To assist pilots transitioning to a visual landing at the conclusion of a precision instrument approach, precision instrument runways have specific markings.

A displaced threshold on an instrument runway is indicated by arrows in the middle of the runway leading to the displaced threshold mark. The runway edge lights to the displaced threshold appear red to an airplane on approach, and to an airplane taxiing to the displaced threshold from the absolute end of the runway. They appear white when taxiing back from the displaced threshold toward the absolute end of the runway. The green runway end lights seen on approach to a runway with a displaced threshold are found off the edge of the runway.

The runway surface with arrows to the displaced threshold is available for taxiing, takeoff and landing roll-out, but not for landing. The initial part of this runway is a non-touchdown area. If chevrons rather than arrows are used to mark the displaced threshold, then the surface is not available for any use, other than aborted takeoff from the other direction.

A precision instrument runway will contain a designation, centerline, threshold, aiming point, touchdown zone, and side strips as seen in the figure below. Runway threshold strips can be configured in two ways. Four solid strips on either side of the centerline or configured as such that the number of strips correlates to the width of the runway (see table). The runway aiming point markers are large rectangular marks on each side of the runway centerline usually placed 1,000 feet after the threshold and serve as a visual aiming point for the pilot. Touchdown zone markers identify the touchdown zone for landing operations, providing coded distance information in 500 foot intervals and shown as either one, two, or three vertical stripes on either side of the centerline.

The post IFR: Precision Instrument Runway Markings 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.

The instrument landing system is known as the ILS. It enables a suitably equipped airplane to make a precision approach to a particular runway. A precision approach is one in which electronic glide slope guidance, as well as tracking guidance, is given. Each ILS is known by the airport and runway it serves, for example, the Lafayette ILS Rwy 10, in Indiana.

The instrument landing system has four main elements:

1. the localizer, which provides course guidance along the extended centerline of the runway (guidance in azimuth left or right of the extended centerline);
2. the glide slope, which provides vertical guidance toward the runway touchdown point, usually at a slope of approximately 3° to the horizontal, or 1:20 (vertical guidance above or below the glide slope);
3. marker beacons, which provide accurate range fixes along the approach path (usually an outer marker and a middle marker) are provided; and
4. approach lights, VASI (visual approach slope indicator), and other lights (touchdown zone lighting, runway lights, etc.) to assist in transitioning from instrument to visual flight.

There may be supplementary NAVAIDs available, including:

• a compass locator (NDB); and
• DME.

The outer marker may be replaced as a range marker on some ILS’s by a compass locator, a DME distance, or an ASR or PAR radar position from ATC. The middle marker, where more accuracy is required, may be replaced as a range marker on some ILS’s by a compass locator or PAR radar position from ATC (but not by a DME distance or ASR radar position). These range markers provide you with an accurate distance fix along the localizer.

A co-located compass locator and outer marker will appear on the approach chart as “LOM.” A co-located compass locator and middle marker will appear on the approach chart as “LMM.”

The ideal flight path on an ILS approach, where the localizer plane and the glide slope plane intersect, is referred to as the glide path. The word glide is really a misnomer carried over from earlier days, since modern airplanes make powered approaches down the glide path, rather than glide approaches. However, the term glide path is still used.

Since ILS approaches will often be made in conditions of poor visibility or at night, there is always associated visual information that can be used once the pilot becomes “visual” (has the runway environment in sight). This may include approach lights leading toward the runway, runway lights, touchdown lights, and centerline lights. Lighting is indispensable for night operations, but it can also be invaluable during daylight hours in conditions of restricted visibility.

There may also be a VASI situated near the touchdown zone to provide visual slope guidance during the latter stages of the approach. This, and other visual information, will assist you in maintaining a stable descent path toward the runway, where you can complete the landing.

The ILS is selected in the cockpit on the NAV/COM radio. Its cockpit display is usually the same instrument as for the VOR except that, in addition to the vertical localizer needle (CDI) that moves left and right for course guidance, there is a second needle or indicators that come into view. It is horizontal, and is able to move up and down to represent the position of the glide slope relative to the airplane. Some ILS indicators have needles that are hinged and move like wipers, others have needles that move rectilinearly. The airplane may be thought of as the center dot, and the intersection of the needles as the relative position of the glide path.

