Flight Deck Research Articles

The Effects of Aeronautical Decision-Making Models on Student Pilots’ Situational Awareness and Cognitive Workload in Simulated Non-Normal Flight Deck Environment

ABSTRACT Objective This paper investigates the effects of using different decision-making models on pilots’ performance while facing non-normal flight circumstances. Background The captain must quickly make appropriate decisions once an aircraft faces emergency. Usually, human error is one primary cause of accidents, which inevitably affects the captain’s decision progress. Method Ten participants carried out a standard non-normal scenario (cargo smoke). Each participant is equipped with simulation experience and executed three sessions using three different decision models: the DOGAM, DECIDE, and CLEAR. After each session, the situation awareness (SA) and perceived workload were assessed using the Situational Awareness Rating Technology (SART) and NASA-TLX. An in-depth interview was also completed to comprehend their subjective perception of decision-making. Results Although the CLEAR outperformed the other models in SART and NASA-TLX scores, their performance regarding workload and SA was comparable. The fixing time of DOGAM was the longest, and the other two models were no significant difference. Subjectively, the DECIDE may require a high mental demand by simultaneously processing lots of information and measuring significant changes, whilst the DOGAM may encourage participants follow their own idea, promoting aggressive decisions. Conclusion This paper clarifies the importance of incorporating decision models into the cockpit and investigates the relatively feasible decision-making model. Variation across our results illustrated applying different decision models to train pilots and solve problems is suggested, thereby improving flight safety.

Numeric assessment of the effect of the twin island design on the airflow dynamics around a generic aircraft carrier

The twin island concept is the most recent innovation in the top-deck architecture of an aircraft carrier. The carrier’s bluff body design presents the pilot with a number of difficulties, with landing on deck posing the biggest problem. The goal of the current study is to carry out the numerical analysis of the aerodynamic behaviour of twin island structure on Generic Aircraft Carrier. The flow characterization has been performed utilizing the normalized axial velocity and turbulent kinetic energy as aids for establishing pilot workload along the glideslope line. In this paper, multiple transverse planes cut across perpendicular to the flow direction are used to analyse the flow across the flight deck of twin island GAC and its downstream. The impacts of the two islands’ longitudinal translations with regard to the initial GAC position were then investigated and the results were analysed and compiled with reference to the landing approach path of the aircraft. The results show that the twin island designs are preferable to a single island. The maximum advantage in terms of turbulence reduction is achieved when the bifurcated islands are longitudinally repositioned forward of the original single island design position. The modified design not only achieves a 72% reduction in peak turbulence but also provides an additional time advantage to the pilot for assessing the environmental conditions while he is approaching the carrier flight deck for landing thus aiding to efficiently and effectively manage the workload. The findings of this study can act as a driving force for the integration and application of twin island concept in future design plans for floating structures and further studies in the field.

Improvement of Helicopter Operations on Frigates Using the Coanda Effect

The flow surrounding a frigate is characterized by high-velocity gradients and flow detachment behind the superstructure of the ship. Therefore, the helicopter pilot’s workload during the recovery maneuvers above the flight deck can increase. Different techniques of flow control have been tested for reducing the flow detachment and pilot workload. In this paper, a combined numerical optimization and experimental tests in a wind tunnel are performed to analyze the implementation of the Coanda effect at the back part of the hangar as an active flow control technique to reduce the flow detachment above the flight deck. The numerical optimization is conducted by testing different velocities and geometries of the Coanda hangars tested. The best results show a complete elimination of the flow detachment above the flight deck and an up to 2.85 times reduction of the low-speed area with respect to the base case. The geometries selected from the numerical results were installed in a scaled simple frigate shape 2 (SFS2) and tested in a wind tunnel with particle image velocimetry (PIV). The experimental results also show a drastic reduction of the flow detachment above the flight deck combined with reduced levels of turbulence intensity at the height where the helicopter rotor must operate during the recovery maneuver.

