VOR Approaches

VOR approaches

Minor revision 8/09/06

VOR approaches are the mainstay of the Instrument system. They differ from a VOR/DME approach in that there is no distance information available to the pilot. The approach must be timed by the pilot so that he knows where he is. Here is a VOR approach plate for Wichita, Kansas.

(A note about the charts used in this tutorial: These are copies of actual instrument approach plates. They are out of date. The newer formats use color to depict terrain changes. Depending on where you get your approach plates, the appearance may vary. However, the procedures for shooting these various type approaches has not changed.)

"The approach must be timed by the pilot"..what do you mean by that?

Take a look at the above plate. Notice that there is no way to tell when you are over the end of the runway? There is no DME information available from the VOR, as it is just a "plain" VOR, not a VORTAC or a VOR/DME. How will you know when you reach this point? Timing. Take a look at the lower left portion the the plate. See the notations:

The "Gnd speed-Kts" refers to your aircraft's ground speed, and the "VOR to MAP" refers to the time it will take your aircraft to travel from the VOR to the MAP- the Missed Approach Point. So, let's say that the surface wind is 140 degrees at 10 knots, and your aircraft uses an approach speed (gear down, approach flaps set) of 130 knots. 130 knots, minus the headwind on 10 knots yields a ground speed of 120 knots. At 120 knots, it will take you 4 minutes and 18 seconds to travel from the VOR to the MAP. For speeds other than those charted, simply use interpolation. So, you cross the VOR at 10 minutes after the hour, in your aircraft's approach configuration, at 130 knots. You descend to the MAP and at 14 minutes and 18 seconds after the hour, if you cannot see the runway you must go Missed Approach.

"Missed Approach", what's that?

When you have descended as low as the plate shows is allowable, and you have reached the MAP without seeing the runway, or it's environs, you must go Missed Approach. For every published approach, there is a Missed Approach procedure. In this case it is shown several ways on the approach plate.

This is the text part. Note that it states "Climb...then turn.." This is important. You must first climb, on your approach heading of 119 degrees, to 3,600 feet, then turn back direct to the ICT VOR. Also, notice the visual graphic:

The dashed line is your Missed Approach course. It shows a straight-ahead course. And, lastly, note the "pull up" arrow over the end of the runway in the profile view:

This further indicates a climbing Missed Approach procedure. This is important. In the event of a Missed Approach, you must have a plan for what you want to do next. Did you do a sloppy job flying the approach? Want to go back and try again? Was the approach below minimums? Perhaps the ILS with lower minimums will "get you in". Whatever, you must have a plan. Someone will ask you what it is.

Take a look at the information box in the upper left hand corner of the approach plate. Notice the "(R)" after Wichita Approach?

That means that there is radar service available. To you, the pilot, it means that you can expect that you will be vectored by Approach right to the ICT VOR, then you will be "turned loose" to shoot the approach. Approach will not expect you to, nor want you to, make a procedure turn.

Procedure Turn, what's a Procedure Turn?

It is important that you safely get your aircraft established on the inbound approach course of 119 degrees. In order to do this, without radar service, you must pass over the ICT VOR, turn around, and proceed back inbound to the ICT VOR on the correct radial, 299 degrees, at the correct altitude, 3,000 feet, and within the correct distance, no more than 10 nautical miles from the ICT VOR.

Pass over the ICT VOR: You would position your aircraft to cross over the ICT VOR at whatever altitude is assigned to you by Center. Once you cross the ICT VOR you would turn as necessary to intercept the 299 degree radial and track outbound on that radial. Note the time that you cross the VOR. You must track outbound on the 299 radial and complete the Procedure Turn without going beyond 10 nautical miles from the ICT VOR.

Turn around: Once established on the 299 degree radial outbound you may descend to 3,600 feet.

Note the reminder that this must be accomplished within 10 nautical miles. Also note the depiction of the Procedure Turn.

Under no wind conditions, you would turn left to a heading of 254 degrees, fly it for, say 30 seconds, then turn back right to a heading of 074 degrees. You would fly the heading of 074 degrees until you capture the 299 degree radial (119 degree inbound). At that point you would descend to 3,000 feet.

The "radar fix"

Notice the minimums box on the lower left of the chart. Note that you may go lower on the approach if Approach Control "calls out" the 5.0 fix.

If Approach calls out this fix for you, you may descend to 1,760 feet on the approach. If they do not, your minimums will be 1,940 feet. In both cases you will need one mile of visibility to complete the approach.

Circle-To-Land: If the surface winds are such that they do not favor landing on runway 14, then you would shoot the approach and then circle to land on another runway more favorable to the wind direction.

In order to do this, on this approach, you would need landing minimums the same as the Straight-In minimums, except that you must have 2 miles of visibility.

OK, I understand all of that. Now, how would I go about shooting this approach?

Without radar

Center will "turn you loose" with a clearance "Red Baron 123, Proceed direct to the Wichita VOR. You're cleared the VOR 14 approach into Wichita Mid-Continent. Maintain at or above 5,000 until established on a published segment of the approach. Contact Wichita Tower at the VOR inbound. The Tower will call the 5 mile fix for you." You acknowledge and fly direct to ICT, maintaining 5,000 feet. Tune #1 nav. to 113.8, and #2 nav. to 113.8. Set the CDI on the HSI to 299 degrees. Set the OBS on the #2 VOR head to 119 degrees. After crossing the ICT VOR, record the time, then turn as necessary to track outbound on the 299 degree radial. All turns are Standard Rate Turns, as shown on the Attitude Indicator, or the Turn and Bank.

