101 questions
Correct: C)
Explanation: A blind transmission is used when two-way communication cannot be established, but the pilot has reason to believe the ground station can still receive. This commonly occurs when the aircraft receiver is faulty. The pilot continues transmitting relevant information — such as position and intentions — so the ground unit can at least track the situation and coordinate as needed.
Correct: C)
Explanation: "Roger" means "I have received all of your last transmission" — it is a receipt acknowledgement only, not a commitment to comply. It must not be used where readback of specific instructions is required (such as clearances, headings, or squawk codes). Pilots sometimes confuse "Roger" with "Wilco" (will comply) — the distinction is important for ATC communication integrity.
Correct: D)
Explanation: "Correction" is used mid-transmission when a pilot or controller realizes they have made an error. The word is spoken, then the correct information follows immediately. This prevents the receiving party from acting on faulty data. It is distinct from "Negative" (which corrects a wrong assumption) and avoids the ambiguity of simply restarting a sentence.
Correct: D)
Explanation: "Approved" grants permission for a specific action that the pilot has proposed or requested. For example, a pilot requesting "request backtrack runway 27" may receive "Approved." It is synonymous with "Cleared" in some contexts but specifically responds to a pilot's proposal. "Wilco" is the pilot's response indicating they will comply with an instruction already given.
Correct: D)
Explanation: "How do you read?" is the standard ICAO phrase used to request a readability check from the receiving station. The expected response uses the readability scale from 1 (unreadable) to 5 (perfectly readable), e.g., "I read you five." This phrase is used when the pilot suspects their transmission quality may be poor, such as after changing frequency or noting interference.
Correct: C)
Explanation: "Request" is the standard ICAO phraseology term for when a pilot wishes to obtain a clearance, service, or permission. Colloquial alternatives such as "I want" or "I would like" are not standard phraseology. For example: "Dusseldorf Radar, D-EAZF, request transit controlled airspace." Using standardized vocabulary reduces the risk of misunderstanding, particularly in high-workload or multilingual environments.
Correct: B)
Explanation: "Affirm" is the standard ICAO word for yes. "Affirmative" is common in military communications but "Affirm" is the correct civil aviation standard. The word "Yes" is not part of standard phraseology and should be avoided as it can be misheard. "Roger" means message received, not agreement, and must not be confused with "Affirm."
Correct: D)
Explanation: "Negative" is the standard ICAO phraseology for "no" or "that is not correct." It is unambiguous and internationally understood. The plain word "No" is not standard phraseology and is avoided because it may be misheard or misunderstood across language barriers. "Negative" also serves to correct an incorrect assumption made by the other party.
Correct: B)
Explanation: "Ready for departure" is the standard phrase indicating the aircraft is at the holding point and prepared to take off. Note that the word "take-off" is only ever used in the actual clearance ("Cleared for take-off") or its cancellation ("Cancel take-off clearance") — pilots say "departure" for all other references to avoid premature action on a misheard word. "Ready" alone is incomplete and non-standard.
Correct: B)
Explanation: "Going around" is the standard ICAO phrase used by a pilot to notify ATC that they are discontinuing an approach and initiating a missed approach or go-around. It must be transmitted immediately when the decision is made, before any other communication. ATC will then provide instructions (e.g., runway heading, altitude to maintain). Non-standard alternatives like "no landing" or "approach canceled" are not recognized phraseology.
Correct: C)
Explanation: When experiencing radio reception failure but still able to transmit, the pilot should begin a blind transmission with the phrase "Transmitting blind" (or "Transmitting blind on [frequency]"). This notifies any receiving station of the one-way nature of the transmission. "Listen", "Blind", or "No reception" are not the ICAO-standard prescribed phraseology.
Correct: C)
Explanation: A blind transmission (transmitting without receiving confirmation) is made once on the current frequency (and once more on the emergency frequency if appropriate), not multiple times. Repeating it once ensures the message is heard without causing frequency congestion. Making it four or three times is excessive and not standard ICAO procedure.
