Spring 2020 Instrument Stage 2 Review

Comprehensive practice flashcards in Question-and-Answer format covering aviation meteorology, flight regulations, structural icing hazards, airport operations, and instrument procedures from the Spring 2020 Instrument Stage 2 question bank.

How is a common ground- or surface-based temperature inversion produced?

By ground radiation cooling the surface on clear, cool nights when the wind is light.

What is the primary cause of all changes in the Earth's weather?

The variation of solar energy received by the Earth's regions, which creates temperature differences that drive atmospheric motion.

What temperature trend characterizes the stratosphere?

Relatively small changes in temperature with an increase in altitude, except for a warming trend near the top.

Steady precipitation preceding a front typically indicates which cloud type and turbulence condition?

Stratiform clouds with little or no turbulence.

What meteorological hazard at higher altitudes is indicated by the presence of ice pellets at the surface?

Freezing rain at a higher altitude.

What conditions must be met for frost to form on a surface?

The collecting surface temperature must be below the dew point of the surrounding air, and the dew point must be colder than freezing.

To which meteorological condition does the term 'dew point' refer?

The temperature to which air must be cooled to become saturated by the water vapor already present in it.

Encountering wet snow at your flight altitude indicates what ambient temperature condition?

The temperature is above freezing at your flight altitude, causing the snow to melt.

What primary atmospheric property determines the maximum amount of water vapor air can hold?

Air temperature (warm air can hold more water vapor than cold air).

What causes surface winds to cross isobars at an angle rather than flowing parallel to them?

Surface friction slows the wind speed and weakens the Coriolis force, allowing the stronger pressure gradient force to turn the wind across the isobars toward lower pressure.

How does the Coriolis force act on wind direction in the Northern Hemisphere?

It acts at a right angle to wind direction and deflects the air to the right.

If the surface air temperature is $+8^\circ\text{C}$ at $1,350\text{ feet MSL}$ under a standard lapse rate of $2^\circ\text{C}\text{ per }1,000\text{ feet}$, what is the estimated freezing level?

$$5,350\text{ feet MSL}$$

What type of air stability and vertical motion is associated with a temperature inversion?

A stable layer of air where vertical convection is suppressed.

What general weather characteristics identify an unstable air mass?

Cumuliform clouds, showery precipitation, turbulence, and good surface visibility.

What general weather characteristics identify a stable air mass?

Stratiform clouds, steady precipitation, smooth air (little or no turbulence), and poor visibility.

What measurement of the atmosphere is used to determine its stability?

The ambient lapse rate (rate of temperature decrease with altitude).

What factor determines whether ascending air forms stratified or cumuliform clouds?

The stability of the air before lifting occurs.

What is the dry adiabatic lapse rate for unsaturated air flowing up slope?

Approximately $3^\circ\text{C}\text{ per }1,000\text{ feet}$ ($5.4^\circ\text{F}\text{ per }1,000\text{ feet}$).

Which surface event signals that a thunderstorm cell has entered its mature stage?

The start of rain/precipitation falling from the cloud base at the surface.

On what frontal boundaries do frontal waves typically form?

Slow-moving cold fronts or stationary fronts.

What cloud type is recognized as having the greatest turbulence and flying hazards?

Cumulonimbus.

What hazard is indicated by the presence of standing lenticular altocumulus clouds in mountainous areas?

Very strong turbulence.

What does the cloud naming root 'nimbus' or 'nimbo-' denote?

A rain-bearing cloud.

Why is the high cloud family least likely to contribute to aircraft structural icing?

High clouds are composed almost entirely of already-frozen ice crystals, which generally do not stick to aircraft surfaces.

What are the four families into which cloud types are categorized?

High clouds, middle clouds, low clouds, and clouds with extensive vertical development.

Where relative to a thunderstorm cell can associated wind shear occur?

On all sides of the cell and in the downdraft directly beneath the cell.

Which weather phenomenon is always associated with the passage of a frontal system?

A wind change in direction, speed, or both.

What is an 'embedded thunderstorm'?

A thunderstorm that is obscured by massive surrounding cloud layers (such as stratus) and cannot be seen visually.

What wind criteria define a reported 'squall'?

