Standard Flight Research Articles

Landing Flare Accident Reports and Pilot Perception Analysis

This study examined flare accident rates and probable causes for improper flares. Measures included the analysis of 6,676 aircraft accident reports published by the National Transportation Safety Board and a 21-item perception questionnaire administered to 134 pilots with varying experience levels. The results revealed relatively high flare accident rates and showed that pilots believed the flare to be more difficult than 9 other standard flight maneuvers. The results also showed that pilots reported experience and instruction as the most important factors for proper flares. This study indicates that those factors are also probable causes for improper flares and discusses how they relate to depth perception.

Design of lunar landing trajectory under constraints

The design of a lunar landing trajectory which satisfies certain constraints is considered and discussed. The constraints are of two kinds, kinetic constraints, which deal with the relative positions among the Sun, the Moon, the Earth, the spacecraft and tracking stations, and dynamic constraints, which deal with the orbital motion of the spacecraft. After a discussion of the characteristics of lunar flight trajectory, a method of designing standard flight trajectory is suggested that satisfies the constraints. This method is applied to the Chinese lunar landing flight and to the pre-design of the orbit of a lunar satellite.

Pilot Education: The Beginnings

For those of us involved with flight education, it is easy to take for granted some of the concepts that we practice daily, concepts such as a standardized flight curriculum, periodic flight checks, clearly defined flight instruction procedures, and progression from the simple to the more complex aircraft. These concepts did not simply appear full-blown, they were born, shaped, and modified via the crucible of world conflict. To find the roots of these flight education concepts, we have to look to Europe, to the early days of flight, to 1914, to what we now call World War I.

Artificial neural networks for predicting nonlinear dynamic helicopter loads

This paper proposes using an artificial neural network (ANN) to predict the loads in critical components based on flight variable information that can be easily measured. The artificial neural network learns the relationship between flight variables and component loads through exposure to a database of flight variable records and corresponding load histories taken from an instrumented military helicopter undergoing standard maneuvers. Eight standard flight variables are used as inputs for predicting the time varying mean and oscillatory components of the tailboom bending load and the pitch link load for seven flight maneuvers

Effects of Error-Proofing and Chemical/Biological/Radiation Protective Glove use on Touch Panel Operation

Previous studies suggested that initial-contact error rates were higher for touch input devices (resistive and infrared) than for various hardware keys. A follow-up study was conducted to evaluate the effects of chemical/biological/radiation (CBR) protective gloves on performance. Error data from this and the preceding study in this series were somewhat misleading due to differences in the input sampling strategies between hardware keys and touch panels. The initially high error rates for the resistive panel (21.6% using flight gloves and a 26.1% using CBR gloves) were considered unrepresentative of a true operating environment because nonkey contacts would be ignored by the system. Revision of the input-sensing logic produced 100% accuracy for the resistive panel in the replication study. However, multiple contacts were required in 5% (median of 4.1%) of the trials. Overall, 4% required only a second contact for correct activation of the designated key while 3- and 4-contact activations amounted to 0.6% of all trials. Conclusions drawn from the research were that CBR gloves do not significantly degrade performance over standard flight gloves or, for that matter, over the bare hand (errors or response times) and that the occurrence of multiple touches is small and virtually disappears with experience and adequate feedback, errors usually occurring in early trials and in no-feedback conditions. Thus, systems using gloved operators are unlikely to experience serious performance degradation if adequate key sizes for bare-handed activation are used and if timely and relevant feedback is provided to the operator.

Assessment of Cycloplegic Effects on the Vistech Contrast Sensitivity Test in Army Aviator Candidates

This study was designed to provide information regarding two aspects of contrast sensitivity testing of aviator candidates: first to determine whether contrast sensitivity functions (CSF's) obtained with the Vistech Visual Contrast Test System (VCTS) are affected by cycloplegia and second to determine whether the VCTS provides useful CSF's under clinical screening conditions in a timely and simple manner. Contrast sensitivity thresholds were obtained at 5 spatial frequencies from 106 aviator candidates before and after administering a cycloplegic. CSF's obtained under cycloplegia were reduced by about 20%. The VCTS provided useful CSF's under military screening conditions, and added about 6 min to the time required for the standard flight physical.

Safety Topics

THIS accident occurred shortly before a Sikorsky S‐16N helicopter was due to depart Sumbrugh on its first flight of the day. The crew of 2 and 16 passengers were embarked. Normal pre‐engine start checks were carried out and after receiving start clearance from ATC, both engines were successively started. The crew encountered no abnormailities during pre‐rotor engagement checks and approximately 1 minutes after starting engines, the rotors were engaged and brought up to 100% rotor speed (Nr) in the usual way. All indications remained normal until an estimated 3–4 minutes later, the crew members became aware of an abnormal whining noise. At the time they were carrying out a standard automatic flight control system check, scheduled prior to the first flight of the day.