Correct: A)
Explanation: A blind transmission (one-way transmission due to reception failure) must be made on the current frequency in use, since that is the frequency being monitored by ATC and nearby traffic. Switching to FIS, tower, or radar frequencies without having been given those frequencies is inappropriate and could cause the transmission to go unheard by the relevant authority.
Correct: B)
Explanation: ICAO recommends a speaking rate of approximately 100 words per minute for radio communications. An excessively high rate reduces intelligibility, especially in degraded radio conditions or for interlocutors whose first language is not English. A steady, moderate rate facilitates understanding and reduces the risk of miscommunication.
Correct: A)
Explanation: ICAO standard phraseology is the norm in aeronautical radiotelephony — it reduces the risk of misunderstandings and ensures mutual understanding in a multilingual environment. Plain language is only permitted for situations that have no corresponding standard phraseology. Exclusively prohibiting plain language is too restrictive, and freely using either approach disregards the safety benefit of standard phraseology.
Correct: C)
Explanation: The read-back of an ATC clearance always ends with the call sign of the aircraft. This allows the controller to confirm unambiguously which aircraft has received and repeated the clearance. Ending with the call sign of the ground station would be a procedural error. "Roger" and "Wilco" may appear in the response but do not replace the final aircraft identification.
Correct: D)
Explanation: Wind information is considered advisory and does not require readback — it is acknowledged with "Roger" or simply absorbed. Items that must be read back include: ATC route clearances, clearances to enter, land on, take off from, cross, or backtrack a runway, runway in use, altimeter settings, SSR codes, level instructions, heading and speed instructions. Wind is not in this safety-critical readback category.
Correct: B)
Explanation: Traffic information (e.g., "traffic at your two o'clock, one thousand feet above") is acknowledged with "Roger" or "Traffic in sight" — it does not require a formal readback. In contrast, altimeter settings, headings, and taxi instructions are all subject to mandatory readback requirements under ICAO procedures, as errors in these items can have direct safety consequences.
Correct: B)
Explanation: The readback must include all safety-critical items: departure instructions (climb straight ahead to 2500 ft, turn right heading 220), runway in use (runway 12), and the take-off clearance. Wind information does not require readback and is correctly omitted. Option A incorrectly reads back the wind, and option C uses "wilco" inappropriately mid-readback. The runway and clearance phrase must be included.
Correct: D)
Explanation: "Wilco" (from "will comply") is the correct response when a pilot understands and intends to comply with an instruction. "Next report PAH" is an instruction requiring future action, so "Wilco" confirms both receipt and intention to comply. "Roger" only confirms receipt without implying compliance. "Positive" is not standard phraseology in this context.
Correct: D)
Explanation: SSR transponder codes (squawk codes) and frequency changes must be read back — they are safety-critical items. The pilot must read back the squawk code (4321) and the new frequency (131.325) to confirm correct receipt. "Roger" alone or "Wilco" alone is insufficient. If the wrong code is set or the wrong frequency dialled, both situations carry serious safety implications.
Correct: B)
Explanation: "You are now entering airspace Delta" is an informational statement from ATC — it describes what is happening, not an instruction requiring future action. "Roger" (I have received your message) is therefore the correct and sufficient response. "Wilco" would imply a future action to comply with, which is inappropriate here. No readback of the airspace type is required for a pure information message.
Correct: B)
Explanation: The items that must always be read back are: runway in use, altimeter settings, SSR codes (transponder), level instructions (altitude/FL), and heading and speed instructions. Surface wind and visibility are advisory information that do not require a read-back. This list corresponds exactly to the ICAO/EASA requirements for VFR operations.
Correct: A)
Explanation: The ICAO phonetic alphabet specifies exact words for each letter. Y is always "Yankee" (not "Yuliett" — that is J), and M is "Mike" (not "Mikro"). H is "Hotel" and B is "Bravo." Using the correct phonetic words is essential to avoid confusion, particularly between letters that sound similar in noisy radio conditions.
