Demo: PPL/A

The correct answer is: When no radio communication can be established with the appropriate aeronautical station, but there is evidence that transmissions are received. This is called a blind transmission. The other options describe different radio situations, not blind transmissions.

Leaving a control frequency must be approved so that air traffic control knows the pilot is no longer reachable. Simply reporting or not reporting is not enough. Double approval is not required.

The correct abbreviation for Visual Flight Rules is VFR. VMC means Visual Meteorological Conditions, VRU and VFS are not recognized aviation abbreviations. Only VFR refers to the rules for flying by visual reference.

'OBST' is the correct abbreviation for 'obstacle'. 'OBS', 'OST', and 'OBTC' are not official abbreviations for this term in aviation. Only 'OBST' is used in charts and documents.

The correct answer is 'Flight Information Service' because FIS refers to this service, which provides pilots with important information during flight. The other options mention flashing or systems that do not exist in aviation.

The correct answer is 'Flight Information Region' because FIR refers to a defined airspace for flight information services. The other options do not relate to airspace or flight information and are incorrect.

'H24' stands for 24 h service, meaning continuous operation day and night. The other answers are incorrect because they refer only to certain times of day or unspecified hours, which does not match the meaning of H24.

'HX' means there are no specific opening hours. The other options refer to fixed time periods or continuous 24 h service, which is not correct here.

QFE is the air pressure at the airfield. Setting the altimeter to QFE makes it read zero on the ground. QNH shows altitude above sea level, QNE is standard pressure, QTE is not used. Only QFE gives zero on the ground.

With QFE set, the altimeter shows altitude above the airfield, i.e., in relation to the air pressure at the reference airfield. The other options are incorrect as they refer to standard pressure, sea level, or terrain, which do not apply to QFE.

QTE means the true bearing from the station, which is the angle from true north to the line from the station to the aircraft. The other options are incorrect as they refer to magnetic bearings or the direction to the station.

QTE is the Q-code for the true bearing from the station. QDM is the magnetic course to the station, QDR is the magnetic bearing from the station, and QUJ is not relevant. Only QTE refers to the true bearing from the station.

'QUJ' is correct because it stands for the true bearing to the station. 'QDM' is the magnetic heading to the station, 'QDR' is the true bearing from the station, and 'QTE' is the true bearing from a point away from the station.

A flight safety message is used for air traffic control because it contains safety-relevant information. Messages related to direction finding, flight regularity, and meteorological messages serve other purposes and are not specifically for air traffic control.

Correct: Distress messages concern aircraft and their passengers facing grave and imminent danger needing immediate help. The other options refer to general safety, operational, or maintenance messages, not emergencies requiring urgent assistance.

Correct: Urgency messages concern the safety of an aircraft, watercraft, other vehicle, or person. They are not limited to grave and imminent danger or immediate assistance. The other options describe distress messages or other types of information.

'Request QDM' has the highest priority because it asks for a position line to the station, which is crucial for flight safety. The other messages are instructions or information, but not as urgent for safety.

'Hotel Bravo Yankee Kilo Mike' is correct because it uses the official ICAO phonetic alphabet. 'Home' and 'Mikro' are incorrect, and 'Yuliett' should be 'Yankee'. Only 'Hotel Bravo Yankee Kilo Mike' follows the international standard.

'Oscar Echo Juliett Victor Kilo' is correct because these are the ICAO phonetic alphabet words for O, E, J, V, and K. 'Omega' and 'Kilogramm' are incorrect, and 'Jankee' should be 'Juliett'. Only the second option uses all terms correctly.

The correct answer is 'four thousand five hundred' because altitudes are transmitted as whole numbers. 'Four five zero zero' and 'four thousand five zero zero' are incorrect, as they do not follow standard phraseology. 'Four five thousand' is also wrong.

The correct way is 'two eight five', as each digit is spoken separately in radio communication. 'Two hundred eight five' and 'two hundred eighty-five' are wrong because they combine digits. 'Two eight five hundred' is incorrect as it changes the number.

The correct way is 'one one niner decimal five.' In aviation, only the required digits and one decimal are used. Extra zeros or 'thousand' are not spoken, as they may cause confusion.

'Twelve o'clock' is correct because in radio communication, directions are given using the full hour. 'One two o'clock', 'one two', and 'one two hundred' are not standard phraseology for directions.

Times are always transmitted as UTC in radio communication to avoid confusion worldwide. Local time, standard time, and time-zone time vary by location and can cause misunderstandings.

'One six two zero' is correct because each digit is spoken separately to avoid confusion. 'Sixteen twenty' and 'one thousand six hundred two zero' do not follow radio communication standards. 'Two zero' is incomplete.