# Flight Performance and Planning --- ### Q1: Exceeding the maximum allowed aircraft mass is… ^t30q1 - A) Not allowable and essentially dangerous - B) Exceptionally allowable to avoid delays - C) Compensated by the pilot's control inputs. - D) Only relevant if the excess is more than 10 %. **Correct: A)** > **Explanation:** The maximum takeoff mass (MTOM) is a hard certification limit determined by the manufacturer based on structural strength, stall speed, and climb performance. Exceeding it increases wing loading, raises the stall speed, degrades climb performance, and may overstress the airframe beyond its certified load factors. B is wrong because no operational convenience justifies exceeding a safety limit. C is wrong because no pilot technique can compensate for structural overloading. D is wrong because there is no regulatory tolerance — any exceedance is prohibited. ### Q2: The center of gravity has to be located… ^t30q2 - A) Between the front and the rear C.G. limit. - B) In front of the front C.G. limit. - C) Right of the lateral C. G. limit. - D) Behind the rear C.G. limit **Correct: A)** > **Explanation:** The aircraft's stability and controllability are only certified within the approved C.G. envelope, which lies between the forward and aft C.G. limits. B is wrong because a C.G. ahead of the forward limit requires excessive elevator authority to flare or rotate, potentially making landing impossible. D is wrong because a C.G. behind the aft limit causes longitudinal instability and uncontrollable pitch-up. C references lateral limits, which are not the primary concern in standard glider mass-and-balance calculations. ### Q3: An aircraft has to be loaded and operated in such a way that the center of gravity (CG) stays within the approved limits during all phases of flight. This is done to ensure... ^t30q3 - A) That the aircraft does not stall. - B) That the aircraft does not exceed the maximum allowable airspeed during a descent - C) That the aircraft does not tip over on its tail while it is being loaded. - D) Both stability and controllability of the aircraft. **Correct: D)** > **Explanation:** The C.G. position relative to the neutral point determines longitudinal static stability (the tendency to return to equilibrium after a disturbance), while the elevator's ability to command pitch changes provides controllability. Both properties must be maintained throughout flight, and the approved C.G. envelope ensures this. A is wrong because stall speed depends primarily on wing loading and angle of attack, not C.G. position. B is wrong because VNE is an airframe limit unrelated to C.G. C describes a ground-handling concern, not an in-flight safety requirement. ### Q4: The empty weight and the corresponding center of gravity (CG) of an aircraft are initially determined… ^t30q4 - A) For one aircraft of a type solely, since all aircraft of the same type have the same mass and CG position - B) By calculation. - C) By weighing. - D) Through data provided by the aircraft manufacturer. **Correct: C)** > **Explanation:** Each individual airframe must be physically weighed, typically on calibrated scales at three support points, to determine its actual empty mass and C.G. position. Manufacturing tolerances, repairs, modifications, and installed equipment create variations between serial numbers. A is wrong because no two aircraft of the same type are guaranteed identical. B is wrong because calculation alone cannot account for all manufacturing variables. D is wrong because manufacturer data provides type-level reference values, not individual aircraft-specific measurements. ### Q5: Baggage and cargo has to be properly stowed and fastened, otherwise a shift of the cargo may cause... ^t30q5 - A) Structural damage, angle of attack stability, velocity stability. - B) Continuous attitudes which can be corrected by the pilot using the flight controls. - C) Uncontrollable attitudes, structural damage, risk of injuries. - D) Calculable instability if the C.G. is shifting by less than 10 %. **Correct: C)** > **Explanation:** Unsecured cargo can shift suddenly during turbulence or maneuvers, moving the C.G. outside limits instantaneously. A sudden aft C.G. shift can cause an unrecoverable pitch-up, loose items can become dangerous projectiles injuring occupants or jamming controls, and asymmetric loads can exceed structural design limits. A uses incorrect technical terminology. B is dangerously wrong because shifted cargo can create attitudes beyond pilot correction capability. D is wrong because no amount of cargo shift is considered acceptable or safely calculable. ### Q6: The total weight of an aeroplane is acting vertically through the… ^t30q6 - A) Center of gravity - B) Stagnation point. - C) Center of pressure. - D) Neutral point. **Correct: A)** > **Explanation:** By definition, the center of gravity (C.G.) is the single point through which the resultant gravitational force (weight vector) acts vertically downward on the entire aircraft. All mass-and-balance calculations are based on locating this point. B (stagnation point) is where airflow velocity reaches zero