Correct: D)
Explanation: O is "Oscar" (not "Omega"), J is "Juliett" (not "Jankee"), and K is "Kilo" (never "Kilogramm"). The ICAO phonetic alphabet uses standardized English-based words chosen for their intelligibility across different languages. Using non-standard alternatives such as "Omega" or "Jankee" can cause confusion and is not permitted in standard radio communications.
Correct: A)
Explanation: The standard ICAO phonetic alphabet: B = Bravo, A = Alpha, F = Foxtrot, O = Oscar. Alternatives such as "Otto", "Anna", "Fox" or "Beta" are non-standard local variants that must not be used in international aeronautical communications.
Correct: B)
Explanation: According to the ICAO phonetic alphabet: N = November, D = Delta, G = Golf, F = Foxtrot. "December", "Gamma", "Norbert", and "Fox" are not part of the standard ICAO alphabet.
Correct: C)
Explanation: When abbreviating a five-character civil aircraft call sign, ICAO standard procedure uses the first character (nationality prefix) plus the last two characters: D-EAZF becomes D-ZF, spoken as "Delta Zulu Foxtrot" or simply "DZF." This abbreviated form may only be used after the ground station has itself used the abbreviation — establishing that both parties have unambiguously identified the aircraft.
Correct: A)
Explanation: The abbreviation rule for five-character civil aircraft call signs retains the first letter (nationality prefix) and the last two characters: AB-CDE becomes A-DE. This rule applies in the same way as for D-EAZF becoming D-ZF. Abbreviation is only permitted after the ground station has used it first.
Correct: C)
Explanation: The pilot may only begin using the abbreviated call sign once the ground station has used it first. This rule ensures that identification is unambiguous — the controller has confirmed which aircraft they are communicating with before the shortened form is adopted. Self-initiated abbreviation can lead to confusion if multiple aircraft with similar endings are on frequency.
Correct: D)
Explanation: At first contact with any ATC unit, the pilot must use the full aircraft call sign (e.g., D-EAZF in full as "Delta Echo Alfa Zulu Foxtrot"). This allows the controller to positively identify the aircraft before any abbreviation is established. Using a partial call sign at first contact risks confusion with other aircraft and is contrary to ICAO standard procedures.
Correct: B)
Explanation: The standard format for initial contact is: station called, then own call sign — "Dusseldorf Tower, Delta Echo Alfa Zulu Foxtrot." The word "Over" is optional at the end of a transmission but not required for initial calls. The format "Tower from D-EAZF" is non-standard and should be avoided. The station is addressed first so they know to listen, then the calling aircraft identifies itself.
Correct: C)
Explanation: The aerodrome control unit — responsible for aircraft on the runway and in the immediate circuit area — uses the call sign suffix "Tower" (e.g., "Dusseldorf Tower"). This distinguishes it from ground movement control ("Ground"), approach control ("Approach" or "Radar"), and area control ("Control"). Glider pilots operating at controlled aerodromes must contact the correct unit using the appropriate call sign.
Correct: C)
Explanation: Surface movement control — responsible for the movement of aircraft and vehicles on the manoeuvring area (taxiways, aprons) other than the runway — uses the call sign suffix "Ground" (e.g., "Frankfurt Ground"). At smaller aerodromes, the tower may handle both functions on a single frequency, but at larger airports these are separated. Pilots should not taxi without clearance from Ground.
Correct: D)
Explanation: FIS units use the call sign suffix "Information" (e.g., "Langen Information" or "Scottish Information"). This service provides traffic information, weather updates, and other advisories to VFR pilots operating outside controlled airspace. Glider pilots frequently use FIS frequencies during cross-country flights and must identify the unit using the correct call sign suffix.
