NORAD’s Santa Tracker website launches each year on December 1, and in 2023 it offers plenty of activities leading up to Santa’s trip. Visitors can explore world traditions at the North Pole’s library, listen to classics like “Here Comes Santa Claus” playing on the music stage, and play a new game every day (as well as the ones from the previous days) at the arcade. You can also find a blueprint of Santa’s sleigh, which, if you’re curious, measures 75 cc (candy canes) or 150 lp (lollipops) by 40 cc (80 lp).

The site also offers plenty of information about NORAD’s tracking abilities. They use radar, satellites, and jet fighters, such as Canadian CF-18s and American F-22s, that escort Santa across North America (see this video and the image below).

According to the website, Rudolph’s nose gives off a signature similar to a rocket launch, and their satellites detect it with “no problem.” Santa’s trip starts at the International Date Line in the Pacific Ocean and travels west visiting the South Pacific first, then New Zealand and Australia. After he finishes his stops in the Australian outback, he travels to Japan, over Asia, across to Africa, then on to Western Europe, Canada, the United States, Mexico, and Central and South America.

Started in 1955 when a phone number mix-up caused children to call the Continental Air Defense Command asking for Santa, the tracking tradition celebrates its 68^th year in 2023 (it was taken on by NORAD in 1958). On December 24^th, trackers worldwide can call 1-877-HI-NORAD from 6 a.m. to midnight MST or visit the website from 4 a.m. to midnight MST to follow Santa’s flight around the world.

When asked about the existence of Santa, NORAD replies, “Mountains of historical data and NORAD tracking information lead us to believe that Santa Claus is alive and well in the hearts of people throughout the world.”

If Santa is in your heart or in the heart of someone close to you, the NORAD Santa Tracker will provide hours of joy (and new videos of Santa every hour). On behalf of ASA, have a wonderful Christmas and a happy New Year.

The post NORAD Has the Watch: Santa Tracker first appeared on Learn To Fly.

Automatic Dependent Surveillance-Broadcast (ADS-B) is a surveillance technology being deployed throughout the entire National Airspace System. ADS-B enables improved surveillance services, both air-to-air and air-to-ground, especially in areas where radar is ineffective due to terrain or where radar is impractical or cost prohibitive. Eventually, ADS-B will replace most ground-based surveillance radars.

The basic principle of ADS-B is that each aircraft broadcasts a radio transmission approximately once per second, which contains the aircraft’s position, velocity, identification, and other information. This capability is referred to as “ADS-B out.” This transmission is received by the ground-based transceivers (GBTs) and by other appropriately-equipped aircraft. (The capability to receive ADS-B information is referred to as “ADS-B in.”) The ADS-B ground station processes the information and uses it to provide surveillance services. The composite traffic information is uplinked as the product, “Traffic Information Service-Broadcast (TIS-B).” In order to detect each other, no ground infrastructure is necessary for ADS-B equipped aircraft (i.e., those with both ADS-B out and in).

There are two completely different methods for aircraft to transmit and receive the ADS-B information. Aircraft that primarily operate in high-altitude airspace send and receive the information using an enhanced Mode S transponder. Aircraft that primarily operate in the low-altitude airspace send and receive the information using the Universal Access Transceiver (UAT). The GBT receives information from both sources and rebroadcasts (ADS-R) it so that all aircraft have all the information.

Another feature related to ADS-B is called Flight Information Services-Broadcast (FIS-B). FIS-B provides current weather products via an uplink from the GBT antennas to the UAT on the airplane. There is no fee for this weather service. More information on FIS-B is given in the “Datalink Weather Systems” section ahead on page 208.

Before FIS-B and datalink weather capability, pilots had to contact Flight Watch or a flight service station to have someone describe the weather radar picture for them. Now that picture is available in the cockpit. For example, NOTAMs and Temporary Flight Restrictions (TFRs) can be graphically presented over the top of electronic charts, so pilots know what areas to avoid.

The ADS-B system also has downlink capabilities that may someday transmit actual weather data to the ground. In the future, airplanes could send down actual (not forecast) wind direction, velocity, freezing levels, turbulence, and more, to be analyzed in real time. The information could be constantly sent to the ground to build an enhanced, comprehensive, and current weather picture. This information is called an electronic PIREP.