on the leading edge. C (center of pressure) is where the resultant aerodynamic force acts. D (neutral point) is an aerodynamic reference for stability analysis. None of these others is where gravity acts. ### Q7: The term "center of gravity" is described as... ^t30q7 - A) The heaviest point on an aeroplane. - B) Half the distance between the neutral point and the datum line. - C) Another designation for the neutral point. - D) Half the distance between the neutral point and the datum line. **Correct: B)** > **Explanation:** The center of gravity is the point through which the total weight of the aircraft acts, determined as the mass-weighted average position of all individual mass elements. It is found by summing all moments about the datum and dividing by total mass. A is wrong because the CG is not the "heaviest point" — mass is distributed throughout the airframe. C is wrong because the neutral point is an aerodynamic stability reference, distinct from the CG. D repeats B and is also not the correct definition of CG. ### Q8: The center of gravity (CG) defines… ^t30q8 - A) The point on the longitudinal axis or its extension from which the centers of gravity of all masses are referenced. - B) The point on the longitudinal axis or its extension from which the centers of gravity of all masses are referenced. - C) The product of mass and balance arm - D) The point through which the force of gravity is said to act on a mass. **Correct: D)** > **Explanation:** The C.G. is defined as the point through which gravity (weight) is considered to act on the entire aircraft, as if all mass were concentrated at that single location. This is the fundamental definition used in all mass and balance calculations. A and B describe the datum point, which is a fixed reference from which moment arms are measured, not the CG itself. C describes a moment (mass times arm), which is a calculation step, not a definition of the CG. ### Q9: The term "moment" with regard to a mass and balance calculation is referred to as… ^t30q9 - A) Sum of a mass and a balance arm. - B) Difference of a mass and a balance arm. - C) Product of a mass and a balance arm. - D) Quotient of a mass and a balance arm. **Correct: C)** > **Explanation:** In mass and balance, a moment equals mass multiplied by balance arm (M = m x d), expressed in units like kg-m or lb-in. This follows the physical definition of a torque. The total C.G. position is then found by dividing the sum of all moments by the total mass. A (sum), B (difference), and D (quotient) would all produce dimensionally and physically incorrect results. Only the product of mass and distance gives a valid moment. ### Q10: The term "balance arm" in the context of a mass and balance calculation defines the… ^t30q10 - A) Point through which the force of gravity is said to act on a mass. - B) Point on the longitudinal axis of an aeroplane or its extension from which the centers of gravity of all masses are referenced. - C) Distance from the datum to the center of gravity of a mass. - D) Distance of a mass from the center of gravity **Correct: C)** > **Explanation:** The balance arm (or moment arm) is the horizontal distance measured from the aircraft's datum line to the center of gravity of a particular mass item (such as the pilot, ballast, or equipment). This distance determines the leverage that mass exerts about the datum for moment calculations. A defines the center of gravity, not the balance arm. B defines the datum point. D describes a distance from the CG, but balance arms are always measured from the datum, not from the CG. ### Q11: The distance between the center of gravity and the datum is called… ^t30q11 - A) Span width. - B) Balance arm. - C) Torque. - D) Lever. **Correct: B)** > **Explanation:** In mass and balance terminology, the balance arm (also called moment arm) is specifically the horizontal distance from the aircraft datum to any given point of interest, including the overall C.G. once calculated. A (span width) is a wing geometric parameter unrelated to longitudinal mass and balance. C (torque/moment) is the product of mass and arm, not the distance itself. D (lever) is a general physics term but not the standard aviation mass-and-balance terminology. ### Q12: The balance arm is the horizontal distance between… ^t30q12 - A) The C.G. of a mass and the rear C.G. limit. - B) The front C.G. limit and the datum line - C) The C.G. of a mass and the datum line. - D) The front C.G. limit and the rear C.G. limit. **Correct: C)** > **Explanation:** The balance arm of any mass item is the horizontal distance from the datum (a fixed reference plane defined in the flight manual) to the center of gravity of that specific mass. All moment calculations use the datum as the common reference, enabling moments to be summed algebraically to find the total C.G. position. A measures from the CG to a limit, not to the datum. B and D describe distances between CG limits or from limits to the datum, which are not balance arms. ### Q13: The required data for a mass and balance calculation including masses and balance arms can be found in the… ^t30q13 - A) Documentation