Once you are established on the 299 degree radial outbound, descend to and maintain 3,600 feet. Keep in mind that you must take into account your groundspeed, adding that you are going faster due to the descent, and that you must get your trusty bird turned around back onto the inbound radial within 10 miles of the ICT VOR. Track outbound on the 299 degree a couple of minutes- this is a "gray area", you want to be far enough out to make your turns and intercepts in a non-rushed manner, yet not so for out that you exceed 10 miles. It's a judgement call, and why you're a pilot.

Turn to a heading of 254 degrees, less than that if the winds aloft are out of the North, more than 254 degrees if the winds are out of the South. Maintain this heading for 45 seconds to a minute, once again it is your call. At this time, reach up and reset the CDI on the HSI to the inbound course for the approach- 119 degrees. Maintaining 3,600 feet, turn right to a heading of 074 degrees, once again compensate if necessary- more to the left if the wind is out of the North, more to the right if the wind is out of the South. When the CDI centers, track the 119 (actually the 299 degree) radial inbound. Descend to and maintain 3,000 feet.

Your power and flaps should be set as necessary for a proper approach speed. In other words, you want to be level at 3,000 feet with a notch of flaps down and your airspeed such that you are in your gear operating speed range on the airspeed indicator. Also, you should know, in advance, what your airspeed will be when you drop your gear at the VOR and commence your descent for the approach. Don't know this? Then take your trusty bird out on a nice VFR day and practice. Find out what power settings will yield what approach speeds. You cannot do a timed approach if you do not know this information.

Level at 3,000, tracking the radial inbound. The CDI becomes extremely sensitive as you close on the VOR and the "radial space" condenses around the station. Don't chase the needle. The "TO/FROM" indicator on the HSI flips over to "FROM". Note the time, drop the gear, start your descent, call on the radio. Remember, fly the airplane first, communicate second. The time is 1310+10. "Good morning Wichita Tower, Red Baron 123 is with you, VOR inbound." "Roger Red Baron 123, not in sight, cleared to land runway 14, wind is 140 at 10 knots, altimeter 29.90. I will call the 5 mile fix for you." "Cleared to land 14, Red Baron 123".

For this example, we'll use an approach speed on the Red Baron of 110 knots. Minus the 10 knot surface wind yields a ground speed of 100 knots. Note the time of VOR crossing and add 5 minutes and 10 seconds. That will make the MAP at 1315+20. Write it down. Or, set the timer as you cross the VOR. Track the 119 degree radial. Descend to and maintain 1,940 feet. "Red Baron 123, Wichita Tower, I show you crossing the 5 mile fix at this time Sir." "Roger, thank you." Descend to and maintain 1,760 feet. Maintain course.

Now's the tricky part, here's where you earn your money. Your 5 minutes and 10 seconds are up. The timer shows 5 minutes and 10 seconds. It's 1315+20. You are at the Missed Approach point. Can you see the runway? Remember, the approach lights count. Remember, flying by reference to the instruments, and looking outside for the runway, is perhaps one of the most dangerous configurations when flying. Use caution. Don't get disorientated. It happens. There it is! Adjust power as necessary and land on runway 14. Good for you, you just shot a pretty difficult approach.

Times up. I can't see the runway! No choice here. Full power, wait on the gear until a positive rate of climb is established. Gear up. Flaps up in increments as necessary. Contact the Tower. "Tower, Red Baron 123, missed approach." "Roger Red Baron 123, contact Departure on 120.6." Climb, straight ahead, to 3,600 feet. Fly the airplane. Contact Departure. "Departure, Red Baron 123 with you, missed approach." "Roger Red Baron 123. What are you're intentions?"

See? I told you that they would ask.

With radar

Approach Control will vector you for the approach. "Good morning approach, Red Baron 123 level at 5,000, information Victor.' (Victor is the current ATIS information.) "Roger Red Baron 123, fly heading 075, descend to and maintain 4,000." "Out of five for four, 075 on the heading, Red Baron 123." "Roger Red Baron 123. This will be vectors for the VOR runway 14 approach into Wichita Mid-Continent." "Roger, Red Baron 123." Approach will give you changing headings until they have you outside of the VOR, and more or less lined up with the 299 degree radial from the ICT VOR. You should have Nav. 1 radio set for the ICT VOR, Nav. 2 as well for a back-up. The CDI on the HSI will be set to 119 degrees, as well as the VOR head on #2. You should be adjusting your power towards your approach power settings.

"Red Baron 123, 5 miles from the Wichita VOR. Descend to and maintain 3,000. Turn left heading 100. Intercept the final approach course on this heading You're cleared the VOR runway 14 approach. Stay with me and I'll call the 5 mile fix." "Out of four for three, 100 on the heading, cleared the approach, we'll stay with you." Track the 299 degree radial inbound. Approach power and the first notch of flaps should be set. The "TO/FROM" indicator flips over to "FROM". Start your timing. Gear down. Adjust power and flaps as necessary and start your descent to 1,940 feet. "Red Baron 123, crossing the 5 mile fix at this time, contact the Tower, 118.2. Good day!" "Good day." Start your descent to 1,760 feet. Fly the airplane. Contact Wichita Tower. "Good morning tower, Red Baron 123 is at the five mile fix inbound." "Red Baron 123, not in sight, cleared to land runway 14." "Not in site, cleared to land, Red Baron 123."

Now, the same criteria as with the non-radar approach applies. See the runway? Land. Don't see the runway? Missed Approach.

This ends the tutorial on VOR Approaches.

This narrative, along with aditional content, is available as a CD or an eBook.

For CD information click here. For eBook information click here.

7/9/05: Remarks in the non-radar time corrected. Thank you to Richard Rankin for pointing this error out.

8/8/2006 Correction made on descent after crossing the VOR on the "With radar" part of the tutorial. Thank you to Bruce Stafford for pointing this error out.

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