Pilot's Ability Research Articles

Sustained Acceleration on Perception of Relative Position and Motion

Air-to-air refueling, formation flying, and projectile countermeasures all rely on a pilot's ability to be aware of his position and motion relative to another object. Eight subjects participated in the study, all members of the sustained acceleration stress panel at Wright-Patterson AFB, OH. The task consisted of the subject performing a two-dimensional join up task between a KC-135 tanker and an F-16. The objective was to guide the nose of the F-16 to the posterior end of the boom extended from the tanker, and hold this position for 2 s. If the F-16 went past the tanker, or misaligned with the tanker, it would be recorded as an error. These tasks were performed during four G(z) acceleration profiles starting from a baseline acceleration of 1.5 G(z). The plateaus were 3, 5, and 7 G(z). The final acceleration exposure was a simulated aerial combat maneuver (SACM). One subject was an outlier and therefore omitted from analysis. The mean capture time and percent error data were recorded and compared separately. There was a significant difference in error percentage change from baseline among the G(z) profiles, but not capture time. Mean errors were approximately 15% higher in the 7 G profile and 10% higher during the SACM. This experiment suggests that the ability to accurately perceive the motion of objects relative to other objects is impeded at acceleration levels of 7 G(z) or higher.

Louis H. Bauer and the Origins of Civil Aviation Medicine

With the passage of the Air Commerce Act in May 1926, civil aviation safety became a federal responsibility under the Department of Commerce (DoC). In November of that year, Louis Hopewell Bauer (1888-1964) became the DoC's first Aviation Medical Director. After earning his medical degree at the Harvard School of Medicine in 1912, Bauer joined the U.S. Army Medical Corps, where he helped develop the role of the military flight surgeon and then served as director of the Army's School of Aviation Medicine. Upon taking the federal position, he undertook to define medical standards and examination frequencies for civilian pilots and identifiy disqualifying conditions that could compromise a pilot's ability to operate an aircraft safely. Bauer also personally selected 57 private physicians (soon to be known as Aviation Medical Examiners) distributed across the country to give medical examinations for pilot licenses. Bauer subsequently played a leading role in organizing the Aviation Medical Association in 1929.

Investigation into Pilot Handling Qualities in Teleoperation Rendezvous and Docking with Time Delay

Teleoperation rendezvous and docking can be used as a backup for autonomous rendezvous and docking (RVD) for an unmanned spacecraft when the autonomous system is failure or for guiding the chaser docking with an uncooperative target. The theoretical model for analyzing the handling qualities in teleoperation RVD process is established based on the previous studies conducted by National Aeronautics and Space Administration (NASA). The predictive factor is introduced to describe the pilot's predictive ability in the teleoperation tasks with time delay, which interrelates with the skills of a pilot and the predictive assist approach used in the tasks such as the predictive display method. Based on the semi-physical simulation system in our laboratory, 900 experiments at two levels of time delay are carried out by 18 volunteers for validating the established model. The experimental results demonstrate the correctness of the theoretical model and indicate that a skilled pilot has a predictive ability of approximately 0.9 in teleoperation RVD tasks. The theoretical analysis shows that the handling qualities are greatly affected by the time delay and the predictive factor, and it is impossible to achieve a teleoperation RVD task for the skilled pilot when the time delay is larger than 9.0 s.

Rolling into Spatial Disorientation: Simulator Demonstration of the Post-Roll (Gillingham) Illusion

Spatial disorientation (SD) is still a contributing factor in many aviation accidents, stressing the need for adequate SD training scenarios. In this article we focused on the post-roll effect (the sensation of rolling back after a roll maneuver, such as an entry of a coordinated turn) and investigated the effect of roll stimuli on the pilot's ability to stabilize their roll attitude. This resulted in a ground-based demonstration scenario for pilots. The experiments took place in the advanced 6-DOF Desdemona motion simulator, with the subject in a supine position. Roll motions were either fully automated with the subjects blindfolded (BLIND), automated with the subject viewing the cockpit interior (COCKPIT), or self-controlled (LEAD). After the roll stimulus subjects had to cancel all perceived simulator motion without any visual feedback. Both the roll velocity and duration were varied. In 68% of all trials subjects corrected for the perceived motion of rolling back by initiating a roll motion in the same direction as the preceeding roll. The effect was dependent on both rate and duration, in a manner consistent with semicircular canal dynamics. The effect was smallest in the BLIND scenario, but differences between simulation scenarios were non-significant. The results show that the effects of the post-roll illusion on aircraft control can be demonstrated adequately in a flight simulator using an attitude control task. The effect is present even after short roll movements, occurring frequently in flight. Therefore this demonstration is relevant for spatial disorientation training programs for pilots.