Correct: B)
Explanation: ICAO phraseology for altitudes uses the words "thousand" and "hundred" where applicable. 4500 ft is correctly spoken as "four thousand five hundred." Digit-by-digit recitation (e.g., "four five zero zero") is used for QNH and transponder codes, not for altitudes.
Correct: B)
Explanation: Headings and bearings are always transmitted as three individual digits, each spoken separately: "two eight five." The words "hundred" or "thousand" are not used for headings. This digit-by-digit method prevents any ambiguity — "two eight five" can only mean 285 degrees, whereas "two hundred eighty-five" could theoretically be misheard.
Correct: B)
Explanation: Radio frequencies are transmitted digit by digit with "decimal" for the decimal point, and trailing zeros are dropped. 119.500 MHz is therefore "one one niner decimal five." Note that "niner" is used for 9 to avoid confusion with the German/Dutch "nein" (no). Only significant digits after the decimal are spoken; ".500" reduces to ".5."
Correct: D)
Explanation: Clock position references used to report traffic or terrain are always spoken as a natural number followed by "o'clock": "twelve o'clock" means directly ahead. This is a standard phraseology format used worldwide for traffic advisories. Omitting "o'clock" (saying just "twelve") could be confused with other numerical data, so the full expression is required.
Correct: B)
Explanation: All aeronautical communications use UTC (Coordinated Universal Time), previously known as GMT or Zulu time. This ensures consistency across time zones and eliminates ambiguity in international operations. Pilots must convert local time to UTC when filing flight plans or making ATC reports, and controllers always issue times in UTC.
Correct: B)
Explanation: When transmitting times and there is any risk of ambiguity (e.g., confusion about whether only minutes or the full time is meant), ICAO requires the full four-digit UTC time spoken as individual digits: "one six two zero." This removes any doubt about whether "twenty" refers to 1620 or 0020. Abbreviated times (just minutes) are only acceptable when the hour is clearly established.
Correct: D)
Explanation: The correct format for transmitting a position/heading is: "Heading" followed by three digits (always three, so "045" not "45"), then the altitude in feet when below the transition altitude. Flight level (FL) is only used above the transition altitude. The format "045 degrees and 2500 feet" mixes the degree symbol and conjunction, which are not part of standard phraseology.
Correct: D)
Explanation: The aviation voice communication band from 118.000 to 136.975 MHz falls within the Very High Frequency (VHF) range. VHF provides reliable line-of-sight communication and is the standard for civil aviation. MF (Medium Frequency), LF (Low Frequency), and HF (High Frequency) are lower frequency bands used for different purposes such as NDB navigation or long-range HF communications.
Correct: D)
Explanation: The ICAO readability scale runs from 1 to 5: 1 = Unreadable, 2 = Readable now and then, 3 = Readable but with difficulty, 4 = Readable, 5 = Perfectly readable. A readability of 1 means the receiving station cannot understand the transmission at all. If a pilot receives a readability 1 report, they should consider changing frequency, transmitter power, or antenna position.
Correct: C)
Explanation: Readability 2 means the transmission is only intermittently intelligible — the receiving station catches parts of the message but cannot reliably understand it. This might result from atmospheric interference, weak signal, or excessive background noise. In practice, a pilot reporting readability 2 should attempt to improve transmission quality or relay through another aircraft.
Correct: D)
Explanation: Readability 3 means the transmission is intelligible but requires effort — words may be unclear and the listener must concentrate. This level is often acceptable for short operational messages but is not ideal for complex instructions or clearances. Pilots and controllers should attempt to improve signal quality if readability remains at 3 for extended periods.
Correct: C)
Explanation: Readability 5 is the best possible signal quality — the transmission is perfectly clear and intelligible. When asked "How do you read?" a response of "I read you five" (or "readability five") indicates ideal communication conditions. Glider pilots should aim for readability 4-5 on all ATC frequencies, particularly when receiving critical instructions such as clearances or emergency guidance.