Mandatory ADS-B Out Requirement
The term “ADS-B out” refers to the broadcast of ADS-B transmissions from aircraft, without the installation of complementary receiving equipment to process and display ADS-B data on cockpit displays to pilots. This complementary processing is called “ADS-B in.” ADS-B out is needed for cockpit displays to be able to directly observe traffic. ADS-B out can be deployed earlier than ADS-B in, since ATC surveillance (air-ground) can operate without ADS-B in.

Effective January 1, 2020, ADS-B out capability will be required for aircraft in the following airspace areas:

• Class A, B, and C airspace;
• all airspace above 10,000 ft MSL over the 48 contiguous states and the District of Columbia (excluding the airspace above 10,000 feet, but within 2,500 feet of the ground);
• within the 30 NM veil of airports listed in 14 CFR §91.225; and
• Class E airspace over the Gulf of Mexico from the coastline of the United States out to 12 nautical miles, at and above 3,000 feet MSL.

The post Navigation: Automatic Dependent Surveillance-Broadcast first appeared on Learn To Fly.

With use of the depicted information on an IAP chart a pilot will be assured of terrain and obstruction clearance and runway or airport alignment during approach for landing.

The IAP chart may be divided into four distinct areas: the Plan View, showing the route to the airport; the Profile View, showing altitude and descent information; the Minimums Section, showing approach categories, minimum altitudes, and visibility requirements; and the Airport diagram, showing runway alignments, runway lights, and approach lighting systems.

1. The Plan View is that portion of the IAP chart depicted at “A” in the figure below. Atop the IAP chart is the procedure identifications which will depict the A/C equipment necessary to execute the approach, the runway alignment, the name of the airport, the city and state of airport location (See Figure Area #1). An ILS approach, for example, requires the aircraft to have an operable localizer, glide slope, and marker beacon receiver. An LOC/DME approach would require the aircraft to be equipped with both a localizer receiver and distance measuring equipment (DME). If the approach is aligned within 30° of the centerline, the runway number listed at the top of the approach chart means straight-in landing minimums are published for that runway. If the approach course is not within 30° of the runway centerline, an alphabetic code will be assigned to tie IAP identification (for example, NDB-A, VOR-C), indicating that only circle-to-land minimums are published. This would not preclude a pilot from landing straight-in, however, if the pilot has the runway in sight in sufficient time to make a normal approach for landing, and has been cleared to land.

The IAP plan view will list in either upper corner, the approach control, tower, and other communications frequencies a pilot will need. Some listings may include a direction (for example, North 120.2, South 120.8).

The IAP plan view may contain a Minimum Sector Altitude (MSA) diagram. The diagram shows the altitude that would provide obstacle clearance of at least 1,000 feet in the defined sector while within 25 NM of the primary omnidirectional NAVAID; usually a VOR or NDB (See Figure Area #2).

An IAP may include a procedural track around a DME arc to intercept a radial. An arc-to-radial altitude restriction applies while established on that segment of the IAP.

2. The Profile View is that portion of the IAP chart depicted at “B” in the Figure. The profile view shows a side view of the procedures. This view includes the minimum altitude and maximum distance for the procedure turn, altitudes over prescribed fixes, distances between fixes, and the missed approach procedure.
3. The Minimums Section is that portion of the IAP chart depicted at “C” in the Figure. The categories listed on instrument approach charts are based on aircraft speed. The speed is 1.3 times V_S0 at maximum certificated gross landing weight.
4. The Aerodrome Data is that portion of the IAP chart which includes an airport diagram, and depicts runway alignments, runway lights, approach lights, and other important information, such as the touchdown zone elevation (TDZE) and airport elevation (See figure area “D”).

Take a look a the IAP Chart Figure below and see if you can determine the following. Answers will be posted in the comments section.

1. What is the minimum equipment required for this approach?
2. What are the noted minimum safe altitudes (MSA)?
3. What is the decision altitude (DA) if conducting a straight in approach?

The post CFI Brief: The Instrument Approach Procedure Chart first appeared on Learn To Fly.