The effect of hypoxia on the critical flicker fusion threshold in pilots

Human reactions to environmental changes have been the subject of numerous investigations related to pathophysiology, aviation psychology, aviation, and sports. The present study aimed at evaluating the perception of light stimulus via the Critical Flicker Fusion threshold (CFF) measurements among aviation pilots. The study was carried out under hypoxic conditions corresponding to 5000 m altitude, for a period of 30 min, without the use of supplemental oxygen. Fourteen volunteer pilots, 23-30 years of age, were examined in the hypobaric chamber (HC). The measurements were performed at normobaria and at the initial and final phase of hypoxia. Heart rate (HR) and blood oxygen saturation (SaO2) were monitored. The high altitude hypoxia was found to produce a decrease in the CFF threshold F(3.39) = 3.207, p < 0.05, and SaO2 F(3.39) = 52.651, p < 0.001, as well as HR increase F(3.39) = 7.356, p < 0.001. The results indicate that the higher the decrease in SaO2 under hypoxic conditions, the higher the decrease in CFF r = .567 p < 0.05. Likewise, the higher the increase in HR, the higher the decrease in CFF r = -0.491 p < 0.05. Under hypoxic conditions, the perceptual ability of the pilots is gradually decreasing. This has been confirmed by the findings of the physiological examinations. The authors express an opinion that it would be advisable to introduce CFF measurement into the hypobaric chamber tests as it allows individual assessment of the pilot's perceptual ability under conditions of incomplete physiological compensation of the high altitude hypoxia.

Flying by Ear: Blind Flight with a Music-Based Artificial Horizon

Two experiments were conducted in actual flight operations to evaluate an audio artificial horizon display that imposed aircraft attitude information on pilot-selected music. The first experiment examined a pilot's ability to identify, with vision obscured, a change in aircraft roll or pitch, with and without the audio artificial horizon display. The results suggest that the audio horizon display improves the accuracy of attitude identification overall, but differentially affects response time across conditions. In the second experiment, subject pilots performed recoveries from displaced aircraft attitudes using either standard visual instruments, or, with vision obscured, the audio artificial horizon display. The results suggest that subjects were able to maneuver the aircraft to within its safety envelope. Overall, pilots were able to benefit from the display, suggesting that such a display could help to improve overall safety in general aviation.

Probabilistic approach for biorhythmic analysis to prevent aviation accidents

This paper presents a new methodology, based on the probabilistic approach, for biorhythmic analysis to prevent aviation accidents. The methodology has been developed using the Gaussian distribution technique for reliability evaluation of the aviation system, keeping in mind the biorhythmic effects of the pilot. The normal distributed data of the US Air Force were tested and analysed based on the performance ability of pilot and the peak demand of the performance. The accident zone is that area of operation during which the performance demand exceeds the performance ability of the aircraft pilot. Failure probabilities, considering peak performance demand and the pilot's ability, have been evaluated using the Gaussian distribution approach. The safety factor concept has also been presented in this paper for biorhythmic analysis to prevent aviation accidents. The stepped incident-duration curve has been utilised to evaluate the pilot's reliability on the aviation system using Simpson's 1/3rd rule.

HUD With a Velocity (Flight-Path) Vector Reduces Lateral Error During Landing in Restricted Visibility

Abstract The operational community has assumed that using a head-up display (HUD) instead of conventional head-down displays will increase accuracy and safety during approach and landing. The putative mechanism for this increase in safety is that previously demonstrated improvements in lateral and vertical control of the aircraft in flight should carry over to the landing situation. Alternatively, it is possible that, during approach and landing, the HUD might affect the pilot's ability to assimilate outside cues at the decision height, thereby reducing the success ratio for landings using an HUD. This article reports a pair of experiments that test these competing hypotheses. Taking advantage of the opportunity when an air transport operator introduced HUD in an existing aircraft fleet, we were able to use a Boeing 737-700 full-motion simulator flown by commercial airline pilots. We explored the effects of (a) HUD use, (b) ambient visibility, and (c) length of approach lighting on the size and location of the touchdown footprint. We also explored the effects of HUD use on approach success ratio. HUD use reduced the width of the touchdown footprint in all tested visibility and lighting conditions, including visibility below the minimum allowed. HUD use had no effect on the length of the touchdown footprint. We could not detect any decrease in approach success rate for HUD approaches. Based on these empirical data, the minimum visibility for approaches using HUDs could be set lower than for approaches without an HUD.

