High Frequency (HF) Communications
In the HF range (3 MHz to 30 MHz) radio waves propagate over long distances due to reflection from the ionised layers in the upper atmosphere.
Global Navigation Satellite System [GNSS] technology freely provides precise 3D position-fixing capability — latitude, longitude, altitude — and velocity data and has excellent navigation capability when combined with a stored flight plan. Planned improvements in the integrity and availability of GNSS, and implementation of ground-based and satellite-based augmentation systems in Australia, will ultimately make ground-based radio navigation systems (ADF, VOR/DME) redundant. However, as with the ground-based radio navigation systems, pilots operating under the day VFR may use GNSS only to supplement map reading and other visual reference navigation techniques.
For more information concerning the current regulatory use of GNSS in VFR navigation see AIP ENR 1.1 paragraphs 19.2 and 19.5 and AIP GEN 1.5 paragraph 8.5.4. Continue reading
All pilots need to be aware of wake turbulence. Depending on the type of aircraft, the phase of flight, and the weather conditions, the potential effect of an aircraft’s wake turbulence on other aircraft can vary. Encountering wake turbulence can be especially hazardous during the landing and takeoff phases of flight, where the aircraft’s close proximity to the ground makes a recovery from the turbulence-induced problems more difficult.
Geometric Altitude is a computed aircraft altitude designed to help ensure optimal operation of the EGPWS Terrain Awareness and Display functions through all phases of flight and atmospheric conditions. Geometric Altitude uses an improved pressure altitude calculation, GPS Altitude, Radio Altitude, and Terrain and Runway elevation data to reduce or eliminate errors potentially induced in Corrected Barometric Altitude by temperature extremes, non-standard altitude conditions, and altimeter miss-sets. Geometric Altitude also allows continuous EGPWS operations in QFE environments without custom inputs or special operational procedures. Since no single sensor can provide an accurate geometric altitude through all phases of flight and atmospheric conditions, the EGPWS computes an estimated average altitude using Pressure and GPS Altitudes, aircraft position, and the internal runway and terrain databases. This is the Geometric Altitude function.
The continued growth of traffic and the need to provide greater flight efficiency makes it necessary to optimize available airspace. This is being achieved world-wide by enhanced Air Traffic Management and by exploiting technological advancements in the fields of Communication, Navigation and Surveillance.
RNP, RNAV and ANP
Required Navigation Performance (RNP) is a type of performance-based navigation (PBN) that allows an aircraft to fly a specific path between two 3-dimensionally defined points in space. RNAV and RNP systems are fundamentally similar. The key difference between them is the requirement for on-board performance monitoring and alerting. A navigation specification that includes a requirement for on-board navigation performance monitoring and alerting is referred to as an RNP specification. One not having such a requirement is referred to as an RNAV specification.
Future Air Navigation System (FANS) is a concept that was developed by the International Civil Aviation Organization (ICAO) in partnership with Boeing, Airbus, Honeywell and others in the air transport industry to allow more aircraft to safely and efficiently utilize a given volume of airspace.