The CASA examinations are delivered electronically by a system called Cyber Exams.The computer system controls the time allowed to complete the COPB Exam, marks the answers and issues the results. The exam supervisors have little knowledge of the exam questions or subject matter. There is no point asking the supervisor any questions about any exam […]

Airflow over a ridge or mountain range may set up an undulating flow downstream provided certain preconditions are met. This undulating flow is called mountain waves and can be the source of strong turbulence, rotors and high vertical wind speeds. Mountain wave activity is often evidenced by lenticular clouds. For mountain waves to form the […]

Flight through or near thunderstorms should be avoided! For thunderstorms to be created there needs to be: Unstable or conditionally stable air through a considerable depth of the atmosphere; A lifting mechanism to trigger the instability, this could be provided by a front, high terrain, heating from below or convergence of air in a low […]

Sea breezes are winds that are caused by the differential heating rates of land and sea. During the day the land heats up more rapidly than the sea because: land has a lower specific heat than water – it requires less heat to raise the temperature of 1 kilogram of earth by 1 degree than […]

In the troposhere temperature tends to decrease as height increases. In the theoretical International Standard Atmosphere the temperature decrease or ‘lapse rate’ is defined as 1.98oC per 1000 feet gain in altitude. Like most things theoretical this doesn’t always happen in practice. Almost always at some level in the troposhere the temperature will increase with […]

Fog is defined as a concentrated suspension of very small water droplets causing the ground level visibility of less than 1000 meters. Fog is cloud which forms at ground level. When more than 10 nautical miles from an aerodrome with a published instrument approach balloons are permitted to operate with visibility down to 100 metres […]