0184 Can Subjective Sleepiness Pre-flight Predict the Use of Controlled Rest on the Flight Deck?

Abstract Introduction Pilot sleepiness in flight continues to be an issue in aviation due to irregular and extended working hours. In some regions of the world, pilots are allowed to use an in-flight countermeasure called controlled rest, which involves taking a short nap on the flight deck. The use of this countermeasure in practice is understudied. We aimed to investigate whether subjective sleepiness ratings taken pre-flight are predictive of controlled rest use. Methods Data from 94 long (> 6 hours flight duration), non-augmented (two flight crewmembers) flights were analyzed (n = 30 pilots). Mixed-effects logistic regression was used to assess the likelihood of controlled rest based on a Karolinska Sleepiness Scale rating (KSS) taken at pre-flight. Results Controlled rest was taken on 62.77% (n = 59) of the analyzed flights. Pilots with higher KSS ratings (i.e., subjectively sleepier) pre-flight were more likely to take controlled rest during the subsequent flight (b ± SE: 1.03 ± 0.33; OR = 2.81, 95% CI [1.47, 5.37]; p = .002; R2 (Marginal): .28, R2 (Conditional): .51). That is, for every one-unit increase in KSS ratings, there was a near three-fold increase in the odds of taking controlled rest in flight. Conclusion Our results suggest that subjective sleepiness prior to a flight may be predictive of the decision to take controlled rest later in the flight. Further research is needed to understand the influence of other scheduling factors and individual differences. Support (if any) NASA Airspace Operations and Safety Program, System-Wide Safety Project.

Avionic Touchscreen Interaction under Vibration: Supported versus Freehand Target Selection in Cockpit Conditions

With touchscreens being installed in aircraft flight decks, reach-and-turbulence-related challenges arise. Using the ISO 9241-411 multidirectional selection task (a 2D Fitts’ task), we quantified the impact of vibration on touchscreen target selection throughput (a performance score combining both speed and accuracy) and error rate in a cockpit layout. 24 participants completed the task under 2 vibration levels (helicopter level flight versus static), 2 hand support methods (using the thumb, while holding onto the screen’s edge, versus using the index finger freehand), 4 touchscreen types (two avionic and two consumer touchscreens), 2 touchscreen positions (main instrument panel versus pedestal), and 4 target sizes (0.8, 1, 1.5 and 2 cm). We found average throughput values of 6.5 bits per second (bps) in static conditions, versus 5.7 bps under vibration, and average error rates of 10.3% in static conditions, versus 16.6% under vibration. Similar to prior work, we found an exponential increase in error rate with decreasing target size. Larger target sizes helped mitigate the impact of vibration. We did not find evidence of a benefit to anchoring the hand on the touchscreen’s bezel edge, compared to the freehand baseline, under vibration or static conditions. Under vibration, the pedestal outperformed the main instrument panel position, with higher throughput and lower error rate. In static conditions, the two positions performed similarly. This work contributes to vibration mitigation methods when interacting with touchscreens in the aviation context.

A heuristic solution framework for the resource-constrained multi-aircraft scheduling problem with transfer of resources and aircraft

Efficient and feasible flight deck operation scheduling plan is of great significance for improving the sortie rate of carrier aircraft. Oxygen filling, fueling, and other operations of each carrier aircraft are executed in the pre-flight preparation stage. Different personnel, support equipments, and supply resources, are required while different operations are being executed. To date, most approaches proposed in the literature are based on the unrealistic assumption that the transfer process of carrier aircraft can be ignored. To close this gap, the resource-constrained multi-aircraft scheduling problem on the flight deck is examined in this study. The main contributions of the study are as follows. First, by considering the transfer process of aircraft on the flight deck operations, the model formulation of resource-constrained multi-aircraft scheduling problem is established. Second, the parallel and serial scheduling framework are proposed, where parking spot priority rules and resource allocation rules are presented to select the most suitable resources. Third, a modified genetic programming algorithm is presented for obtaining efficient activity priority rules. Fourth, the well-performed scheduling framework, priority rules, and allocation rules are selected by conducting computational experiments. Furthermore, experiment results show that the parallel scheduling framework outperforms the serial framework in most experiments (average outperformance is 10.19%), and the parking spot priority rules slightly affect the serial scheduling framework.

