Loss Of Control In Flight Research Articles

Studies on in-flight aircraft rerouting

With the publication of this article, the authors continue the research on the development and testing of a methodology for in-flight aircraft rerouting which have begun in previously published articles in the Civil Aviation High Technologies of the Moscow State Technical University of Civil Aviation. This article presents the results of the study in terms of developing the potentials of the methodology from reconfiguring a route of a hypothetical aircraft and obstacles in the horizontal plane, which were previously demonstrated, prior to rerouting in both the horizontal and vertical planes for two different types of obstacles: 1) ground natural or artificial (mountain, power line support, etc.); 2) air (squall line, prohibited flight area, etc.) and their combinations using an example of a Mi-8 helicopter flight on route using a real digital map of the terrain. As mentioned above, a large amount of aviation accidents is associated with the loss of control in-flight, as well as the collision with terrain in a controlled flight (categories LOC-I, CFIT, LALT). As a result of the investigation of the aviation accidents, it was found that these accidents are often caused by the requirement to reroute quickly due to obstacles, for example, a squall line. When determining alternatives to avoid an obstacle, as well as while implementing the selected route for avoiding action, the crew makes errors due to the increased psychophysiological load and lack of time. The methodology and the algorithms, proposed by the authors, make it possible to assess the safety of an original route, estimate options for alternatives to avoid around obstacles detected in-flight, check them for feasibility, taking into account aircraft performance, flight envelope, and also select the optimal route from the view of some criterion, for example, based on minimizing the route length increase, reducing additional fuel consumption, the time required to implement a new route of flight, etc.

Human Factors in General Aviation Loss of Control: Survey of Pilot Experiences

Inflight loss of control (LOC-I) is a major cause of general aviation (GA) accidents. Previous studies have identified LOC-I causes from sources such as the National Transportation Safety Board (NTSB) database. NTSB GA accident reports include limited detail on human factors. Getting pilots’ perspectives from other sources, such as surveys, may reveal insights into pilot actions and conditions. This study investigates the role of human factors in LOC-I by analyzing demographics in NTSB accidents and conducting a survey of pilots’ LOC-I experiences based on the Human Factors Analysis and Classification System framework. Note that 80% of the LOC-I events shared by the pilots involved pilot error, most of which were skill-based and decision errors. About one-quarter of pilots mentioned that their instructor had not prepared them well or taught them methods to recover from LOC-I. Several pilots mentioned that, because of their lack of LOC-I recovery training, they could not recover from LOC-I. The study helped in identifying specific pilot errors and issues in training that were not mentioned explicitly in the NTSB reports. Findings from the study may help improve training methods and operating procedures for GA pilots to prevent loss of control in the future.

Severity assessment of sudden plunging motion for jet transport aircraft in response to severe atmospheric turbulence

