As an aviation writer, I’m always on the prowl for interesting approach charts (so if you have a favorite, drop me a line). One that recently appeared in my email was the ILS or LOC Rwy 27 at Williamsport, PA (KIPT). The striking curiosity was plan view note, “RNAV 1-GPS or RADAR AND DME REQUIRED.” The investigation yielded a longer explanation than I expected. Too bad I don’t get paid by the word.
This note says a transition from the enroute environment to the approach requires either an RNAV 1 level GPS navigator or you a combination of both ATC radar and DME on the aircraft. The lowercase “or” separating the two groups of capital letters means you can have either group of capitals. Don’t send an email if you find an example where these capitalization rules are broken. It’s not consistently employed due to evolving standards for this stuff, but that’s what it means.
(Interesting and vaguely related aside: Did you ever wonder why a writing credit for a Hollywood movie was “Written by Jack Jones & Wilma Mead and Bobby French”? It looks like they couldn’t agree on whether to abbreviate or not, but it means Jack and Wilma wrote as a team, while Bobby wrote separately, and probably later. Same idea as the approach note’s uppercase “and” versus the lowercase “or.”)
The ILS or Loc Rwy 27 at KIPT is hybrid of two approaches. It’s a conventional ILS with the terminal arrival area (TAA) from the RNAV (GPS) Rwy 27 approach grafted on. To transition from enroute to the localizer: Enter one of the three sectors at or above 4300 feet, fly to the initial approach fix for that sector (ZEKNO, JIBGO, or HULRO), intercept the localizer and cross JIBGO, and descend to cross the final approach fix of ZUMEY at or above 3700 feet. There’s no course reversal charted because there’s no direction from which a procedure turn is required, or for that matter, allowed.
Don’t let the “RNAV 1” part trip you up. For our purposes in GPS-driven GA, this means any terminal certified GPS, which must be accurate to within one mile a minimum of 95 percent of the time.
If you have an approach-certified GPS, you’ve got at least RNAV 0.3, which is more than three times an accurate. With that navigator, using the TAA to an ILS is as simple as loading the ILS approach because the waypoints for the TAA will be included.
If you’re still squeezing the life out of an antique GPS that’s terminal only, like the Apollo GX55 in one of the planes I fly, you can’t load approaches, but you can still use its RNAV-1 capability for this approach. The waypoints will be in the database, so if you were approaching from the east via JIBGO, you could enter direct JIBGO and tune the localizer. Navigate via GPS until you’re on the localizer and use the GPS to identify crossing JIBGO. If you were approaching from the northwest, you’d add both ZENKO and JIBGO to your flight plan so you could fly direct ZENKO and then track to JIBGO and then the localizer. That’s not cheating. That’s legitimate use of a terminal GPS that has no approach capability.
If you had no GPS, you could get vectors onto the localizer. This removes the need for the TAA. However, you’d still need to identify JIBGO to know when a descent to 3700 was allowed.
Apparently, ATC can’t help you out with this, or it would say “RADAR” over the JIBGO fix in the profile and plan views. Without that, you’d need DME — or at least RNAV 1 GPS, but then you wouldn’t need the vector in the first place.
A similar situation exists on the missed, where you climb to 980, then make a climbing right turn to intercept MIP R-314 to ZIMEL, which is itself an intersection. With an approach GPS, you simply unsuspend navigation, switch back to GPS guidance and fly to ZIMEL. With a terminal GPS, you can still create a direct-to ZIMEL on a course of 314. This may not be an identical track to flying the VOR radial, but it’s close enough and any difference diminishes rapidly as you approach ZIMEL.
With an approach-certified WAAS GPS, you’d probably skip the ILS entirely and fly the RNAV approach. There’s a pound sign for the DA of 777, which requires a cross-reference. You’ll see a higher-than-standard required climb gradient in the textual missed approach instructions, and that the inoperative table doesn’t apply in the notes. The latter is because the visibility requirement is already 3/4 miles, so you don’t need to add more if the approach lights are out of service.
The Matching Game
Speaking of cross-reference, check out all the inverse (white on black) characters on this plate. Some are simple, others require finding the associated information elsewhere.