Correct: B)
Explanation: A distress situation — signaled by the phrase MAYDAY (spoken three times) — exists when an aircraft or its occupants face a grave and imminent danger requiring immediate assistance. This is the highest priority category of aeronautical communication. The transponder code 7700 is squawked to alert radar services. Urgency (PAN PAN) is the next level down, involving a serious but not immediately life-threatening condition.
Correct: B)
Explanation: Urgency messages (PAN PAN) concern the safety of an aircraft, vessel, vehicle, or person in sight — situations that are serious but not immediately life-threatening. A distress message (Mayday) concerns aircraft and passengers facing a grave and imminent threat requiring immediate assistance. Spare parts logistics are not urgency message subjects.
Correct: B)
Explanation: Regularity messages relate to the operation and maintenance of facilities necessary for flight operations — essentially administrative and logistical communications. They carry the lowest priority in the ICAO message hierarchy, below distress, urgency, flight safety, meteorological, and NOTAM messages. They should never delay safety-critical transmissions.
Correct: D)
Explanation: An urgency message (lower priority than distress) is preceded by the phrase "Pan Pan" spoken three times. This alerts ATC and other aircraft to a serious but not immediately life-threatening situation. "Mayday" (spoken three times) is used for distress, and "Urgent" or "Help" are not ICAO-standard radiotelephony phrases.
Correct: C)
Explanation: The distress phrase "MAYDAY MAYDAY MAYDAY" or the urgency phrase "PAN PAN PAN PAN PAN PAN" — the key word is repeated three times. This repetition is required by ICAO to ensure that the nature of the message is clearly identified even in poor radio conditions or with partial interference.
Correct: C)
Explanation: The initial distress or urgency call should be made on the frequency currently in use, because that frequency is already monitored by the appropriate ATC unit. Switching to another frequency risks losing contact and wasting time. If there is no response, the pilot may then try the emergency frequency 121.5 MHz.
Correct: A)
Explanation: An urgency message (PAN PAN) should, where possible, contain: the identification and type of aircraft, the nature of the emergency, the intentions of the crew, and the position, level and heading of the aircraft. These elements allow ATC services to provide effective assistance and coordinate the necessary resources.
Correct: B)
Explanation: A complete distress message must contain: aircraft call sign and type, nature of the distress situation, pilot's intentions, position, altitude, and heading. This comprehensive information allows ATC and rescue services to assess the situation and provide appropriate assistance.
Correct: D)
Explanation: The order of priority in the aeronautical mobile service is: 1. Distress messages (MAYDAY), 2. Urgency messages (PAN PAN), 3. Flight safety messages. Meteorological messages (SIGMET, etc.) and then regularity messages follow. This order ensures that life-threatening situations are always addressed first.
Correct: C)
Explanation: A request for QDM (magnetic heading to steer to reach a station) implies the pilot may be uncertain of position or unable to navigate independently — making it a potential urgency or flight safety matter. Among the options listed, it carries the highest priority because it relates to navigation assistance and pilot safety. Wind and QNH information are routine, while "Turn left" is a standard ATC instruction.
Correct: D)
Explanation: ICAO classifies aeronautical messages by priority. Flight safety messages — which include ATC instructions, position reports, and related communications — hold the highest priority after distress and urgency messages. This classification ensures that safety-critical information is never delayed by lower-priority traffic such as administrative or regularity messages.
Correct: C)
Explanation: ATC clearances, instructions, and weather information are messages concerning flight safety. They have high priority in the aeronautical message hierarchy, ranking below distress and urgency messages but above meteorological and regularity messages.
Correct: D)
Explanation: The urgency signal in radiotelephony is PAN PAN (preferably spoken three times). MAYDAY is the distress signal (imminent danger). PAN PAN indicates a less severe emergency requiring timely assistance. URGENCY and ALERFA are not standard radiotelephony signals.
