(39428) AERONAUTICS BULLETIN NUMBER FIVE UNIVERSITY OF ILLINOIS THE INSTITUTE OF AVIATION URBANA, ILLINOIS Evaluation of the School Link As an Aid in Primary Flight Instruction By A. C. Williams, Jr. and Ralph E. Flexman UNIVERSITY OF ILLINOIS BULLETIN VOLUME 46; NUMBER 71; JUNE, 1949. Published seven times each month by the University of Illinois. Entered as second-class matter December 11, 1912, at the post office at Urbana, Illinois, under the Act of August 24, 1912. Office of Publication, 358 Administration Building, Urbana, Illinois. THE INSTITUTE OF AVIATION, established in 1945 as the Institute of Aeronautics, is operated as the administrative agency responsible for the fostering and correlation of the educational and research activities related to aviation in all parts of the University. Other functions include academic instruction, flight training, management of the University of Illinois Airport, and aeronautical research. In connection with the latter function, the Institute issues two types of publications . . . first, a group of reports on research results, and sec- ond, a series of bulletins on aviation subjects of an extension service nature to the citizens of the State. The following publications have been issued : Bulletin One: Municipal Airport Management, Leslie A. Bryan, 1947. Bulletin Two: Landscape Planting for Airports, Florence B. Robinson, 1948. Bulletin Three: Labor Relations in the Air Transport Industry Under the Amended Railway Labor Act, E. B. McNatt, 1948. Airport Zoning, J. Nelson Young, 1948. Evaluation of the School Link as an Aid in Primary Flight Instruction, A. C. Williams, Jr., and Ralph E. Flexman, 1949. Publications of the Institute of Aviation will be sent free of charge upon request. Bulletin Four: Bulletin Five: 2500—4-49—41033 UNIVERSITY OF ILLINOIS THE INSTITUTE OF AVIATION Leslie A. Bryan, Ph.D., LL.B., Director Bernice Schrader, A.M., Editor Evaluation of the School Link . As an Aid in Primary Flight Instruction By A. C. Williams, Jr. Research Assistant Professor of Psychology College of Liberal Arts and Sciences and Ralph E. Flexman Flight Instructor, Institute of Aviation University of Illinois Published by the University of Illinois, Urbana 1949 THE LIBRARY OF THE JUN221949 UNIVERSITY OF \l 5 FOREWORD THIS MONOGRAPH is the fifth in a series of bulletins on aviation subjects which is being issued from time to time by our Institute of Aviation. It reports the significant results of two experiments in the evaluation of a synthetic training aid — the School Link. Both authors are trained in psychology and are certificated pilots. Dr. A. C. Williams holds an appointment as Research Assistant Pro- fessor of Psychology in the College of Liberal Arts and Sciences. During World War II he served as a Naval aviator. Mr. 'Ralph E. Flexman has been a flight instructor in the Institute of Aviation since it was established in 1945. He served in World War II as an Air Force flight instructor. The writers wish to express their thanks and appreciation to those who have aided in the experiments: to Link Aviation, Inc., for fur- nishing the trainer and for the services of Mr. Paul E. Dittman of their staff who helped construct the training syllabi and made many helpful suggestions throughout the course of the study; to Mr. Jesse W. Stonecipher, Chief Flight Instructor, Institute of Aviation, who arranged for the subjects and the instructors to participate in the experiments, as well as for use of the aircraft; to the flight instructors - Mr. Delbert P. Shroyer, Mr. David H. Shroyer, Mr. Phillip Hen- derson, Mr. Willis C. Culberson, Mr. Scott G. Hasler, and Mr. Robert L. Ayers — who conscientiously performed their part in the project and helped set up the standards of flight tolerances which were used. The Institute of Aviation is glad to make available the information contained in this monograph, which is the forerunner of a series of reports on experiments. In it, as in all publications of the Institute, the authors have been given complete freedom to express any opinions they may wish with the understanding that they take sole responsi- bility therefor. , A _ J Leslie A. Bryan, Director May, 1949 us INTRODUCTION Many devices which do not leave the ground have been built to simulate the flight of aircraft. Some simulate contact flight; others, instrument flight; while still others simulate a specific aspect of flight such as taxiing, navigation, pursuit gunnery, and so on. The purpose of all these devices is to train flight personnel. It is believed that if training can be accomplished by such means on the ground, a great saving in time, money, and lives will be realized. However, in order for any of these trainers to be effective, a transfer of training from the device to the function it simulates must occur. The skills learned in the trainer must carry over and apply to performance in the actual situation. Strangely enough, although transfer of training is the lifeblood of a training device, very little effort has been made to determine whether or not transfer actually occurs, or, if it does, to what extent it occurs. Trainers have been used for years without anyone knowing, except as a matter of opinion, whether or not the devices were effective in training personnel for performance on the actual operational task which they were designed to simulate. It was naturally assumed that if the trainer accurately reproduced the functions of the pertinent characteristics of the aircraft, and if the task of operating the trainer were analagous to the task of operating the aircraft, transfer of train- ing could not help but occur, and, therefore, the trainer could be said to be valid. Validity of this sort is known as face validity. Face validity is based on the obviousness of the analogy between the opera- tion of the trainer and the operational task itself and is largely a matter of opinion. Face validity may or may not be dependable. A more certain estimate of the validity of a training device can be obtained by actually measuring the extent to which skills learned in the trainer transfer to the performance of the real task. There are a variety of techniques for obtaining these measurements, but most of them are based on a technique whereby two groups of subjects, one of which has received instruction in the training device, are contrasted in their ability to learn the operational task. The group receiving instruction in the training device is known as the Transfer Group; the other group is known as the Control Group. If the device is an effec- tive trainer, it would be expected that the Transfer Group would out- perform the Control Group in learning the operational task. If this is the case, then positive transfer is said to occur. If there is no differ- ence between the groups in their ability to learn the operational task, it 4 EVALUATION OF THE SCHOOL LINK is then evident that the special training received by the members of the Transfer Group has not helped them and that no transfer has occurred. It is also possible, and not infrequently true, that instruction in the training device interferes with learning the operational task. In such a case, the Control Group would outperform the Transfer Group. This is known as negative transfer. The amount of transfer, whether positive or negative, is usually expressed as a per cent of the total learning which is possible, thus: % transfer = C ~ T X 100 c-x "C" equals the Control Group learning score, "T" equals the Transfer Group learning score, and X represents the total possible learning score on the operational task. This equation takes different