We’ll have more to share on the ILS, and much more on IFR, in future Monday posts.

The post IFR: The Instrument Landing System (ILS) first appeared on Learn To Fly.

This requires a different pitch attitude and a different power setting. To slow the airplane, the pilot reduces power and gradually raises the pitch attitude to maintain altitude; to increase airspeed, the pilot increases power, and gradually lowers the pitch attitude to maintain altitude.

Once the desired airspeed is achieved, the pilot adjusts the power to maintain it. The precise power required for steady flight will depend upon the amount of total drag, which, in level flight, varies with angle of attack and airspeed. Higher power will be required for:

• high speed cruise (when total drag is high mainly due to parasite drag); and
• low speed cruise (when total drag is high mainly due to induced drag).

Medium power is required for normal cruise. The ASI confirms whether or not correct power is set. The ASI is the primary performance guide to power requirements during level flight if you fly a particular airspeed.

Practicing airspeed changes in cruise is excellent instrument flying practice since pitch, bank (and balance) and power changes must all be coordinated to maintain constant altitude and heading. When the pilot changes power, a single-engined propeller- driven airplane will tend to move around all three axes of movement. If the propeller rotates clockwise as seen from the cockpit (the usual case), adding power will cause the nose to pitch up and yaw left, with a tendency for the airplane to roll left.

The pilot can counteract this by applying forward elevator pressure to prevent the nose pitching up, with right rudder and right aileron pressure to overcome the tendency to yaw and roll left. The converse applies when reducing power, hold the nose up and apply left rudder pressure. Refer to the AI to keep the wings level and hold the pitch attitude, and keep the ball centered.

Some hints on changing cruising speed follow:

• The attitude indicator gives a direct picture of pitch and bank attitudes.
• The ball gives a direct indication of coordination.
• Useful performance instruments are the altimeter and VSI—they ensure altitude is being maintained, and the heading indicator to ensure heading is being maintained.
• The airspeed indicator indicates the power requirements. If too slow, add more power; if too fast, reduce power.

The pilot’s scan rate of the flight instruments during any power change needs to be reasonably fast to counteract the pitch/yaw effects smoothly and accurately. For this reason, it is good to develop the skill of judging power changes by throttle movement and engine sound, rather than only by observation of the power indicator. This allows the pilot to concentrate on the flight instruments until after the power change has been made, at which time a quick glance at the power indicator for fine adjustment suffices.

When you memorize the approximate power settings necessary to maintain the various cruise speeds, then power handling and airspeed changes become simpler to manage.

Small airspeed changes (say five knots either way) can generally be handled by a single small power change, then allowing the airplane to gradually slow down or accelerate to the desired speed. Large airspeed changes, however, are most efficiently achieved within a few seconds by underpowering on the initial power change for a speed decrease, or overpowering on the initial power change for a speed increase. This allows more rapid deceleration or acceleration to the desired speed, at which time the necessary power to maintain that airspeed is set.

Once the desired airspeed is achieved and suitable power is set, the ASI will indicate if further fine adjustment of power to maintain airspeed is required. In level flight, the ASI is the primary guide to power requirements.

The post Aircraft Performance: Changing Airspeed in Straight-and-Level Flight 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.

It was dark and a bit blustery that evening. While at 9,000 ft MSL and on an IFR flight plan in IMC we began picking up light icing on the wings of our Piper Cherokee. It was my first experience in an icing condition so I looked to my instructor for guidance. He told me to check the left wing with my flashlight every few minutes to note the ice build-up and he would do the same on the right wing. If conditions got worse we would re-evaluate, but for now we both felt comfortable continuing on. About 2 minutes later I grabbed my flashlight and started inspecting the left wing out the pilot’s side window to note any additional ice build-up. After a thorough inspection I turned my head back into the cockpit only to see my attitude indicator showing a 40° bank to the left and my vertical speed indicator showing a 500 ft per minute descent. I was so overly concerned with checking the wing for ice I forgot to fly the airplane, and my instructor didn’t notice because he at this same time was checking the right wing for ice. The first thing that popped into my head was to yell “UNUSUAL ATTITUDE!” at which point I’m sure my instructor’s head swung around rather quickly. I began correcting to put the airplane back in a straight and level flight attitude, reduce power, level the wings, and raise the nose. For the next 10 or so minutes my head was glued to the instrument panel until we finally exited out of the IMC into VMC and landed without incident.