Evaluation of Cognitive Function in Aviators

The FAA is concerned that flight-safety could be compromised by undetected cognitive impairment in pilots due to conditions such as substance abuse, mental illness and neuropsychological problems. Interest has been shown in the possibility of adding a brief “mini mental exam”, or a simple automated test-battery to the standard flight medical to screen for such conditions. This paper reports an empirical evaluation of four such tests, focusing upon a prototype version of an automated screening battery, SPARTANS (Simple Portable Aviation Relevant Test-battery and Answer-scoring System).

Typhoon Structure as Revealed by Aircraft Reconnaissance. Part I: Data Analysis and Climatology

Abstract This is the first of two papers describing the structure of northwest Pacific tropical cyclones as revealed by U.S. Air Force aircraft reconnaissance. This first paper describes the background philosophy for this research, the types of flight missions flown, data reduction procedures, and the general climatological characteristics of this region's typhoons and tropical storms. Analysis has been performed on 700 mb aircraft data from ova 500 Guam-based, WC-130 aircraft missions into 66 tropical cyclones, two-thirds of which were of typhoon intensity sometime during their life cycle. All flight missions followed similar standardized flight tracks. Data are analyzed for the three seasons of 1980–82. This aircraft dataset is unique in providing wind and pressure-height profile information at radial resolutions of 0.5° (56 km) from a tropical cyclone's center out to 4° radius. This allows a cyclone°s outer-core wind strength to be measured in relation to its inner-core intensity. The varying relations...

Characterizing Height-keeping Error Distribution Based on Indirect Observation

Mathematical collision risk models, e.g. the Reich (1966) model, may be useful for evaluating the safety of air traffic control systems. The model requires parameters associated with the navigational errors of aircraft. Among navigational errors the distribution of height-keeping errors (HKE) is of great interest for evaluating the feasibility of reducing the current 2000 ft vertical separation standard above flight level 290 (29000 ft). The distribution is closely related to the probability of vertical overlap which is a key parameter of the collision risk model.

Body Size and Condition, Timing of Breeding, and Aspects of Egg Production in Eastern Kingbirds

Abstract Variation in timing of breeding in Eastern Kingbirds (Tyrannus tyrannus) was correlated only weakly with external morphological characters, but was correlated positively and significantly with estimates of body size based on measurements of skeletons and muscle weights. Small females apparently held a reproductive advantage in being able to mobilize resources for reproduction before large females. Egg weight was independent of all measures of female size, but was directly and significantly (P = 0.03) correlated with standard flight muscle weight, a relative index of body condition. Egg size was thus a function more of female body condition than size. On average, shell, yolk, and albumen comprised 5.6%, 21.9%, and 72.5%, respectively, of fresh egg weight. Dry albumen and dry shell increased proportionately with fresh egg weight, but dry yolk did not. Total protein, lipid, and energy of fresh eggs all increased proportionately with weight. Comparison of egg composition and standard flight muscle weight of laying females indicated moderate positive, although nonsignificant, correlations between body condition and measures of egg quality, especially lipid content. Based on post-egg-laying body composition and nutrient requirements for the production of one egg, it appeared that most females probably could have laid an additional egg almost solely from body reserves. Clutch size thus appears to be independent of body condition.

Optimal Short-Range Trajectories for Helicopters

An optimal flight path algorithm using a simplified altitude state model and a priori climb cruise descent flight profile was developed and applied to determine minimum fuel and minimum cost trajectories for a helicopter flying a fixed range trajectory. In addition, a method was developed for obtaining a performance model in simplified form which is based on standard flight manual data and which is applicable to the computation of optimal trajectories. The entire performance optimization algorithm is simple enough that on line trajectory optimization is feasible with a relatively small computer. The helicopter model used is the Silorsky S-61N. The results show that for this vehicle the optimal flight path and optimal cruise altitude can represent a 10% fuel saving on a minimum fuel trajectory. The optimal trajectories show considerable variability because of helicopter weight, ambient winds, and the relative cost trade off between time and fuel. In general, reasonable variations from the optimal velocities and cruise altitudes do not significantly degrade the optimal cost. For fuel optimal trajectories, the optimum cruise altitude varies from the maximum (12,000 ft) to the minimum (0 ft) depending on helicopter weight.