Single-Pilot Aircraft in Commercial Air Transport Operations: A Comparison of Potential Architectures

Single-pilot operations (SPOs) in commercial air transport present a range of benefits and challenges, but there is a need to define architectures and compare them in different operational contexts. Here, we identified various combinations of architectural decisions based on the literature, and we compared them to current operations (in different operating contexts) on a safety versus cost tradespace. Safety was defined as a function of the pilot nominal operations workload, handling of off-nominal situations, and pilot incapacitation; whereas the cost was defined as a combination of acquisition and operating costs. Our analysis suggests that different classes of aircraft (wide bodies, narrow bodies, and regional jets) have different levels of benefits and costs in moving to SPOs. The capabilities of automation need to improve drastically before the second human in the flight deck can be replaced, and this is borne out by the dominance of human-centered architectures in the tradespace. The analysis also reveals that regional aircraft may be prime candidates to move to SPOs first because most regional architectures generate positive savings.

On the influence of Bow region vortices on SFS2 bistable airwake

The flow field of a full-scale simplified frigate model SFS2 is simulated numerically in ANSYS Fluent® 19.0 environment using embedded LES turbulence model. The emphasis of this manuscript is to provide insight into the influence of bow region coherent vortical structures on the characteristics of the bistable airwake impacting the hovering region of flight deck. The constructive interaction of bow leading edge vortex on starboard side with the respective lobe of horseshoe vortex, generated at foot of forward face of superstructure, is found to be responsible for so called “locking” of otherwise uniform incoming flow towards starboard side. Hence, the asymmetry or bias of the bistable airwake towards starboard side can also be explained. Spectral analyses of the velocity measurements recorded in the bow region and the superstructure airwake supplements and validates the influence of bow vortical system on the airwake, as dominant frequencies associated with these vortices are also observed in airwake spectrum. Moreover, the drag force of the SFS2 as well as the airwake dynamics are found to be influenced by the turbulent flow structures shed from the both the port and starboard sides of superstructure.

대형 비행갑판을 갖는 함정과 풍동시험 결과를 활용한 고신뢰도 함정 Airwake 예측

Developing high-fidelity Computational Fluid Dynamics (CFD) simulation methods used to evaluate the airwake characteristics along a flight deck of a large ship, the various kind of data such as actual ship measurement and wind tunnel results are required to verify the accuracy of CFD simulation. Inflow velocity profile at the bow, local unsteady flow field data around the flight deck, and highly reliable wind tunnel data which were measured after reviewing Atmospheric Boundary Layer (ABL) simulation and Reynolds Number effects were also used to determine the key parameters such as turbulence model, time resolution and accuracy, grid resolution and type, inflow condition, domain size, simulation length, and so on in STAR CCM+. Velocity ratio and turbulent intensity difference between Full-scale CFD and actual ship measurement at the measurement points show less than 2% and 1.7% respectively. And differences in velocity ratio and turbulence intensity between wind tunnel test and small-scale CFD are both less than 2.2%. Based upon this fact, the selected parameters in CFD simulation are highly reliable for a specific wind condition.

Effect of the incident wind angle in a frigate with Coanda active flow control

The aerodynamic environment around frigates can be complex. This can cause helicopter pilots operating on frigates to face risky situations during the recovery maneuver. In this paper, the introduction of active flow control using Coanda effect has been tested to improve flow characteristics above a frigate flight deck. Wind tunnel tests with Particle Image Velocimetry (PIV) have been performed in order to analyze the effectiveness of introducing Coanda effect at the hangar at four different wind over deck conditions. Applying Coanda effect on the upper part of the frigate hangar the re-attachment distance, and the recirculation areas are reduced. When the Coanda effect is applied also on the sides, the flow recirculation can be completely eliminated, especially for WOD angles different from 0°. The profiles of velocities at the height where the helicopter rotor operates are also corrected, making them uniform and similar to the free stream velocity. In exchange, there is an increase in turbulence intensity close to the hangar, without affecting the rest of the flight deck. The results have shown that Coanda effect clearly improves the aerodynamics over the flight deck where the helicopter operates, and it could help to increase the safety of helicopter operations around frigates.