forms, depending upon the kind of learning score obtained and whether or not relative or absolute transfer is to be computed. In the form given, learning must be measured in terms of savings, such as number of air trials. This bulletin is a report of two transfer of training experiments which were conducted with a contact ground trainer known as the School Link. The experiments were conducted at the University of Illinois Airport, the first one during the fall semester, 1947-48, the second during the spring semester, 1948. The purpose of the experi- ments was to discover to what extent skills learned in the trainer transferred to the task of learning to fly a light aircraft. The trainer, which was provided by Link Aviation, Inc., for the experiments, was designed primarily as a classroom demonstrator and not as a flight trainer. However, it was believed that its performance was sufficiently realistic to warrant its evaluation as a preflight trainer. The trainer, which is mounted on a pedestal, consists of an open cockpit with wings and a tail group attached. It is free to pitch, yaw, bank, and turn. These movements are accomplished by the manipula- tion of conventional aircraft controls within the cockpit. The trainer used was surrounded for 270 degrees by a circular screen eleven feet high placed seven feet from the cockpit. This screen was made of white cloth and was unmarked except for a black horizontal line repre- senting the horizon and two reference marks which, when viewed from the cockpit, served as a guide to normal climb and normal glide attitudes. There were also marks on it indicating cardinal compass directions. THE UNIVERSITY OF ILLINOIS 5 The trainer possesses many of the characteristics of an aircraft, including dynamic stability, negative yaw, loss of lift resulting in nose heaviness during turns, change in pitch attitude as a result of change in power, overbanking tendency, and "live" feel to the controls. Operative light aircraft instruments are included, together with throttle, elevator trim tab, ignition switch, carburetor heat, fuel shut- on valve, and so forth, for the purpose of learning cockpit procedure. Also, to make the flight situation more realistic, the effects of turbulent air can be simulated. The manufacturers of the trainer believed that a great deal of what is learned in the normal course of primary flight instruction could be learned in the School Link and that, as a result, preflight training in the trainer could be substituted for part of the time spent in the air, or, if direct substitution were not possible, at least instruc- tion in the trainer would facilitate training in the air. Accordingly, as a practical example of trainer use, an experiment was designed to determine whether or not preflight instruction in the School Link would reduce the number of hours of dual flight instruction normally required before solo in a real aircraft. THE FIRST EXPERIMENT Method and Procedure Forty-eight of the students' enrolled in the primary flight training course offered by the University were selected on a voluntary basis for the experiment. None had had previous flight experience as a pilot or as a regular member of a flight crew. The students were divided into three equal groups. Group A, the Control Group, received no preflight instruction in the School Link; Group B received two hours of preflight instruction in the School Link; and Group C received four hours of preflight instruction in the School Link. The students were assigned to four experienced flight instructors. Each instructor re- ceived twelve students, four from each group. The design called for a separate group of instructors to give the preflight training in the Link. At the end of this training the students were turned over to their flight instructors. These instructors were unaware of the Link history of their individual students, except that they knew they had four from each of the three groups. Their task was to train the students according to the ordinary flight training 6 EVALUATION OF THE SCHOOL LINK syllabus, and to move each as fast as he was able to progress. These flight instructors were permitted to solo a student whenever they felt the student was ready, regardless of the amount of instruction that had been given. Special permission from the Civil Aeronautics Admin- istration was obtained for this purpose. If preflight training in the Link were effective, it would be expec- ted that those who had received it would solo after fewer hours of flight instruction than those who had not received it. Furthermore, if the amount of Link instruction were a factor, some difference in time to solo between the two-hour group and the four-hour group would occur. The syllabus for the training offered in the Link was based on the regular flight syllabus which had been adapted for' the trainer by Mr. Paul Dittman of Link Aviation, Inc. It consisted of the usual exercises on effect of controls, straight and level flight, turns, climbs, glides, stalls, and traffic pattern, but no take-offs or landings, since the Link does not simulate these maneuvers. Both the two-hour and the four- hour group practiced the same exercises, the four-hour group in eight half-hour periods, the two-hour group in eight quarter-hour periods. A more detailed description of the Link and the flight syllabus is not pertinent to the results and, therefore, will not be included. Results When all of the students had soloed, an analysis of the number of hours of dual flight instruction necessary before solo showed that there was no real difference between groups in this respect. Those who had received preflight training in the School Link took as many flying hours before solo as did those who had not received such training. Similarly, there was no difference between the two-hour and the four- hour groups in time to solo. The times to solo required by all students are shown in Table 1. They are arranged according to group and instructor and given in hours and tenths of hours. Arranged in this way, the data form twelve subgroups of four students each. An analysis of variance using within-group variance as the estimate of error, shows that the difference between the means of the zero-hour, two-hour, and four-hour groups is no greater than would be expected by chance. On the other hand, the difference be- tween the means of the instructor groups is greater than would be expected by chance, being significant at the 1 per cent level. Evidently, the instructor was a significant source of variation in time to solo (as might be expected from other studies) in that his differential influence was great enough to dominate individual differences in student ability. THE UNIVERSITY OF ILLINOIS Table 1. Number of Hours of Dual Flight Instruction Before Solo Zero-Hour Two -Hour Four-Hour Link Link Link Instructor 6.3 6.5 8.7 A 5.5 6.3 8.1 Total = 72.7 5.8 6.7 3.6 5.8 4.9 4.5 Mean = 6.06 Instructor 4.0 3.7 5.0 B 5.0 5.8 2.5 Total = 54.6 4.0 5.0 5.5 4.1 5.0 5.0 Mean = 4.55 Instructor 5.0 6.0 4.3 C 4.1 5.0 4.0 Total = 52.8 2.5 3.0 4.2 6.9 3.8 4.0 Mean = 4.40 Instructor 11.0 4.7 5.0 D 8.0 5.7 4.2 Total = 73.2 6.3 8.3 3.9 4.0 8.0 4.1 Mean = 6.10 Total = 88.3 = 88.4 = 76.6 = 253.3 Mean = 5.52 = 5.53 = 4.79 = 5.28 Discussion of Results Since transfer of training as measured by time to solo evidently did not occur in this group of students, it is well to ask why it did not. It could be either that nothing which was applicable to flight was learned in the trainer, or that what was learned was applicable but did not affect the particular criterion used. It was the assumption of most of those