Michael A. Bromfield

Sixty uncrewed aerial vehicle (UAV) accident reports were analysed to identify causal and contributory factors leading to loss of control in flight – the most prominent category of UAV accident (36%). Design and manufacturing errors were dominant causal factors (22 events, 34%) and contributory factors (18 events, 22%). Recovery was not attempted in the majority of events (35 events, 55%). The relationship between operator age, total hours of experience, experience on type and recovery attempts were analysed. The number of accidents decreased as total hours of experience increased as well as attempted recovery. Using this data, existing accident analysis frameworks HFACS, AcciMap and Accident Route Matrix were applied to a sample of accidents and suitability compared. An adapted version of the Accident Route Matrix – Uncrewed Aerial Vehicle is proposed to assist current and future operators to understand causal and contributory factors to mitigate future loss of control in flight accidents and improve the likelihood of recovery. Using the results of the statistical analysis and the data gathered, a new definition for LOC-I for UAVs was defined by considering the different operating environment of UAVs.

This paper presents the development of a robust sizing method to efficiently estimate and compare key performance parameters in the conceptual design stage for the two main classes of fully electric vertical take-off and landing (eVTOL) aircraft, the powered lift and wingless aircraft types. The paper investigates hybrids of classical root-finding methods: the bisection, fixed-point and Newton-Rapson methods for use in eVTOL aircraft sizing. The improved convergence efficiency of the hybrid methods is at least 70% faster than the standard methods. This improved efficiency is significant for complex sizing problems. The developed sizing method is used to investigate the comparative performance of the wingless and powered lift eVTOL aircraft types for varying mission lengths. For a generic air taxi mission with a payload of 400 kg, the powered lift type demonstrates its mass efficiency when sized for missions above 10 km in range. However, the simpler architecture of the wingless eVTOL aircraft type makes it preferable for missions below 10 km in range when considering energy efficiency. The results of the sizing study were compared against a selection of eVTOL aircraft data. The results showed a good agreement between the estimated aircraft mass using the proposed sizing method and published eVTOL aircraft data.

In January 2017, a business jet flew in Norway on a short repositioning flight with two pilots onboard, no passengers or cargo. Initially, the take-off proceeded as normal but as the landing gear was retracted both pilots observed that the airspeed was rapidly approaching the flap limiting speed of 200kts. When the flaps were fully retracted at a height of approximately 2,100ft above ground level, the crew experienced a violent nose-down pitch motion. Control was regained at a height of approximately 170ft above ground level and, following the accident, data from the flight data recorder showed that the aircraft experienced –2.62G during the pitch upset. A tailplane stall due to icing was suspected; however, the flight data recorder, being limited to 36 parameters, was not able to confirm this. For expediency during the accident investigation process, a simplified, linear flight dynamics model was developed using Matlab/Simulink to assess static and dynamic stability for a range of tailplane efficiency factors to simulate the effects of tailplane icing.

Loss of control in flight is the primary fatal accident category in general aviation. Forty-six fixed-wing United Kingdom accidents from 2018 and 2019 were analyzed to identify precursors, human fa...

High levels of automation in future aviation technologies such as Unmanned Aircraft Systems could lead to human operators losing essential Situation Awareness and becoming ‘out-of-the-loop’. Research into Human Autonomy Teaming proposes that improved communication between the human and autonomous agents of a system can address this problem. However, knowledge around the effect of automation audio communication is lacking in the literature and we propose audio-voice conversation would provide the optimum form of communication. In this study we evaluated the impact that providing a conversational interface to a synthetic teammate had on the performance, Situation Awareness and perception of teaming of the human teammate. Twenty-four participants conducted experimental trials on a computer-based task adapted from a Levels Of Automation test method developed by Endsley and Kaber ( 1999 Endsley, M. R. , and D. B.Kaber . 1999. “Level of Automation Effects on Performance, Situation Awareness and Workload in a Dynamic Control Task.” Ergonomics 42 (3): 462–492. doi:10.1080/001401399185595. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar] ). The results show that synthetic voice communication had a significant positive effect on human performance and perception of teaming. Also demonstrated was that teaming structure has an effect on how that performance increases, with participants in higher Levels Of Automation where the automation provides decision making advice demonstrating a habit of consistently following voice provided advice, even when that advice results in the participant adopting new behaviours and taking more risks.

Loss of Control In Flight (LOC-I) is the most lethal type of accident in recent aviation history and the one that has experienced the least reduction in the past 20 years. These, combined with recent accidents such as Lion Air 610 and Ethiopian Flight 302, help explain the attention dedicated by several aviation stakeholders to prevent it from happening. Prior to that, however, the understanding of the characteristics of the phenomenon is of paramount importance. Pilots, aircraft and systems are deeply related in LOC-I accidents, but current definitions tend to examine these in isolation and not as a human-in-the-loop system. Following experiments in a flight simulator with a group of test pilots, this paper investigates the use of the Cooper-Harper rating scale and the Quantitative Loss of Control Criteria to assess controllability in a series of manoeuvres performed in four different sets of LOC-I test scenarios. The experimental design, including the selection of pilots, adaptation of test scenarios, conception of tasks and data gathering procedure, is thoroughly discussed. From a statistical correlation analysis, results indicate the existence of a positive weak to moderate monotonic relationship between the qualitative and quantitative approaches, however the resemblance of events indeed impacting on controllability issues is low. Finally, a discussion is taken on ways to conceive tasks with regard to the application of the Cooper-Harper scale and the possibility of adapting the quantitative method, both in the sense of being more faithful to the actual aircraft condition and pilots' workload.

During the period 2003–2011, worldwide accident rates for business/corporate aviation were nearly four times that for commercial aviation. Flight Operations Quality Assurance (FOQA) or Flight Data Monitoring—the collection of real-time flight data for continuous safety improvement—has been routinely used by commercial aviation for over 50 years. Regulatory authorities only require airplanes over 27 tonnes maximum takeoff weight to operate an FOQA Program. Corporate/business aviation operators generally operate airplanes less than 20 tonnes using a diverse range of airplanes, which may include a single engine, twin engine, turbo-prop, and/or very light jets. This study investigates the use of low-cost, independent commercial off-the-shelf technologies using a combination of Global Positioning Systems and Attitude Heading & Referencing Systems to sense and record key flight data parameters in support of an FOQA program for corporate operators with diverse, lower-weight-category and legacy airplanes. The preliminary results suggest that such systems and Electronic Flight Information Systems (where installed) can usefully support an FOQA for lower-weight-category and legacy airplanes.