PurposeThe purpose of this paper is to present a comparative study of flight circumstances, dynamic stability characteristics and controllability for two transport aircraft in severe atmospheric turbulence at transonic cruise flight for the purpose to obtain the prevention concepts of injuries to passengers and crew members for pilot training in International Air Transport Association (IATA) – Loss of Control In-flight (LOC-I) program.Design/methodology/approachA twin-jet and a four-jet transport aircraft encountering severe atmospheric turbulence are the study cases for this paper. The nonlinear unsteady aerodynamic models are established through flight data mining and the fuzzy-logic modeling technique based on the flight data of flight data recorder. This method can be adopted to examine the influence of horizontal wind shear and crosswind on loss of control, dynamic stability characteristics and controllability for transport aircraft in different weights and different sizes in tracking aviation safety of existing different types of aircraft.FindingsThe horizontal wind shear or crosswind before the turbulence encounter will easily induce rolling motion and then initiate the sudden plunging motion during the turbulence encounter. The roll rate will increase the oscillatory rolling motion during plunging motion, if the rolling damping is insufficient. The drop-off altitude will be enlarged by the oscillatory rolling motion during the sudden plunging motion.Research limitations/implicationsA lack of the measurement data of vertical wind speed sensor on board to verify the estimated values of damping term is one of the research limitations for this study. The fact or condition of being severe in sudden plunging motion can be judged through the analysis of oscillatory derivatives with both dynamic stability and damping terms.Practical implicationsThe roll rate will increase the oscillatory rolling motion during plunging motion, if the rolling damping is insufficient. The drop-off altitude will be enlarged by the oscillatory rolling motion during the sudden plunging motion. The horizontal wind shear or crosswind before the turbulence encounter will easily induce rolling motion and then initiated the sudden plunging motion during the turbulence encounter. If the drift angle is large, to turn off the autopilot of yaw control first and stabilize the rudder by the pedal. When passing through the atmosphere turbulence area, the pilots do not need to amend the heading angle urgently.Social implicationsThe flight safety prevention in avoidance of injuries for passengers and cabin crews is essential for the airlines. The horizontal wind shear or crosswind before the turbulence encounter will easily induce rolling motion and then initiated the sudden plunging motion during the turbulence encounter.Originality/valueThe flight safety prevention in avoidance of injuries for passengers and cabin crews is essential. The present assessment method is an innovation to examine the loss of control problems of aviation safety and promote the understanding of aerodynamic responses of the jet transport aircraft. It is expected to provide a valuable lecture for the international training courses for IATA – LOC-I program after this paper is being published.

Flight Test Investigation on Loss of Control Due to Flap and Landing Gear Configuration Change

Extension of flaps during landing and take-offs not only increases the lift produced by the wing due to change in camber of the aerofoil but also increases the wing downwash which reduces the angle of attack on the horizontal tail and reduces the tail efficiency resulted in to significant change in pitch attitude, aircraft altitude and airspeed. Lowering of landing gear increases the interference drag and lead to vortex shedding which reduces the pressure underneath the wing, as a result aircraft have pitching down moment. During this phase pilot is pre-occupied and might be distracted and if requisite control input is not provided by the pilot to maintain required aircraft attitude it can lead to uncontrollable flight condition and loss of control in flight. To investigate these effects, Flight tests were carried out on Hansa-3 and Cessna-206H aircraft at IIT Kanpur along with Pilot and on Cirrus Jet SF-50 in X-Plane 11 Flight Simulator. During flight test aircraft exhibited significant change in pitch attitude, roll angle, aircraft altitude and airspeed and aircraft even stalled. Extension of flaps with 30° bank along with extended landing gear has given more stability to the aircraft and increase in pitch attitude and altitude was less in comparison of retracted Landing Gear.

Pilot performance and workload whilst using an angle of attack system

Loss of control in flight is the primary category of fatal accidents within all sectors of aviation and failure to maintain adequate airspeed – leading to a stall - is often cited as a causal factor. Stalls occur when the critical angle of the aircraft is exceeded for a given airspeed. Using airspeed as an indicator of the potential to stall is an unreliable proxy. Systems that measure the angle of attack have been routinely used by military aircraft for over 50 years however rigorous academic research with respect to their effectiveness has been limited. Using a fixed-base flight simulator fitted with a simulated, commercially available angle of attack system, 20 pilots performed normal and emergency procedures during the circuit/pattern in a light aircraft. Experimental results have shown that pilot performance was improved when angle of attack was displayed in the cockpit for normal and emergency procedures during the approach phase of flight in the pattern/circuit. In relation to pilot workload, results indicated that during the approach phase of flight, there was a moderate but tolerable increase in pilot workload. The use of such a display may assist pilots to maintain the aircraft within the optimum range and hence reduce occurrences of unstable approaches. Overall, fewer stall events were observed when angle of attack was displayed and appropriate pilot decisions made during emergencies. These results provide a new perspective on pilot workload and aviation safety.

