LEAFLET NO

Document Sample
LEAFLET NO Powered By Docstoc
					                              JAA Administrative & Guidance Material
      Section Six: Synthetic Training Devices (STD), Part Three: Temporary Guidance Leaflet


LEAFLET NO. XX:           Guidance on the Qualification of New Technology Visual Systems

1.       Note: The material contained in this Leaflet has been issued in accordance with Chapter 9
         of Administrative & Guidance Material Section Six: Synthetic Training Devices (STD), Part
         Two: Procedures (JAR-STD). The proposed text is being distributed for consideration by
         Authorities in advance of the normal consultation (NPA) process.
         Following the results of the NPA, this material will be incorporated into JAR-STD whereupon
         this Leaflet will be withdrawn. Until that occurs, the material in this Leaflet should be used as
         guidance material.


2.        General

2.1       The current JAR-STD requirements for visual systems, are written against the standards
          achievable with the technologies available over the past 10 years. New Technologies, such as
          Laser based systems and LCoS projection systems are now becoming available and are
          being offered for qualification both on new devices and as retrofit on older simulators. These
          new technologies offer potential for significant overall improvement in the quality of the visual
          system and, therefore, the quality of training provision. Generally, the introduction of such
          systems is to be encouraged. However, there are features associated with the new
          technologies that require careful attention to ensure the current standards are not significantly
          degraded such as to adversely affect the training value of the simulator.

2.2       Initial experience of JAA member Authorities has indicated that the current JAR-STD
          standards for visual systems may not provide adequate objective testing against which the
          new visual systems can be evaluated. This TGL proposes additional objective tests to address
          the identified areas of concern and proposes that such tests should be added to the master
          QTG of the devices concerned.


3.        Proposed Objective Test Criteria for New Technology Visual Systems

3.1       As previously stated the enhanced quality that the new technologies can bring to the
          reproduction of the visual scene compared with the existing CRT based systems is considered
          to be of significant value. For devices being qualified for the first time, the criteria for
          acceptance must be such as to allow no significant reduction in quality of the visual system
          compared with a current JAR-STD 1A, Amendment 3 compliant system. For retrofit on an
          existing pre-Amendment 3 device, where no upgrade or increase in training credit is sought,
          acceptance standards are required to be defined that ensure there are no areas of the visual
          scene reproduction where a significant degradation occurs, that adversely affects the quality
          of training.

3.2      Both new technology visual systems evaluated to date offer a significant improvement in the
         level of detail available in the scene and a significant increase in the level of brightness. These
         improvements can greatly increase the effects of any mirror distortion that is present. For new
         simulators the applicable JAR-STD 1A, Amendment 3, System Geometry Test as defined in
         ACJ to JAR-STD 1A.030, Para 2.3.4.b.(2) provides an adequate standard to ensure that any
         distortion is adequately controlled to ensure no adverse impact on training. For retrofit to pre-
         amendment 3 simulators, no System Geometry test is included in the qualification basis. Such
         a test is necessary to ensure adequate quality of the visual image and the JAR.STD 1A,
         Amendment 3, System Geometry test should be included in the qualification basis of the visual
         system.

      3.2 Light Point Size: Experience has shown that the new technology visual systems can have
          problems meeting the latest JAR-STD standards for light point size. For new simulators the
          JAR-STD 1A, Amendment 3 requirements provide an acceptable and attainable standard.
          However, for retrofit installations the applicable standards may not be adequate to provide an
          acceptable standard. As a minimum compliance with the subjective test defined in ACJ to
          JAR-STD 1A, Amendment 3, Para 3.3.m.(4) should be required.




Section 6/Part 3                                  page xx                                 date16-7-2011
                                 JAA Administrative & Guidance Material
         Section Six: Synthetic Training Devices (STD), Part Three: Temporary Guidance Leaflet


   3.3       Experience has shown that on retrofit installations where an attempt has been made to use an
             existing image generator (IG) with a new technology projection system, the quality of the
             image, particularly texturing can be unrealistic. Careful attention should be paid to this aspect
             if qualification of such a system is sought. A new IG, optimised for the projection system
             technology is recommended.
   3.4       Both Laser and LCoS visual systems offer a significant reduction in weight on the roof of the
             simulator cab. If the existing projectors have not been replaced with equivalent weights, it may
             be necessary, for retrofit installations, to re-optimise the motion system for the significant
             change to the weight and vertical centre of gravity of the device. Appropriate objective tests
             should be required to ensure the motion system is unaffected by any change.