A sudden increase in wind speed of at least $16\text{ knots}$, rising to a sustained speed of $22\text{ knots}$ or more, and lasting for at least $1\text{ minute}$.

Which stage of a thunderstorm's life cycle is characterized predominantly by downdrafts?

The dissipating stage.

Which weather phenomenon is always present in a thunderstorm?

Lightning (and thunder).

What are the three essential requirements for thunderstorm formation?

Sufficient water vapor (moisture), an unstable lapse rate, and an initial upward boost or lifting action.

Why is frost accumulation on an aircraft wing considered hazardous to flight?

The surface roughness spoils the smooth airflow, causing early airflow separation and a significant loss of lift.

In which meteorological environment is aircraft structural icing most likely to accumulate at the highest rate?

Freezing rain (an environment with large supercooled water droplets).

What is the average height of the troposphere in the middle latitudes?

$$37,000\text{ feet}$$

What minimum wind speed is required by definition to classify concentrated winds as a jet stream?

$50\text{ knots}$ or greater.

Under what conditions does advection fog typically form?

When warm, moist air moves horizontally over a colder surface of ground or water.

Under what meteorological conditions is radiation fog most conducive to forming?

Clear skies, little or no wind, high relative humidity (small temperature/dew point spread) over a land surface at night or near daybreak.

How does the jet stream shift in seasonal strength and geographic location from winter to summer?

It is weaker and shifts farther north during the summer, while it is stronger and shifts farther south during the winter.

According to test data, how significantly can frost or ice with sandpaper roughness reduce lift and increase drag?

It can reduce lift by up to $30\%$ and increase drag by $40\%$.

What weather conditions are typical beneath a low-level temperature inversion when relative humidity is high?

Smooth air and poor visibility due to trapped fog, haze, smoke, or low clouds.

How is 'light turbulence' defined regarding aircraft motion?

Turbulence that momentarily causes slight, erratic changes in aircraft attitude and/or altitude.

What thermal feature marks the boundary of the tropopause?

An abrupt change in the temperature lapse rate.

What is the expected maximum duration of an individual microburst from surface impact to dissipation?

Seldom longer than $15\text{ minutes}$.

How strong can maximum downdrafts be in a microburst encounter?

Up to $6,000\text{ feet per minute}$.

What total wind shear across a microburst should be anticipated if entering a $45\text{-knot}$ headwind?

$90\text{ knots}$ (transitioning from a $45\text{-knot}$ headwind to a $45\text{-knot}$ tailwind).

What aircraft performance changes occur when flying a glide slope and a constant headwind shears to a tailwind?

Pitch attitude decreases, indicated airspeed decreases initially before recovering, vertical speed increases, and the aircraft tends to sink below the glide slope.

Why should an airplane be slowed to design maneuvering speed ($V_A$) upon encountering severe turbulence?

To reduce the excess structural load that gusts can impose on the wings before the aircraft stalls.

What warning symptoms indicate tailplane icing or an impending tailplane stall?

A sudden change in elevator control force, elevator pulsing/vibrations, loss of elevator effectiveness, or an uncommanded nose-down pitch change.

What corrective procedure should be initiated if tailplane icing or a tailplane stall is suspected?

Immediately retract the wing flaps to the previous setting, apply nose-up elevator pressure, and increase engine power.

What action should a pilot take if uncommanded roll upset occurs due to severe icing?

Reduce the wing angle of attack by increasing airspeed or extending flaps to the first setting, set power for a controlled descent, and avoid retracting flaps if already extended.

What is the recommended autopilot usage policy when operating in in-flight icing conditions?

Disengage the autopilot and hand-fly the aircraft, or periodically disengage it, to prevent the system from masking aerodynamic degradation and control trim anomalies.

Why does an aircraft's tailplane typically collect structural ice faster and earlier than the wings?

The tailplane presents a thinner aerodynamic cross-section to the airflow, making it a more efficient collector of supercooled droplets.

What atmospheric conditions favor the formation of clear ice rather than rime ice?

Temperatures close to freezing, high liquid water content with large droplets, and higher aircraft airspeeds.

What is the function of a 'weeping wing' icing protection system?

It pumps an antifreeze solution out through microscopic holes along the leading edges to chemically prevent and break the bond of accumulating ice.

What is residual or intercycle ice?

Ice that remains or forms on the protected deicing boot surface between expansion/inflation cycles.

