Instrument Approach Procedures

S3 – Instrument Approach Procedures Instrument Approach Procedures IntroductionAn Instrument Approach Procedure (IAP), or Instrument Approach Plates ...
Author: Buddy Bennett
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S3 – Instrument Approach Procedures

Instrument Approach Procedures IntroductionAn Instrument Approach Procedure (IAP), or Instrument Approach Plates as they were once called, are published FAA approved instrument approaches for U.S. airports. An IAP provides a series of predetermined maneuvers to be made by an aircraft under IFR rules of flight and provides a graphical depiction to be followed by the pilot for a particular approach into an airport or specific runway, or to a point from which a landing may be made visually. They will also include instructions on what to do in the event of a missed approach. Also referred to as Terminal Procedures, IAPs are classified as either precision or non-precision. Precision approaches provide both lateral (localizer) and vertical (glideslope) information. An ILS instrument approach is the most commonly used approach on VATSIM. GPS or RNAV approaches may also be considered precision approaches based on the equipment type of the aircraft if properly equipped with a Wide Area Augmentation System (WAAS). Non-Precision approaches utilize only lateral instrument guidance. Examples of these approaches are VOR, NDB and Localizer approaches. Understanding the equipment suffix code of an aircraft will be important in properly setting an aircraft up for an IAP. Some approaches even require that the aircraft be equipped with specific equipment to conduct the approach. We will discuss this later when learning how to vector for an IAP. One thing to keep in mind is that Visual Approaches, although not an Instrument Approach, are only given to IFR aircraft (VFR aircraft are always visual). Although there are published Visual Approach procedures (KPHX – Power Plant Visual RWY 25R), a visual approach does not rely solely on instruments to guide the pilot to the airport or runway. They make visual contact with the airfield (or follow an aircraft they have visual contact with) to conduct the approach. Although many airlines require pilots to tune in any localizer that may be available for the runway they are conducting the visual approach to, it is still not considered an instrument approach when a visual approach has been authorized. VFR aircraft are not authorized to conduct instrument approaches at controlled airfields. When requested, they must be approved as a “practice” approach. Unless the practice approach is being conducted within Class B or C airspace, you will also inform the pilot that no separation services are provided. When executing a practice IAP, a VFR aircraft is not authorized to execute the missed approach procedure without additional authorization from ATC.

ZAB Training Program -S3- “Introduction to Instrument Approach Procedures” – 08/15/2011 Tim Reeves – Training Administrator

Understanding a Published Instrument Approach Procedure ChartAn Instrument Approach Chart may seem overwhelming at first glance. In fact, as a controller, most of the information is not even necessary for you to do your job correctly. Most VATSIM pilots wouldn’t even have a clue what all this information means. Regardless, using two ZAB IAP charts, we are going to teach you everything that is contained so you’ll be one step ahead of even the most serious flight sim pilot you will encounter. For this tutorial, we will be using the “VOR or GPS-A” and the “VOR-C” for Scottsdale. You can find these, and all published charts for free at any one of these sites: www.airnav.com, www.myairplane.com or www.skyvector.com. The chart can be broken down into the following sections: Header Pilot Briefing

Plan View

Profile View Airport Diagram

Footer

ZAB Training Program -S3- “Introduction to Instrument Approach Procedures” – 08/15/2011 Tim Reeves – Training Administrator

The Header and Footer Areas

Starting from the left, we have the City and State the airport is located. The middle code is the FAA Code for the type of chart and the airport it is associated with. At the far right, the Approach Type and Runway are listed in large letters. Since this approach is not within 30 degrees of the final course for any runway, there is no specific runway listed, and a circling approach to the active runway will have to be conducted once the pilot has made a visual on the airport. Underneath the Approach Type is the Airport Name and FAA Alphanumeric 3 or 4 digit code.

