Aerospace Sciences

Training pilots to avoid, react to stalls

The Modeling and Simulation Technical Committee focuses on simulation of atmospheric and spaceflight conditions to train crews and support design and development of aerospace systems.

This is the view of a possible go-around condition in a 747-400 simulator study. Credit: NASA

The commercial transport airplane community will soon comply with a requirement to train all of its pilots on upset prevention and recovery. In the U.S., this requires training airline pilots to prevent full aerodynamic stalls or, if not prevented, to recover from such a stall. All of this training will be performed in a flight simulator. Aircraft manufacturers and engineering consulting firms are developing improved aerodynamic models to enable the stall and upset training, and as of September, the FAA had approved approximately 40 upgraded flight simulators to meet the training requirements.

In September, the University of Toronto, with subcontractor Bombardier, completed a transfer-of-training simulation study in Toronto on a turboprop aircraft model. The study examined how upgraded stall aerodynamics — developed using a combination of engineering judgment, certification flight test data and existing static wind-tunnel data — might influence stall training.

Several high-fidelity simulators are being used to examine possible simplified criteria for commercial transport go-arounds. While criteria currently exist for stabilized approaches, a Flight Safety Foundation study originally published in 2012 showed that crews conduct a go-around only about 3 percent of the time these criteria are exceeded. Fewer, but key, criteria were to be examined in Oklahoma City in October with the decision altitude being lowered to hopefully reflect actual decision-making by today’s crews.

A final study on objective flight simulator motion cueing criteria was completed in February on the NASA Ames Vertical Motion Simulator at Moffett Field near Palo Alto, California. New simulators in the U.S. must now objectively measure their motion responses using the Objective Motion Cueing Test, first published in 2009 by the International Civil Aviation Organization. To date, while solid measurement techniques are being used, consensus criteria to assess the measurements are lacking. Results from this final study will propose criteria.

In June, flight simulation experts gathered at the Royal Aeronautical Society in London and agreed on a list of seven flight simulator problems that need further attention. These are: better aligning simulator qualification procedures with training objectives; reducing flight test hours significantly via simulation; creating consensus objective motion standards; developing a cost-effective and widely accessible rotorcraft simulator; finding good objective measures for training effectiveness; seamless sharing of scenarios across simulator environments; and making simulated turbulence feel more like real aircraft turbulence.

Throughout 2017, model-based development and model-based system engineering industry trends continued. These concepts are slowly gaining acceptance as a way to reduce aerospace product development costs by enabling early requirements validation and systems integration long before any real hardware is built. These models are also being used as single-source-of-truth models to enable lossless knowledge transfer across engineering domains and lifecycle phases.

At Moffett Field in June, NASA developed the basic framework for simulations to evaluate technologies for integrating unmanned aircraft into the national airspace. The goal is to develop a relevant test environment for validating human systems integration guidelines, sense and avoid, and command and control standards.

In military applications, at the Society of Experimental Test Pilots Annual Symposium in September, the U.S. Navy made a presentation on its use of a Calspan Learjet in-flight simulator at Niagara Falls Airport in New York to test the feasibility of a landing signal officer on the ground remotely piloting the landing of an unmanned aerial vehicle with degraded automatic landing system or of piloted vehicles with fatigued pilots or rough seas. The concept was favorably demonstrated nearly to touchdown with just under 100 passes over eight flights.

Training pilots to avoid, react to stalls