Correct: D)
Explanation: Transponder code 7600 is the internationally standardized squawk code for loss of radio communication (NORDO — no radio). Code 7700 indicates a general emergency, 7500 indicates unlawful interference (hijacking), and 7000 is the standard VFR conspicuity code in many European countries. Squawking 7600 alerts ATC to the communication failure without declaring a full emergency.
Correct: D)
Explanation: Transponder code 7700 is the internationally standardized emergency squawk. It alerts radar controllers to an emergency situation and triggers alarms on ATC displays. Code 7600 indicates radio failure, 7500 indicates hijacking, and 7000 is the standard VFR conspicuity code in European airspace.
Correct: D)
Explanation: Transponder code 7600 is specifically assigned for loss of radio communication (NORDO). Squawking 7600 alerts ATC radar controllers to the situation so they can provide appropriate separation and visual signals. Code 7700 is for emergencies, 7500 for hijacking, and flight into clouds is not a transponder emergency code situation.
Correct: B)
Explanation: The instruction "Squawk 1234" means: set code 1234 on the transponder and activate the appropriate mode (mode C or mode S depending on equipment). It does not relate to radio frequencies or bearings.
Correct: B)
Explanation: "Squawk ident" is the controller's instruction asking the pilot to press the IDENT button on their transponder. This generates a special signal on the radar display that makes the aircraft's symbol blink or stand out, allowing the controller to identify it quickly among surrounding traffic. Identification is confirmed by the controller with "Identified" or "Squawk confirmed."
Correct: C)
Explanation: In VFR flight, radio is mandatory in Class C airspace. Without radio, the previously obtained clearance is insufficient — the pilot must set the transponder to code 7600 (radio failure), leave the controlled airspace as quickly as possible and land at the nearest suitable aerodrome.
Correct: C)
Explanation: ICAO procedures for radio failure in controlled airspace (Class D) require the pilot to continue the flight according to the last ATC clearance received while complying with VFR flight rules, or to leave the airspace by the shortest route. Flying above 5000 feet is not specified; using a "standard routing" without relation to the last clearance is also incorrect.
Correct: D)
Explanation: Entry into Class D airspace without radio contact is only permissible when prior approval has been granted (e.g., when the pilot has already received a clearance to enter and the radio failure occurs while inside or just before entry). Without prior approval, Class D airspace cannot be entered without two-way radio communication.
Correct: D)
Explanation: If an aircraft fails to establish contact, it should try to establish communication with other aircraft or stations that could relay the message. Code 7500 is for hijacking, not radio failure. Landing immediately or proceeding to the alternate are premature actions before exhausting relay options.
Correct: D)
Explanation: ABM is the ICAO-standard abbreviation for "abeam," meaning a position at a right angle to the aircraft's track — i.e., directly to the side. This abbreviation appears in flight plans, ATC communications, and aeronautical charts. It is important to use the standardized form rather than informal alternatives to ensure unambiguous interpretation across language barriers.
Correct: C)
Explanation: VFR stands for Visual Flight Rules, the regulatory framework under which a pilot operates by visual reference to the ground and other aircraft. VMC (Visual Meteorological Conditions) refers to the weather conditions themselves, not the rules. VFR and VMC are related but distinct terms — a pilot files and flies VFR when the weather meets VMC criteria.
Correct: B)
Explanation: OBST is the ICAO-standard abbreviation for obstacle, as defined in ICAO Annex 10 and used in NOTAMs, aeronautical publications, and ATC communications. It appears frequently in aerodrome obstacle data and NOTAM texts. OBS, while intuitively plausible, is reserved for other terms (e.g., observation) in ICAO documentation.
Correct: D)
Explanation: FIS — Flight Information Service — is a service provided by ATC units to give pilots information useful for the safe and efficient conduct of flight, such as weather, NOTAMs, and airspace activity. In many countries, glider pilots operating outside controlled airspace will communicate with an FIS unit (e.g., on a national FIS frequency) rather than a tower or radar controller.