The Footer repeats the City and State, Airport Name and Approach Type. In addition, the left side shows the Amendment Number, and Date of last amendment in the format of year-day. In this case, this amendment was made on the 181st day of 2011. In some cases, the date will be shown as day/month/year, as shown on the VOR-C approach. The middle gives the Latitude/Longitude of the airport.

ZAB Training Program -S3- “Introduction to Instrument Approach Procedures” – 08/15/2011 Tim Reeves – Training Administrator

Pilot Briefing

The Pilot Briefing area contains 3 rows of information pertinent to the approach, airport and runways.

The first row will contain 3 or 4 boxes. If the approach type uses a radio navigational aid such as ILS, LOC, VOR or NDB, then you will find the Type, Identifier, Frequency, and Channel (typically TACAN for military) of the navaid. Some RNAV and GPS approaches will not have this first box. However, if a WAAS channel is listed on either one of these types of approaches, then the approach becomes a precision approach for properly equipped aircraft. Notice the underline under the frequency, 115.6. An underline means that the frequency has no voice capability. Some navaids will have voice transmissions in addition to the morse code identifier, such as current weather conditions in the vicinity or other NOTAMs. In our flight sim environment, you will only ever hear the morse code on any navaid frequency. The next box gives the magnetic heading of the Final Approach Course of the approach. The last box gives information for the runway the approach is for. Again, since this approach course is more than 30 degrees from the course of any runway, a circle to land will have to be initiated by the pilot to the active runway. Therefore, the Runway Landing Length (Rwy ldg) and the Touch Down Zone Altitude (TDZE) are not applicable. The Airport Elevation (Apt Elev) will appear. The second row includes general information for the airport and missed approach instructions. The white “T” in the black triangle indicates to the pilot that the take-off minimums at Scottsdale are non-standard or that there are published departure procedures. The white “A” in the black triangle signifies that the airport has non-standard IFR alternate minimums. Pilots should refer to an Airport Facility Directory for further specifics. On approaches to a specific runway, a third box in the middle will have information about approach and runway lighting. If specific equipment is required for the approach, it will be found on this row. The third row of boxes includes all of the communications frequencies that will be used in the order of use, from left to right. The black star next to the ATIS or Tower frequencies means that it is not under continuous operation. Thus, you see “CTAF” next to the tower frequency, which means Common Traffic Advisory Frequency. If there is no tower, then a CTAF frequency will be shown. When the tower is not in operation, pilots should still use this frequency to announce intentions. On VATSIM, we obviously use 122.8 for all Common Traffic Advisory transmissions. The “L” in the black oval means the runway ZAB Training Program -S3- “Introduction to Instrument Approach Procedures” – 08/15/2011 Tim Reeves – Training Administrator

lighting can be controlled by the pilot clicking his mic several times on the frequency to activate them. A nifty real world tool but not typically found in flight sim except possibly on some add on sceneries.

Plan View The Plan View is the most important tool for the controller when an aircraft requests an instrument approach. The first thing a controller or pilot should be aware of is the Minimum Safe Altitude circle. Across the top of the circle, it reads “MSA PXR 25 NM”, which lets us and the pilot know that these are the minimum safe altitudes to descend an aircraft to within 25nm of the specified reference point, the Phoenix VOR in this case. Based on the magnetic course of flight of the aircraft towards the reference point, varying altitudes may be applied. The MSA altitudes provide a 1,000 ft. clearance from all terrain and known obstructions. Centered in the plan view are the horizontal, or lateral, details of the approach. This overhead view is drawn to scale within 10nm of the airport. The overhead view provides the locations of fixes, intersections, points, radials, holding areas, missed approach procedures, terrain, obstacles and much more. The next items to be identified are any terrain or obstacles depicted. Dots with MSL altitudes signify terrain and show the measured ground elevations. A “⟑” wedge marker signifies some sort of obstacle, usually man-made, such as buildings or antennas. The largest dot, either terrain or wedge marker, signifies the highest obstacle on the diagram. In the diagram above, it is the peak on the mountain terrain NE of the airport, labeled as 4067 ft. above sea level. These altitudes are the actual altitudes, so you must be above the altitude noted or you will hit them. A “±” next to an altitude means the altitude is an estimate.