Both my instructor and I took something home of value that day. For me, it was to always remember to first and foremost fly the airplane. For my instructor, it was to never trust your students, or at least that’s what he told me afterwards.

During training for both Private and Instrument Pilot Airplane you will be taught recognition and recovery for both nose-low and nose-high unusual attitudes. Your instrument training however will focus more on recognition and recovery solely by reference to flight instruments or with no outside visual reference cues, like the situation in my story above. Discussed below are recognition and recovery from both types of unusual attitudes as outlined in the Instrument Flying Handbook (FAA-8083-15), but remember the same principals will apply to a Private Pilot as well, who might find him or herself in inadvertent IMC.

Recognizing Unusual Attitudes
As a general rule, any time an instrument rate of movement or indication other than those associated with the basic instrument flight maneuvers is noted, assume an unusual attitude and increase the speed of cross-check to confirm the attitude, instrument error, or instrument malfunction.

Nose-high attitudes are shown by the rate and direction of movement of the altimeter needle, vertical speed needle, and airspeed needle, as well as the immediately recognizable indication of the attitude indicator (except in extreme attitudes). Nose-low attitudes are shown by the same instruments, but in the opposite direction. These are shown in the figures below.

Nose-High Attitudes
If the airspeed is decreasing, or below the desired airspeed, increase power (as necessary in proportion to the observed deceleration), apply forward elevator pressure to lower the nose and prevent a stall, and correct the bank by applying coordinated aileron and rudder pressure to level the miniature aircraft and center the ball of the turn coordinator. The corrective control applications are made almost simultaneously, but in the sequence given above. A level pitch attitude is indicated by the reversal and stabilization of the ASI and altimeter needles. Straight coordinated flight is indicated by the level miniature aircraft and centered ball of the turn coordinator.

Procedures to recover from a nose-high unusual attitude:

1. Add Power
2. Apply Forward Elevator Pressure
3. Level the Wings

Nose-Low Attitudes
If the airspeed is increasing, or is above the desired airspeed, reduce power to prevent excessive airspeed and loss of altitude. Correct the bank attitude with coordinated aileron and rudder pressure to straight flight by referring to the turn coordinator. Raise the nose to level flight attitude by applying smooth back elevator pressure. All components of control should be changed simultaneously for a smooth, proficient recovery. However, during initial training a positive, confident recovery should be made by the numbers, in the sequence given above. A very important point to remember is that the instinctive reaction to a nose-down attitude is to pull back on the elevator control.

After initial control has been applied, continue with a fast cross-check for possible over controlling, since the necessary initial control pressures may be large. As the rate of movement of altimeter and ASI needles decreases, the attitude is approaching level flight. When the needles stop and reverse direction, the aircraft is passing through level flight. As the indications of the ASI, altimeter, and turn coordinator stabilize, incorporate the attitude indicator into the cross-check.

The attitude indicator and turn coordinator should be checked to determine bank attitude and then corrective aileron and rudder pressures should be applied. The ball should be centered. If it is not, skidding and slipping sensations can easily aggravate disorientation and retard recovery. If entering the unusual attitude from an assigned altitude (either by an instructor or by air traffic control (ATC) if operating under instrument flight rules (IFR)), return to the original altitude after stabilizing in straight-and-level flight.

Procedures to recover from a nose-low unusual attitude:

1. Reduce Power
2. Level the Wings
3. Raise the Nose

For additional training and information on upset prevention and recovery (or unusual flight attitudes), you can refer to either the Airplane Flying Handbook (FAA-H-8083-3) or Instrument Flying Handbook (FAA-H-8083-15), both great references.

The post CFI Brief: Unusual Attitude Recoveries first appeared on Learn To Fly.