   4.        Laser Visual Systems

         4.1 Speckle Test: Laser visual systems can suffer from a phenomenon known as speckle. This
             can result in very unrealistic textures and shimmering of the picture which can have an
             adverse effect on training. The corrective action to prevent speckle involves multiple, very thin
             coatings on the xxx. These coatings may deteriorate with time and a repeat test for speckle
             should be added to the mQTG for the device.

4.a.11 speckle test             Speckle contrast should       Not applicable   An SOC is required describing the test
                                be <10%                                        method.

                                                                               This test is generally only required for laser
                                                                               projectors. An SOC should be provided if
                                                                               test is not run stating why.



   5.        LCoS Visual Systems

   5.1       Black Level: Due to the different projection system functionality it is not possible to produce
             true black with an LCoS system. The achievable black levels, however, are such that the
             quality of training can be unaffected. In order to ensure a consistent, minimum, standard of
             black level throughout the life of the device an additional objective test should be included in
             the mQTG.

4.a.10 black level and          Black intensity:              Not applicable   The light meter should be mounted in a fixed
    sequential contrast         Background brightness                          position viewing the forward centre area of
                                – Black Polygon                                each display. All projectors should be turned
                                brightness <0.015                              off and the cockpit environment made as
                                Candelas/m2 (0.004ft                           dark as possible. A reading should be taken
                                lamberts)                                      of the remaining ambient light on the screen.
                                Sequential contrast:                           The projectors should then be turned on and
                                Maximum brightness –                           a black polygon displayed, a second reading
                                (Background brightness                         should then be taken and the difference
                                - Black Polygon                                between this and the ambient level
                                brightness) >2000:1                            recorded. A full brightness white polygon
                                                                               should then be measured for the sequential
                                                                               contrast test

                                                                               This test is generally only required for light
                                                                               valve projectors. An SOC should be
                                                                               provided if test is not run, stating why.


   5.2         Motion Blur: LCoS projectors suffer from motion blurring. This is apparent as smearing of the
               visual scene during rapid directional or attitude changes or the high-speed parts of take-offs
               and landings. This can be distracting to the pilot and significantly degrade the quality of
               training. The currently achievable standard using projectors without additional anti-smearing
               features is considered to provide a significant overall improvement compared with older CRT
               based visual systems and provided the minimum standard for, motion blur, defined below is
               achieved, the installation should be accepted.




   Section 6/Part 3                                       page xx                                    date16-7-2011
                                JAA Administrative & Guidance Material
        Section Six: Synthetic Training Devices (STD), Part Three: Temporary Guidance Leaflet


4.a.9 motion blur              When a pattern is             Not applicable   A test pattern consisting of an array of 5
                               rotated about the eye                          peak white squares with black gaps between
                               point at 10 degrees/sec                        them of decreasing width. The range of
                               the smallest detectable                        black gap widths should at least extend
                               gap should be 5 arc min                        above and below the required detectable
                               or less.                                       gap, and be in steps of 1 arc min. The
                                                                              pattern is rotated about the eye point at 10
                                                                              degrees/sec and while the pattern is moving
                                                                              the smallest detectable gap should be 5 arc
                                                                              min or less. Two arrays of squares should
                                                                              be provided, one rotating in heading the
                                                                              other in pitch provide testing in both axes. A
                                                                              series of stationary numbers identifies the
                                                                              gap number.

                                                                              This test is generally only required for light
                                                                              valve projectors. An SOC should be
                                                                              provided if test is not run, stating why.




              For new simulators, it is considered that the overall improvement offered by the LCoS based
              visual systems compared with the quality offered by the current generation of CRT based
              systems is not sufficient to merit acceptance of a relatively high level of motion blur. For new
              simulators, inclusion of anti-smear technology in the projection system should be required.




   Section 6/Part 3                                      page xx                                    date16-7-2011

				
DOCUMENT INFO