Retention of Helicopter Flight Skills: Is there a “Critical Period” for Proficiency Loss?

Abstract

This paper presents and discusses data on the proficiency loss of Army helicopter pilots following no-flying periods of one year or longer. On two separate occasions, a group of 24 Army Individual Ready Reserve (IRR) aviators were retrained on each of 37 contact flying tasks in the UH-1 helicopter. The first retraining occurred shortly after the aviators joined the IRR Aviator Training Program. At that time, the aviators had not engaged in active-duty flying for periods ranging from 2 to 12 years; the median duration of the no-flying was 9.3 years. All IRR aviators were retrained a second time--on the same 37 contact flying tasks--one year after completing the first retraining period.The primary dependent variable was aircraft hours required to achieve proficiency on all flying tasks.In addition, each aviator's proficiency on each flying task was rated at the beginning and at the end of each retraining period.The results show that, on the average, the number of flying hours that IRR aviators required to regain proficiency was 16.2 hours for the first training period and 13.8 for the second period.The number of flight hours required to retrain aviators was found to be inversely related to the total number of flying hours an aviator accumulated while on active duty.The ratings on pre training checkrides showed that no aviator was proficient prior to either training period; however, proficiency was rated considerably less at the outset of the first training period than at the outset of the second. When considered together with the results of other recent research on flight proficiency loss, the results of this study suggest that there may be a "critical period" of'no flying during which an operationally important loss of flight proficiency occurs.

Retention of Manual Control Skills in Multi-Axis Tracking Tasks

“…As the aim of the current experiment was to model the decay curve of skill-based human operator control behavior, it was expected that skill decay could be captured by a positively accelerating decay curve, with fairly little skill loss right after training and a higher rate of decay later on (hypothesis 3). Such a decay curve was found in previous experiments with flying tasks comparable to the current tracking task [67,68]. The first RT of each of the groups showed that all groups exhibited significantly degraded tracking performance compared to the end of training in both pitch and roll.…”

“…When comparing the retention results of the three groups, it was hypothesized that skill decay can be captured by a positively accelerating decay curve, meaning that at first, skills are retained fairly well, but at some point start to deteriorate at an increasing rate (hypothesis 3). This skill-decay trend has been found in two flying task experiments [67,68] that are most comparable to the control task used in the current research.…”