connected with the experiment that the Control Group, those with zero-hours Link, would solo in close to the standard time of eight hours. Consequently, it was believed that the Link students had the opportunity to save a maximum of about 5.5 hours, allowing an aver- age of two and a half hours for landing practice and spins which could not be learned in the Link. The fact that for non-Link students the average time to solo was 5.5 hours, well below eight hours, re- duced the total possible savings which could be achieved by the Link group to about 2.5 hours. Also, the fact that the instructors were unaware of which students had had Link training made it necessary for all students to take some time to demonstrate their ability to do 8 EVALUATION OF THE SCHOOL LINK airwork. Consequently, the total possible savings were reduced still further. After the first hour of dual instruction the instructors could identify their Link students with fair accuracy, although they were not informed about the correctness of their identifications. According to the instructors, this identification was based on the superior initial performance of members of the Link group. If the Link group was in fact superior during the first few hours, this advantage was lost by the time the students soloed. It may be either that proficiency in air- work beyond a certain easily attained minimum is unimportant as a criterion for solo, or that the flight syllabus is so unexacting that the non-Link students were able to make up their initial deficiency on airwork during landing practice. In any event, it was decided that the experiment was not conclusive either way. The criterion used was so heavily weighted in landing and take-off performance, which the Link does not teach, that any transfer which might have occurred was overshadowed. Accordingly, a second experiment was planned in which only performance in airwork would would be measured, since it was believed that any transfer would have to occur in this area. THE SECOND EXPERIMENT Method and Procedure The second experiment was different from the first in design and procedure. As a measure of learning, it was decided to use a conven- tional method of recording the number of trials required to reach a given standard of proficiency. Eight airwork exercises were con- structed and arranged in what was designed to be a logical progression from effect of controls to flying the traffic pattern. In order, these exercises were as follows: 1. Effect of controls 2. Return to level flight 3. Climbs and glides 4. Level 180 degree turns to a point 5. Alternate 180 degree climbing and gliding turns 6. Stalls, normal and complete, power-on and power-off 7. Entry into traffic pattern 8. Elying in the traffic pattern THE UNIVERSITY OF ILLINOIS 9 Each exercise was broken down into a number of items on which the student was checked as having either passed or failed. As an example, Exercise 4, "Level 180 Degree Turns to a Point," consisted of the following items: Entry a. Look to right and left b . Aileron and rudder — coordination c . Constant 30 degree bank ± 5 degrees d. Nose level Recovery e . Aileron and rudder — coordination f . Directional control ± 10 degrees g. Altitude constant ± 50 feet h. Nose level i. Wings level The student's performance was checked — passed or failed — on each item of the exercise as it occurred. A failure on any item was considered an error. A trial was considered one performance of the complete exercise. The criterion of learning for the exercise was the performance of three consecutive errorless trials. The amount of learning was measured by the number of trials required prior to reach- ing the criterion. The student was required to repeat the exercise until the criterion was reached. After the first trial, if the student appeared not to understand the exercise at all, the instructor gave one demonstration. Thereafter, he gave demonstrations from time to time if he felt they were essential to the student's understanding of the maneuver. Demonstrations were kept to a minimum, and a record of them was kept. During a trial, no word was spoken by the instructor until the student made an error. The instructor could point out the error either at that time or at the end of the trial. The instructor reviewed each trial in which an error was made, pointing out what errors were made and what was done correctly and suggesting ways to correct the error on the next trial. If an errorless trial was accomplished, the instructor said nothing. This procedure placed great reliance on the judgment of the in- structor. He was responsible for deciding if the performance were satisfactory or unsatisfactory on each item. These judgments ulti- mately determined the number of trials taken by a student. In order to obtain some degree of standardization, the four instructors used in 10 EVALUATION OF THE SCHOOL LINK the experiment participated in the construction of the exercises, and themselves set up the standards to be used as criteria. By means of conferences and mutual demonstrations in the Link and in the air, tolerances in meeting the criterion for each item were established. Scoring forms for all exercises were made up, and instructors prac- ticed rating each other in the air and in the Link. Four extra subjects were obtained to pretest the procedure and to give the instructors added practice in the new methods of instruction and scoring. These subjects were trained to criterion in each exercise, first in the Link and then in the air. As a result of this experience, several changes were made in the exercises and tolerances used. In spite of these efforts to achieve standardization, it was not expected that the instructor would be eliminated as a variable in the experiment nor that the scoring system used would be uninfluenced by instructor differences. An estimate of scoring reliability was ob- tained by having combinations of two instructors simultaneously and independently score the performance of a third, both in the Link and in the air. Unfortunately, the short time available before the new semester started and poor flying weather prevented a systematic study of reliability by this promising method. The few data obtained this way showed satisfactory reliability for the scoring procedure, but the question of variation between instructors was left to be handled by the design of the main experiment itself. Experimental Design Forty-eight students without previous flight training were divided at random into two groups of twenty-four each. One of these groups, the Control Group, received training only in the air. The other group, the Transfer Group, received training both in the Link and in the air. The students were assigned at random to four instructors — twelve students to an instructor. Half of each instructor's students were from the Control Group; the other half were from the Transfer Group. The Transfer Group received both their Link training and their flight training concomitantly from the same instructor. They were trained to criterion in Exercise 1 in the Link and then trained to criterion in the same exercise in the air. The same procedure was used with the other exercises in turn. In case proficiency was reached on an exercise in the Link before the end of a Link period, practice on the next exercise was started, but training in the air never preceded training in the Link. Thus, a student always reached the criterion pro- THE UNIVERSITY OF ILLINOIS 11 ficiency of three consecutive errorless trials on an exercise in the Link before starting the exercise in the air. This procedure resulted in three