Upwind thermal radiation prediction of multi-scale aviation kerosene pool fire on the flight deck for emergency rescue: Experiment, numerical simulation and machine learning

The fire caused by aviation kerosene leakage on the flight deck under the environmental wind is a typical pool fire, which can seriously harm to human and damage to the equipment nearby by thermal radiation. The previous studies paid high attention to the more dangerous downwind radiation, but the key requirement of exact upwind radiation prediction for the emergency rescue is often ignored. The aim of current study is to explore the dimensionless relationship among radiant heat flux, wind speed and pool scale. Three different scale pool fire experiments were chosen and coupled with numerical simulation to provide the validation data. Based on the verified simulation setup, more predicted radiant heat fluxes in the upwind area are obtained according to a wider wind speed range. Furthermore, the Artificial Neural Network machine learning method is applied to obtain more data at wider pool scales by training the simulation data. Eventually, the fitting process is conducted and the dimensionless relationship of radiant heat flux, wind speed and scale is deduced: Qr″*=2.19(u*L*)−1. The radiant heat flux in the upwind area can be estimated by the proposed equation, and similarly, the horizontal distances according to critical heat fluxes can also be obtained. The current proposed dimensionless equation can be used as an important reference to avoid radiation harm or damage of aviation kerosene pool fire in the upwind area for emergency rescue.

A comparative analysis of helicopter recovery maneuvers on a SFS by means of PIV and balance measurements

The flow field around a frigate is complex due to flow detachments, high velocity gradients, and flow unsteadiness. These flow patterns can endanger helicopter operations around frigates and increase pilot workload above the flight deck. This paper contains a comparative analysis of three different recovery maneuvers: an approach from the stern in the centerline plane (S); a diagonal maneuver (D); and an L-shaped maneuver. The comparison is made using wind tunnel tests with a scaled frigate and a motorized helicopter. For the three maneuvers, velocity contours around the helicopter with Particle Image Velocimetry are obtained. An internal balance is also used to obtain forces and moments on the helicopter during the flight path of the maneuvers. Those measurements show that the wake of the ship mostly affects longitudinal and thrust forces. In addition, pitch torque is highly reduced when the helicopter is behind the frigate superstructure, and the roll moment is also important when the wind angle increases. In the end, an estimation of pilot workload is presented to conclude that L-shaped maneuver is the best for 0° and small WOD angles and D or S recoveries for moderately high negative WOD angles.

Development of a theoretical model of pilot decision making with conflicting information

AbstractThe advancement of technology on the modern commercial flight deck has allowed flight crew members to utilise multiple sources of information to maintain the safety of their flight. Having multiple sources of flight deck information, capable of displaying the same type of information, can lead to a situation in which a pilot encounters conflicting information. Understanding how a pilot makes a decision when faced with an information conflict on the flight deck is important to ensure appropriate design of flight-deck information systems and effective pilot training. This effort utilised data collected from 25 airline pilots who experienced information conflicts on a simulated B-737 flight deck, in conjunction with a theoretical review of how information conflicts impact decision making, to develop a theoretical model of pilot decision-making in the presence of an information conflict. This manuscript describes the model, along with the theory-driven and data-driven approaches utilised to develop the model.