of the annual inspection. - B) Certificate of airworthiness - C) Performance section of the pilot's operating handbook of this particular aircraft. - D) Mass and balance section of the pilot's operating handbook of this particular aircraft. **Correct: D)** > **Explanation:** The POH/AFM contains a dedicated mass and balance section with the aircraft's empty mass, empty C.G. position, datum reference, C.G. limits, and approved loading configurations. This is the authoritative source for all weight and balance data. A (annual inspection documentation) records maintenance history. B (certificate of airworthiness) merely certifies the type approval. C (performance section) contains speed, climb, and glide data, not mass and balance information. Only D provides the specific data needed for loading calculations. ### Q14: Which section of the flight manual describes the basic empty mass of an aircraft? ^t30q14 - A) Normal procedures - B) Performance - C) Weight and balance - D) Limitations **Correct: C)** > **Explanation:** The Weight and Balance section of the flight manual (typically Section 6 in EASA-standardized AFM structure) contains the aircraft's basic empty mass, empty C.G. location, allowable C.G. range, and loading instructions. A (Normal Procedures) covers checklists and standard operating procedures. B (Performance) covers speeds, climb rates, and glide data. D (Limitations) covers maximum speeds, load factors, and operating envelope boundaries. Each section has a specific purpose in the regulatory framework. ### Q15: Which factor shortens landing distance? ^t30q15 - A) High pressure altitude - B) Strong head wind - C) Heavy rain - D) High density altitude **Correct: B)** > **Explanation:** A strong headwind reduces groundspeed at touchdown for a given indicated airspeed, so the aircraft crosses the threshold with less kinetic energy relative to the ground, significantly shortening the ground roll. As a rule of thumb, a headwind component equal to 10% of approach speed reduces landing distance by approximately 19%. A and D (high pressure/density altitude) increase true airspeed for a given IAS, increasing groundspeed and lengthening the landing roll. C (heavy rain) can reduce braking effectiveness and visibility, potentially increasing landing distance. ### Q16: Unless the aircraft is equipped and certified accordingly… ^t30q16 - A) Flight into forecast icing conditions is prohibited. Should the aircraft enter an area of icing conditions inadvertantly, the flight may be continued as long as visual meteorological conditions are maintained. - B) Flight into known or forecast icing conditions is prohibited. Should the aircraft enter an area of icing conditions inadvertantly, it should be left without delay. - C) Flight into known or forecast icing conditions is only allowed as long as it is ensured that the aircraft can still be operated without performance degradation. - D) Flight into areas of precipitation is prohibited. **Correct: B)** > **Explanation:** For aircraft not certified for flight in known icing (FIKI), operating in known or forecast icing conditions is a regulatory prohibition. Ice accretion on wings dramatically increases weight, increases drag, reduces the maximum lift coefficient, and raises the stall speed simultaneously. If icing is inadvertently encountered, the pilot must exit the icing environment immediately by changing altitude or heading. A is wrong because maintaining VMC is irrelevant to the icing danger. C is wrong because performance degradation is inevitable once ice forms. D is overly broad since not all precipitation causes icing. ### Q17: The angle of descent is described as... ^t30q17 - A) The ratio between the change in height and the horizontal distance distance travelled within the same time, expressed in degrees [°]. - B) The angle between a horizontal plane and the actual flight path, expressed in degrees [°]. - C) The ratio between the change in height and the horizontal distance travelled within the same time, expressed in percent [%]. - D) The angle between a horizontal plane and the actual flight path, expressed in percent [%]. **Correct: B)** > **Explanation:** The angle of descent (glide angle) is geometrically defined as the angle between the horizontal plane and the actual flight path vector, measured in degrees. For a glider with a 1:30 glide ratio, this corresponds to approximately 1.9 degrees. A and C describe a gradient (ratio of height change to horizontal distance), not an angle. D incorrectly expresses an angle in percent rather than degrees. The distinction between an angle (in degrees) and a gradient (as a ratio or percentage) is important in navigation and performance calculations. ### Q18: Which is the purpose of "interception lines" in visual navigation? ^t30q18 - A) They help to continue the flight when flight visibility drops below VFR minima - B) To visualize the range limitation from the departure aerodrome - C) To mark the next available en-route airport during the flight - D) They are used as easily recognizable guidance upon a possible loss of orientation **Correct: D)** > **Explanation:** Interception lines are prominent linear geographic features — rivers, coastlines, railways, motorways — selected during pre-flight planning that run roughly perpendicular to the planned route. If a pilot becomes disoriented, flying toward the nearest interception line produces an unmistakable landmark for position recovery. A is wrong because interception lines do not permit flight below VFR minima. B describes range circles, not interception lines. C describes alternate airports, a different planning element. Interception lines are specifically a lost-procedure navigation tool. ### Q19: The upper limit of LO R 16 equals… ^t30q19 > *Note: This question originally references a chart excerpt (PFP-056) showing LO R 16 airspace boundaries.