Under 14 CFR regulations, what are the minimum IFR fuel requirements when an alternate airport is required?

Sufficient fuel to fly to the destination airport, fly to the alternate airport, and fly thereafter for $45\text{ minutes}$ at normal cruising speed.

Under what forecast weather conditions is an alternate airport required for an IFR destination?

An alternate is required unless the destination forecast from $1\text{ hour}$ before to $1\text{ hour}$ after ETA has a ceiling of at least $2,000\text{ feet}$ above field elevation and visibility of at least $3\text{ statute miles}$.

How should a pilot transition from VFR to IFR on a composite flight plan?

Contact the nearest Flight Service Station (FSS) prior to the transition point, close the VFR portion, and request ATC clearance.

Under what conditions is an IFR flight plan and ATC clearance required?

When operating within Class E airspace under Instrument Meteorological Conditions (IMC), or when operating in Class A airspace regardless of weather.

Which approach clearances can ATC issue without an explicit request from the pilot?

Visual approaches, Departure Procedures (DPs), and Standard Terminal Arrival Routes (STARs). (Contact approaches require pilot request).

What operational authority is granted by an ATC clearance reading '…CRUISE SIX THOUSAND…'?

Authority to conduct flight at any altitude from the minimum IFR altitude up to and including $6,000\text{ feet}$, level off, climb, or descend within this block at the pilot's discretion.

In which airspace category are VFR-On-Top operations strictly prohibited?

Class A airspace.

What cruising altitudes must be maintained when operating on an IFR flight plan with a VFR-On-Top clearance?

VFR cruising altitudes appropriate to the magnetic course being flown (and as restricted by ATC).

What landing minimums apply if a pilot diverts to a filed alternate airport?

The standard published landing minimums for the selected instrument approach procedure at that alternate airport.

What standard weather minimums must be forecast at the ETA for an alternate airport served by a precision approach?

A ceiling of at least $600\text{ feet}$ and visibility of at least $2\text{ statute miles}$.

What are the standard visual glidepath angle and light indication for an aircraft on-slope with a 2-bar VASI?

A glidepath angle of $3.00^\circ$ showing red lights on the far bars over white lights on the near bars.

At what distance increments are runway touchdown zone markings spaced along the runway centerline?

$500\text{-foot}$ increments.

What runway surface marking designates the presence of a displaced threshold?

White arrows painted along the centerline leading up to the displaced threshold bar.

What data must be recorded in the aircraft log or record after completing a required VOR operational check?

The date, place of operational check, amount of bearing error, and the pilot's signature.

What indication confirms station passage when tracking directly over a VOR station?

The first positive, complete reversal of the TO-FROM indicator.

How can an airborne DME receiver be identified as inoperative if mileage digits still appear?

The DME will fail to transmit its synchronized Morse code identification tone (ordinarily audible once every $30\text{ seconds}$).

Where and when is a pilot permitted to cancel an IFR flight plan?

Only when operating in visual meteorological conditions (VMC) outside of Class A airspace.

What does the Runway Visual Range (RVR) value represent?

The horizontal distance a pilot looking down a runway from a moving aircraft should be able to see standard high-intensity runway lights.

What weather conditions are implied when an airport ATIS broadcast omits sky condition and visibility?

The ceiling is greater than $5,000\text{ feet}$ and visibility is $5\text{ statute miles}$ or more.

What do daytime operations of an airport rotating beacon in Class B, C, D, or E airspace typically indicate?

Ground visibility is less than $3\text{ miles}$ and/or the ceiling is less than $1,000\text{ feet}$ (weather is below basic VFR).

What does a 'T' symbol inside a black triangle in the notes section of an approach plate indicate?

Non-standard IFR takeoff minimums and/or published Departure Procedures (DPs) exist for that airport.

What missed approach procedure must a pilot execute if visual reference is lost while circling to land?

Make an initial climbing turn toward the landing runway and continue turning until established on the published missed approach course.

What is the maximum indicated airspeed permitted when flying an approach procedure turn?

$200\text{ knots IAS}$ ($200\text{ KIAS}$).

How is the Final Approach Fix (FAF) designated on a published precision approach profile view?

By a lightning bolt symbol marking the glide slope intercept altitude.