HUD With a Velocity (Flight-Path) Vector Reduces Lateral Error During Landing in Restricted Visibility

The operational community has assumed that using a head-up display (HUD) instead of conventional head-down displays will increase accuracy and safety during approach and landing. The putative mechanism for this increase in safety is that previously demonstrated improvements in lateral and vertical control of the aircraft in flight should carry over to the landing situation. Alternatively, it is possible that, during approach and landing, the HUD might affect the pilot's ability to assimilate outside cues at the decision height, thereby reducing the success ratio for landings using an HUD. This article reports a pair of experiments that test these competing hypotheses. Taking advantage of the opportunity when an air transport operator introduced HUD in an existing aircraft fleet, we were able to use a Boeing 737-700 full-motion simulator flown by commercial airline pilots. We explored the effects of (a) HUD use, (b) ambient visibility, and (c) length of approach lighting on the size and location of the touchdown footprint. We also explored the effects of HUD use on approach success ratio. HUD use reduced the width of the touchdown footprint in all tested visibility and lighting conditions, including visibility below the minimum allowed. HUD use had no effect on the length of the touchdown footprint. We could not detect any decrease in approach success rate for HUD approaches. Based on these empirical data, the minimum visibility for approaches using HUDs could be set lower than for approaches without an HUD.

Applications of Pilot Training in the Swedish Dynamic Flight Simulator

Since 2003 Sweden is using a Dynamic Flight Simulator for advanced pilot acceleration training. The DFS is equipped with some unique capabilities including a flight simulation system consisting of hardware and software simulating the JAS 39 Gripen aircraft. This new functionality provides means to extend the traditional G-training into a more natural way of training with the pilot being in control of the flight. A new method was developed for evaluation of pilot's ability to follow a pre-recorded “target” while been exposed to alternating +Gz-levels, replicating an Aerial Combat Maneuver. This method was based on a graphical tool capable of replaying the recorded flight data in the three-dimensional space. A study was performed for which ten pilots in active flight duty volunteered. The study showed that pilots were able to perform the task despite some disturbing vestibular sensation during decelerations. The simulation proved to be both physically and mentally challenging.

비대칭 무장 형상의 조종성 개선에 관한 연구

현대의 고성능 전투기는 공대공 및 공대지 전투 임무를 수행하기 위해 여러 가지 무장 형상을 하고 있고, 무장투하 시 비대칭 형상(Asymmetric Configuration)으로 임무를 수행하는 경우가 많다. 현재, 개발이 진행 중인 T-50 훈련기의 비대칭 무장형상 비행시험에서 세로축 기동 시 가로축 방향으로 조종사가 원하지 않는 운동이 발생하는데, 이는 항공기 안정성 및 조종성에 영향을 미칠 수 있다. 본 연구에서는 이러한 현상을 개선하기 위하여 기존의 가로축 제어법칙인 미끄럼각-미끄럼각속도 귀환 구조를 F-16과 같이 단순 롤각속도 귀환구조로 적용하였다. 연구결과, 단순 롤각속도 귀환구조로 가로축 제어법칙을 변경하였을 때 비대칭 무장형상에서 세로축 기동 시 가로축 운동의 발생이 줄어들었으며, 시스템의 안정도 여유는 설계기준에 만족한다는 것을 알 수 있었다. Modern versions of supersonic jet fighter aircraft have several different weapon loading configuration to support air-to-air combat and air-to-ground delivery of weapon modes. These various aircraft loading conditions could result in asymmetric configurations to the aircraft once delivered. These asymmetric configurations could result in decreased handling qualities for the pilot maneuvering, stability, control issues and aerodynamic performance of the aircraft. In order to eliminate or decrease these adverse impacts on the pilot's ability, development of T-50 flight control law attempts to control the aircraft in both longitudinal and lateral-directional axes. Especially, the design of the lateral-directional roll axis control laws, utilizing a simple roll rate feedback structure and gains such as F-16, is developed for the T-50 aircraft to meet the aircraft's design requirements. Consequently, it is found that the improved control law decreases the roll-off phenomenon in lateral axes during pitch maneuver.