* - A) 1 500 m MSL. - B) FL150. - C) 1.500 ft GND. - D) 1 500 ft MSL. **Correct: D)** > **Explanation:** Low-level restricted areas (LO R) on aeronautical charts express vertical limits using standard altitude references. The upper limit of LO R 16 is 1,500 ft MSL (above mean sea level), an absolute altitude that does not vary with terrain. A (1,500 m MSL) confuses feet with metres — 1,500 m would be approximately 4,900 ft. B (FL150) is 15,000 ft on standard pressure, far too high for a low-level restriction. C (1,500 ft GND) references above ground level, which would vary with terrain and is not correct here. ### Q20: The upper limit of LO R 4 equals… ^t30q20 > *Note: This question originally references a chart excerpt (PFP-030) showing LO R 4 airspace boundaries.* - A) 4.500 ft MSL - B) 1.500 ft AGL - C) 4.500 ft AGL. - D) 1.500 ft MSL. **Correct: A)** > **Explanation:** Restricted area LO R 4 has its upper limit at 4,500 ft MSL (Mean Sea Level), a fixed altitude reference. MSL provides an absolute altitude datum that does not change with terrain, which is the standard for regulatory airspace boundaries. B (1,500 ft AGL) and D (1,500 ft MSL) are both too low and reference incorrect values. C (4,500 ft AGL) uses the correct number but the wrong reference — AGL varies with terrain, whereas the actual limit is defined as a fixed MSL altitude. ### Q21: Up to which altitude is an overflight prohibited according to the NOTAM? ^t30q21 > *Note: This question originally references a NOTAM excerpt (PFP-024).* - A) Flight Level 95 - B) Height 9500 ft - C) Altitude 9500 ft MSL - D) Altitude 9500 m MSL **Correct: C)** > **Explanation:** The NOTAM prohibits overflight up to 9,500 ft MSL (Mean Sea Level), an absolute altitude. In ICAO convention, "Altitude" refers to height above MSL, "Height" refers to above ground level, and "Flight Level" is a pressure altitude reference. A (FL95) uses a flight level designation, which differs from an MSL altitude when QNH is not 1013.25 hPa. B (Height 9,500 ft) implies above ground level rather than MSL. D (9,500 m MSL) confuses metres with feet — that would be approximately 31,000 ft, clearly unreasonable for a typical VFR restriction. ### Q22: What must be considered for cross-border flights? ^t30q22 - A) Transmission of hazard reports - B) Approved exceptions - C) Requires flight plans - D) Regular location messages **Correct: C)** > **Explanation:** Under ICAO Annex 2 and national regulations, flight plans are mandatory for international flights crossing state borders, even for VFR glider flights. A filed flight plan is required for border coordination, search and rescue alerting, and compliance with customs and immigration procedures. It ensures all relevant Air Traffic Services and SAR units are aware of the flight. A (hazard reports) and D (location messages) are separate operational procedures (AIREP/PIREP). B (approved exceptions) is not the primary consideration for cross-border flights. ### Q23: During a flight, a flight plan can be filed at the… ^t30q23 - A) Next airport operator en-route. - B) Flight Information Service (FIS). - C) Aeronautical Information Service (AIS) - D) Search and Rescue Service (SAR). **Correct: B)** > **Explanation:** The Flight Information Service (FIS), contacted on the published FIS frequency in each Flight Information Region, can accept an airborne flight plan (AFIL) during flight. This is the standard procedure when a plan was not filed before departure or needs to be extended en route. A (airport operator) handles local arrivals and departures, not en-route plan filing. C (AIS) distributes aeronautical information but does not accept real-time flight plans from airborne aircraft. D (SAR) is a response service activated when aircraft are overdue or in distress. ### Q24: While planning a cross country gliding flight, what ground structure ought to be avoided enroute? ^t30q24 - A) Stone quarries and large sand areas - B) Moist ground, water areas, marsh areas - C) Highways, railroad tracks and channels. - D) Areas with buildings, concrete and asphalt. **Correct: B)** > **Explanation:** Thermal convection depends on differential ground heating by the sun. Moist ground, water bodies, and marshes have high thermal inertia and specific heat capacity — they absorb solar energy without heating up quickly, suppressing thermal development above them. Flying over these areas