ZAB Training Program -S3- “Introduction to Instrument Approach Procedures” – 08/15/2011 Tim Reeves – Training Administrator

The Runway Layout is also shown in the plan view to show the placement of the airport on the diagram, shown by dark, solid lines. The Procedure Track will be a bold line with an arrow and a heading value associated with the Approach Course, 002° in our example. IAPs often use Radial Identifiers to mark points, fixes or intersections on the approach, and are depicted in the plan view with thin lines from the VOR being used and the Radial identified within the line. In our example above, the GELTS intersection is located by the intersection of the R-299 radial from the Willie VOR, 5.5 miles from the PXR VOR on the R-002 radial. We know the distance is measured from the PXR VOR because of the PXR, we highlighted, next to the distance. In some cases, the distance may be measured from another reference VOR, such as IWA, and would be marked IWA instead. Other radial identifiers on the plan view include the R-336 PXR radial which intersects with the R-056 BXK radial, thus producing the intersection AVENT. Notice that AVENT is not a point on the approach, but rather a point for an aircraft to hold at in the event of a missed approach. You may often find points on an IAP chart that are not actual points for the approach. Be sure you are aware of the actual points to be used in vectoring. The Initial Approach Fix (IAF) are points on the approach that an aircraft can enter the IAP. On our example, the IAF is the PXR VOR. Some approaches have several IAFs for different directions of arriving aircraft. The IAF is the point you should vector all aircraft to for the IAP, although it is acceptable to vector to intermediate or final fixes as well. Depending on the type of approach, and the equipment of the aircraft, you will give radar vectors to the IAF or tell the aircraft to proceed direct the IAF. (ie. “Proceed direct the Phoenix VOR, cross Phoenix at or above 4,000. Cleared for the VOR-GPS Alpha Approach into Scottsdale, circling right to land runway 21.” Or “Fly heading 120, intercept the Phoenix VOR 002 radial proceed inbound to the Phoenix VOR. Cross Phoenix at or above 4,000. Cleared for the VOR-GPS Alpha approach into Scottsdale.”) Make note that if you are clearing an aircraft for anything, you should say “cleared” and not just “clear”. When controlling a radar area where multiple airports exist other than the primary airport, you must also state which airport the approach is for. Thus, in the above example we stated “….Cleared for the VOR-GPS Alpha approach into Scottsdale…” An Intermediate Fix (IF) identifies the point at which an aircraft begins to configure speed, position and altitude adjustments and prepares to make visual contact with the airport or runway. The IF is not always labeled on a diagram. It is permissible in most cases to vector an aircraft to an intermediate fix as well. A Final Approach Fix (FAF) is typically the last point prior to an aircraft making the decision to complete the approach or go missed. It is possible to vector an aircraft to a FAF, but depending on the distance from the runway or airport, the turn they may need to intercept the FAF may not exceed 20 degrees. Although not labeled on the plan view of our example, the FAF can be found on the Profile View, marked with a “ ” Maltese Cross symbol. Generally, the remainder of the IAP is flown visually after the FAF on nonZAB Training Program -S3- “Introduction to Instrument Approach Procedures” – 08/15/2011 Tim Reeves – Training Administrator

