This experiment was designed to examine aspects of human visual perception during approaches to a runway. The runway width illusion has commonly been reported to contribute to the dangerous tendency of pilots to fly low approaches to runways that are wide and high approaches to runways that are narrow. Attempts to prevent the runway width illusion have not attempted to identify the ideal location for an indicator of altitude. Thus the present experiment examined the effect of varying runway width and manipulated scenes in order to determine whether the runway width illusion was present and where participants were focusing their attention in the scenes. Thirty-two non-pilot participants and 3 pilots took part in the experiment and viewed static and dynamic scenes of runways that were narrow (30.48m), medium (60.96m) or wide (91.44m) at one of three viewing heights low (30.48m), medium (45.72m) or high (60.96m). After viewing scenes, participants were required to estimate their altitude and aim-point. The results of this experiment revealed that participants were fairly inaccurate at estimating altitude and were inclined to overestimate aim-point, however the data also indicated that there was a robust runway width illusion that was present across static and dynamic trials and in both altitude and aim-point data. The standard marking on the runway in an attempt to prevent the runway width illusion was not effective at preventing incorrect altitude estimations but did assist participants to estimate aim-point. It was also found that the objects that participants' most commonly reported using to estimate altitude in the visual scene were located in the lower segment of the scenes.

Aluminium har flera fördelar inom konstruktion och produktframtagning. Aimpoint AB har resonerat för kostnad samt viktreducering i sikteshuset Micro T-2. Syftet med rapporten var att undersöka möjligheterna att implementera polymera material som tillfredsställer framlagd kravspecifikation för Aimpoint AB. Målet med arbetet var att identifiera lämpligt material i form av polymer, med lämplig tillverkningsmetod som kan appliceras för sikteshuset utan att påverka de mekaniska egenskaperna negativt.  Lämpliga material som identifierades under litteraturstudien i arbetet var termoplasterna polyfenylensulfid (PPS) och polyetereterketon (PEEK) med implementerat kolfiber. Valet av polymerbaserade material utgjorde ett mindre omfång av lämpliga tillverkningsmetoder, som med hjälp av leverantörer och kostnadskalkylscenarier i Excel jämfördes.  Med hjälp av tredimensionella verktyg utfördes FEM-analyser i ABAQUS CAE® av det exemplifierade sikteshuset. Baserat på simuleringarna i ABAQUS CAE®, presenterar arbetet en jämförelse mellan befintligt sikteshus av Al6082-T6 och sikteshus av polymera material med implementerad förstärkning för modellen Micro T-2. Simuleringarna konstaterade deformation vid det dynamiska explicita fallet mot en konstruerad laminatskiva enligt standarden MIL-STD-810G.  För att bekräfta material och tillverkningsmetod krävs vidare undersökning. Detta för att med säkerhet besvara arbetets frågeställningar då FEM - analyser är en approximativ lösning. / SvenskaAluminum has several advantages in construction and product development. Aimpoint AB requires to reduce both the costs and the weight of their aluminum reflex sight of model Micro T-2.   The aim with the report was to investigate the possibility to implement polymeric materials as a substitute to aluminum that fulfills the requirements specification set by the manufacturer Aimpoint AB.   In addition to that, the aim was also to find suitable polymeric materials with an alternative production technique that is applicable for the reflex sight without compromising the mechanical integrity.  Suitable materials identified during the literature part of this report were two types of thermoplastic materials, polyphenylene sulfide (PPS) and polyetheretherketone (PEEK), both with addition of carbon fiber. The selection process of the polymeric materials was based on several factors and together with contractors, different cost estimation scenarios were compared in Excel. By help from three dimensional tools, FEM-analysis of the sight were performed in ABAQUS CAE®. Based on the results from the simulations performed in ABAQUS CAE®, the report presents a comparison between the original aluminum sight with the two types of carbon fiber reinforced thermoplastic sights. During the dynamic explicit case the simulation was performed as a drop test against a laminate board according to standard MIL-STD-810G. The results of the simulation presented a deformation of the tested sight. To confirm the material and manufacturing method, further investigation is required. This is necessary to address the questions posed in the current project since the FEM - analysis is an approximate solution. / <p>2023-06-28</p>