How Radio Waves Propagate
All matter has a varying degree of conductivity or resistance to radio waves. The Earth itself acts as the greatest resistor to radio waves. Radiated energy that travels near the ground induces a voltage in the ground that subtracts energy from the wave, decreasing the strength of the wave as the distance from the antenna becomes greater. Trees, buildings, and mineral deposits affect the strength to varying degrees. Radiated energy in the upper atmosphere is likewise affected as the energy of radiation is absorbed by molecules of air, water, and dust. The characteristics of radio wave propagation vary according to the signal frequency and the design, use, and limitations of the equipment.

Ground Wave
A ground wave travels across the surface of the Earth. You can best imagine a ground wave’s path as being in a tunnel or alley bounded by the surface of the Earth and by the ionosphere, which keeps the ground wave from going out into space. Generally, the lower the frequency, the farther the signal travels.

Ground waves are usable for navigation purposes because they travel reliably and predictably along the same route day after day and are not influenced by too many outside factors. The ground wave frequency range is generally from the lowest frequencies in the radio range (perhaps as low as 100 Hz) up to approximately 1,000 kHz (1 MHz). Although there is a ground wave component to frequencies above this, up to 30 MHz, the ground wave at these higher frequencies loses strength over very short distances.

Sky Wave
The sky wave, at frequencies of 1 to 30 MHz, is good for long distances because these frequencies are refracted or “bent” by the ionosphere, causing the signal to be sent back to Earth from high in the sky and received great distances away. Used by high frequency (HF) radios in aircraft, messages can be sent across oceans using only 50 to 100 watts of power. Frequencies that produce a sky wave are not used for navigation because the pathway of the signal from transmitter to receiver is highly variable. The wave is “bounced” off of the ionosphere, which is always changing due to the varying amount of the sun’s radiation reaching it (night/day and seasonal variations, sunspot activity, etc.). The sky wave is, therefore, unreliable for navigation purposes.

For aeronautical communication purposes, the sky wave (HF) is about 80 to 90 percent reliable. HF is being gradually replaced by more reliable satellite communication.

Space Wave
When able to pass through the ionosphere, radio waves of 15 MHz and above (all the way up to many GHz), are considered space waves. Most navigation systems operate with signals propagating as space waves. Frequencies above 100 MHz have nearly no ground or sky wave components. They are space waves, but (except for global positioning system (GPS)) the navigation signal is used before it reaches the ionosphere so the effect of the ionosphere, which can cause some propagation errors, is minimal. GPS errors caused by passage through the ionosphere are significant and are corrected for by the GPS receiver system.

Space waves have another characteristic of concern to users.Space waves reflect off hard objects and may be blocked if the object is between the transmitter and the receiver. Site and terrain error, as well as propeller/rotor modulation error in very high omnidirectional range (VOR) systems, is caused by this bounce. Instrument landing system (ILS) course distortion is also the result of this phenomenon, which led to the need for establishment of ILS critical areas.

Generally, space waves are “line of sight” receivable, but those of lower frequencies “bend” somewhat over the horizon. The VOR signal at 108 to 118 MHz is a lower frequency than distance measuring equipment (DME) at 962 to 1213 MHz. Therefore, when an aircraft is flown “over the horizon” from a VOR/DME station, the DME is normally the first to stop functioning.

Disturbances to Radio Wave Reception
Static distorts the radio wave and interferes with normal reception of communications and navigation signals. Lowfrequency airborne equipment, such as automatic direction finder (ADF) and LORAN (LOng RAnge Navigation), are particularly subject to static disturbance. Using very high frequency (VHF) and ultra-high frequency (UHF) frequencies avoids many of the discharge noise effects. Static noise heard on navigation or communication radio frequencies may be a warning of interference with navigation instrument displays. Some of the problems caused by precipitation static (P-static) are:

• Complete loss of VHF communications.
• Erroneous magnetic compass readings.
• Aircraft flying with one wing low while using the autopilot.
• High-pitched squeal on audio.
• Motorboat sound on audio.
• Loss of all avionics.
• Inoperative very-low frequency (VLF) navigation system.
• Erratic instrument readouts.
• Weak transmissions and poor radio reception.
• St. Elmo’s Fire.

The post Navigation: Basic Radio Principles first appeared on Learn To Fly.