Analysis of the existing approaches to in-flight aircraft rerouting

Currently, the large number of aircraft accidents is associated with the loss of control in flight and a controlled flight into terrain. It frequently occurs due to a change of flight conditions, relatively which a preparation for departure was carried out, and involves the necessity to reroute efficiently in the conditions of increased psychophysiological load and time constraint for decisionmaking. Generated thunderstorm cells on route, artificial or natural obstacles, not considered while planning a route, can result in amending a flight plan, which was earlier accepted and implemented in the automatic, flight director or manual modes of control. The lack of comprehensive situational awareness is fairly a frequent cause of aviation accidents for general aviation aircraft. Aviation accidents of transport category aircraft are typically associated with incorrect crew actions when dangerous flight zones are detected along the route. The article represents an overview and analyzes modern onboard facilities to detect obstacles, as well as required pilot actions to reroute a flight for in-flight detected obstacle avoidance. The current level of avionics development provides situational awareness necessary for obstacles avoidance but requires timely, correct and sometimes non-obvious flight crew rerouting decisions. The algorithms used with robotic packages of various applications in related fields ensure the automatic rerouting for obstacle avoidance. They cannot be directly used or adapted for the implementation on board an aircraft due to the lack of consideration for aircraft specific features when obstacle avoidance routing, i.e., restrictions of control parameters (an angle of attack, overload, roll angle), capabilities of a control system (available rate of overload, available and maximally allowable angular rolling velocity, etc.). Therefore, the issue to develop a system to support pilot decisions for obstacle avoidance is relevant. It encompasses the synthesis of safe alternatives for obstacle avoidance which are optimal by a pilot-assigned criterion (minimum loss of time, minimum additional fuel consumption, etc.).

Risk Analysis of Airplane Upsets in Flight: An Integrated System Framework and Analysis Methodology

Generally, airplane upsets in flight are considered a precursor to loss of control in flight (LOC-I) accidents, and unfortunately LOC-I is classified as the leading cause of fatal accidents. To further explore the risk factors, causal relationships, and coupling mechanism of airplane upsets, this study proposed a risk analysis model integrating the Interpretative Structural Modeling (ISM) and Bayesian Network (BN). Seventeen key risk factors leading to airplane upsets were identified through the analysis of typical accident cases and the literature. The ISM approach was used to construct the multi-level interpretative structural model of airplane upsets, which could reveal the causal relationship among various risk factors and risk propagation paths. Then, taking 286 accident/incident investigation data as training samples, a data-driven BN model was established using machine learning for dependency intensity assessment and inference analysis. The results reveal that the interaction among risk factors of fatal accidents caused by airplane upsets is more significant than that of non-fatal accidents/incidents. Risk factors such as pilot-induced oscillations/airplane-pilot coupling and non-adherence to Standard Operating Procedures (SOPs)/neglect of cross-validation have a significant effect on airplane upsets in flight among seventeen risk factors. Moreover, this study also identifies the most likely set of risk factors that lead to fatal accidents caused by airplane upsets. The research results have an important theoretical significance and application value for preventing airplane upsets risk.

Movement mechanisms for transport aircraft during severe clear-air turbulence encounter

AbstractThe objective of this paper is to present the movement mechanisms of transport aircraft response to severe clear-air turbulence to obtain the loss of control prevention for pilot training in IATA – Loss of Control In-flight (LOC-I) program. The transport aircraft in transonic flight is subjected to severe clear-air turbulence, resulting in a sudden plunging motion with the abrupt change in flight attitude and gravitational acceleration. The comparative analyses of the flight environment and aircraft response to severe clear-air turbulence for two four-jet aircraft are studied. The one with a larger dropped-off altitude during the plunging motion will be chosen to construct the movement mechanism. The nonlinear unsteady aerodynamic model of the chosen transport is established through flight data mining and the fuzzy-logic modeling of artificial intelligence technique based on post-flight data. The crosswind before the turbulence encounter will easily induce a rolling motion and then the sudden plunging motion during the turbulence encounter. The influences of the varying vertical wind and crosswind on loss of control are presented. To formulate preventive actions, the situation awareness of varying crosswind encountering for the operational pilot will be studied further in the future. The present study is initiated to examine the possible mitigation concepts of accident prevention for the pilot training course of IATA – Loss of Control In-flight (LOC-I) program.