At the top of the chart, the inverse A5 by the lights in the briefing strip means this MALSR is at least partially pilot controlled. Likewise, the inverse L by the tower/CTAF frequency means there are at least partially pilot-controlled lights (PCL) when the tower is closed. How do you know the tower will close? That’s what the star after the “Williamsport Tower” in the briefing strip means.
Many folks stop there but don’t be one of them. Down in the airport diagram in the lower left, you’ll see the same inverse L saying it’s the runway end identifier lights (REIL) for Runway 9 and high-intensity runway lights (HIRL) for Runways 9-27 that are pilot controlled. The star here for the medium intensity runway lights (MIRL) for Runways 12-30 means the PCL is non-standard. If you want details, you’ll have to look it up in the A/FD. There you’ll find that the approach, runway, and taxiway lights are controlled via the CTAF frequency—and that the lights for Runway 12-30 are simply off. That could be important information if you’re planning a night arrival after hours. It’s landing Runway 9-27 or going elsewhere.
The inverse T and A indicate non-standard takeoff and alternate-filing minimums, respectively. This time, you’ll reference the chart supplement to see that all departures from all runways demand higher than standard climb gradients and textual departure procedure to follow. These aren’t required for Part 91 flights, but it’s a life-extending practice to comply. Alternately, you could follow the visual climb over airport (VCOA) instructions of climbing in visual conditions to 2800 over the airport before proceeding on course in any direction climbing at least the standard 200 feet per nm.
The non-standard alternate minimums are another lookup, which reveals you’d better have an approach GPS if the tower will be closed, and the forecast weather better be essentially VFR. This is for filing Williamsport as an alternate, not flying there. See the sidebar below for clarification.
Back on the approach chart, the inverse snowflake under the T and A means cold-weather corrections apply to this airport. This requires referencing a document many pilots don’t know exists: Cold Temperature Restricted Airports. You can find it at https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/dtpp/search/ if you scroll to the bottom of the page. Or you can subscribe to the digital document in ForeFlight. Look in there, and you’ll see the correction only applies to the intermediate legs. There’s no change to final approach minimums.
Two more inverse letters and we’re done. The inverse D in the airport diagram means there’s runway declared distance information available takeoff and landing distances in the A/FD (you’re call whether the D is for “declared” or “distance”). These are the TORA, TODA, ASDA, LDA that sounds like a battle cry in an eastern language, but actually stands for takeoff runway available, takeoff distance available, accelerate-stop distance available, and landing distance available.
The inverse C by the circling minimums is the simplest of all. That means the new circling radii apply, that are both a bit wider, and correct or increasing true airspeed with altitude. See IFR Focus #8 for details.
Speaking of circling, note that circling south of Runway 9 and southwest of 30 is NA at night. Circling to land on Runway 12-30 is also NA at night. These prohibitions are usually because of close in obstacles obstacle you’re expected to avoid visually. If you’re wondering what those obstacles might be, you can find a list after any takeoff minimums and obstacle departure procedures. This might take some time. Williamsport has one of the longest lists of low, close-in obstacles I’ve ever seen.
Maybe the FAA survey folk were getting paid by the word.
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GPS VLOC Auto Switch and Autoslew
The Missing MSA
Approach charts like these are a boon to the designated examiner pushing the bounds of a candidate’s knowledge on an instrument checkride: “What’s the minimum safe altitude (MSA) for this approach?” Search as you may, you won’t find the familiar circle with its 25-mile ring of safety on this chart. That’s because its equivalent is staring you in the face: The TAA extends out 30 miles from each reference fix with a safe altitude to fly. A published MSA would be superfluous.
ForeFlight Question of the Month:
When you’re viewing an approach chart in ForeFlight, what’s the fastest way to see other approaches for that same airport?
A. Close the chart, type the identifier for the airport in the upper right, select the new airport from the list.
B. Load the airport full screen in the Airports tab, then select the other approach from the list of procedures.
C. Swipe left or right on the full-screen approach chart with three fingers.
D. It depends on how you loaded the approach chart you’re viewing.
Jeff Van West is PilotWorkshops’ Creative Director with the primary responsibility for managing the development and creation of the company’s pilot proficiency training programs, including our flagship IFR and VFR Mastery programs.