means encountering less lift and risking a forced landing in unsuitable terrain. A (stone quarries, sand) and D (buildings, concrete, asphalt) are dark, dry surfaces that heat rapidly and generate strong thermals. C (highways, railways) serve as navigation references and also generate thermals. ### Q25: During a cross-country flight, you approach a downwind turning point. The point ought to be taken ... (2,00 P.) ^t30q25 - A) As high as possible. - B) With as less bank as possible - C) As low as possible. - D) As steep as possible. **Correct: A)** > **Explanation:** At a downwind turning point, the glider must reverse direction and fly back into the wind, immediately losing the tailwind advantage and gaining a headwind. Arriving high provides maximum altitude reserve for the subsequent upwind leg, where groundspeed is reduced and glide distance over the ground is shortened. C (as low as possible) is tactically dangerous because any failure to find lift on the return leg leaves no margin for safe outlanding selection. B and D relate to bank angle, which is not the primary concern at a turning point. ### Q26: After getting around a turning point, what should a glider pilot be prepared for? (2,00 P.)... ^t30q26 - A) For weakening thermals due to the progressing time - B) For a changed horizontal picture due to lower cloud bases - C) For increased cloud dissipation due to the progressing time - D) For a changed cloud picture due to the apparently changed position of the sun **Correct: D)** > **Explanation:** When a glider turns through a large heading change at a waypoint, the pilot's perspective of the sky shifts dramatically. The sun appears to have "moved" relative to the new heading, and cumulus clouds that were previously behind or to the side now appear in different positions relative to the cockpit. This perceptual shift can make the sky look completely different even if conditions are objectively unchanged. Pilots must re-orient their thermal assessment to the new heading. A, B, and C describe meteorological changes that are time-dependent, not heading-dependent. ### Q27: According ICAO, what symbol indicates a group of unlighted obstacles? ^t30q27 ![ICAO Obstacle Symbols](figures/PFP-061-icao-obstacle-symbols.svg) - A) D - B) C - C) B - D) A **Correct: B)** > **Explanation:** ICAO aeronautical chart symbology (defined in Annex 4 and Document 8697) uses distinct symbols to differentiate between obstacle types: lighted vs. unlighted, and single vs. group. Symbol C in the referenced figure represents a group of unlighted obstacles. Knowing these symbols is essential for cross-country flight planning to identify terrain and obstruction hazards that would not be visible at dusk or in poor visibility. A, C, and D represent other obstacle categories such as single obstacles, lighted groups, or other types. ### Q28: According ICAO, what symbol indicates a civil airport (not international airport) with paved runway? ^t30q28 ![ICAO Airport Symbols](figures/PFP-062-icao-airport-symbols.svg) - A) C - B) A - C) B - D) D **Correct: B)** > **Explanation:** ICAO aeronautical chart symbology uses specific symbols to differentiate airports by category: civil vs. military, international vs. domestic, and runway type (paved vs. unpaved). Symbol A in the referenced figure represents a civil, non-international airport with a paved runway. Glider pilots use these symbols during cross-country planning to identify potential alternate landing sites. A, C, and D represent other aerodrome categories such as international airports, unpaved fields, or military facilities. ### Q29: According ICAO, what symbol indicates a general spot elevation? ^t30q29 ![ICAO Spot Elevation Symbols](figures/PFP-063-icao-spot-elevation.svg) - A) C - B) B - C) A - D) D **Correct: A)** > **Explanation:** On ICAO aeronautical charts, different symbols distinguish between types of elevation information: general spot elevations, surveyed elevation points, maximum elevation figures, and obstacle heights. Symbol C in the referenced figure represents a general spot elevation, marking a notable terrain height for situational awareness. Cross-country glider pilots must recognize these symbols to identify terrain clearance requirements, especially when planning routes through valleys or near mountain ranges. B, C, and D represent other elevation-related symbols. ### Q30: What distance can be covered during a glide in a glider plane with glide ratio 1/30 from a height of 1500 m? (Neglect wind and thermal effects)... ^t30q30 - A) 45 NM - B) 30 km - C) 45 km - D) 81 NM **Correct: C)** > **Explanation:** Glide distance equals glide ratio multiplied by available height. With a glide ratio of 1:30 (30 meters forward per 1 meter of height lost) and 1,500 m of altitude: distance = 30 x 1,500 m = 45,000 m = 45 km. A (45 NM) equals approximately 83 km, requiring a glide ratio of about 1:55 — far beyond this aircraft. B (30 km) uses the ratio number directly without multiplying by height. D (81 NM) is even more excessive. Always verify units: mixing nautical miles and metres/kilometres is a common source of calculation errors.