General Aviation Loss of Control in Flight Accidents: Causal and Contributory Factors

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 factors, and possible reasons for unsuccessful recovery. Most of the events were nonfatal (82.6%), and most occurred during low-altitude flight phases: particularly, landings and go-arounds. Pilots under the age of 40 and over the age of 75 were disproportionately more likely to experience loss of control in flight. It was mostly precipitated by ineffective recovery from an upset, inadequate energy management, abnormal/inadvertent control inputs or maneuvers, or improper procedures. Insufficient height above the ground was a factor in most unsuccessful recoveries, followed by limited pilot capability. Fatal accidents were much more likely to be unrecoverable due to a hazardous mental or physical state or incorrect recognition of the situation. Decision- and skill-based human errors contributed to most events; more than half of the cases involved both errors. Fatal accidents were more complex in terms of preflight and latent human errors. These results informed a new definition of loss of control in flight for general aviation combined with a conceptual framework to inform future intervention strategies.

BowTie Methodology for the Risk Management of the Spin Maneuver During Flight Training in Brazil

This paper aims to present the BowTie methodology as a practical tool for the Risk Management of the spin maneuver during flight instruction, identifying hazards, controls and consequences related to the loss of control in-flight (LOC-I). Exploratory research was carried out regarding its objectives, through a literature review. Initially, a comparison is made between the Brazilian and international training programs, then the particularities of this training in Brazil was analyzed. Finally, a step-by-step construction of a BowTie developed is presented to reduce LOC-I occurrences during spin training.

ANALYSIS OF GENERAL AVIATION FIXED-WING AIRCRAFT ACCIDENTS INVOLVING INFLIGHT LOSS OF CONTROL USING A STATE-BASED APPROACH

Inflight loss of control (LOC-I) is a significant cause of General Aviation (GA) fixed-wing aircraft accidents. The United States National Transportation Safety Board’s database provides a rich source of accident data, but conventional analyses of the database yield limited insights to LOC-I. We investigate the causes of 5,726 LOC-I fixed‑wing GA aircraft accidents in the United States in 1999–2008 and 2009–2017 using a state-based modeling approach. The multi-year analysis helps discern changes in causation trends over the last two decades. Our analysis highlights LOC-I causes such as pilot actions and mechanical issues that were not discernible in previous research efforts. The logic rules in the state-based approach help infer missing information from the National Transportation Safety Board (NTSB) accident reports. We inferred that 4.84% (1999–2008) and 7.46% (2009–2017) of LOC-I accidents involved a preflight hazardous aircraft condition. We also inferred that 20.11% (1999–2008) and 19.59% (2009–2017) of LOC-I accidents happened because the aircraft hit an object or terrain. By removing redundant coding and identifying when codes are missing, the state-based approach potentially provides a more consistent way of coding accidents compared to the current coding system.

Methodic aspects of aircraft glide slope correction for prevention of CFIT category accidents during pre-landing descent

Aviation accidents of the category of controlled flight into terrain in world commercial aviation are included into three "killers" in aviation together with loss of control in flight (LOC-I) and runway excursions (RE). As a result of long-term research of this problem the methods of CFIT risk level reduction, pilot training and retraining programs were developed and put into practice. Also several generations of onboard ground proximity or obstacle warning systems were created (GPWS, EGPWS, TAWS), the disadvantage of which is a passive – advisory type of warnings. The conclusions of the commissions concerning the results of aviation accidents investigations indicate the cases of crew disregard of an alarm of a ground proximity warning system and possibility of a go-around procedure to make a missed approach. Despite the aviation community actions, accidents of this category continue to occur. Therefore, search of new methods and solutions of the controlled flight into terrain problem is necessary. One of the possible ways to resolve this problem is making proximity warning systems active and two-mode operative. The first one is some type of warning to the crew about approaching the boundaries of a safe maneuvering area during approach to land as well as the recommendations to avoid a glide path deviation. The second way is that if the crew members don`t take any actions with a warning on or crew actions are not effective enough, it is necessary to regain a glide slope with temporary pilot disengagement from a control loop.