For 19 years, Jeff ran many noteworthy aviation media projects with his own firm, Van West Communications, including magazines, books, videos and live seminars. Jeff previously served as editor-in-chief of IFR Magazine and co-editor of Aviation Consumer, and his work appears in AOPA Pilot, Flight Training Magazine, Plane and Pilot, and AVweb. He’s an experienced CFII/MEI with ratings for single- and multi-engine airplanes, seaplanes, and gliders. Jeff was the creator of the first pilot transition program for new Cirrus aircraft.
Want to see some mumbling and hand waving? Ask a dozen instrument-rated pilots to explain “... for climb in visual conditions ...” in the textual departure procedures for an airport.
It’s not their fault. Departures, in general, are the overlooked middle child of instrument procedures, which makes the Visual Climb Over Airport (VCOA) akin to the weird uncle who shows up at Thanksgiving and gets politely ignored.
The key is that a VCOA is an alternative to the obstacle departure procedure (ODP). You do one or the other, but not both. You must also inform ATC you’re planning on flying the VCOA when you request your clearance. Step one on that planning process is determining if obstacles are even an issue.
A Diversity of Departures
Every airport that has a published instrument approach has also been surveyed for departures. It's assumed that an aircraft will cross the departure end of the runway (DER) at 35 feet AGL, and climb to 400 feet AGL on runway heading, with a climb gradient of 200 feet per NM.
This creates a point in space. The survey then asks, if the aircraft continues to climb at 200 feet/NM, could it turn in any direction on course and maintain required obstacle clearance? For airports in the middle of Nebraska and other level places, the answer is usually, “yes.” This means the runway qualifies for a "diverse vector area," and no departure procedure is published. This older term for this is a "diverse departure," and that makes more sense from a pilot's perspective. You can depart in any of a diversity of directions, so long as you keep climbing at least 200 feet/NM.
The survey is done for every potential departure runway, and if all qualify for a diverse departure, the airport might not even appear in the departures section of the terminal procedures.
If a departure runway fails this test, a remedy is published. This simplest fix restricts how early the aircraft can turn, such as the procedure for Runway 24 at Conrad, MT (S01), where the aircraft must climb on runway heading to 4300 feet MSL—after which, it may continue to climb on a diverse departure.
That second part is key: Almost all ODPs get you to a point from which you can continue to climb at 200 feet/NM up to your assigned altitude. If you’re departing Runway 06 at S01, it’s a diverse departure from the standard 400 feet AGL.
Another remedy is defining a higher required climb gradient. The bottom of the entry for Corvallis, OR (KCVO) shows Runway 17 has a normal diverse vector area, but Runway 35 requires 210 feet/NM to 800 feet MSL. The implicit part is that above 800 feet MSL, the required climb gradient reverts to 200 feet/NM.
If a simple fix won’t do, a more complex departure procedure might be published. Sometimes this is a fully charted procedure, which is worthy of its own article. However, the more complex departure is usually a textual procedure.
For KCVO, there’s one textual procedure for each of four runways. Runway 09 requires you to climb on heading 097 to 1200 feet MSL, before turning left, back to the CVO VOR as you continue to climb. The other runways are similar. Further down in the text, it notes that all aircraft should climb in a hold on the 261 radial inbound until 3400 feet before departing on course. That on-course departure is ... wait for it ... a diverse departure from 3400 feet MSL over the VOR. It’s assumed you'll continue to climb at 200 feet/NM to your assigned altitude.
When do you start flying a heading of 097? These procedures all start at 400 feet AGL, so that’s your starting point. However, there’s one more essential requirement. Even though the takeoff minimums for ceiling and visibility technically don’t apply to Part 91 ops, the climb gradients in here do. At least, they do if you want to keep space between tree branches and the empennage.
Departing Runway 09 at KCVO on the published departure procedure requires a climb gradient of 270 feet/NM to 2900 feet MSL. Above 2900 feet, it’s the standard climb gradient — but you must continue flying the ODP until over the CVO VOR and above 3400 feet before turning on course.