different sets of scores designated as LL (Link-Link), LA (Link-Air), and CA (Control-Air). The first set consisted of the number of trials required by the Transfer Group to reach criterion in the Link. The second consisted of the number of trials taken by the Transfer Group to reach criterion in the air. The third consisted of the number of trials taken by the Control Group to reach criterion in the air. The design was such that the total variation in the number of trials required to reach proficiency could be analyzed, and portions assigned to various sources. The source of primary interest was the fact that half of the students had Link training and the other half did not. If this constituted a significant source of variation in the number of air trials, and if the resulting difference between groups were in favor of Link-trained students, then positive transfer of training could be said to have occurred. Other pertinent sources of variation were the students themselves, the exercises, the instructors, and various first order interactions between these variables. If the analysis of variance should show evidence of transfer, then the amount of transfer could be computed for any exercise or group of students from the following formula: ^ r Control Group score — Transfer Group score . . .^ % transfer = - : X 100 Control Group score — total possible score In this case, the total possible score equalled zero trials, indicating that the limit of learning was perfect performance on the first three trials (the criterion measure). By computing per cent transfer for each exercise, the relative effectiveness of the Link in training for different maneuvers could be studied, and data obtained which might be useful in designing a practical training syllabus for Link use. In addition to per cent transfer, a second coefficient, called an efficiency ratio, was developed. The efficiency ratio represents the number of air trials saved per Link trial spent, and is an indication of the economy of the Link in accomplishing whatever transfer may have qj^ L^ occurred. The ratio is stated by the relationship . The numerator CA — LA represents the savings in air trials of the Trans- fer Group over the Control Group, and the denominator LL represents 'J- OF ILL Lift 12 EVALUATION OF THE SCHOOL LINK the cost of the savings in terms of the number of Link trials taken by the Transfer Group. In addition to these ratios, estimates of transfer of training could be obtained from the frequency of errors within each exercise. Since each exercise consisted of a number of separate items on which the students were checked, the number of errors made on each item by various students or groups of students could be computed. If Link training were effective, it would be expected that the Transfer Group would make fewer errors in the air than would the Control Group. Transfer measures based on errors could be computed for each item of an exercise, or for the exercise as a whole. In the former case, information should be obtained which would be valuable in evaluating the flight characteristics of the trainer itself, since the items are relevant to the kind of performance obtainable from the Link. In the latter case, the transfer measures obtained could be compared directly with those based on trials. In the case of all transfer measures, it becomes necessary to decide if they indicate significant positive transfer, no transfer, or significant negative transfer. In general, a high positive or negative per cent transfer, when based upon a sufficient number of trials or errors, can be considered significant. However, the significance of low percentages, or high percentages based on a few cases, is uncertain unless there is some way of evaluating them. A low per cent transfer, either positive or negative, which is not significant is equivalent, of course, to no transfer at all. In order to determine the significance of the per cent transfers obtained, and at the same time establish clear and reasonable definitions of positive transfer, no transfer, and negative transfer, each difference in trials or errors between Transfer Group and Control Group was tested for significance by the x 2 method. It was arbitrarily decided that differences in frequency of trials or errors in favor of the Transfer Group at the 1 per cent level of significance or greater would be considered positive transfer; differences not significant at the 1 per cent level would be considered to indicate no transfer; and differences in favor of the Control Group significant at the 1 per cent level or greater would be considered negative transfer. Results The number of trials to reach criterion proficiency required by each subject in each exercise according to Link status and instructor is shown in Appendix B. A summary of these data is shown in Table 2. Here it is evident that Transfer Group students required 368 fewer THE UNIVERSITY OF ILLINOIS 13 Table 2. Distribution of Total Trials for Subgroups of Six Students Classified According to Link Status, Instructor, and Exercise n nk-Link Link- Air Control- Air Instructor Instructor Instructor Exercises I II III IV Total I II III IV Total I II III IV Total 1 2 1 11 14 2 2 2 6 4 2 8 4 18 2 28 41 29 14 112 35 55 37 10 137 42 40 42 28 152 3 44 23 74 41 182 37 57 57 29 180 54 45 69 37 205 4 70 70 123 69 332 42 62 116 39 259 38 66 141 55 300 5 61 55 69 71 256 19 57 31 34 141 28 38 54 57 177 6a 17 18 13 8 56 53 43 38 34 168 46 42 75 58 221 6b 19 10 21 7 57 27 15 16 21 79 16 29 47 33 125 6c 23 29 29 18 99 64 61 68 37 230 80 102 58 63 303 6d 24 9 20 11 64 26 16 18 9 69 38 7 20 6 71 7 19 19 30 25 93 11 21 10 5 47 6 15 24 24 69 8 6 13 27 25 71 14 26 6 21 67 17 24 29 40 110 Totals 313 288 446 289 1336 328 415 399 241 1383 369 410 567 405 1751 air trials than the Control Group students. This is a significant differ- ence at the 1 per cent level of confidence. An analysis of the variance of the Link-Air and Control-Air trials gave the results shown in Table 3. As an estimate of error, the variance of three first order and second order interactions were pooled, giving a mean square variance of 13.93 for 440 degrees of freedom. When compared with this, all sources of variation listed in the table proved significant. It can be said then, that the number of trials required in any instance is deter- mined by the student himself, whether or not he has had Link train- ing, his instructor, and, of course, the particular exercise being done. Among these, the subject seems to be least important, since the others are significant even when compared with subject variation. Since Link training proved to be a significant factor in the number of trials taken, and since the effect of the Link training was to reduce the number of air trials taken, it can be safely assumed that positive transfer of training did occur in this experiment. An analysis of trials according to exercise is the first step in trac- ing the source of transfer. Table 4 shows three coefficients of transfer for each exercise. First is listed the per cent transfer based on trials, next the per cent transfer based on errors, and finally, the efficiency ratio or number of air trials saved per Link trial spent. Those per cent transfers which proved to be significant are starred (*). 14 EVALUATION OF THE SCHOOL LINK Table 3. Results of Analysis of Variance of Link-Air and Control-Air Trials Source of Variation Degrees of Sum of Freedom Squares Estimate of Variance Link-Air — Control-Air 1 256 . 48 256 . 48* Instructors 3 465.28 155.09* Exercises 10 6134.02 613.40* Students 40 1229.30 30.73* Link X Instructors 3 174.02 58.01* Instructors X Exercises 30 2009.01 66.97* Link X Exercises 10 88 . 