Effect of voice type and message format on speed and accuracy of response to voice warnings

The effect of LPC voice type and of message format on the speed and accuracy of response to voice warning signals were investigated at various levels of a simulated military inflight noise environment. LPC voice types were male, female, and machine, and the message formats were voice warning, repeat voice warning, and tone‐voice warning. The primary task was a manual tracking task that required continuous attention whereas the secondary task required individual manual responses to randomly presented warning messages. A background signal of inflight aircraft voice communications was presented via the subject's earphones throughout the experiment. The voice warning messages were also presented via the earphones at levels of 0, 5, and 10 dB above this background communication level. Ten subjects completed the experimental tasks while wearing standard Air Force flight helmets and oxygen masks in the presence of the emulated aircraft noise at levels of 105 and 115 dB (SPL). The effects of LPC voice type and message format on voice warning effectiveness will be presented and discussed.

Engine performance trend analysis

THE INITIAL engine monitoring of the JT9D powerplant in the B.747 has been accomplished through analysis of data manually recorded by flight crews from standard flight deck instrumentation.

La dynamique du vol ascendant des fusées-sondes

Throughout the history of sounding rockets, there has been a steady flow of analytical studies trying to explain and predict the, often untoward, dynamic phenomena attendant on upward flight. This article offers a summing-up of these contributions, and of the main results so far achieved. Following a brief review of the specific conditions incident to ascent, and of the mathematical model generally adopted to represent the sounding rocket, the general equations of motion are set up, then simplified so as to enable each phenomenon to be studied on its own merits. Under standard flight conditions, the linear theory provides analytical expressions for the variation of the angle of attack, thus revealing the respectively convergent or divergent modes of oscillation at incidence. More particularly, it helps to make the stability criteria explicit, with due allowance for the variation in air density, the gyroscopic effect and the Magnus effect. The phenomenon of resonance, provoked by the disturbances peculiar to rockets set in rolling motion, is also explored. Dynamic processes not explicable in terms of linear theory must be grappled with by suitable analyses making use of some simplifying assumptions. This provides the means of explicitly expressing the conditions under which such phenomena as roll lock-in, catastrophic yaw and persistent resonance occur as a result either of rocket unbalance or a rolling moment induced at an oblique angle of attack, complicated by the presence of an aerodynamic side moment. A further study is made of wide-amplitude limit cycles and their stability. Lastly, there is an analysis of the sensitivity of sounding-rocket trajectories to external disturbances, such as the impact of stage separation and the wind.

PILOT EYE FIXATIONS WHILE FLYING SELECTED MANEUVERS USING TWO INSTRUMENT PANELS.

The primary purpose of this study was to investigate the eye fixations as they occurred while flying instruments in two panel configurations. The first panel was equipped with vertical moving tape instruments; the second was equipped with round dial instruments. The study was conducted in a MBS Simulator with the flight-characteristics of a high performance jet aircraft. A standardized flight profile was used allowing comparison of both instrument panels across identical representative maneuvers. System performance measurements were taken during scoring periods for which a film record of the pilots' eyes were also taken. Thus the data collected in this study allows an analysis of system performance, eye movements, and the correlation of performance and eye movements for each combination of maneuvers and instrument panels.

Physiological Effects of Heat and Cold

On July 10, 1945, a reportl was submitted to Allied authorities which made notorious history. In this extraordinary report on the Dachau concentration camp (i), those who have an interest in the social responsibilities of science may gain new insight into the type of rationalization of those who support such activities. The sub­ ject of investigation in these discreditable experiments was the physiology of cold exposure. A full review of the credible portions of the work is warranted by reason of their intrinsic interest and the relative inaccessibility of the report. The Dachau experiments were conducted by a certain S. Rascher, apparently a pharmacologist, under direct orders from Himmler, and with the collaboration of the medical division of the Luftwaffe. Their object was to determine the most effective meth­ od of resuscitation for sea or land exposure cases recovered with reduced body temperature and evidences of exposure shock. One section of the general plan provided for the exposure of nude prisoners to air temperatures of -6°C. for as long as· fourteen hours, a period sufficient to freeze peripheral tissue and to reduce rectal temperatures to 25°C. A more fully reported series provided for the experimental immersion in water at 2° to 12°C. of subjects either nude or dressed in standard flight equipment. In these procedures not less than 103 persons were used, few of whom appeared to have survived the complete experimental pro­ gram. In one table, seven deaths are specifically recorded. Because of the bearing of this record on absolute tolerance to extreme cold,