The takeoff minimums section is where we finally find the VCOA. For each runway, the requirements for flying the VCOA are ceiling 3300 feet AGL and visibility 3 miles. Barring any further restrictions, if you can climb in visual conditions to 3300 MSL directly over the airport, from that point on you could continue to climb in the clouds on a diverse departure. That's because the goal of a VCOA is to raise the floor of the diverse departure and place its starting point directly over the airport. Get there however you want by avoiding obstacles visually. Then, from that point, continue on course climbing 200 feet/NM.
That’s the goal, but for KCVO, there’s one last twist. At the bottom of the departure procedures section, it says, “VCOA: All runways ... Climb in visual conditions to cross CVO VOR/DME at or above 3400.” This seems contradictory at first: The VCOA requires a ceiling of 3300 feet but you’re supposed to climb in visual conditions to 3400 feet?
It's AGL versus MSL: 3300 is feet AGL because it’s a ceiling, while 3400 is feet MSL because it’s an altitude you read on your altimeter. KCVO is about 250 feet elevation.
Slide over to Cody, WY (KCOD) by Yellowstone (I hear there are some hills around there), and you’ll see the uncommon "routed VCOA," meaning it has a departure you follow even after you enter the clouds. Spiral up over the airport to 9400 feet MSL, and then proceed via the COD VOR 189 radial inbound to cross the COD VOR at or above the MEA.
KCOD also shows how a VOCA can really pay off. The ODP climb gradients are 400 or 385 feet/NM to altitudes of 8000 feet MSL or 7400 feet MSL, respectively. This requires an 800 foot-per-minute climb, if you have a 120-knot groundspeed. Many light aircraft can’t maintain that climb at 7000 feet MSL. The VCOA has no required climb gradient until you reach the on-course altitude, after which it’s only 200 feet/NM. Ignore the published ODP routing and take as long as you need to climb. Enjoy the view — and use it to stay off the rocks — as you do.
As with KCVO, don’t let the VCOA ceiling of 4200 feet and the spiraling up to 9400 feet phase you. KCOD’s airport elevation is 5102 feet. But, you say, that means there’s a 100-foot difference between the required ceiling (9302 MSL) and the 9400 climb-to altitude. Yeah, that happens. How you climb for that last 100 feet is up to you. Just stay over the airport.
And that’s an interesting point, because, technically, Part 91 flights aren’t bound by takeoff minimums or required to follow ODPs. You could take off in your Cirrus on a private flight on a zero-zero and spiral up over any airport, whether a VCOA is published or not. I wouldn’t recommend it, but at least your estate can claim you didn’t break any rules.
For the rest of us who like options that offer a bit more buffer for safety, check out the VCOA, if published, as an alternative way to avoid the rocks before you climb into the clouds and proceed on your way.
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We don’t have climb gradient instruments in our aircraft. (Although, a terrain display can be a life saver.) Instead, we have climb rate instruments. Converting is basic math of groundspeed/60 multiplied by the climb gradient. For a groundspeed of 90 knots, the standard climb gradient of 200 feet/NM converts to 300 feet/min (90/60 * 200).
If you know your climb rate for the standard gradient, you can do a quick estimate for non-standard ones. If the required gradient is 375 feet/NM, round up to 400 feet/NM, which is twice standard. Assume you’ll need 600 feet/min, if you expect 90 knots groundspeed.
Just remember that it’s groundspeed, not airspeed that matters. You must factor winds into your departure planning. It’s also average climb rate that matters. If the departure requires 600 fpm while you climb and you see 700 fpm initially that drops to 590 fpm for the last 1000 feet before you join the airway, you should be fine.
Not that you could do much about it at that point anyway.
ForeFlight Question of the Month:
How do you load a departure procedure into your flight plan so the departure procedure appears on your map?
A. View the chart or takeoff minimums, and then tap the sent-to-map icon.
B. Edit the flight plan and tap the procedure button. Then, choose the departure procedure and departure runway from the list.
C. Loading of departures in ForeFlight is limited to charted procedures, and even these may not show critical sections. They’re loaded from the procedure button.
D. Departures can’t be loaded automatically, but you can create your own proxies with user waypoints.