AMC2 FSTD(H).300  Guidance on design and qualification of level ‘A’ helicopter full flight simulators (FFSs)

Decision 2012/011/R

(a)     Background

(1)     When determining the cost effectiveness of any FSTD many factors should be taken into account such as:

(i)      environmental

(ii)     safety

(iii)     accuracy

(iv)     repeatability

(v)      quality and depth of training

(vi)     weather and crowded airspace

(2)     The requirements as laid down by the various regulatory bodies for the lowest level of FFS do not appear to have been promoting the anticipated interest in the acquisition of lower cost FFS for the smaller helicopter used by the general aviation community.

(3)     The significant cost drivers associated with the production of any FSTD are:

(i)      type-specific data package

(ii)     QTG flight fest data

(iii)     motion system

(iv)     visual system

(v)      flight controls

(vi)     aircraft parts

Note: To attempt to reduce the cost of ownership of a level A FFS, each element has been examined in turn and with a view to relaxing the requirements where possible whilst recognising the training, checking and testing credits allowed on such a device.

(b)     Data package

(1)     The cost of collecting specific flight test data sufficient to provide a complete model of the aerodynamics, engines and flight controls can be significant. In the absence of type‑-specific data packages the use of a class specific data package that could be tailored to represent a specific type of helicopter is acceptable. This may enable a well-engineered baseline data package to be carefully tuned to adequately represent any one of a range of similar helicopters. Such work including justification and the rationale for the changes would have to be carefully documented and made available for consideration by the Agency as part of the qualification process. Note that for this lower level of FFS, the use of generic ground handling and generic ground effect models is allowed.

(2)     However, specific flight test data to meet the needs of each relevant test within the QTG should be required. Recognising the cost of gathering such data, the following points should be borne in mind:

(i)      For this class of FFS, much of the flight test information could be gathered by simple means e.g. stopwatch, pencil and paper or video. However, comprehensive details of test methods and initial conditions should be presented.

(ii)     A number of tests within the QTG have had their tolerances reduced to “correct trend and magnitude” (CT&M) thereby avoiding the need for specific flight test data.

(iii)     The use of CT&M is not to be taken as an indication that certain areas of simulation can be ignored. Indeed, in the class of helicopter FSTD envisaged, that might take advantage of level A, it is imperative that the specific characteristics are present, and incorrect effects would be unacceptable (e.g. if the helicopter has a weak positive spiral stability, it would not be acceptable for the FFS to exhibit neutral or negative spiral stability).

(iv)     Where CT&M is used, it is strongly recommended that an automatic recording system be used to “footprint” the baseline results thereby avoiding the effects of possible divergent subjective opinions on recurrent evaluations.

(c)      Motion

(1)     For level A FFS, the requirements for both the primary cueing and buffet simulation have not been specified in detail. Traditionally, for primary cueing, emphasis has been laid on the numbers of axes available on the motion system. For this level of FFS, it is felt appropriate that the FFS manufacturer should be allowed to decide on the complexity of the motion system. However, during the evaluation, the motion system should be assessed subjectively to ensure that it supports the piloting task, including engine failures, and never provides negative cueing.

(2)     Buffet simulation is important to add realism to the overall simulation; for level A, the effects can be simple but they should be appropriate, in harmony with the sound cues and never provide negative training.

(d)     Visual

(1)     Other than field of view (FOV) technical criteria for the visual systems are not specified. The emergence of lower cost ‘raster only’ day light systems is recognised. The adequacy of the performance of the visual system should be determined by its ability to support the flying tasks. e.g. “visual cueing sufficient to support changes in approach path by using runway perspective”.

(2)     A single channel direct viewing system would be acceptable for this level of FFS.

(3)     The vertical field of view FOV specified (30°) may be insufficient for certain tasks. Some smaller helicopters have large downward viewing angles which cannot be accommodated by the ±15° vertical FOV. This can lead to two limitations:

(i)      at the CAT 1 decision height, the appropriate visual ground segment may not be “seen”; and

(ii)     during an approach, where the helicopter goes below the ideal approach path, during the subsequent pitch up to recover, adequate visual reference to make a landing on the runway may be lost.

(e)     Flight controls

The specific requirements for flight controls remain unchanged. Because the handling qualities of smaller helicopters are inextricably intertwined with their flight controls, there is little scope for relaxation of the tests and tolerances. It could be argued that with reversible control systems that the “on ground” static sweep should in fact be replaced by more representative “in air” testing. It is hoped that lower cost control loading systems would be adequate to fulfil the needs of this level of simulation (i.e. electric).

(f)      Aircraft parts

As with any level of FSTD, the components used within the cockpit area need not be helicopter parts. However, any parts used should be robust enough to endure the training tasks. Moreover, the level A FFS is type-specific, thus all relevant switches, instruments, controls etc. within the simulated area will be required to look, feel and have the same functionality as in the helicopter.