Raton Airport in Florida
The development of a more risk-sensitive and flexible airport safety area strategy: Part I. The development of an improved accident frequency model
This two-part paper presents the development of an improved airport risk assessment
methodology aimed at assessing risks related to aircraft accidents at and in the vicinity
of airports and managing Airport Safety Areas (ASAs) as a risk mitigation measure.
The improved methodology is more quantitative, risk-sensitive, flexible and
transparent than standard risk assessment approaches. As such, it contributes to the
implementation of Safety Management Systems at airports, as stipulated by the
International Civil Aviation Organisation.
The first part of the paper presents the methodological advances made in the
development of accident frequency models; namely the building of a single
comprehensive database of all relevant accident types, the collection and use of
normal operations data in quantifying the criticality of a series of risk factors, and
modelling accident frequency using multivariate logistic regression. The resulting
models have better goodness-of-fit, sensitivity and specificity than standard risk
assessment methodologies
Quantifying and characterising aviation accident risk factors
This paper compares normal flights’ exposure to a number of meteorological factors with
the equivalent for certain accident flights. The factors examined include visibility, ceiling
height, temperature, crosswind, tailwind and instrument or visual meteorological
conditions. Differences in exposure and to measure accident propensity related to
different levels of risk exposure are quantified based on relative accident involvement
ratios. Four categories of aircraft accidents relevant to the assessment of airport safety are
examined
Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial
Background:
Many patients with COVID-19 have been treated with plasma containing anti-SARS-CoV-2 antibodies. We aimed to evaluate the safety and efficacy of convalescent plasma therapy in patients admitted to hospital with COVID-19.
Methods:
This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]) is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. The trial is underway at 177 NHS hospitals from across the UK. Eligible and consenting patients were randomly assigned (1:1) to receive either usual care alone (usual care group) or usual care plus high-titre convalescent plasma (convalescent plasma group). The primary outcome was 28-day mortality, analysed on an intention-to-treat basis. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.
Findings:
Between May 28, 2020, and Jan 15, 2021, 11558 (71%) of 16287 patients enrolled in RECOVERY were eligible to receive convalescent plasma and were assigned to either the convalescent plasma group or the usual care group. There was no significant difference in 28-day mortality between the two groups: 1399 (24%) of 5795 patients in the convalescent plasma group and 1408 (24%) of 5763 patients in the usual care group died within 28 days (rate ratio 1·00, 95% CI 0·93–1·07; p=0·95). The 28-day mortality rate ratio was similar in all prespecified subgroups of patients, including in those patients without detectable SARS-CoV-2 antibodies at randomisation. Allocation to convalescent plasma had no significant effect on the proportion of patients discharged from hospital within 28 days (3832 [66%] patients in the convalescent plasma group vs 3822 [66%] patients in the usual care group; rate ratio 0·99, 95% CI 0·94–1·03; p=0·57). Among those not on invasive mechanical ventilation at randomisation, there was no significant difference in the proportion of patients meeting the composite endpoint of progression to invasive mechanical ventilation or death (1568 [29%] of 5493 patients in the convalescent plasma group vs 1568 [29%] of 5448 patients in the usual care group; rate ratio 0·99, 95% CI 0·93–1·05; p=0·79).
Interpretation:
In patients hospitalised with COVID-19, high-titre convalescent plasma did not improve survival or other prespecified clinical outcomes.
Funding:
UK Research and Innovation (Medical Research Council) and National Institute of Health Research
The development of a more risk-sensitive and flexible airport safety area strategy: Part II. Accident location analysis and airport risk assessment case studies
The development of a more risk-sensitive and flexible airport safety area strategy: Part I. The development of an improved accident frequency model
ACRP Report 3: Analysis of aircraft overruns and undershoots for runway safety areas
ACRP Report 3: Analysis of Aircraft Overruns and Undershoots for Runway Safety Areas
covers four areas: (1) Research collected on accident/incident data from several notable
sources; (2) inventory of the conditions relating to each; (3) assessment of risk in relation
to the runway safety area; and (4) discussion on a set of alternatives to the traditional runway
safety area.
Overruns and undershoots are factors in the design or improvement of runway safety
areas (RSAs). The traditional approach to mitigate risk associated with accidents or incidents
is to enlarge the runway safety area, but many airports do not have sufficient land
to accommodate standard Federal Aviation Administration or International Civil Aviation
Organization recommendations for RSAs. Airports that pursue this approach face
extremely expensive and controversial land acquisition or wetlands filling projects to make
sufficient land available.
This report uses a probabilistic approach—a quantitative assessment—to analyze the
RSA and begins a discussion on how alternatives to a standard 1,000-foot RSA may adequately
mitigate risk. The report also assesses the factors that increase the risk of such accidents
occurring, helps with understanding how these incidents may happen, and suggests
that aircraft overrun and undershoot risks are related to specific operational factors.
The report suggests that significant improvement to airport operations safety may be
achieved by monitoring and managing these operational factors for both RSA planning and
during actual aircraft operations, and it provides recommendations for collection and
reporting of data in future accident and incident investigations and reporting to allow future
improvements to these models