Simulation of SFS2 using Embedded LES: Part-II Understanding the asymmetry in bistable airwake at zero yaw

The turbulent flow field of simplified frigate model SFS2 is numerically studied using an embedded Large Eddy Simulation (ELES) turbulence model in Ansys Fluent® 19.0 environment for its characterization. The focus of this research work is to understand the underlying reasoning of the generation of bistable airwake of the superstructure and to ascertain the influence of its upstream flow field such as bow region turbulent vortical structures, if any, on the nature and characteristics of airwake. The asymmetry in the mean airwake behind superstructure was attributed to “locking” and/or differential momentum flux on sides of superstructure in literature, however no concrete evidence of causation was reported. In this research, the in-depth analysis of turbulent boundary layer buildup, vorticity distribution, relative size and orientation of vortices on and along starboard and port sides of superstructure provide clear understanding and evidence of the influence of bow region flow field on airwake. It has been observed that dynamics of bow leading edge vortices and horseshoe vortex generated upstream of superstructure forward facing step, and their interaction are the main contributor towards the generation of asymmetrical airwake. The asymmetrical bias towards starboard side, which has also been observed in the previous experimental and numerical studies, can also be explained from this finding. That is the relatively larger turbulent eddies on starboard side generates more entrainment of the freestream upon reaching the flight deck compared to the portside. Later, the correlation and spectral analyses of the velocity measurements recorded on bow region and in the superstructure airwake supplements and validates the influence of bow region turbulent vortical structures on the airwake as dominant frequencies associated with bow vortical structures are also observed in airwake spectrum.

Quick coherence technique facilitating commercial pilots’ psychophysiological resilience to the impact of COVID-19

This study investigates the effect of quick coherence technique (QCT) on commercial pilots’ resilience to the unprecedented impact of a pandemic. Eighteen commercial pilots voluntarily participated in a 2-day training course on QCT followed by 2 months of self-regulated QCT practicing during controlled rest in the flight deck and day-to day life. There are subjective and objective assessments to evaluate the effects of QCT on commercial pilots’ psychophysiological resilience. Results demonstrated that QCT training can significantly increase pilots’ psychophysiological resilience thereby improving their mental/physical health, cognitive functions, emotional stability and wellness on both subjective (PSS & AWSA) and objective measures (coherence scores). Moreover, pilots who continued practicing self-regulated QCT gained the maximum benefits. Current research has identified great potential to enhance pilots’ mental/physical health via QCT training. Operators can develop peer support programs for pilots to increase resilience and maintain mental and physical health using the QCT technique. Practitioner summary: QCT breathing has been proven to increase commercial pilots’ resilience by moderating psychophysiological coherence, strengthening mental/physical capacity and sustaining positive emotions to deal with the challenges both on the flight deck and in everyday life. HIGHLIGHTS Pilots have suffered from the impact of the Covid-19 pandemic across many factors including social, economic, mental, physical, emotional, and operational issues Biofeedback training can increase commercial pilots’ resilience by moderating psychophysiological coherence, strengthening mental and physical capacity Self-regulated practicing QCT to form a habitual behaviour is required to sustain the maximum benefits either in the flight or day-to-day life QCT is an effective intervention for aviation authorities and airline operators to develop peer support programs to increase pilots’ fatigue resilience

No Time to Die

Back After the first heavy Sleep of jetlag, I see through the sheer Curtain a silhouette Leaning too far Over the railing of the carpark Opposite the hotel. Up all night as the plane Shook, the crew Mum on the flight deck, I thought this was it As I watched Daniel Craig Await his missile strike. Driving us to Limerick Dan told us how His friend, blind After seventy days on hunger strike, Woke from his coma To a nurse repeating softly, You’re in the Royal Constabulary Hospital.

Modeling efficiency and safety on an aircraft carrier flight deck

Aircraft carrier flight decks present high-risk mission-critical environments that need to be both efficient and safe. The concept of optimal manning, having just enough people to do the job safely and efficiently, is paramount in order to put the least amount of people at risk while not sacrificing mission effectiveness. To this end, an agent-based model, the optimal manning simulation (OMS) was developed, which specifically looks at the launch process of the flight deck in order to quantify the risk and efficiency of people working on the flight deck. OMS models different classes of crew members on the flight deck, aircraft, and resources like catapults. OMS measures safety through collisions or near-collisions of people and aircraft, as well as how long it takes to execute a launch cycle, the primary efficiency metric. Validation and sensitivity analyses provide confidence in OMS results. To demonstrate its utility, OMS is also used to predict how the future introduction of unmanned aerial vehicles could impact staffing and performance measures.