The information contained within the Chart Supplement U.S. is no different than the information that was contained in the formerly named A/FD. There are a total of 7 regional supplements issued for the lower 48 states, Puerto Rico, and the U.S. Virgin Islands. Each supplement contains invaluable pre-flight planning information for pilots. A complete listing of public-use airports, including seaplane bases, heliports, and some military facilities. The airport entries will include such information as airport location, elevation, runways and lighting facilities, available services like fuel and oxygen, air traffic control frequencies, and nearby navigational aids to name a few. Some airport entries will also contain additional textual information concerning operations at that particular airport; this is known as the Airport Remarks section. For example notes on wildlife activity in the vicinity of the airport, noise abatement procedures, or specific hazards associated with operations conducted at that particular airport. Here is an example of the Airport Remarks for Walla Walla Regional Airport (KALW).

AIRPORT REMARKS: Attended 1400–0230Z‡. Self svc credit card fueling facility lctd 600´ north of twr. 24 hr fuel svc call 509–525–9851. Sfc conds unmonitored 0430–1130Z‡. ARFF svcs avbl dur scheduled air carrier opr. Clsd to unscheduled air carrier ops with more than 30 pax seats exc PPR call arpt mgr 509–525–3100. Rwy 07–25 clsd to scheduled air carrier. Rwy 07–25 dalgt use only. Twy C, west of Rwy 02–20 dalgt use only. Rwy 07–25 large cracks and sfc variations may impair directional ctl.

As you can see from the sample, many of the words are abbreviated which can take some getting used to. You can find a listing of abbreviations in the legend on the first few pages of each of the 7 publications.

In addition to airport information, the Chart Supplements will provide airport diagrams, preferred IFR routing, a directory of FAA telephone numbers including key air traffic control facilities, and special or regulatory notices. Again this is just a sampling of some of the information contained in the Chart Supplements.

Every 56 days each of the 7 regional supplements are updated and published. The front cover will list the area covered (i.e. South Central U.S.) by that supplement and the effective dates of use. As a pilot, you want to make sure you are using a current and valid copy. The information contained in the Chart Supplements U.S. is usually the latest available information in print and should be used in preference to information given on the back of charts if conflicting information is identified. It is important to cross-reference NOTAMs with anything printed in the Chart Supplements; the NOTAM information will take precedence where any differences appear.

The Chart Supplement U.S. is also available and searchable in an online format through this link.
https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/dafd/search/

The post CFI Brief: Chart Supplement U.S. first appeared on Learn To Fly.

• flight planning;
• chart-reading (also known as pilotage) which means determining your position over the ground by comparing the ground features with those marked on the chart;
• using navigation aids to assist and confirm your map-reading;
• making corrections to your flight path over the ground so as to regain your planned course and reach your destination; and
• using dead reckoning to back up your other visual navigation methods.

Today, we’ll feature an excerpt from this chapter specifically on chart-reading in flight. Ground School is available in hardcover and in multiple eBook formats.

Chart-Reading in Flight
The success of map-reading depends on four basic factors:

• a knowledge of direction;
• a knowledge of distance;
• a knowledge of groundspeed; and
• the selection and identification of landmarks and checkpoints.

Select good checkpoint features. Landmarks and checkpoints that can be easily identified, and which will be within your range of visibility when you pass by them, are best. Just how conspicuous a particular feature may be from the air depends on:

• the flight visibility;
• the dimensions of the feature;
• the relationship of your selected feature to other features; the angle of observation;
• the plan outline of the feature if you are flying high; and
• the elevation and side appearance of the feature if you are flying low.

Preferably the feature should be unique in that vicinity so that it cannot be confused with another nearby similar feature. A feature that is long in one dimension and quite sharply defined in another is often useful, because:

• if a long feature (such as a railroad, canal or road) runs parallel to your planned course, it can assist in maintaining accurate tracking; and
• if a long feature crosses the course it can be used as a position line to aid in determining an updated groundspeed (GS).

The relationship between your selected feature and other nearby ground features is very important for a positive confirmation of your position. For example, there may be two small towns near each other, but you have chosen as a feature the one that has a single-track railroad to the west of the town and with a road that crosses a river on the north side of the town, whereas the other town has none of these features. This should make positive identification fairly easy.

The post Navigation: Chart-Reading in Flight first appeared on Learn To Fly.