56 8 . 86 1 ] Students X Exercises 400 5591.70 13.984 I Link X Instructors X Exercises 30 449.44 14. 98 1 * The estimates of variance which are starred are significant at the 1 per cent level when compared with the pooled estimate of error variance. 1 Constitutes the pooled estimate of error variance. Table 4 shows that roughly 25 per cent (22 per cent trials, 28 per cent errors), or one quarter, of their flight training was accomplished by the Transfer Group students in the Link. In accomplishing this saving, one trial in the Link was worth .29 trials in the air. Exercises did not contribute equally to the over-all transfer. In terms of trials, only four out of a possible eleven exercises showed significant positive transfer, although the others were all in the direction of positive transfer. In terms of errors all but one exercise showed significant positive transfer. The discrepancy between the results for trials and errors will be discussed later, but in general these differences in signifi- cance occurred because there were many more errors than there were trials. With the exception of Exercise 1, no exercise was outstanding in its contribution to transfer. On the other hand, except for Exercise 6d, the Link was successful in saving a moderate amount of flight training in all maneuvers either in terms of trials or errors. These results do not suggest any special uses for the School Link within the scope of maneuvers employed in the experiment. The greatest saving was made in the case of Exercise 1. However, this exercise was not difficult for students to master even without Link training so that although the savings were relatively great, they are of little practical significance. If the maneuvers are broken down according to the items of which they are composed, it is possible to trace the source of transfer still farther. In all eight exercises for eleven, when stalls are considered separately) there are over two hundred items on which students were THE UNIVERSITY OF ILLINOIS 15 Table 4. Per Cent Transfer (Trials), Per Cent Transfer (Errors), and Efficiency Ratio According to Exercises Efficiency Per Cent Per Cent R at™ exercises Transfer Transfer CA LA {trials) {errors) LL 1 Effect of controls 67 79* 86 2 Return to level flight 10 15* .13 3 Climbs and glides 12 31* .14 4 Level 180 degree turns to a point 14 28* .12 5 Alternate 180 degree climbing and gliding turns . . 20 40* .14 6 Stalls, normal and complete, power-on and power-off 6a Normal stalls, power-on 24* 31* .95 6b Normal stalls, power-off 37* 27* .81 6c Complete stall, power-on 24* 13* .74 6d Complete stall, power-off 3 -17 .03 7 Entry into traffic pattern 32 42* .24 8 Flying in the traffic pattern 39* 33* .61 Total (all exercises) 22* 28* .29 * Significant coefficient at 1 per cent level of confidence (not applicable to efficiency ratio). scored for errors. On each of these items, therefore, a certain fre- quency of errors occurred. By comparing the frequency of errors made by the Link- Air group with the frequency made by the Control- Air group the per cent transfer of training could be computed for each item. Table 5 shows the per cent transfer based on errors. Just as in the case of Exercise 1, which showed large transfer of training but small absolute saving because of the ease of the exercise, the transfer of training obtained on each individual item must be evaluated in the light of the difficulty or importance of that item. In order to achieve savings of practical importance to flight training, the School Link must provide transfer of training on items in which many errors are normally made. The two hundred items in the present experiment 16 EVALUATION OF THE SCHOOL LINK were not equally difficult. An estimate of their difficulty is provided by the frequency of errors made by the Control Group. Those items on which the Control Group students made the most errors are evi- dently the most difficult items to learn. They are the items which provide the Link with its best opportunity to achieve savings of practical significance. Consequently, in Table 5 the items have been removed from their context within the exercises and listed instead according to order of their difficulty — from the most difficult to the least difficult. The items can be identified by their code numbers, the key to which is given in Appendix A. Also listed in the table are the total errors made on each item by the Link-Air group and by the Control-Air group, the latter being the basis on which the rank order was constructed. Finally, the per cent transfer for each item is shown. Those preceded by a minus sign indicate negative transfer. Per cent transfers based upon significant differences between Link-Air and Control-Air are starred. Table 5 shows that significant positive transfer occurred in the case of only twenty-nine of the two hundred items on which students were scored for errors. Significant negative transfer occurred in the case of two items. On the remaining items, there was a reduction of errors in most cases in favor of the Link trained students; but either the reduction was not great enough, or the total number of errors made was not great enough for the difference between groups to be significant. The important items of the table are, perhaps, the first quarter in order of difficulty. These are the items on which a training device should make its greatest contribution. Of these fifty items, positive transfer occurred in the case of sixteen and there were no instances of negative transfer. The savings achieved on these sixteen items were of respectable proportions ranging from 46 to 62 per cent. But items on which significant transfer did not occur are of greater interest. These items identify the major weaknesses of the trainer. They are the items on which transfer should occur if the effectiveness of the trainer is to be improved. An analysis of them, in an attempt to account for lack of transfer, shows that many tend to fall into clusters based on common elements. Thus, eight of them concern directional control with changes in power and airspeed. In controlling direction under these circumstances, the pilot must move the controls so as to compensate for the effect of torque. The fact that no torque effect was built into this trainer suggests a reason for lack of transfer on those items. THE UNIVERSITY OF ILLINOIS 17 Table 5. Per Cent Transfer Based on Errors Listed According to Order of Difficulty of Items Code TOTAL ERRORS Per Cent Transfer Rank Order Code TOTAL ERRORS Rank Order Link- Air Con- trol- Air Link- Air Con- trol- Air Per Cent Transfer 1 4a 109 241 55* 34.5 611 46 62 26 2 6qq 133 170 21 37 2r 57 60 05 3 6rr 117 136 14 38 3c 48 59 18 4.5 3aa 48 104 54* 39 31 37 55 32 4.5 4d 88 104 15 40.5 3x 45 54 17 6 3bb 64 94 31 40.5 5v 26 54 52* 7 6k 54 88 39* 42 5p 24 53 55* 8.5 6nn 78 87 10 44 3m 44 51 13 8.5 6oo 48 87 44* 44 3p 12 51 76* 10 3t 60 82 27 44 6pp 20 51 61* 12 3r 57 81 29 46 3q 27 50 46* 12 3ee 89 81 -10 47 5u 23 49 53* 12 6mm 89 81 -10 49 2b 38 48 20 • 14 5i 57 80 29 49 5s 32 48 33 15 3h 64 78 17 49 8f 30 48 37 16 4c 60 77 22 51 5r 38 47 19 17.5 3u 40 76 47* 52.5 3dd 25 46 45* 17.5 6h 40 76 47* 52.5 5g 24 46 48* 19.5 2n 52 75 30 54 6d 40 44 09 19.5 3gg 85 75 -13 56 3f 18 43 58* 21 33 50 71 29 56 3cc 45 43 -04 22 5h 35 70 50* 56 5x 12 43 72* 23.5 3w 57 68 16 58.5 2o 46 42 -10 23.5 4b 52 68 24 58.5 5z 16 42 62* 26 2g 53 67 20 61 3g 15 41 63* 26 3ff 25 67 62* 61 51 36 41 12 26 4e 41 67 39 61 8u 28 41 31 28.5 3k 61 66 07 63 5gg 28 40 30 28.5 3z 52 66 21 65 3d 16 39 58* 30.5 4f 64 64 65 6ee 30 39 23 30.5 6j 50 64 22 65 6i 27 39 31 32 5e 27 63 57* 68 5m 42 38 -10 34.5 3n 68 62 -09 68 5t 26 38 31 34.5 6f 33 62 46* 68 5aa 47 38 -24 34.5 6g 57 62 08 70 5y 22 37 41 * x 2 is significant at 1 per cent level. 