precision approaches. If vectoring to an Intermediate of Final Approach fix, you should use the PTAC vectoring rules (Position, Turn, Altitude, Clearance) for vectoring to final. (ie. “You are 4 miles from GELTS, turn left heading 010, intercept the Phoenix Vortac 002 radial. Maintain 3,700 until established on the final course. Cleared for the VOR-GPS Alpha approach into Scottsdale, circling right to land runway 21.) A Procedure Turn (PT) is a standardized way of having aircraft make turns that allow it to enter the final approach course, regardless of the direction of their arrival. Simply put, it allows an aircraft to turn around. Procedure turns are a required part of an instrument approach. On our example above, our procedure turn is actually a 1 minute holding pattern SE of the PXR VORTAC. A note below the IAF label states “NoPT for arrivals on PXR VORTAC airway radials 143 clockwise to 185”. In other words any aircraft arriving in the blue shaded triangle added to our diagram above does not execute the procedure turn and enter the 1 minute hold, but continues straight in on the approach. Any time you see NoPT, it means No Procedure Turn. Unless ATC authorizes a straight-in or specifically states “no procedure turn” or “no hold”, an aircraft is expected to fly the procedure turn as part of the approach.

Tear Drop Procedure Turn

Other procedure turns include intercepting the outbound or back course away from the airport, making a 45 degree turn to the left or right as published, and making a 180 degree turn back towards the approach course as shown by a barbed arrow. 45° Procedure Turn Tear Drop turns are also a frequent way of reversing course to turn around into the final approach course.

The Missed Approach Point (MAP) is normally the final point shown on an IAP. On our example, the fix called MABAW is the missed approach point. A pilot must have made a visual on the airport prior to reaching the MAP, otherwise they are to execute the missed approach procedure. The missed approach procedure is shown by a dotted line with an arrow signifying the turn necessary for the missed approach. In our example, the aircraft is to make a left turn, climbing to 7,000 and fly heading 280 until intercepting the PXR R-336 outbound to AVENT and hold. Airport Diagram The Airport Diagram gives a simple and basic layout of the airport, which comes in handy for those smaller, uncontrolled airports where a full airport diagram may not be available. The airport diagram shows the placement of runways and their numbers, taxiways and parking,

ZAB Training Program -S3- “Introduction to Instrument Approach Procedures” – 08/15/2011 Tim Reeves – Training Administrator

elevations, obstacles very near the airport, and the types of approach lighting available. The field elevation is noted in the upper left corner. The types of runway approach lighting is shown below the field elevation. There are many different variations of approach lighting and codes. As a controller, we aren’t concerned with them. Just know where to find them in the event a pilot asks you for that information. Underneath the airport diagram, we find a chart labeled “FAF to MAP 3.3 NM”. This chart is used to estimate the time it takes to travel from the Final Approach Fix to the Missed Approach Fix, a distance of 3.3 miles, based on the speed of the aircraft. A handy little tool for the pilot in timing his decision to go missed if the airport is not in sight within that period of time. It can be used to help the controller in timing multiple IFR arrivals into a controlled airfield as well. Profile View

Missed Approach Indicators

The plan view did not provide us altitude information other than the minimum safe altitudes for the approach. The Profile View gives the controller and the pilot the procedure altitude information. As a controller, you will vector the aircraft to the PXR VORTAC, have it cross at or above 4,000 ft, and enter the 1 minute hold (unless the procedure turn is not necessary), then clear the aircraft for the VOR Alpha Approach Scottsdale, circling to land runway 3 or 21. An aircraft should not descend below the altitudes shown until after crossing each point.

ZAB Training Program -S3- “Introduction to Instrument Approach Procedures” – 08/15/2011 Tim Reeves – Training Administrator

The boxes in the top right give, in order, the steps of the missed approach. The first box shows the climbing left turn to 7,000 to a heading of 280, the next box shows the radial they are to intercept to proceed to the the third box, AVENT, for the hold. The chart below the profile view is called the Approach Minimums. Different categories of aircraft are shown here, A B C D E and COPTER. In our example, only categories A-D are shown. Aircraft are categorized based on its maneuvering speed. Maneuvering speed is defined as 1.3 times the stall speed at maximum gross weight in the landing configuration. To make it easy on you, here’s how they are categorized:

As a general rule, you can categorize the aircraft as shown below: Category A – Smaller GA aircraft, piston driven. Category B – Larger GA aircraft and Turbo-Prop aircraft. Some twin engine piston aircraft. Category C & D– The majority of turbo-jet driven aircraft. Category E – Mostly military fighter jets and supersonic capable aircraft. If this IAP were for a specific runway, the first line of the minimums would be for a straight in approach to the runway (ie. S-21, if this were an approach specifically to runway 21). However, since this is not for a specific runway, we are given two “Circling” minimums; one for having the local altimeter, and another set for using the KPHX altimeter setting. The Circling to land minima for this approach is 2,540 ft. Minimum Descent Altitude (MDA) and 2½ statute miles for Categories A & B aircraft. The MDA is the elevation that the aircraft cannot descend below during the approach unless the approach-end of the runway or the airport is clearly in sight and a safe, normal, visual landing can be made. The numbers in the parenthesis apply to military aircraft only. The smaller numbers before the parenthesis is the actual height of the MDA above the airport (AGL). Aircraft Equipment Types (Suffix Codes)Certain IAPs require that aircraft to be properly equipped and the pilot to be properly certified to execute them. Obviously, if an aircraft is not equipped with Area Navigation equipment (RNAV or GPS), there is no way for it to be able to execute an RNAV or GPS approach. Similarly, some approaches require Distance Measuring Equipment (DME). There is an entire FAA document related to instrument approaches and the equipment necessary for the different types of approaches. For the purposes of VATSIM and the typical VATSIM pilot, we will keep it as simple as possible.

ZAB Training Program -S3- “Introduction to Instrument Approach Procedures” – 08/15/2011 Tim Reeves – Training Administrator

Same as above, but also capable of cruising altitudes in RVSM airspace (FL290-410).

/I with RVSM (Without Advanced RNAV)

Simply put, the first 3 groups of equipment types cannot go direct to any point (No DME, DME & TACAN Only). Therefore, they would need radar vectors to a point. An aircraft with Area Navigational Equipment may proceed direct to any point, but may still request radar vectors. For RNAV-GPS approaches with a WAAS channel listed, aircraft with at least a /G or /L suffix can execute the approach as a full precision approach.

An RNAV (RNP) approach requires an /R or /Q suffix. With a little time, you will be able to identify these requirements quickly by referring to the suffix chart.

ZAB Training Program -S3- “Introduction to Instrument Approach Procedures” – 08/15/2011 Tim Reeves – Training Administrator

Radar Vectors

Cannot proceed Direct No GPS or RNAV approaches

Proceed Direct

No RNAV (RNP) approaches

Although an aircraft may have a “NO DME” suffix, it does not disqualify it from executing any published IAP. It may still be equipped with VOR or NDB equipment that will allow it to intercept a radial or localizer. They just may not have a pointer to help them navigate efficiently to the navaid. However, it will not be able to execute a GPS or RNAV approach, or any approach that states “DME required”, and you must deny their request until they can confirm they have the appropriate equipment on board.

Capable of all IAPs

By using the Equipment Capability Suffix Codes, you will be able to determine what types of approaches an aircraft is authorized to fly, and what you must do as a controller to properly vector an aircraft for the approach. You may deny a pilot’s request for a certain approach if they do not have the necessary equipment. If visibility is 3 miles or greater, the easiest alternative is to vector the aircraft for a visual approach.

Test Your Knowledge Use the VOR-C chart to answer the following questions. 1. What is the altitude of the Touch Down Zone of the landing runway? a. 1,510 b. 1,741 c. N/A d. 1,525 2. What is the navaid being used for the basis of this approach? a. BXK VORTAC b. JONHH c. SAENT d. PXR VORTAC e. IWA VORTAC 3. The MAP is: a. SAENT b. AVENT c. COSGR d. JONHH 4. Is the 1 minute holding pattern considered a procedure turn? a. Yes b. No 5. Is the procedure turn shown mandatory for this approach? a. Yes b. No c. Only if ATC authorizes it. d. Yes, unless ATC authorizes straight-in or no procedure turn. e. Only if entering the approach from the north. 6. What is the MDA for a Category C aircraft conducting the approach? a. 970 agl b. 8,900 msl c. 2,480 msl d. 5,600 agl e. Both a & c f. Either b or d

