CPL Practice Exam 6

AIM RAC 2.8.6 Class F Airspace

Class F airspace is airspace of defined dimensions within which activities must be confined because of their nature, and within which limitations may be imposed upon aircraft operations that are not a part of those activities.

Class F airspace may be restricted airspace, advisory airspace, military operations areas, or danger areas and can be controlled airspace, uncontrolled airspace, or a combination of both.

Unless otherwise specified, the rules for the surrounding airspace apply in areas of Class F airspace, no matter if these areas are active or inactive.

Class F airspace is designated in the DAH (TP 1820) and published on the appropriate aeronautical charts.

Reference From the Ground Up 7.4

Lambert Conformal Conic — Useful for long distances because a straight line on the map is very close to a great circle course. Most VFR charts are Lambert Conformal Conic.

Mercator — The most commonly used projection for navigating in small areas because of its accuracy and the fact that a straight line is also a rhumbline.

Magnetic Dip

Magnetic dip creates the most substantial errors in a compass. As you get closer to the North or South Pole, magnetic flux lines point downwards towards the poles, and your compass magnets dip towards the low side of a turn. When magnetic dip is pronounced, it’s difficult to get actual readings. This error isn’t much of a problem near the equator, where your compass points more or less horizontally and magnetic dip isn’t a concern.

Acceleration And Deceleration Error

Another major problem with magnetic compasses in airplanes is acceleration error. In the Northern Hemisphere, as you accelerate, your compass will show a turn to the North. And as you decelerate, your compass will show a turn to the South. When the speed stabilizes, the compass returns to normal. This error is greatest on East or West headings.

Use the acronym ANDS: “Accelerate-North, Decelerate-South.”

Turning Errors

During a turn from a Northerly heading, the compass briefly indicates a turn in the opposite direction. As for aircraft turning from a Southerly heading, the compass indicates a turn in the correct direction, but at a faster rate than is actually being turned.

Use the acronym NOSE: “North-Opposite, South-Exaggerated.”

NDB Time and Distance to the Station Formula(s):

3 minutes x 60 seconds/min = 180 seconds

Time to the Station (Mins) = 180 seconds/10 degrees change = 18 mins

Distance to the Station (NM) = 140 Knots x 18 mins/60 = 42 NM

VOR Time and Distance to the Station Formula(s):

An aircraft is tracking inbound on the 250° radial of a VOR. The aircraft is traveling at 110 Kts TAS and the pilot notes that in 3 minutes the CDI shows a deflection of 2 dots. What is the distance to the VOR station in this example?

3 mins x 60 seconds = 180 seconds

2 dots x 2°/dot = 4°

Time to the station (mins) = 180/4 = 45 mins

Distance to the Station (NM) = 110 knots x 45 mins/60 = 82.5 NM

VOT Signal:

With a VOT, you can check the VOR accuracy from your plane before takeoff. So what is a VOT? It’s an approved VOR test signal, and it’s located on an airport. Not all airports have VOTs, so you’ll need to check the chart supplement to see if your airport has one. If your airport does have a VOT, here’s what to do:

1. Tune your VOR to the VOT signal.
2. Set the course selector to 0 degrees, and the track indicator should be centered.
3. The TO-FROM indicator should read FROM.
4. Next, set the course selector to 180 degrees
5. The TO-FROM indicator should read TO, and the track bar should then be centered.
6. The maximum indicated bearing error is plus or minus 4 degrees.

Draw a VOR Compass Rose:

This will help us visualize it better. We are on the 045° radial, which means we are NE of the station.

Use the acronym, I.B.O.T.

Inbound Bottom, Outbound Top. Since we are flying inbound, we set the desired VOR radial at the BOTTOM of the VOR indicator.

Determine where the CDI needle will swing:

If we were flying intercepting outbound on the 360 radial, then the needle will swing to our left. But, since we will turn the airplane and point inbound towards the station, the 360° radial will be to your right side.

Read the intercept angle in the direction of the needle swing:

We are using an easy 90° intercept angle. This will be to the edge of the VOR display.

Draw the radials on a compass rose:

By drawing the 130° radial we can see that we are SE of the station.

Next draw the 200° radial. We see that it is clock-wise from our current position.

This means that the CDI needle would swing right.

ADF Intercepts Inbound Formula

350 + 300 = 650

Since, there is a max of 360 degrees in direction.

650 – 360 = 290 degrees

This also means that we are South East of the Station

NDB Time and Distance to the Station Formulas(s):

Time to NDB in Mins = 45 secs/10 bearings crossed = 4.5 mins

Method 1: Draw a Compass Rose:

This will help us visualize it better. We are on the 300° radial which means we are to the NW of the station. Remember that VOR’s are position only and does not change based on the aircraft’s heading.

Our desired radial is 010*. When we draw it out we see that the radial is to our right (in a clock-wise direction).

010° + 90° = 100°

Method 2: Use the aircraft’s VOR indicator

This is easier in the airplane. Just set the desired inbound radial at the BOTTOM of the VOR indicator. You will notice the the needle swings all the way to left. Since, we are using an easy 90° intercept. Read the number to the left of the VOR indicator, which is 100°.

AIM COM 4.7 Distance Measuring Equipment (DME) 

The DME slant range error is the greatest when the airplane is at a high altitude close to or over the ground station. Moreover, slant range error also affects groundspeed and time-to-staion displays when you are close to the station.

AIM COM 4.8 TACTICAL AIR NAVIGATION (TACAN)

Tactical air navigation aid (TACAN) is a navigation aid (NAVAID) used primarily by the military for en route, non-precision approaches (NPAs) and other military applications. It provides azimuth in the form of radials and slant distance in nautical miles (NM) from the ground station. The system operates in the ultrahigh frequency (UHF) range with the frequencies identified by channel number.

TACAN users may obtain distance information from a distance measuring equipment (DME)  that is paired with the VHF omnidirectional range (VOR). This TACAN paired channel number is published in the Canada Flight Supplement (CFS) for every VOR/DME facility.

CAUTION:
Only DME information is being received by the TACAN avionics. Any apparent radial information obtained through the TACAN avionics from a VOR/DME facility can only be false signals.

Reference From the Ground Up 7.4

Lambert Conformal Conic — Useful for long distances because a straight line on the map is very close to a great circle course. Most VFR charts are Lambert Conformal Conic.

Mercator — The most commonly used projection for navigating in small areas because of its accuracy and the fact that a straight line is also a rhumbline.

AIM 1.5.2 Civil Twilight