18 EVALUATION OF THE SCHOOL LINK Table 5. Continued Code TOTAL ERRORS Per Cent Transfer Rank Order Code TOTAL ERRORS Rank Order Link- Air Con- trol- Air Link- Air Con- trol- Air Per Cent Transfer 72.5 3e 12 36 67* 106.5 7g 9 24 62* 72.5 5j 6 36 83* 106.5 8d 8 24 67 72.5 6bb 23 36 36 109.5 2f 16 23 30 72.5 6ss 19 36 .47 109.5 2i 18 23 21 77 2d 30 35 14 109.5 2p 28 23 -21 77 2h 37 35 -05 109.5 3o 8 23 65* 77 3i 17 35 51 112.5 5c 23 22 -04 77 3s 15 35 57* 112.5 7a 15 22 31 77 5o 17 35 51 116.5 2c 17 21 19 81.5 2e 19 34 44 116.5 6i 27 21 -28 81.5 2k 42 34 -23 116.5 61 11 21 48 81.5 3v 17 34 50 116.5 6kkk 20 21 05 81.5 5f 19 34 44 116.5 7b 18 21 14 85 21 34 33 -03 116.5 8x 25 21 -19 85 3b 27 33 18 121.5 2q 28 20 -40 85 6e 17 33 48 121.5 5dd 14 20 30 87.5 4g 61 32 -90* 121.5 8g 8 20 60 87.5 5n 19 32 41 121.5 8v 14 20 30 89.5 5ff 26 31 16 125 4h 9 19 53 89.5 6b 19 31 38 125 6dd 12 19 36 91.5 5cc 20 29 31 125 6iii 2 19 89 91.5 6aa 21 29 27 129 5k 7 18 61 94 5ee 15 28 46 129 6y 16 18 11 94 7d 10 28 64* 129 6ii 26 18 -44 94 7e 18 28 35 129 6kk 36 18 -105 98.5 2m 12 27 55 129 8y 15 18 17 98.5 3a 15 27 44 132.5 6a 12 17 29 98.5 3y 14 27 48 132.5 6v 5 17 70 98.5 5w 18 27 33 132.5 5a 10 16 38 98.5 6x 17 27 31 135.5 5hh 6 16 62 98.5 8w 20 27 26 135.5 8c 6 16 62 102.5 2a 26 26 135.5 81 7 16 56 102.5 7c 17 26 35 138.5 5q 4 15 73 104.5 5d 23 25 08 138.5 6p 7 15 53 104.5 5ii 13 25 48 141 5bb 2 14 86 THE UNIVERSITY OF ILLINOIS Table 5. Concluded 19 Code TOTAL ERRORS Per Cent Transfer Rank Order Code TOTAL ERRORS Rank Order Link- Air Con- trol- Air Link- Air Con- trol- Air Per Cent Transfer 141 6cc 12 14 14 169 6111 7 7 141 8m 7 14 50 172 5 lb 2 6 67 145 2j 7 13 46 172 5 6u 7 6 -17 145 8e 11 13 15 177 lh 5 100 145 8h 6 13 53 177 6zz 3 5 40 145 8n 5 13 61 177 6ggg 6 5 -20 145 8t 10 13 23 177 6mmm 1 5 80 149 6c 9 12 25 177 8k 3 5 40 149 7f 7 12 42 177 8p 1 5 80 149 8j 9 12 25 182 5 If 1 4 75 151.5 5b 3 11 72 182 5 lg 1 4 75 151.5 6fff 8 11 27 182 5 6aaa 5 4 -25 154.5 6ff 3 10 70 182. 5 6eee 9 4 -125 154.5 ogg 7 10 30 188 Id 2 3 33 154.5 6hhh 21 10 -110 188 6q 3 3 154.5 8z 15 10 -50 188 6xx 8 3 -167 158 lc 1 9 89 188 6bbb 6 3 -100 158 6z 6 9 33 188 6ddd 6 3 -100 158 6hh 4 9 56 188 6jjj 2 3 33 163 6m 5 8 38 188 8s 3 3 163 6jj 36 8 -350* 193. 5 le 2 100 163 6ccc 5 8 38 193. 5 6w 2 2 163 8b 7 8 12 193. 5 6tt 3 2 -50 163 8o 7 8 12 193. 5 8a 4 2 -100 163 8q 9 8 -12 198 la 163 8r 6 8 25 198 6n 169 8o 7 7 198 6uu 169 6s 10 7 -42 198 6vv 4 -00 169 6t 5 7 28 198 6yy 4 -00 169 6ww 7 7 A second group of six items is associated with the characteristics of a power-on stall, particularly the power-on complete stall. The trainer does not stall in the same way as the aircraft. The stall is less violent, with much greater lateral and directional stability. Since the items where transfer failed to occur are concerned largely with directional and lateral stability in this maneuver, the explanation for 20 EVALUATION OF THE SCHOOL LINK lack of transfer is fairly evident. The results indicate that the stall characteristics of the trainer should be improved; specifically, the trainer should be made directionally and laterally unstable during the stall. Similarly, other item clusters suggest that the ball-bank mechanism should be improved, not with respect to its readings during entry into a turn, but rather on the recovery to level flight from a turn. On recovery from a turn, a different use of rudder and aileron to keep the ball centered is required in the trainer than in the aircraft, whereas on an entry into a turn there is high positive transfer. In like manner, transfer did not occur on items which required use of the altimeter to achieve or maintain a given altitude performance. The altimeter used in the trainer did not display the customary "lag" found in altimeters in aircraft. This fact may have been responsible for lack of transfer. The preceding examples are cited only to illustrate the way in which these data may be used to identify trainer characteristics which need improvement. Whether or not the modifications indicated would result in improved transfer on those items is still a matter for specula- tion. Until such changes are made and evaluated, there is no sure answer. All that can be said is that these results do show which items of an airwork syllabus are difficult and, therefore, important, and on which of these the trainer is effective in achieving transfer. Examination of those items on which the School Link failed suggests discrepancies between trainer performance and actual aircraft performance which might be responsible for lack of transfer. Discussion and Conclusions It is evident from these results that those students who received Link training were aided by it in learning to fly. Link training substi- tuted for approximately one quarter of the normal amount of flight training as determined by the Control Group. The amount of over- all transfer of training was greater when measured in terms of errors than in terms of trials. This may be accounted for by the hypothesis that repetition of errors on a single item within an exercise may unduly extend the number of trials, with the result that the number of trials becomes a less representative index of learning than the number of errors. It does suggest that the most economical use of the Link should be based on errors made rather than on whole trials. Instruction should be aimed at eliminating errors without requiring performance of complete trials in the process. In attempting to trace the source of the over-all transfer, the results indicate that each exercise contributes a relatively small amount THE UNIVERSITY OF ILLINOIS 21 to the total. In terms of trials, only four of the eleven exercises show significant positive transfer. The other seven all have positive co- efficients, but either they are not large enough or the number of trials on which they are based is not large enough to reach significance. This indicates that the significant over-all transfer derives from an accumu- lation of small amounts of transfer, themselves not significant, in each exercise. In terms of errors, the same interpretation may be advanced with the difference that here all exercises except one are themselves significant. The highest per cent transfers — 79%, 42%, and 40% — are found in Exercises 1, 7, and 5, respectively. These, however, are not the most important exercises in terms of number of errors made. The Link's greatest contribution, therefore, occurred among the easier exercises. Had it occurred on the most difficult exercises, the over-all amount of transfer would have been greater. Tracing the source of transfer still further to the items within each exercise, the results are similar. Among the items found to be the most difficult, only a small proportion showed significant positive transfer. The total over-all transfer must come then from the accumulation of small savings from many items both difficult and easy. Included among the items were some with coefficients of negative transfer. All of these were unimportant — that is to say, easy - — items which did not con- tribute greatly to the total. Analysis of those items where transfer did not occur shows promise of providing useful information for improv- ing the characteristics of the trainer. By classifying items according to difficulty, it is possible to identify those which are of practical importance to training. These are also the items