Space-Time Characterization of Ship Airwakes

The turbulent airwakes produced by a generic navy frigate (Simple Frigate Ship 2) was investigated in a low-speed wind tunnel. The frigate model was subjected to a headwind and immersed in a simulated atmospheric boundary layer. High-speed stereoscopic particle image velocimetry (PIV) was performed at six different spanwise planes over the flight deck. A spatio-temporal analysis of the PIV airwake measurements was conducted by applying the proper orthogonal decomposition (POD) to individual frequency bands of the airwake. Physical interpretations of the leading POD modes were substantiated by other complementary analyses. In particular, it was discovered that turbulent structures were shed from the funnel and superstructure edges. The flow recirculation region behind the superstructure exhibited a strongly three-dimensional bistable behavior. A pair of vortices near the stern also demonstrated low-frequency bistable dynamics. Notably, the bistable flow recirculation region appeared to influence or interact with the low-frequency behavior of the other major flow features.

Autonomous dispatch trajectory planning on flight deck: A search-resampling-optimization framework

There is a growing expectation to realize the autonomous dispatch on flight deck, where dispatch trajectory planning is seen as the key technique. Optimal-control based method has shown great advantages in high degree of constraint satisfaction over its counterparts in the last decade. However, it suffers from low computational efficiency even numerical divergence under scenarios with complicated obstacles. To deal with such an issue, a search-resampling-optimization (SRO) framework is proposed in this paper. A hybrid A* algorithm is employed to generate a coarse path according to the boundary conditions in the search stage. Then a resampling process is implemented to pave a series of safe dispatch corridors (SDCs) along the coarse path. Finally, by replacing the common one-to-one collision-avoidance with the constructed within-SDC constraints, an optimal control problem whose scale is totally independent of the number of obstacles can be formulated. The resampled result is further fed into the optimization stage to facilitate the numerical solution. Dispatch trajectory planning for taxiing aircraft and tractor can be treated uniformly under this framework. And numerical simulations demonstrate that the SRO framework is efficient and robust even with narrow accessible tunnels. The SRO is inherently flexible and can be easily extended to the trajectory planning problem in other fields. A video of the main idea and numerical simulations in this paper is available at www.bilibili.com/video/BV1tP4y1d7xy/.

Sustainable air transportation through the operational use of a social cost index

Air transportation is responsible for more than 10% of transportation related greenhouse gas emissions in the U.S. As policymakers and engineers search for methods to reduce aviation fuel consumption and the associated negative externalities, a metric used by aircrew on the flight deck may hold the key. The cost index metric and associated ECON speeds inputted into the flight management system control the aircraft's flying speed and ultimately the fuel consumed, and emissions produced. This study assesses the use of this operational tool to further green air transport production in U.S. domestic operations. Data from four major airline Boeing 737 NG routes are analyzed to estimate the effect of each carrier's cost index and ECON speeds on fuel consumption and emissions. Then a social cost index, which incorporates environmental costs, is estimated and tested using a Boeing 737 NG simulator across identical routes to determine the changes in fuel consumption and emissions. On average, we find that for every one unit decrease in an airline's cost index they reduce their fuel consumption by 5.37 lbs. per hour. Further, the average impact of implementing a social cost index is estimated to save nearly 22 gallons of jet fuel and reduce CO2 emissions by 453 lbs. per flight hour. These fuel and emissions reductions are estimated to generate a penalty of 1 min and 43 s on average per flight hour. Overall, we find that airlines can substantially reduce fuel consumption and emissions with minimal impact to operations via implementation of a social cost index.