An Analysis of in-Flight Impairment and Incapacitation in Fatal General Aviation Accidents (1990–1998)

In-flight impairment and incapacitation are defined as states wherein the pilot's ability to effectively control the aircraft is adversely affected. They are of special concern in general aviation given there may be no second pilot to take over the controls. The purpose of the present study was to examine the characteristics of fatal general aviation accidents associated with impairment and incapacitation. A comprehensive review of 2,696 fatal general aviation accidents from 1990–1998 using database records maintained by the NTSB and FAA yielded 216 accidents (8.01%) that had some form of impairment/incapacitation or physiological causes mentioned in the accident report. Impairment due to drugs ( n = 88, 40.7%) and alcohol ( n = 68, 31.5%) were the most common causes. Cardiovascular causes were cited in 12.03% (n = 26) of the cases. Significant relationships were observed between age and impairment/incapacitation due to alcohol, drugs, and cardiovascular causes. Some disparities were observed between the prevalence of alcohol in toxicology samples and alcohol impairment being cited in the accident report as a contributory factor. The analysis provides some insight into the possible causes of pilot impairment and incapacitation in general aviation. Education and risk management training may serve as effective interventions.

The Effect of Visual System Time Delay on Helicopter Control

There is interest in the development of synthetic visual systems to improve the capability of aircraft to takeoff and land in poor visibility. These systems often have inherent processing delays that can affect a pilot's ability to control an aircraft and a pilot's sense of orientation. The goal of the current study was to determine how much time delay a pilot could tolerate before control was affected, and whether physiological effects would be apparent at the same point. Pilots hovered at a predetermined position in a full flight simulator equipped with a Computer Image Generation (CIG) system and a helmet mounted display. The pilot's visual image was delayed by 67 to 334 milliseconds and varying levels of turbulence were applied to increase the task difficulty. Pilot performance was assessed by collecting objective data on aircraft position error. Handling qualities ratings and reports of physiological symptoms were collected by questionnaire. The results showed that visual time delay increased the variability of position error when as little as 134 ms of delay was encountered. At long delays, sickness symptoms were reported in addition to handing qualities decrements. Turbulence had a minimal effect on performance with long time delays, however it resulted in increased station keeping errors and degraded handling qualities at low delays.

Evaluation of a Motion Fidelity Criterion with Visual Scene Changes

An experiment examined how visual scene and platform motion variations affected a pilot's ability to perform altitude changes. Pilots controlled a helicopter model in the vertical axis and moved between two points 32-ft apart in a specified time. Four factors were varied: visual-scene spatial frequency, visual-scene background, motion-filter gain, and motion-filter natural frequency. Drawing alternating black and white stripes of varying widths between the two extreme altitude points varied visual-scene spatial frequency. The visual-scene background varied by either drawing the stripes to fill the entire field of view or by placing the stripes on a narrow pole with a natural sky and ground plane behind the pole. Both the motion-filter gain and natural frequency were varied in the motion platform command software. Five pilots evaluated all combinations of the visual and motion variations. The results showed that only the motion-filter natural frequency and visual-scene background affected pilot performance and their subjective ratings. No significant effects of spatial frequency or motion system gain were found for the values examined in this tracking task. A previous motion fidelity criterion was found to still be a reasonable predictor of motion fidelity.

Impact of Aviation Highway-in-the-Sky Displays on Pilot Situation Awareness

Thirty-six pilots were tested in a flight simulator on their ability to intercept a pathway depicted on a highway-in-the-sky (HITS) display. While intercepting and flying the pathway, pilots were required to watch for traffic outside the cockpit. Additionally, pilots were tested on their awareness of speed, altitude, and heading during the flight. Results indicated strong practice effects for a pilot's ability to intercept the pathway and that the presence of a flight guidance cue significantly improved performance. The ability to spot traffic was relatively unaffected by, display novelty, and new display concepts are needed for supporting secondary flight information present on the HITS display. Recommendations for training and use of HITS displays are given, along with recommendations for display enhancements to support situation awareness.