At the end of one hour of flight, the aircraft is in a position that results from a combination of the following two motions:

• Movement of the air mass in reference to the ground; and
• Forward movement of the aircraft through the airmass.

As shown in the figure below, an aircraft flying eastward at an airspeed of 120 knots in still air has a groundspeed (GS) exactly the same—120 knots. If the mass of air is moving eastward at 20 knots, the airspeed of the aircraft is not affected, but the progress of the aircraft over the ground is 120 plus 20 or a GS of 140 knots. On the other hand, if the mass of air is moving westward at 20 knots, the airspeed of the aircraft remains the same, but GS becomes 120 minus 20 or 100 knots.

Assuming no correction is made for wind effect, if an aircraft is heading eastward at 120 knots and the air mass moving southward at 20 knots, the aircraft at the end of 1 hour is almost 120 miles east of its point of departure because of its progress through the air. It is 20 miles south because of the motion of the air. Under these circumstances, the airspeed remains 120 knots, but the GS is determined by combining the movement of the aircraft with that of the air mass. GS can be measured as the distance from the point of departure to the position of the aircraft at the end of 1 hour. The GS can be computed by the time required to fly between two points a known distance apart. It also can be determined before flight by constructing a wind triangle.

The direction in which the aircraft is pointing as it flies is called heading. Its actual path over the ground, which is a combination of the motion of the aircraft and the motion of the air, is called track. The angle between the heading and the track is called drift angle. If the aircraft heading coincides with the TC and the wind is blowing from the left, the track does not coincide with the TC. The wind causes the aircraft to drift to the right, so the track falls to the right of the desired course or TC.

The following method is used by many pilots to determine compass heading: after the TC is measured, and wind correction applied resulting in a TH, the sequence TH ± variation (V) = magnetic heading (MH) ± deviation (D) = compass heading (CH) is followed to arrive at compass heading.

By determining the amount of drift, the pilot can counteract the effect of the wind and make the track of the aircraft coincide with the desired course. If the mass of air is moving across the course from the left, the aircraft drifts to the right, and a correction must be made by heading the aircraft sufficiently to the left to offset this drift. In other words, if the wind is from the left, the correction is made by pointing the aircraft to the left a certain number of degrees, therefore correcting for wind drift. This is the wind correction angle (WCA) and is expressed in terms of degrees right or left of the TC.

To summarize:

• Course—intended path of an aircraft over the ground or the direction of a line drawn on a chart representing the intended aircraft path, expressed as the angle measured from a specific reference datum clockwise from 0° through 360° to the line.
• Heading—direction in which the nose of the aircraft points during flight.
• Track—actual path made over the ground in flight. (If proper correction has been made for the wind, track and course are identical.)
• Drift angle—angle between heading and track.
• WCA—correction applied to the course to establish a heading so that track coincides with course.
• Airspeed—rate of the aircraft’s progress through the air.
• GS—rate of the aircraft’s inflight progress over the ground.

The post Navigation: The Effect of Wind first appeared on Learn To Fly.

TIME
To determine time you need two pieces of information: distance (in nautical miles) and ground speed (in knots).

Distance / Ground Speed = Time 

How long will it take you to fly a distance of 190 NM at a ground speed of 135 knots?

190/135 = 1.4 hours

To convert the .4 to minutes you need to multiply by 60.

0.4 x 60 = 24 minutes

Your answer is 1 hour and 24 minutes.

DISTANCE
This next calculation is used to determine distance flown in a given time.

Ground Speed (in knots) X Time (in hours) = Distance (in nautical miles)

How far will the aircraft fly in 1 hour and 30 minutes at a ground speed of 120 knots? The first step is to convert the 30 minutes into equivalant hours, instead of multiplying by 60 like we did above, here we will divide by 60 (30/60=0.5).

120 X 1.5 = 180 NM

GROUND SPEED
Lastly, to find ground speed we need to know distance and time.

Distance (in nautical miles)/ Time (in hours) = Ground Speed (in knots)

What is our average ground speed if we travel 250 NM in 2 hours ?

250 / 2 = 125 knots

Here are a few to try on your own.

Problem: What it the approximate time en route for a 60 NM leg with a ground speed of 110?