with respect to which most effort should be spent improving the trainer so as to increase transfer. We may conclude that training in the School Link does not save any flight time prior to solo because readiness to solo does not depend upon the airwork skills taught in the trainer. A direct measure of airwork skills shows that a portion of them may be learned in the School Link. A breakdown of these skills into their component parts shows that, in general, Link training results in small savings through- out, the accumulation of which results in a significant over-all transfer of training of about 25 per cent. In a small proportion of cases Link training resulted in significant savings on the parts themselves. Analy- sis of some of the remaining components can yield information which suggests ways of modifying the trainer in order to increase transfer of training. APPENDIX A This appendix contains a breakdown and description of the exercises according to items on which subjects were checked. The items are coded for identification in the text. Notes elaborating on tolerances' used in checking the less obvious items are included. The student's proficiency in performing each of the eight exercises both in the Link and in the air was recorded on check sheets on which the maneuver or maneuvers were broken down into their component parts. It was thought that if an exercise were minutely analyzed and the pilot's performance on its parts recorded, there would be less variability in instructor judgment on the student's over-all performance of an exercise, not in relation to a grade but according to whether or not a trial was satisfactorily accomplished. The tolerances on the attitude and directional control of the aircraft were associated with certain agreed-upon reference points on the aircraft itself. For recording the wings as being level, the wings were to be in a bank of not more than eight degrees. An eight degree bank was attained if the wing tip appeared to touch the horizon. The airplane was said to be in level flight longitudinally if the angle formed by the underside of the wing and the horizon did not exceed five degrees. Directional variance was measured by the angle formed by the longitudinal axis of the aircraft and a section line. The aircraft was recorded as flying straight if this angle did not exceed ten degrees. Where judgments concerning the coordinated use of aileron and rudder were required, a more definite tolerance measure — whether or not the ball from a turn and bank indicator was displaced more than its own diameter — was used. In Exercise 1, each of the eight adjustments was considered satisfac- tory if the first response to the verbal order to make the adjustment was in the correct direction. Extent of movement was not considered. In Exercise 2, each of the adjustments had a time limit of ten seconds. The instructor would put the airplane in a certain attitude and then tell the student to return the airplane to straight and level flight. At the end of a ten second period the instructor recorded whether or not the airplane was in straight and level flight. In Exercise 3, throttle coordination in the climb entry was determined by whether or not the power was increased as the angle of attack was increased and whether or not full throttle had been applied by the time a normal climb attitude was established. In returning from a climb to straight and level flight, the throttle was not to be retarded until the airplane had been back to straight and level flight for at least three seconds. In the glide entry, the carburetor heat control was to be in the full on position before the throttle was retarded. The "attitude held" in the glide entry referred to how straight and level the airplane remained while the cruising airspeed was dissipated to that for a normal glide. Throttle coordination in the recovery from a glide was determined by whether or not the power was increased as the nose of the airplane came back to level flight. In Exercise 4, the student was required to look to the right and to the left prior to each turn. This was considered to be just as important as any 22 THE UNIVERSITY OF ILLINOIS 23 of the other elements in the turn exercise. The standard for a thirty degree bank required that the wing strut appear to be parallel to the ground. The tolerance was approximately five degrees on either side of the standard attitude. In Exercise 5, the rate of turn judgment was largely a matter of in- structor standardization. The degree of bank in the climbing turn was required to be plus or minus five degrees from a standard attitude. This standard attitude occurred when the wing tip appeared to be just on the horizon. The carburetor heat was to be applied within ten degrees either side of the forty-five degree point. The recovery to straight and level flight was to be started twenty degrees before the desired direction with a ten de- gree tolerance on either side. The nose attitude in the glide was that re- quired for a sixty mile per hour glide, with an allowable tolerance of five miles per hour on either side. In Exercise 6, the nose attitude for the power-on stalls was an angle of approximately forty-five degrees. The standard from which this angle was judged was the angle formed by the horizon and the underside of the wing tip. The maximum variation allowable for this attitude was about plus or minus ten degrees. For the power-off stalls, the student was ex- pected to use the same procedure for entering a glide as in Exercise 5, and then from this attitude to enter the stall. Exercises 7 and 8 were procedural type exercises for which the various adjustments were based upon a temporal factor. In Exercise 7, the student was to establish an entry leg to the traffic pattern that was at least one mile in length, at a forty-five degree angle to the downwind leg of the pattern; maintain an altitude of eight hundred feet plus or minus one hundred feet; look carefully for other traffic; and intersect the downwind leg somewhere in the middle third. In Exercise 8, the student was given control of the airplane right after take-off, at which time recording of the exercise began. CODE DESCRIPTION CODE DESCRIPTION EXERCISE 1 — EFFECT OF CONTROLS From left wing low attitude la b c d e f Nose up Right wing down Nose right Add power Nose down Left wing down d e f g Nose level Directional control Wings level Aileron and rudder — co- ordination From nose low attitude g Nose left h Nose level h Decrease power J Directional control Wings level EXERCISE 2 — RETURN TO LEVEL FLIGHT From climbing turns 2a b From nose high attitude Nose level Directional control k 1 m n Nose level Directional control Wings level Aileron and rudder — co- c Wings level ordination 24 EVALUATION OF THE SCHOOL LINK CODE DESCRIPTION CODE DESCRIPTION From diving turn EXERCISE 4 — LEVEL 180 DEGREE o Nose level TURNS TO A POINT P Directional control Entry q Wings level 4a Look to right and left r Aileron and rudder — co- b Aileron and rudder — co- ordination ordination EXERCISE 3 CLIMBS AND GLIDES c Constant 30 degree bank ±5 degrees Nose level Climb entry d 3a Wings level Recovery b c d e Climb attitude Directional control Throttle — amount Throttle — coordination e f Aileron and rudder — co- ordination Directional control ± 10 degrees Maintaining climb for 300 feet g Altitude constant ± 50 feet f Wings level h Nose level g Climb attitude i Wings level h Directional control EXERCISE 5 ALTERNATE 180 DEGREE Recovery CLIMBING AND GLIDING TURNS i Wings level Nose level Directional control Entry to right climbing turn J k 5a Coordinated use of throttle 1 Throttle — amount b Coordinated use of elevator m Throttle — coordination c Coordinated use of aileron n Recover +50 feet d Coordinated use of rudder e Constant rate of turn Glide entry f Climb attitude established o Carburetor heat on g Climb attitude held P Throttle — amount h Degree bank established q Throttle — smoothness i Degree bank held r Nose level Wings level Recovery to gliding turn s j Carburetor heat on at 45 de- t Directional control u Glide attitude established gree point V Wings level k Start recovery at 20 degree point Coordinated use of throttle w Directional control 1 Maintain for 300 feet m Coordinated use of elevator X Glide attitude held n Coordinated use of aileron y Wings level o Coordinated use of rudder z Directional control At level flight point Recovery P Directional control aa bb Throttle — amount Throttle — coordination q r Wings level Nose level cc Nose level Gliding turn, left entry dd Wings level s Coordinated use of throttle ee Directional control t Coordinated use of elevator ff Carburetor heat off u Coordinated use of aileron gg Recover ± 50 feet V Coordinated use of rudder THE UNIVERSITY OF ILLINOIS 25 CODE DESCRIPTION CODE DESCRIPTION w Constant rate of turn y Maintaining — directional con- X Glide attitude established trol y Glide attitude held z Maintaining — wings level z Degree bank established aa Recovery — start at break aa Degree bank held bb Recovery — full throttle Glide recovery cc dd Recovery — forward stick Recovery — wings level bb Start recovery at 20 degree ee Recovery — directional control point ff Recovery — retard throttle cc dd Coordinated use of throttle Coordinated use of elevator gg Recovery — carburetor heat off ee Coordinated use of aileron Complete stall, power-on ff Coordinated use of rudder hh Entry — stall attitude estab- gg Directional change at level lished flight point ii Entry — directional control hh Wings level at level flight point jj Entry — wings level ii Nose level at level flight point kk Maintaining — stall attitude 11 Maintaining — directional con- EXERCISE 6 — STALLS, NORMAL AND COM- trol PLETE, POWER-ON AND POWER-OFF mm Maintaining — wings level Normal stall, power-on nn Recovery — start at horizon 6a Entry — stall attitude estab- lished Entry — directional control oo PP Recovery — full throttle Recovery — forward stick b qq rr Recovery — directional control Recovery — wings level c d Entry — wings level Maintaining — stall attitude ss Recovery — retard throttle e Maintaining — wings level Complete stall, power-off f Maintaining — directional con- tt Entry — carburetor heat on trol uu Entry — retard throttle g Recovery — start at break vv Entry — nose level h Recovery — full throttle WW Entry — directional control i Recovery — forward stick XX Entry — wings level J k Recovery — wings level Recovery — directional control yy Entry — glide attitude estab- lished 1 Recovery — retard throttle zz Entry — directional control Normal stall, power-off aaa Entry — wings level m Entry — carburetor heat on bbb Entry — stall attitude estab- n Entry — retard throttle lished o Entry — nose level ccc Entry — directional control P Entry — directional control ddd Entry — wings level q Entry — wings level eee Maintaining — stall attitude r Entry — glide attitude estab- fff Maintaining — directional con- lished trol s Entry — directional control ggg Maintaining — wings level t Entry — wings level hhh Recovery — start at horizon u Entry — stall attitude estab- iii Recovery — no throttle lished jjj Recovery — forward stick V Entry — directional control kkk Recovery — directional control w Entry — wings level 111 Recovery — wings level X Maintaining — stall attitude mmm Recovery — add throttle 26 EVALUATION OF THE SCHOOL LINK CODE DESCRIPTION CODE DESCRIPTION EXERCISE 7 — ENTRY INTO Second turn on downwind leg TRAFFIC PATTERN i Look to right and left 7a Flight path 45 degrees to down- J Start at 600 feet ± 50 feet wind leg k Climbing turn b Intersection point correct 1 Attitude control c Altitude held ± 100 feet m Level off at 800 feet + 100 feet d Check for traffic n Throttle and elevator co- e Look to right and left ordination f Path 180 degrees to runway o Directional control g Altitude held ± 100 feet P Carburetor heat on q Opposite spot — establish glide EXERCISE 8 — FLYING IN THE r Throttle and elevator co- TRAFFIC PATTERN ordination After take-off s Directional control 8a Maintain climbing attitude t Glide attitude held b Level off between 400-500 feet u First gliding turn — look to c Throttle and elevator co- right and left ordination V Maintain glide attitude w Establish crab First turn X Clear engine d Look to right and left y Second gliding turn — main- e Level turn ± 100 feet tain glide attitude f Proper crab z Line up with runway g Start climb right after turn h Throttle and elevator co- ordination APPENDIX B This appendix shows the number of trials to reach criterion proficiency required by each subject in each exercise according to Link status and instructor. Subjects are grouped according to instructor assignments. LINK-LINK Instructor A Instructor B Subject No. 1 2 3 4 5 6 7 8 9 10 11 12 Exercise 1 . . . . 1 1 1 2 4 8 8 1 6 1 9 6 5 7 7 7 3. . . . 6 10 13 8 5 2 3 3 2 10 4 1 4 16 8 14 11 6 15 10 12 15 14 10 9 5. . . . 8 7 23 9 6 8 3 8 6 16 14 8 6a. . . 1 2 4 3 3 4 9 1 1 2 2 3 6b. . . 1 3 4 8 1 2 4 1 2 1 2 6c... 2 3 3 5 6 4 7 6 6 4 6 6d. . . 2 7 5 7 2 1 1 1 4 1 2 7. . . . 3 6 4 2 1 3 3 3 2 3 5 3 8. . . . 3 1 1 1 4 3 1 2 3 Instructor C 1 NSTRUCTOR D Subject No. 13 14 15 16 17 18 19 20 21 22 23 24 Exercise 1 . . . . 2 4 2 2 1 2 5 6 2 4 6 6 3 1 2 8 3. . . . 6 11 6 25 15 11 9 3 4 4 12 9 4 28 14 25 29 13 14 11 8 13 6 16 16 5. . . . 7 16 17 7 10 12 9 8 12 14 19 9 6a. . . 4 2 5 2 2 1 1 1 3 6b. . . 4 3 7 2 5 2 1 3 1 6c.... 3 1 1 12 12 4 2 2 4 3 3 6d. . . 12 1 1 6 2 2 1 5 1 7. . . . 3 2 8 5 3 9 2 4 6 1 7 5 8. . . . 1 4 3 7 6 6 4 4 5 2 6 4 27 28 EVALUATION OF THE SCHOOL LINK LINK-AIR Instructor A Instructor B Subject No. 12 3 4 5 6 7 8 9 10 11 12 Exercise 1 . . . . 2 3 4 5. . . . 6a. . . 6b. . . 6c... 6d. . . 7 8 5 6 6 6 6 6 5 4 11 6 8 3 6 8 4 6 10 8 2 4 2 10 1 3 4 15 5 13 13 2 4 5 3 11 2 10 12 19 8 4 11 4 3 2 3 11 3 1 3 2 4 ' 1 4 2 2 2 4 10 10 4 4 5 24 14 4 9 11 7 16 10 4 24 8 3 9 9 9 9 10 4 16 13 5 4 8 10 11 9 1 3 2 12 16 6 7 11 17 13 7 4 13 6 2 6 13 6 4 1 8 2 3 7 2 4 Instructor C Instructor D Subject No. 13 14 15 16 17 18 19 20 21 22 23 24 Exercise 1 . . . . 2 3 4 5. . . . 6a. . . 6b. . . 6c... 6d. . . 1 .... 8 110 2 4 2 10 16 3 14 9 5 6 9 14 14 7 16 13 48 18 2 1 7 14 4 3 6 7 5 12 1 7 3 3 2 14 3 8 6 9 12 24 9 12 12 4 8 10 17 1 112 10 1 110 7 111 5 3 9 2 7 3 3 3 2 1 16 14 2 2 8 6 5 11 7 1 4 7 13 2 3 1 3 2 10 2 2 9 9 7 6 4 3 2 13 2 3 5 15 13 6 THE UNIVERSITY OF ILLINOIS 29 CONTROL-AIR Instructor A Instructor B Subject No. 25 26 27 28 29 30 31 32 33 34 35 36 Exercise 1 . . . . ! 2 1 1 1 2 9 6 6 4 8 9 4 9 8 4 7 8 3. . . . 14 8 8 6 10 8 9 3 5 10 5 13 4 5 4 5 12 4 8 18 3 20 5 5 15 5. . . . 1 4 5 8 6 4 3 6 5 10 4 10 6a. . . 15 6 3 4 8 10 7 3 9 7 7 9 6b. . . 2 5 3 4 2 3 2 5 5 8 6 6c... 22 7 12 13 12 14 23 11 26 17 15 10 6d. . . 7 3 7 2 8 11 2 3 2 7. . . . 1 2 2 1 2 2 2 4 2 3 8. . . . 1 4 3 3 2 4 4 4 7 5 2 2 Instructor C I NSTRUCTOR D Subject No. 37 38 39 40 41 42 43 44 45 46 47 48 Exercise 1 . . . . 1 1 5 1 1 1 1 1 2 5 8 3 8 5 13 1 10 8 4 5 3. .. . 5 14 14 12 10 14 7 10 7 8 2 3 4 8 31 30 18 17 37 4 8 11 10 8 14 5. . . . 5 16 6 12 8 7 8 12 12 15 5 5 6a. . . 13 14 12 16 12 8 5 10 11 7 11 14 6b. . . 13 2 11 3 14 4 5 4 8 1 6 9 6c... 12 16 7 8 11 4 3 20 15 11 8 6 6d.. . 2 3 2 5 6 2 2 1 3 7. . . . 4 4 5 6 3 2 7 4 4 1 5 3 8. . . . 3 9 3 4 4 6 5 6 10 7 8 4 3 0112 005630444 II III "%