SAFA Skysailor Magazine

SKY SAILOR 29 July | August 2020 background.” Aircraft paint schemes, including fluoro painted aircraft, have been shown not to improve the visual tracking of aircraft against a light background. Lack of relative motion on collision course “The human visual system is particularly attuned to detecting movement, but is less effective at detecting stationary objects. Unfortunately, because of the geometry of collision flight paths an aircraft on a collision course will usually appear to be a stationary object in the pilot’s visual field”. Anti-collision lighting Although anti-collision strobes mounted on an aircraft can be useful in low light conditions, in daylight they are not effective. To be effective in daylight, the strobe must produce a brightness of around 100,000 candelas. Evasive action Time required to recognise a threat and take evasive action FAA advisory circular 90-48-C advises that the time it takes a pilot to recognise an approaching aircraft as a collision threat and execute an evasive manoeuvre is 12.5 seconds So assuming a paraglider was thermalling (effective speed of Zero) and a GA aircraft travel- ling at 100kt was on a collision course with the paraglider, the GA aircraft would travel 642m in the 12.5 seconds that it would take for either pilot to react –if the aircraft was a light twin engine with a typical cruising speed of 150kt, the aircraft would be 1000m away at the 12.5 second mark. You can understand now why there is a 1500m horizontal separation from cloud defined in VMC conditions – if a light twin exited cloud on a colli- sion course, you just have enough time to perform an evasive manoeuvre. Think back to the earlier information about how a proper visual scan takes 54 seconds, yet there are only 12 .5 seconds available for a pilot to rec- ognise a collision situation and perform an evasive manoeuvre! Alerted See-and-Avoid A pilot performing a visual scan where traffic in- formation has been provided, i.e. knowing where to look, greatly enhances the chance of sighting traffic. Research found that alerted See-and-Avoid was eight times more effective than unalerted See-and-Avoid. A traffic alert from listening to the VHF area/CTAF frequency provides a similar result. VHF and SAFA SAFA aircraft have gone from skimming sand dunes in the ’70s to flights that cover distances over 100, 200 and 300km and up to 10,000ft. We share this airspace with many different types of aircraft, and because we are in the same airspace as general aviation aircraft that usually travel at 100kt plus, we must play our part in Alerted See-and-Avoid. This is why we have embedded the VHF rating in the qualifications and endorsements that allow cross-country flight – because only then can SAFA aircraft play their part in Alerted See-and-Avoid . It is also why any aircraft flying in a CAR 166 non-controlled aerodrome area must carry and use an airband radio. These aerodromes have a high traffic density where the possibility of a conflict is increased. We already have AIRS reports of near misses where conflicts between SAFA aircraft and GA air- craft have occurred – luckily these were near miss incidents only, so far. I urge that if you are flying in airspace that is shared with other types of aircraft you use VHF radio for position reports and keep a listening watch to reduce the possibility of a collision. References: [www.atsb.gov.au/media/4050593/see_and_ avoid_report_print.pdf ] [www.atsb.gov.au/media/4117372/AR-2008- 044(1).pdf ] [www.faa.gov/documentLibrary/media/Ad- visory_Circular/AC_90-48D_CHG_1.pdf ] Human Factors Air (the environment) - Man (I’m safe) - Ship (the aircraft) I’M SAFE I llness? Do I have an illness or any symptoms of an illness or disorder? M edication and other drugs? Have I been taking or mixing prescription, over-the-counter or recreational drugs? S tress? Am I under psychological pressure from my job or personal circumstances? Am I worried about financial matters, health problems or family matter? A lcohol? Have I been consuming alcohol within the previous eight hours? Is my blood alcohol level less than 0.02? Would my average alcohol consumption be greater than ‘very low risk’? F atigue? Am I tired or inadequately rested? E ating and Drinking? Am I adequately nourished and hydrated? Alerted See-and-Avoid is eight times more effective than unalerted See-and-Avoid.