Human Factors Approaches and Models in LOC-I Accident Analysis and Prevention: Flight Crew Resource Management Techniques as a Risk Mitigation Tool

Increased cockpit automation on modern jet aircraft aim to reduce the risk of Undesired Aircraft State (UAS) instances such as Loss of Control in Flight (LOC-I). Although LOCI globally accounts for only 9% of all analysed accidents IATA has reported that it was responsible for 58% of all accident fatalities in 2017. The focus of this paper is to answer whether Threat and Error Management and Crew Resources Management (CRM) techniques are an efficient risk management tool when facing a LOC-I threat. Three LOCI final aircraft accident reports were analysed to understand the structure of Human Factors (HF) during these flights. Methods from the HF field such as the Generic Error Modelling System (GEMS) and Skill-, Rule- and Knowledge-based (SRK) error approach provided invaluable insights to identify potential findings. A holistic investigation of cognitive structures in flight path management helped to visualise latent conditions and cognitively demanding tasks during LOC-I in routine operations. Bearing in mind the limited number of cases considered in this paper it should be considered as an overview in LOC-I accident analysis. It shows that leadership and teamwork, as essential aspects of CRM training, can serve as key strategies to mitigate HF problems and LOC-I risks.

Civil Aviation Occurrences in Indonesia

Globally, civil air traffic has been growing rapidly in recent years, and with this growth, there has been a considerable improvement in air safety. However, in Indonesia, the recent rate of incidents and accidents in aviation is far higher than the global average. This study aims to assess civil aviation safety occurrences in Indonesia and, for the first time, to investigate factors contributing to these occurrences within commercial Indonesian aviation operations. In this study, 97 incident/accident investigation reports published by the Indonesian National Transportation Safety Committee between 2007 and 2015 were analysed. The most common occurrences involved Runway Excursions, Loss of Control In-Flight, and Controlled Flight into Terrain. In terms of the likelihoods of the occurrences and the severity of consequences, Runway Excursions were more common while Loss of Control In-Flight and Controlled Flight into Terrain events were more severe and often involved fatalities. In Indonesia, Runway Excursions were usually nonfatal and comprised 45% of the occurrences for commercial flights, compared to 34% globally. Further, in this study, weather and Crew Resource Management issues were found to be common contributing factors to the occurrences. Weather was a contributing factor for almost 50% of the occurrences involving Indonesian commercial flights. Adverse weather contributed to Loss of Visual Reference for visual flight operations in mountainous areas, which contributed to the majority of Indonesian fatal accidents. The combination of Indonesian monsoon climate and mountainous weather characteristics appears to provide many risks, mitigation of which may require specialist pilot training, particularly for multicrew aircraft. In identifying the main contributing factors, this study will hopefully provide motivation for changes in training and operations to enhance future aviation safety in Indonesia.

On Flight Risk Analysis Method Based on Stability Region of Dynamic System Under Icing Conditions

The occurrence of loss of control in flight is often accompanied by deep coupling of flight parameters. In order to explore the mechanism of coupling induced flight risk, a method of flight risk assessment based on the stability region of a nonlinear dynamic system was proposed. The Monte Carlo method was improved to identify the boundary of the stability region, and the key parameters that can represent the flight safety were set. The risk quantification method and the colorized flight risk characterization method were proposed. Combined with the case of aircraft encountering icing, the variation trend of flight stability region and flight risk under different icing degrees was calculated. The results showed that with the aggravation of icing, the flight stability region was significantly reduced and the coupling of flight parameters was aggravated. And compared with the traditional angle of attack protection method, this method can find the potential flight risk earlier, and characterize the way of parameters’ coupling and the flight risk evolution process. The proposed method can improve the pilot’s situational awareness, and also provide theoretical support for the prevention of flight risk under adverse conditions, and provide reference for the further development of boundary protection control law.

