AMC8 FSTD(A).300  Engineering simulator validation data – approval guidelines

(a)     Background

(1)     In the case of fully flight test validated simulation models of a new or major derivative aircraft, it is likely that these models will become progressively unrepresentative as the aircraft configuration is revised.

(2)     Traditionally, as the aircraft configuration has been revised, the simulation models have been revised to reflect changes. In the case of aerodynamic, engine, flight control and ground handling models, this revision process normally results in the collection of additional flight test data and the subsequent release of new models and validation data.

(3)     The quality of the prediction of simulation models has advanced to the point where differences between the predicted and the flight test validation models are often quite small.

(4)     Major aircraft manufacturers utilise the same simulation models in their engineering simulations as released to the training community. These simulations vary from physical engineering simulators with and without aircraft hardware to non-real-time workstation-based simulations.

(b)     Approval guidelines – for using engineering simulator validation data

(1)     The current system of requiring flight test data as a reference for validating training simulators should continue.

(2)     When a fully flight test-validated simulation is modified as a result of changes to the simulated aircraft configuration, a qualified aircraft manufacturer may choose, with prior agreement of the competent authority, to supply validation data from an engineering simulator/simulation to selectively supplement flight test data.

(3)     In cases where data from an engineering simulator is used, the engineering simulation process should be audited by the competent authority.

(4)     In all cases a data package verified to current standards against flight testing should be developed for the aircraft entry-into-service configuration of the baseline aircraft.

(5)     Where engineering simulator data is used as part of a qualification test guide (QTG), an essential match is expected as described in Appendix 1 to CS FSTD(A).300.

(6)     In cases where the use of engineering simulator data is envisaged, a complete proposal should be presented to the appropriate regulatory body(ies). Such a proposal should contain evidence of the aircraft manufacturer’s past achievements in high fidelity modelling.

(7)     The process should be applicable to one step away from a fully flight-validated simulation.

(8)     A configuration management process should be maintained, including an audit trail which clearly defines the simulation model changes step by step away from a fully flight-validated simulation, so that it would be possible to remove the changes and return to the baseline (flight validated) version.

(9)     The competent authorities should conduct technical reviews of the proposed plan and the subsequent validation data to establish acceptability of the proposal.

(10)    The procedure should be considered complete when an approval statement is issued. This statement should identify acceptable validation data sources.

(11)    To be admissible as an alternative source of validation data an engineering simulator should:

(i)      have to exist as a physical entity, complete with a flight deck representative of the affected class of aircraft, with controls sufficient for manual flight;

(ii)     have a visual system and preferably also a motion system;

(iii)     where appropriate, have actual avionics boxes interchangeable with the equivalent software simulations, to support validation of released software;

(iv)     have a rigorous configuration control system covering hardware and software; and

(v)      have been found to be a high fidelity representation of the aircraft by the pilots of the manufacturers, operators and the competent authority.

(12)    The precise procedure followed to gain acceptance of engineering simulator data will vary from case-to-case between aircraft manufacturers and type of change. Irrespective of the solution proposed, engineering simulations/simulators should conform to the following criteria:

(i)      the original (baseline) simulation models should have been fully flight test validated;

(ii)     the models as released by the aircraft manufacturer to the industry for use in training FSTDs should be essentially identical to those used by the aircraft manufacturer in their engineering simulations/simulators; and

(iii)     these engineering simulation/simulators should have been used as part of the aircraft design, development and certification process.

(13)    Training FSTDs utilising these baseline simulation models should be currently qualified to at least internationally recognised standards such as contained in the ICAO Document 9625 Manual of Criteria for the Qualification of Flight Simulators (1995 or as amended).

(14)    The type of modifications covered by this alternative procedure will be restricted to those with well-understood effects:

(i)      software (e.g., flight control computer, autopilot, etc.);

(ii)     simple (in aerodynamic terms) geometric revisions (e.g., body length);

(iii)     engines – limited to non-propeller-driven aircraft;

(iv)     control system gearing/rigging/deflection limits; and

(v)      brake, tyre and steering revisions.

(15)    The manufacturer who wishes to take advantage of this alternative procedure, is expected to demonstrate a sound engineering basis for his/her proposed approach. Such analysis should show that the predicted effects of the change(s) were incremental in nature and both easily understood and well defined, confirming that additional flight test data were not required. In the event that the predicted effects are not deemed to be sufficiently accurate, it might be necessary to collect a limited set of flight test data to validate the predicted increments.

(16)    Any applications for this procedure should be reviewed by the Agency.