Steve Jarvis

Development of a bespoke human factors taxonomy for gliding accident analysis and its revelations about highly inexperienced UK glider pilots

Low-hours solo glider pilots have a high risk of accidents compared to more experienced pilots. Numerous taxonomies for causal accident analysis have been produced for powered aviation but none of these is suitable for gliding, so a new taxonomy was required. A human factors taxonomy specifically for glider operations was developed and used to analyse all UK gliding accidents from 2002 to 2006 for their overall causes as well as factors specific to low hours pilots. Fifty-nine categories of pilot-related accident causation emerged, which were formed into progressively larger categories until four overall human factors groups were arrived at: ‘judgement’; ‘handling’; ‘strategy’; ‘attention’. ‘Handling’ accounted for a significantly higher proportion of injuries than other categories. Inexperienced pilots had considerably more accidents in all categories except ‘strategy’. Approach control (path judgement, airbrake and speed handling) as well as landing flare misjudgement were chiefly responsible for the high accident rate in early solo glider pilots. Statement of Relevance: This paper uses extant accident data to produce a taxonomy of underlying human factors causes to analyse gliding accidents and identify the specific causes associated with low hours pilots. From this specific, well-targeted remedial measures can be identified.

Nighttime approaches to offshore installations in Brazil: Safety shortcomings experienced by helicopter pilots.

Accident rates for night sorties by helicopters traveling to offshore oil and gas platforms are at least five times higher than those during the daytime. Because pilots need to transition from automated flight to a manually flown night visual segment during arrival, the approach and landing phases cause great concern. Despite this, in Brazil, regulatory changes have been sought to allow for the execution of offshore night flights because of the rapid expansion of the petroleum industry. This study explores the factors that affect safety during night visual segments in Brazil using 28 semi-structured interviews with offshore helicopter pilots, followed by a template analysis of the narratives. The relationships among the factors suggest that flawed safety oversights, caused by a combination of lack of infrastructure for night flights offshore and declining training, currently favor spatial disorientation on the approach and near misses when close to the destination. Safety initiatives can be derived on the basis of these results.

Crosswind Landings in General Aviation: A Modified Method of Reporting Wind Information to the Pilot

Crosswind conditions are a contributory factor in many general aviation landing incidents and accidents. In an online survey, it was observed that 98% of respondents either failed to or could not accurately calculate the runway crosswind component from air traffic control (ATC) reports passed using the International Civil Aviation Organization (ICAO) standard phraseology; the majority of pilots also severely underestimated the crosswind strength. Furthermore, nearly 30% of these respondents could not recall or inaccurately recalled the crosswind limit of their aircraft. In a 2nd study using a series of approach and landing trials in a general aviation simulator, wind reports were passed to participants using either the standard ICAO format or in a modified format, where the runway crosswind component was explicitly stated. The results showed that for the group receiving wind reports in the standard format, the mental arithmetic associated with calculating the runway crosswind impaired flying performance. As with the online survey, these calculations were also performed poorly. These results suggest that ATC reports on the approach should be amended to specifically include the runway crosswind component and that all aircraft should have their crosswind limit clearly indicated in the cockpit.

A multistage multinational triangulation approach to hazard identification in night-time offshore helicopter operations

When visibility is poor offshore helicopter operations are prone to accidents. Given that a significant increase in night-time activities is predicted in the near future, this paper proposes a systemic approach to account for all the factors underlying such accidents. It presents the results of accident analysis and interviews of pilots from five different scenarios using cognitive task analysis, followed by rigorous application of Grounded Theory and Template Analysis to the narratives. The results are used to compile a comprehensive list of the factors that affect the ability of pilots to fly at night. These factors should form the basis for future data collection and safety interventions.

A systems perspective on the unstable approach in commercial aviation

Unstable approaches remain a significant contributory factor in commercial aviation accidents that occur during the approach and landing phase. A safe approach requires a carefully ordered sequence of changes to the configuration and speed of the aircraft in order to carry out a safe landing and criteria regarding configuration and speed must be met for an approach to be classified as stable. When an approach does not meet these criteria, often because of unexpected changes, the approach is classified as unstable and the risk of a landing accident or incident is greatly increased. Traditional accident models follow a linear path from cause to effect or describe a linear path through absent or weakened defences. A systems perspective attempts to understand failures by understanding successes under dynamic conditions. Pilots were interviewed about how they choose a particular configuration style during approaches and their reactions to influences that caused them to adapt their profile. Grounded theory method was used to uncover how pilots successfully manage to adapt their working practices in dynamic environments and why these adaptations sometimes fail. The grounded theory based on the data was that pilots must reconcile multiple goals, including those of outside agencies, and it is the success or failure of this reconciliation that determines the success or failure of the approach. The theory of multiple goal reconciliation formed the basis of recommendations to improve the safety of approach procedures, the key one being that a published speed profile would unify the goals of pilots and air traffic controllers, the sole aim then being to get the aircraft to particular positions at particular speeds.

Factors affecting safety during night visual approach segments for offshore helicopters

Accident rates for night sorties, by helicopters operating offshore, are estimated to be five times higher than for daytime. Recent attempts to redress this problem include new instrument descent procedures and changes to helideck lighting. However, there still remains a need for pilots to transition from automated flight to a manually flown night visual segment during the arrival, and three recent accidents have again highlighted the dangers of this phase. In order to explore what factors affect safety during night visual segments 33 semi-structured interviews were administered to pilots from a number of companies, and grounded theory was employed to analyse the narratives. From this, a template was developed representing pilots’ perceptions of factors affecting safety, and the relationships among factors were hypothetically mapped. Visual spatial disorientation figured as the main concern of participants, stemming from substandard pilot communication, loss of scanning skills during summer months, autopilot limitations, and the requirement to fly to too low meteorological minima. Concerted actions and further areas of research have been proposed to the different stakeholders involved in offshore nighttime operations, going beyond ongoing safety initiatives.

Accident rates for novice glider pilots vs. pilots with experience.

INTRODUCTION It is a popular notion in gliding that newly soloed pilots have a low accident rate. The intention of this study was to review the support for such a hypothesis from literature and to explore it using UK accident totals and measures of flying exposure. METHOD Log sheets from UK gliding clubs were used to estimate flying exposure for inexperienced glider pilots. This was used along with accident data and annual flight statistics for the period 2004-2006 in order to estimate accident rates that could be compared between the pilot groups. RESULTS The UK accident rate for glider pilots from 2004-2006 was 1 accident in every 3534 launches and 1590 flying hours. The lowest estimated rate for pilots with up to 1 h of experience was 1 accident every 976 launches and 149 h flown. For pilots with up to 10 h of experience the figures were 1 accident in 1274 launches and 503 h. DISCUSSION From 2004-2006 UK glider pilots with 10 h or less experience in command had twice the number of accidents per launch and three times as many accidents per hour flown than average for UK glider pilots. Pilots with only 1 h of experience or less were involved in at least 10 times the number of accidents per hour flown than the UK average and had more than 3.5 times the number of accidents per launch.