Wind detection in a microcosm: Ship/aircraft environment sensors

One of the most demanding aspects of a Navy helicopter pilot's job is landing his aircraft on the flight deck of a pitching, rolling, heaving and yawing ship. The complex airwake velocity field associated with the ship and aircraft interface directly affects the pilot's ability to control the aircraft during takeoff, approach, hover, landing, and deck operations. Dynamic Interface (DI) testing is performed to define safe aircraft operational envelopes; however, not all conditions can be realized within the limited test period and asset/condition availability. In addition, exact wind conditions that affect the aircraft cannot be measured with existing wind sensors. These sensors measure wind in the ship's mast area which does not represent the wind flow field encountered by the aircraft. A means of non-intrusively measuring the appropriate wind data is required. This paper presents an overview of the unique aspects of the ship/aircraft interface, the overall naval DI environment and the sensor requirements for measuring this complex environment.

Success and Failure at Self-Separation in Simulated Free Flight

Pilots in free flight will assume responsibility for self-separation. This paper discusses research that identifies constraints on a pilot's ability to maintain self-separation in a free-flight. It documents a principled approach to scoring the concurrent verbal reports of pilots engaged in simulated en-route traffic scenarios. One such protocol is used to identify a mismatch between the tacit criteria for self-separation invoked by professional airline pilots and the separation criterion currently mandated by the FAA: five miles laterally and 1,000 feet vertically.

Rules and reason in the forced retirement of commercial airline pilots at age 60

Abstract In this salute to Tom Singleton, a logic to discuss a mandatory retirement age is suggested. Mandatory retirement in airline pilots is examined as a framework for the discussion. In the thirty-five years since the age 60 mandatory retirement age for commercial airline pilots was adopted by the Federal Aviation Administration, many changes have occurred in life expectancy, mortality and morbidity rates, economic conditions, and in the nature of flying itself that impact upon that decision. It is suggested that the policymakers look at the following three general areas as criteria when adjusting the age of mandatory retirement: actual job performance, information processing capacity and physical capacity. Information processing and physical capacity provide information about the necessary, but not sufficient conditions that must be met in order to fly an aircraft. Actual job performance is the final measure of a pilot's ability to fly at any age.

Individual Task Proficiency and Team Process Behavior: What's Important for Team Functioning?

This research examined specific team-interactional processes that relate to effective team performance beyond the task proficiency of the individual team members. Subjects were 66 female and 44 male undergraduate volunteers who were assigned to teams of two (pilot and copilot) in a low-fidelity flight simulation task. Team members were assigned separate tasks (e.g., the pilot operated a joystick and the copilot a keyboard), but the task was divided in a manner that required the team members to coordinate to complete their mission. The measures of task proficiency were the pilot's ability to control the joystick and the copilot's ability to operate the keyboard. The interactive processes examined included such behaviors as providing information in advance, mak- ing long- and short-term plans, asking for input, assigning tasks, and stepping in to help others. Effectiveness of the team was determined by an independent measureif mission performance and by the number of targets destroyed in the scenario. Multi...

Visual field information in low-altitude visual flight by line-of-sight slaved helmet-mounted displays

The pilot's ability to derive control-oriented visual field information from teleoperated helmet-mounted displays in nap-of-the-earth flight is investigated in this paper. The visual field with these types of displays, commonly used in Apache and Cobra helicopter night operations, originates from a relatively narrow field-of-view forward looking infrared radiation (FLIR) camera, gimbal-mounted at the nose of the aircraft and slaved to the pilot's line of sight, providing a wide-angle field of regard. Pilots have encountered considerable difficulties in controlling the aircraft by these devices. The experimental simulator results presented here indicate that part of these difficulties can be attributed both to the narrow camera field of view and to head/camera slaving system phase lags and errors. In the presence of voluntary head rotation, these shortcomings are shown to impair the control-oriented visual field information vital in vehicular control, such as the perception of the anticipated flight path or the vehicle yaw rate. Since the pilot will tend to minimize head rotation in the presence of slaving system imperfections, the full wide-angle field of regard of the line-of-sight slaved helmet-mounted display is not always fully utilized. The findings in this paper are valid for a general class of head-slaved displays which are used in teleoperation and virtual environments and in which correct self-motion estimation is an essential part of the operator task.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>