Pitch Instruments:
• Attitude Indicator
• Altimeter
• Airspeed Indicator
• Vertical Speed Indicator

Bank Instruments:
• Attitude Indicator
• Heading Indicator
• Turn Coordinator

Power Instruments:
• Manifold Pressure Gauge
• Tachometer
• Airspeed Indicator

When climbing and descending, it is necessary to begin level-off in enough time to avoid overshooting the desired altitude. The amount of lead to level-off from a climb varies with the rate of climb and pilot technique. If the aircraft is climbing at 1,000 feet per minute, it will continue to climb at a descending rate throughout the transition to level flight. An effective practice is to lead the altitude by 10% of the vertical speed (500 fpm would have a 50 foot lead; 1,000 fpm would have a 100 foot lead).

The amount of lead to level-off from a descent also depends upon the rate of descent and control technique. To level-off from a descent at descent airspeed, lead the desired altitude by approximately 10%. For level-off at an airspeed higher than descending airspeed, lead the level-off by approximately 25%.

When making initial pitch attitude corrections to maintain altitude during straight-and-level flight, the changes of attitude should be small and smoothly applied. As a rule-of-thumb for airplanes, use a half-bar-width correction for errors of less than 100 feet and a full-bar-width correction for errors in excess of 100 feet.

These are the types of attitude instrument flying questions you can expect to see on an instrument knowledge test. Using the information above you should be able to easily answer each of the three questions.

1. Which instruments, in addition to the attitude indicator, are pitch instruments?
A—Altimeter and airspeed only.
B—Altimeter and VSI only.
C—Altimeter, airspeed indicator, and vertical speed indicator.

2. Which instruments should be used to make a pitch correction when you have deviated from your assigned altitude?
A—Altimeter and VSI.
B—Manifold pressure gauge and VSI.
C—Attitude indicator, altimeter, and VSI.

3. For maintaining level flight at constant thrust, which instrument would be the least appropriate for determining the need for a pitch change?
A—Altimeter.
B—VSI.
C—Attitude indicator.

Answers

↓

↓

↓

↓

The answer to all three questions is C.

For additional sample FAA Knowledge Test questions pick up a copy of the ASA Test Prep or Prepware Software for Instrument Rating.

The post CFI Brief: Attitude Instrument Flying first appeared on Learn To Fly.

The best time to organize these things is prior to flight.

Today, we’ll discuss preflight considerations for an IFR flight with excerpts from our textbook The Pilot’s Manual: Instrument Flying (PM-3).

Preflight considerations, which are all logical, include:

• Am I properly qualified (instrument rated and qualified for this airplane, instrument current)?
• Am I medically fit today?
• Is the airplane suitably equipped (serviceable radios, anti-icing equipment, lighting, etc.)?
• What is the weather? Are changes expected?
• Is the departure airport suitable for my operation?
• Is the destination airport suitable for my operation?
• Is an alternate airport required (or more than one)?
• What routes are suitable in terms of terrain, weather and available en route NAVAIDs?
• Are there any relevant NOTAMs (FDC, Class I, Class II)?
• Are there any Terminal Flight Restrictions (TFRs) for my planned route of flight?
• Prepare charts (DPs, en route charts, instrument approach charts, VFR sectionals, etc.).
• Compile a flight log with courses, distances, times, MEAs and cruising altitudes calculated.
• Compile a fuel log, with adequate fuel reserves.
• File an IFR flight plan.
• Prepare the airplane.
• Organize the cockpit for flight—select charts, ensure that a flashlight is kept handy for night flying, etc.
• Brief passengers.

To operate in controlled airspace (Classes A–E) under IFR, you are required to:

• file an IFR flight plan (usually done in person or by telephone to FSS or ATC on the ground at least 30 minutes prior to the flight); and
• obtain an air traffic clearance (usually requested by radio immediately prior to departure or entering controlled airspace).

The 30 minutes is required to allow time for ATC to process your flight data and (hopefully) avoid delays to your flight. The preferred methods of filing a flight plan are: in person by telephone or by DUATs — by radio is permitted, but discouraged because of the time it takes. Closing a flight plan by radio is typical because it takes just a few seconds.