A state-based approach to modeling general aviation accidents

This paper develops a state-based accident model that we apply to General Aviation (GA) accidents recorded in the National Transportation Safety Board (NTSB) accident database. We demonstrate our approach on 6180 helicopter accidents that occurred in the United States between 1982 and 2015, with emphasis on inflight loss of control (LOC-I) accidents. Our model helps remove the redundancies in the NTSB coding system by logically grouping various NTSB accident codes that convey the same meaning. Further, this model checks for logical gaps or omissions in NTSB accident records, and potentially fills the omissions in. This approach uses NTSB coding data to define a set of states (safe or hazardous) for a system and triggers that move the system into (or out of) these states. We identify the most frequent triggers for LOC-I and compare the results from the state-based approach with those obtained from a conventional analysis of NTSB accident codes.

Wind prevents cliff-breeding birds from accessing nests through loss of flight control.

For fast-flying birds, the ability to respond to wind during landing is critical, as errors can lead to injury or even death. Nonetheless, landing ability, and its ecological significance, remain unstudied. We show that for auks, 60% of attempts to land at their cliff nests fail in a strong breeze (80% in near-gale winds). This is most likely because wind interferes with the ability to maintain flight control in the last phase of landing. Their extreme flight costs mean that the energetic penalty for multiple landing attempts is high. We propose that exposure, and ability to respond to, such conditions will influence the suitability of breeding habitat. In support of this (i) auk colonies appear to be orientated away from prevailing winds and (ii) landing success within colonies is higher on crowded ledges with more airspace for manoeuvring. More generally, the interplay between wind and flight capacities could impact breeding distributions across species and scales.

Proof of concept simulator demonstration of a physics based self-preserving flight envelope protection algorithm

This article discusses the development of an adaptive protection algorithm which is based on a physical approach, with the purpose to keep a closed loop aircraft with manual control laws within the actual safe flight envelope, even in the presence of failures or disturbances. Adaptive estimation of the flight envelope guarantees that not only flap changes, but also damage (e.g. icing) and external disturbances such as wind can be taken into account. This method is robust with respect to uncertainties in the estimates for the aerodynamic properties. This updated information makes the flight control laws more self-preserving and prevents loss of control in flight. This development can extend the functional envelope of the nominal law and reduce the need to switch from nominal to alternate law in the presence of certain failures. This algorithm has been applied on a simulation model of a medium range passenger aircraft and the setup has been implemented and evaluated in the DLR Robotic Motion Simulator at the German Aerospace Center as a proof of concept demonstration.

LOC-I(Loss of Control In Flight)(【基礎・応用編】, えあろすぺーすABC)

LOC-I(Loss of Control In Flight)(【基礎・応用編】, えあろすぺーすABC)

Design and Piloted Simulator Evaluation of Adaptive Safe Flight Envelope Protection Algorithm

This paper discusses the design and evaluation of an efficient safe flight envelope protection method for keeping an augmented aircraft with manual flight control laws within the safe envelope bounds. This flight envelope is estimated adaptively, so that configuration changes and possible failures can be taken into account. The updated information of the safe envelope is used in the flight control laws to prevent loss of control in flight. It has been found that a control architecture involving separate pilot command filtering is particularly well suited to incorporate these adaptive protections. Moreover, haptic feedback to the pilot controls can be included as well, based on the same adaptive bounds. This has the potential to further increase the flight crew awareness about the risk of losing control in flight. These algorithms have been evaluated in the Simulation, Motion, and Navigation Research Simulator at Delft University of Technology to investigate the impact on the awareness of the crew. Commercial airline crews flew multiple challenging approach and landing scenarios in a relevant simulated environment. Results show that the algorithms support the flight crew significantly. They contribute to “carefree” flying and to avoiding loss of control in flight.