| What are the (3) conditions necessary for the formation of a thunderstorm? | 1.) Sufficient water vapor
2.) An unstable lapse rate
3.) An initial lifting force |
| What is a lapse rate? | The rate at which air temperature falls with increasing altitude |
| For thunderstorm creation, list causes of the lifting action..? | 1.) Heating from below
2.) Frontal Lifting (when warm and cold air masses meet)
3.) Mechanical Lifting (wind blowing air upslope on a mountain) |
| What are the (3) stages of a thunderstorm? | 1.) Cumulus stage - characterized by continuous updrafts which create low pressure areas
2.) Mature stage - will be the greatest intensity of the storm and is characterized by updrafts and downdrafts inside the cloud. The start of rain from the base of the cloud signals the beginning of this stage
3.) Dissipating stage - characterized predominantly by downdrafts |
| What is the precipitation (during a thunderstorm) that evaporates before reaching the ground called? | Virga |
| What is one way to determine the distance between a PICs location and a thunderstrom? | Count the number of seconds it takes between when you see lightning and then hear thunder. Take the result and divide by 5 to give you the distance in statute miles. |
| What type of thunderstorms generally produce the most intense hazard to aircraft? | Squall-line thunderstorms. They are non-frontal, narrow bands of thunderstorms that develop ahead of a cold front. |
| What are small scale intense downdrafts which, as they get near the ground, spread outward from the center in all directions? | Microbursts |
| How far away from a thunderstorm might a pilot expect to experience wind shear? | 20 NM |
| What is considered the most hazardous condition when flying an sUAS in the vicinity of thunderstorms? | Lightning |
| What is the expected duration of an individual microburst? | Seldom longer than 15 minutes from the time the burst strikes the ground until dissipation |
| At what altitude are squal-line thunderstorms mot likely to form? | At any altitude |
| What is a situation conducive to any icing? | Flying in the vicinity of a front |
| What are the effects of structural icing on a sUAS? | Lift decreases
Weight Increases
Thrust deceases
Drag Increases |
| When does structural icing occur? | Whenever supercooled condensed droplets of water make contact with any part of the aircraft that is also at a temperature below freezing |
| The presence of ice pellets at the surface is evidence that....? | there is freezing rain at a higher altitude |
| The presence of wet snow at the surface indicates that....? | the temperature at your altitude is above freezing |
| What are (2) conditions necessary for the structural icing in flight? | 1.) the aircraft must be flying through visible water such as rain or cloud droplets
2.) The temperature at the point where the moisture strikes the aircraft must be 0 C (32 F) or colder |
| What is radiation fog? | Also called ground fog, is formed when terrestrial radiation cools the ground, which in turn cools the air in contact with it. When the air is cooled to its dewpoint (or within a few degrees), fog will form.
This fog will form most readily in warm, moist air over low, flatland areas on clear, calm (no wind) nights |
| How is advection fog formed? | Also called sea fog, is formed when warm air moves (wind is required) over colder ground (e.g. an air mass moving inland form the coast in winter) |
| How is upslope fog formed? | Formed when moist, stable air is cooled to its dew point as it moves up along slopping terrain (wind is required). Cooling will be at the dry adiabatic lapse rate of approximately 3 C per 1,000 feet |
| How is Precipitation-induced fog formed? | Also called rain or drizzle fog (commonly associated with frontal activity), is formed by relatively warm drizzle or rain falling through cooler air. Evaporation from the precipitation saturates the cool air and fog forms.
This fog is especially critical because it occurs in the proximity of precipitation and other possible hazards such as icing, turbulence, and thunderstorms. |
| How is steam fog formed? | Forms in the winter when cold, dry air passes from land areas over comparatively warm ocean waters.
