SAFA Skysailor Magazine

35 March | April 2022 SKY SAILOR aerodromes. I use RocketRoute’s Aero Metar from the Google Play store. After exhausting other avenues of acquiring the forecast Area QNH, a method that should satisfy altimetry within the tolerances of the Area QNH Zone you are operating in is to set the altimeter to the known take-off elevation AMSL prior to flight, whilst you are standing on launch. Note that while this is not a BOM deriv- ed setting or approved method for setting your altimeter, it can get you out of trouble if other attempts to acquire a forecast Area QNH fail. If every aircraft in the area is using a current Area QNH setting and yours is not current, or you are using a GPS-derived altitude, then you could mistakenly enter airspace due to an incorrect altitude reading. An even more potentially disastrous outcome would be possible conflict with other airspace users. SAFA member and retired Qantas pilot, Tony Renshaw explains: “In the case of shared airspace accurate altimetry will mean amongst other things that circuit patterns are flown with standard vertical separations from other faster aircraft, minimum 500ft. As we proceed towards a CTAF boundary the altitude being the height above MSL we report from the ‘corrected’ altimeter ensures other aircraft know where in the sky to look for us, or what other altitudes they might choose to fly if a conflict exists. It also allows us to fly away from those known altitudes normally flown by light aircraft, normally 500ft off whole altitudes, such as 1500ft and 3500ft for eastward tracks, 2500ft and 4500ft for westbound tracks. Below 3000ft AMSL VFR aircraft should comply with standard altitudes for cruising but can fly at any level, although typically will fly at 500ft increments. With this knowledge of the hemispherical levels that light aircraft fly we can conservatively choose to fly at altitudes away from these, to reduce our likelihood of collision.” This also becomes an issue where we are flying in Class G, under the overlying-con- trolled airspace. Your altimeter must be properly calibrated so as to avoid an airspace incursion. And just on that it needs to be stressed that we PG and HG pilots cannot fly inside or through controlled airspace (CTA) without a special instrument in place or if you hold the necessary authorisations and meet the requirements as laid out in CAO 95.8 10.2. In effect, Class E and G only. My advice is to thoroughly read your instruments owner’s manual to find out how to change your QNH values, or your altitude to the elevation on launch, if that is known. In summary At present under CAO 95.8: • • PG & HG pilots can now fly up to 12500ft amsl without the carriage and use of oxygen. • • You must carry a serviceable altimeter/vario for flights above 300ft agl, and have it set to pressure altitude (calibrated to area QNH or a known elevation) • • You must carry and use an airband VHF radio for flights at altitudes in excess of 5000ft amsl and the greater of 3000ft amsl in VMC or 1000ft agl • • The new CAOs are interim or temporary until the making of the CASR Part 103 MOS. Fly safe. References and hyperlinks: CASR Part 91 – Legislation CASR Part 91 – MOS CASR Part 91 – Plain English Guide CASA Visual Flight Rules Guide