Closing an IFR flight plan is automatically done by ATC at tower-controlled airports after landing. At an airport without an active control tower, you must close the flight plan with FSS or ATC by radio or telephone. Do this within 30 minutes of the latest advised ETA, otherwise search and rescue (SAR) procedures will begin.

• An IFR flight plan is required in both IMC and VMC in Class A airspace, and in IMC conditions in Classes B, C, D and E (controlled) airspace (and also in VMC, if you want to practice);
• An IFR flight plan is not required in Class G (uncontrolled) airspace.

To assist you in completing the flight plan and performing the flight, you should compile a navigation log, calculating time intervals and fuel requirements. A typical navigation log is shown in figure 1, and a typical flight plan form is shown in figure 2.

Figure 1. Click for full-size.

Figure 2. Click for full-size.

Important navigation log items to be inserted on the flight plan include:

• the planned route;
• the initial cruise altitude or flight level (later altitudes or flight levels can be requested in flight);
• the estimated time en route (ETE), in hours and minutes, from departure to touchdown at the first point of intended landing;
• the total usable fuel on board at takeoff, converted to endurance in hours and minutes.

If you wish to fly part of the route according to IFR procedures and part according to VFR procedures, you can file a composite flight plan, signified by you checking both IFR and VFR in the Item 1 box on the flight plan form. You should also indicate the clearance limit fix in the flight-planned route box, to show where you plan to transition from IFR to VFR.

The post IFR: Preparation for Flight first appeared on Learn To Fly.

In instrument conditions, when the natural horizon cannot be seen, pitch attitude and bank angle information is still available to the pilot in the cockpit from the attitude indicator. The pitch attitude changes against the natural horizon are reproduced in miniature on the attitude indicator.

In straight-and-level flight, for instance, the wings of the miniature airplane should appear against the horizon line, while in a climb they should appear one or two bar widths above it.

In a turn, the wing bars of the miniature airplane will bank along with the real airplane, while the horizon line remains horizontal. The center dot of the miniature airplane represents the airplane’s nose position relative to the horizon. Today, there are a variety of attitude indicators you might see. Some are referred to as a primary flight display (PFD). In any display, the principles remain the same: the center dot or center point’s position relative to the horizon indicates a climb or descent.

Scanning the instruments with your eyes, interpreting their indications and applying this information is a vital skill to develop if you are to become a good instrument pilot. Power is selected with the throttle, and can be checked (if required) on the power indicator. Pitch attitude and bank angle are selected using the control column, with frequent reference to the attitude indicator. With both correct power and attitude set, the airplane will perform as expected. The attitude indicator and the power indicator, because they are used when controlling the airplane, are known as the control instruments. The actual performance of the airplane, once its power and attitude have been set, can be cross-checked on what are known as the performance instruments—the altimeter for altitude, the airspeed indicator for airspeed, the heading indicator for direction, and so on.

• in holding patterns (which, for example, may be racetrack patterns with legs of 1 or 2 minutes duration);
• in timed turns (a 180° change of heading at standard-rate of 3° per second taking 60 seconds); and
• to measure time after passing certain radio fixes during instrument approaches (at 90 knots groundspeed, for instance, it would take 2 minutes to travel the 3 NM from a particular fix to the published missed approach point).

Another area on the instrument panel contains the navigation instruments, which indicate the position of the airplane relative to selected navigation facilities. These NAVAIDs will be considered in detail later in your training, but the main ones are:

• VHF omni range (VOR) cockpit indicator, which indicates the airplane’s position relative to a selected course to or from the VOR ground station;
• automatic direction finder (ADF), which has a needle that points to a nondirectional beacon (NDB); and
• distance measuring equipment (DME) or VORTAC, which indicates the slant distance in nautical miles to the selected ground station.

Instrument scanning is an art that will develop naturally during your training, especially when you know what to look for. The main scan to develop initially is that of the six basic flight instruments, concentrating on the AI and radiating out to the others as required. Then as you move on to en route instrument flying, the navigation instruments will be introduced. Having scanned the instruments, interpreted the message that they contain, built up a picture of where the airplane is and where it is going, you can now control it in a meaningful way.

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