ZAB Training Program -S3- “Introduction to Instrument Approach Procedures” – 08/15/2011 Tim Reeves – Training Administrator

7. N6399B, a C152/A is IFR approaching from the North as shown on the chart. What would be the best vector to give him to join the IAP? a. Fly heading 180, intercept the Phoenix VOR 040 outbound radial to COSGR, cross COSGR at 4,000. Cleared for the VORCharlie approach into Scottsdale. b. Fly heading 130, intercept the Willie VOR 313 radial inbound to COSGR, cross COSGR at or above 4,000. Cleared for the VOR-Charlie approach into Scottsdale. c. Airport 11 O’Clock, 7 miles, report field in sight. d. Turn left heading 130, proceed direct COSGR. Cross COSGR at or above 4,000. Cleared for the VOR-Charlie approach. 8. How is COSGR identified on the chart? a. Initial Approach Fix (IAF). b. Final Approach Fix (FAF). c. The intersection of the PXR Radial 040 and the IWA Radial 313. d. 16 miles from IWA on the IWA Radial 313. e. All of the above. 9. What is the distance to JONHH? a. 25 nm from IWA VOR. b. 9 nm from SAENT. c. 25nm from BXK VOR. d. 25 nm from PXR VOR. 10. What does the “

“ in the Scottsdale Tower Frequency box signify?

a. Alternate IFR minimums are in use; Pilots should consult the Airport Facility Directory for further information. b. Contact this frequency first. c. Tower is not under continuous operation; Pilots should consult the Airport Facility Directory for further information. d. Also serves as clearance delivery. **Extra Credit** - What would be the estimated time it would take for a 737 to travel from the Final Approach Fix to the Missed Approach Point if it were traveling 130 kts? (Whoever told you there is no math involved with flying was lying!) a. 2:32 b. 3:10 c. 2:18 d. 2:05

***CHECK YOUR ANSWERS ON THE FOLLOWING PAGE***

ZAB Training Program -S3- “Introduction to Instrument Approach Procedures” – 08/15/2011 Tim Reeves – Training Administrator

ANSWERS 1. c Since this approach is not aligned within 30 degrees of any runway, a circling approach will be necessary. Therefore the TDZE in the top left is Not Applicable N/A. 2. e chart.

The Williams (IWA) VORTAC is the main navigational aid used in this approach, as shown in the first box at the top left of the

3. a MAF.

SAENT it is the last point shown on the approach before the missed approach begins. JONHH would be the Missed Approach Fix

4. a

Yes, holding patterns may be used in lieu of other procedure turns, but accomplish the same thing.

5. d A procedure turn is a mandatory part of an instrument approach unless ATC authorizes “No Procedure Turn” or “Straight-in, no procedure turn.” 6. e

Both 2,480 msl and 970 agl are correct.

7. b Although a. is acceptable, it not the best way for the equipment type and d. would be perfect if the aircraft was equipped with Area Navigation, which it is not. C. would only be valid for a visual approach. 8. e

All of the above.

9. d

25nm from the PXR VORTAC.

10. c

Tower is not in continuous operation. Operational hours are posted in the airport facility directory.

**Extra Credit ** How good are your math skills? If you came up with 2:32, you get an A+. By using the “FAF to MAP 5.5nm” chart under the Airport Diagram, you could come up with a rough estimate quickly as well. Here’s the math work for you, just like the teacher makes you do. 60 mins = .46kts X 5.5nm = 2.53min. or 2 min:32 sec. 130kph

ZAB Training Program -S3- “Introduction to Instrument Approach Procedures” – 08/15/2011 Tim Reeves – Training Administrator