Correct: D)
Explanation: A Flight Information Region (FIR) is a defined volume of airspace within which flight information service and alerting service are provided. Each country or group of countries has one or more FIRs, and they cover all airspace including lower and upper airspace. Glider pilots should know the FIR they are operating in, as this determines which FIS frequency applies.
Correct: D)
Explanation: H24 indicates continuous operation — 24 hours a day, 7 days a week. This designation appears in AIP entries and NOTAMs to describe permanently staffed facilities such as major ATC centres or rescue coordination centres. It contrasts with HX (no specific hours), HJ (sunrise to sunset), and HN (sunset to sunrise).
Correct: D)
Explanation: HX means the facility operates at no specific or predetermined hours — it may be available on request or intermittently. Pilots must verify actual availability via NOTAM or direct contact before relying on such a service. This is distinct from H24 (always open), HJ (daylight only), and HN (night only).
Correct: C)
Explanation: HJ means "from sunrise to sunset" (from French: Heure de Jour). It is the standard ICAO abbreviation used in AIPs and NOTAMs. H24 means continuous service, HN means sunset to sunrise, and HX means no fixed operating hours.
Correct: C)
Explanation: ATIS stands for "Automatic Terminal Information Service". It is the looping recording of meteorological and operational information for an aerodrome, updated every 30 minutes or when conditions change significantly.
Correct: D)
Explanation: AFIS (Aerodrome Flight Information Service) is the flight information service specific to an aerodrome. It provides pilots with information about aerodrome activity (wind, runway in use, known traffic) but is not a control service — AFIS does not issue clearances. It is distinct from FIS (Flight Information Service) which covers a larger region.
Correct: C)
Explanation: UTC (Coordinated Universal Time) is the time standard used in international aviation. Although GMT (Greenwich Mean Time) is historically similar, UTC is the official designation adopted by ICAO. LT (Local Time) and LMT (Local Mean Time) are not used in official aeronautical communications and publications.
Correct: D)
Explanation: An aeronautical station is a ground station of the aeronautical mobile service. It can provide communication services to aircraft in flight. In certain cases it may be located on a ship or offshore platform rather than on land.
Correct: D)
Explanation: QFE is the atmospheric pressure at aerodrome level. When set on the altimeter's subscale, the instrument reads zero when the aircraft is on the ground at that aerodrome. This setting is sometimes used at glider aerodromes so circuit heights are read directly as heights above field. QNH, by contrast, gives altitude above mean sea level.
Correct: D)
Explanation: QNH is the local altimeter setting that, when dialled into the subscale, causes the altimeter to indicate the aircraft's altitude above mean sea level (AMSL). It is the standard setting used for navigation and ATC altitude assignments below the transition altitude. Glider pilots use QNH to ensure terrain clearance and compliance with published airspace limits.
Correct: C)
Explanation: With QFE set, the altimeter reads height above the reference aerodrome — typically showing zero on the ground and the circuit height directly as a height above field. While useful at the home aerodrome, QFE requires care when operating away from base, as the reading no longer relates to sea level or terrain elsewhere.
Correct: C)
Explanation: QNH is the altimeter setting referenced to mean sea level. When set in the altimeter subscale, the instrument reads aerodrome elevation above mean sea level when on the ground. It is distinct from QFE (pressure at aerodrome level, altimeter reads zero on the ground) and QNE (standard 1013.25 hPa, used in flight level airspace).
Correct: C)
Explanation: QFE is the atmospheric pressure at the aerodrome elevation (or runway threshold). With QFE set on the altimeter, the instrument shows height above the aerodrome (zero on the ground).
Correct: C)
Explanation: QDM is the magnetic heading to steer to reach the station (without wind correction). It is distinct from QDR (magnetic bearing from the station) and QTE (true bearing from the station). A request for QDM often indicates that the pilot is trying to orientate — which gives it a potentially urgent character.
Correct: D)
Explanation: QDR means the magnetic bearing from the station to the aircraft (magnetic bearing FROM station). Not to be confused with QDM (magnetic heading TO the station).