Low-level turbulence can occur and icing can become hazardous in steam fog |
| Manufacturer predicted performance information is often based upon what temperature and atmospheric pressure? | This combination is called a standard day and is A sea level temperature of +15 deg C (+59 deg F) and an atmospheric pressure of 29.92 "HG (1013.2 mb) |
| What are weather related conditions that can affect the density altitude? | 1.) Temperature deviations from standard
2.) Pressure deviations from standard
3.) Relative humidity |
| Overall, sUAS flight performance will decrease as.....? | pressure decreases, altitude increases, temperature increases, and marginally as humidity increases |
| How would a high density altitude affect the performance of a small unmanned aircraft? | Decreased performance (High altitude i.e low pressure, high temperature, and high humidity result in a density altitude higher than the pressure altitude) |
| To get a complete weather overview for the planned flight, the remote PIC should obtain | A standard briefing |
| To obtain supplement mass disseminated data or when only one or two items are needed, the remote PIC should obtain | A abbreviated briefing |
| When the proposed departure time is six or more hours from the time of briefing, the remote PIC should request | A outlook briefing |
| A TAF is a report established (typically for larger airports) for an airport around what radius? | 5 SM |
| What are the times that a TAF is updated every day? | 0000Z
0600Z
1200Z
1800Z |
| What is the time period a TAF is valid for? | 24hr or 30hr time period |
| When are Convective SIGMETs (WSTs) issued? | Severe thunderstorms with
1.) winds greater than 50 knots
2.) hail at the surface greater than or equal to 3/4 inch in diameter
3.) tornadoes
Embedded thunderstorms
Lines of thunderstorms
Thunderstorms with heavy or greater precipitation that affect 40% or more of a 3,00 sq mi or greater region |
| What constitutes the primary control system and are required to control and airplane safely during a flight? | 1.) Ailerons - Controls Roll
2.) Elevator (Stabilizer) - Controls Pitch
3.) Rudder - Controls Yaw |
| What constitutes the secondary control system and improve the performance characteristics of an airplane or relieve the pilot of excessive control forces? | 1.) Wing flaps
2.) Leading Edge Devices
3.) Spoilers
4.) Trim Systems |
| Navigation solely by means of computations based on time, airspeed, distance, and direction is.....? | Dead Reckoning. The products derived from the variables listed, when adjusted by windspeed and velocity, are heading and ground speed |
| Navigation by reference to landmarks and checkpoints is......? | Pilotage |
| Navigation using triangulation is......? | Wind Triangle. |
| The most common performance deficiencies of an overloaded aircraft are....? | 1.) Reduced rate of climb
2.) Lower maximum altitude
3.) Shorter endurance
4.) Reduced Maneuverability |
| What is included in the Empty Weight of the aircraft? | Airframe, power source, all fixed equipment, and unusable fuel
Typically obtained from manufacturers' documentation |
| What is included in the Useful Load for the aircraft? | Power source (battery or fuel) and payload or mission equipment (such as a camera) |
| The launch weight is....? | Empty Weight + the Useful Load |
| The Landing weight is......? | The launch weight minus any fuel or jettisoned load |
| The Arm is the horizontal distance measured in inches from the datum line and is.......? | (+) when measured aft (towards the defined rear of the aircraft)
(-) when measured forward |
| When will an aircraft become unstable or uncontrollable? | When the moment(s) exceed the control capacity of the aircraft |
| What is the vortex ring state (also referred to as settling with power? | Something Remote pilots of rotor type unmanned aircraft should use particular caution.
Happens when descending in a vertical straight line. The turbulent downward airflow can disrupt the normal production of lift by the propellers as well as cause problematic air circulation producing vertices.
Recovery from this state of flight requires forward or rearward motion - counterintuitively, the addition of power to arrest the descent only make the situation worse |
| When will an unmanned aircraft stall? | When the critical angle of attack of the wing or rotors/propeller is exceeded |
| What can cause an aircraft to stall? | When the aircraft is tuned too sharply/tightly
When the aircraft is pitched up too steeply or rapidly |
| The amount of excess load that can be imposed on the wing of an airplane depends upon the ? | Speed of the airplane |
| A structure or body that produces a useful reaction to air movement is called...? | An Airfoil |
| The imaginary straight line from the leading edge to the trailing edge of an airfoil is called.....? | The Chord Line |
| The wind "felt" or experienced by the an airfoil is.....? | Relative Wind |
| What is Relative Wind created by? | The movement of air past an Airfoil, the motion of an Airfoil through the air, or a combination of both |
| What direction, in relation to the direction of the flight, is Relative wind? | Parallel to, and in the opposite direction of the flight path of the airfoil |
| The angle between the Chord Line of the Airfoil and the Relative Wind is called.......? | Angle of Attack |
| To increase lift, the angle of attack is.....? | Increased |
| At what angle of attack (for most airfoils) will the turbulence over the upper wing surface decrease lift so drastically that flight cannot be sustained and the airfoil stalls? | 18 degrees to 20 degrees (upward)
Note: This would be the critical angle of attack |
| An unmanned aircraft will always stall at the same ......... no matter the airspeed or altitude | Critical angle of attach |
| To encounter the same strength of relative wind at a higher altitude as would be experienced at lower altitudes, an aircraft.....? | Must have greater forward speed because at higher altitudes air density decreases |
| An increase in load factor will cause an unmanned aircraft to...? | Stall at higher airspeed |
| Maximum endurance is obtained at the point of minimum power to maintain the aircraft...? | In steady, level flight |
| When range and economy of operation are the principle goals, the remote PIC must ensure that the sUAS will be operated at the recommended | Long-range cruise performance |
| What is the best source for sUAS performance data and information? | Manufacturer publications |
