Loss of control resulting from unsuccessful upset recovery during flight remains a significant safety issue in civil aviation. There is a clear need for improved training of such situations which has been voiced by several stakeholders including regulators such as the Federal Aviation Authorities (FAA).
An aircraft upset can be defined as an airplane that unintentionally exceeds the parameters normally experienced in line operations. This may concern unusual attitudes (large pitch or bank attitudes), and also inappropriate airspeeds which may result in stall. It is important to train pilots to adopt alternate control strategies to sustain or regain controlled flight.
Exercising upset conditions with large commercial aircraft is unsafe, prohibitively expensive and, if performed in smaller aircraft, may not be representative of large transport aircraft. Therefore, ground-based simulation of these extreme conditions might be the only viable option for effective and cost-efficient pilot instruction. To do this effectively in a flight simulator, the simulator should realistically reflect the aircraft behaviour in upset conditions.
Current flight simulator technology is incapable of reproducing upset conditions, and aviation professionals are conservative in advocating the use of simulators for upset recovery training because the risk of negative transfer-of-training. The objective of the SUPRA project was to develop simulator technologies that allow for better upset recovery training.
The SUPRA project investigated the simulator requirements necessary for upset recovery training. To this end, basic mathematical aircraft models were extended to cover out-of-the-envelope behaviour. The models currently used in commercial flight simulation are typically validated within the normal envelope only, and will have to be extended as part of the project.
In addition, research in SUPRA also concerned simulator motion cueing required to support effective training of upset recovery manoeuvres. The motion cueing developments will be supported by experiments on pilot's motion perception in conditions similar to aircraft upset.
The project will result in guidelines on simulator requirements (aerodynamic modelling and motion cueing), presented at an international workshop.
Project SUPRA successfully extended a generic aerodynamic model to capture the key aerodynamic behaviour of transport category aircraft at high incidence flight. The enhancement of the aerodynamic model, combined with modifications to the motion cueing on both hexapod- and centrifuge-type simulators provide a state-of-the-art platform for upset recovery training. Based on the judgements of highly experienced test pilots it was shown that current hexapod motion can be improved without introducing new unacceptable false cues, so as to provide realistic feedback about the lateral and directional dynamics occurring at the initial part of the upset and stall entry.
The S&T activities within SUPRA produced innovative knowledge and introduced new concepts in the following five areas:
- Upset scenarios
- Aerodynamic modelling
- Motion cueing
- Motion perception
- Pilot evaluation
- An efficient and integrated mobility system
- Secure Transport
- Acting on transport safety: saving thousands of lives