Problem: How far has the aircraft traveled in 1 hour 24 minutes at a ground speed of 140 knots?

Problem: What is your ground speed if you have covered 200 NM in 1 hour 45 minutes?  

The post CFI Brief: Basic Planning Calculations first appeared on Learn To Fly.

91.171 VOR equipment check for IFR operations.
(a) No person may operate a civil aircraft under IFR using the VOR system of radio navigation unless the VOR equipment of that aircraft—
(1) Is maintained, checked, and inspected under an approved procedure; or
(2) Has been operationally checked within the preceding 30 days, and was found to be within the limits of the permissible indicated bearing error set forth in paragraph (b) or (c) of this section.

VOR accuracy may be checked by means of a VOR Test Facility (VOT), ground or airborne checkpoints, or by checking dual VORs against each other. A VOT location and frequency can be found in the Airport/Facility Directory (A/FD). To use the VOT, tune to the appropriate frequency and center the CDI. The omni-bearing selector should read 0° with a FROM indication, or 180° with a TO indication. The allowable error is ±4°. VOR receiver checkpoints are listed in the A/FD. With the appropriate frequency tuned and the OBS set to the published certified radial, the CDI should center with a FROM indication when the aircraft is over the designated check point. Allowable accuracy is ±4° for a ground check, and ±6° for an airborne check. If the aircraft is equipped with dual VORs, they may be checked against each other. The maximum permissible variation when tuned to the same VOR is ±4°.

The pilot must log the results of the VOR accuracy test in the aircraft logbook or other record. The log must include the date, place, bearing error, if any, and a signature. Most rental aircraft keep a separate log in a dispatch binder or in the aircraft for pilots to easily determine when the last inspection was conducted.

The post CFI Brief: Checking the accuracy of your VOR first appeared on Learn To Fly.

This Thursday, we’ll pick up where we left off with flight planning last week, but today we have a post on another cockpit navigation aid: the automatic direction finder (ADF). This post is excerpted from the Pilot’s Handbook of Aeronautical Knowledge.

Many general aviation-type aircraft are equipped with ADF radio receiving equipment. To navigate using the ADF, the pilot tunes the receiving equipment to a ground station known as a nondirectional radio beacon (NDB). The NDB stations normally operate in a low or medium frequency band of 200 to 415 kHz. The frequencies are readily available on aeronautical charts or in the A/FD.

All radio beacons except compass locators transmit a continuous three-letter identification in code except during voice transmissions. A compass locator, which is associated with an instrument landing system, transmits a two-letter identification.

Standard broadcast stations can also be used in conjunction with ADF. Positive identification of all radio stations is extremely important and this is particularly true when using standard broadcast stations for navigation.

NDBs have one advantage over the VOR. This advantage is that low or medium frequencies are not affected by line-of-sight. The signals follow the curvature of the Earth; therefore, if the aircraft is within the range of the station, the signals can be received regardless of altitude.

The following table gives the class of NDB stations, their power, and usable range:

One of the disadvantages that should be considered when using low frequency (LF) for navigation is that low frequency signals are very susceptible to electrical disturbances, such as lightning. These disturbances create excessive static, needle deviations, and signal fades. There may be interference from distant stations. Pilots should know the conditions under which these disturbances can occur so they can be more alert to possible interference when using the ADF.

Basically, the ADF aircraft equipment consists of a tuner, which is used to set the desired station frequency, and the navigational display.

The navigational display consists of a dial upon which the azimuth is printed, and a needle which rotates around the dial and points to the station to which the receiver is tuned.

Some of the ADF dials can be rotated to align the azimuth with the aircraft heading; others are fixed with 0° representing the nose of the aircraft, and 180° representing the tail.

Tracking to the station requires correcting for wind drift and results in maintaining flight along a straight track or bearing to the station. When the wind drift correction is established, the ADF needle indicates the amount of correction to the right or left. For instance, if the magnetic bearing to the station is 340°, a correction for a left crosswind would result in a magnetic heading of 330°, and the ADF needle would indicate 10° to the right or a relative bearing of 010°.

Although the ADF is not as popular as the VOR for radio navigation, with proper precautions and intelligent use, the ADF can be a valuable aid to navigation.

The post Navigation: Automatic Direction Finder first appeared on Learn To Fly.