Correct: D)
Explanation: In METAR cloud coverage reporting, FEW means 1 to 2 oktas (eighths) of sky covered — a very sparse cloud layer. SCT (Scattered) is 3-4 oktas, BKN (Broken) is 5-7 oktas, and OVC (Overcast) is 8 oktas (full coverage). These standardized ICAO designations are used worldwide in aviation weather reports.
Correct: D)
Explanation: SCT stands for Scattered, representing 3 to 4 oktas (eighths) of sky covered by a cloud layer in a METAR report. FEW is 1-2 oktas, BKN (Broken) is 5-7 oktas, and OVC (Overcast) is 8 oktas. Using these standardized terms ensures unambiguous cloud coverage reporting globally.
Correct: D)
Explanation: BKN stands for Broken, representing 5 to 7 oktas (eighths) of sky covered by a cloud layer in a METAR report. FEW is 1-2 oktas, SCT is 3-4 oktas, and OVC (Overcast) is 8 oktas. A broken layer still means the sky is predominantly covered, which can have significant implications for VFR flights.
Correct: C)
Explanation: An ATIS (Automatic Terminal Information Service) broadcast is updated at 30-minute intervals (or whenever conditions change significantly) and is valid for approximately 30 minutes. Pilots should obtain the latest ATIS before contacting ATC on initial call. 45 or 60 minutes would be too long given how rapidly aerodrome conditions can change.
Correct: D)
Explanation: VOLMET is the continuous radio broadcast service for METARs and TAFs for several aerodromes. It allows pilots in flight to obtain real-time meteorological observations for their destination and alternate aerodromes. SIGMET and AIRMET relate to significant meteorological phenomena over a region, not observations for specific aerodromes.
Correct: C)
Explanation: VOLMET (from the French vol — flight, and meteo — weather) is a radio service that continuously broadcasts meteorological information (current weather reports, METARs) for a series of aerodromes. It provides weather information specifically, not navigational data, NOTAMs, or general bulletins.
Correct: D)
Explanation: In aviation meteorology (METAR), visibility is reported in meters when it is 5 km or less (up to 5000 m in 100 m steps below 800 m, then 100 m steps up to 5000 m). When visibility is greater than 5 km, it is reported in kilometers. This threshold ensures precision at lower visibilities that are operationally critical for flight safety.
Correct: C)
Explanation: In METAR reporting, visibility is reported in kilometers when it is greater than 5 km (e.g., "6KM" or "9999" for 10 km or more). When visibility is 5 km or less, it is expressed in meters for greater precision. This convention is standardized under ICAO Annex 3.
Correct: D)
Explanation: VHF reception quality depends mainly on flight altitude (line-of-sight range) and topographical conditions (terrain between transmitter and receiver). The ionosphere affects HF propagation (sky wave), and the twilight effect and shoreline effect affect NDB/ADF reception, not VHF.
Correct: C)
Explanation: Long waves (LW / LF, Low Frequency) travel the greatest distance because they diffract around the curvature of the Earth. VHF and UHF waves used in aviation for radio communications propagate by line of sight and are therefore limited by the radio horizon distance. Medium waves (MW) have an intermediate range.
Correct: D)
Explanation: Electromagnetic waves (including radio waves and light) propagate at the speed of light, approximately 300,000 km/s (3 x 10^8 m/s) in a vacuum. The other options are incorrect by orders of magnitude — 123,000 m/s is far too slow, and 300,000 m/s or 123,000 km/s are also wrong.
Correct: D)
Explanation: ATC frequencies must not be used for personal requests (taxi). Such a message is inadmissible because it monopolizes a frequency reserved for aeronautical communications and does not meet any criteria for flight safety or regularity.
Correct: B)
Explanation: The international VHF distress frequency is 121.500 MHz. This is the universal guard frequency monitored by ATC and many aircraft. Note that 121.500 KHz would be in the HF band, not VHF — the correct unit is MHz.
