Circling Can Be a Very Risky Approach

[Mooneymite]

While the thrust of this report is probably aimed at jet operators, it has a lot of good information about why circling approaches are dangerous for all operators.

https://www.ainonline.com/aviation-news/blogs/ainsight-circling-can-be-very-risky-approach?utm_hsid=28755669&utm_campaign=AIN Alerts&utm_medium=email&_hsmi=186969484&_hsenc=p2ANqtz-8GDScZOkWjMvb1ACWTOGGWaYioV3l1S9sFczEylN05i7SRn00e1TFNHtze5WfVU2GRqwz-bgWWQ5nBtGCgUlHWkaelfQ&utm_content=2&utm_source=hs_email

From AIM - November 26, 2021, 10:00 AM

 

Circling Can Be a Very Risky Approach

 

Pilots continue to demonstrate widespread confusion on the key elements of flying a circling approach, according to a recent Flight Safety Foundation (FSF) survey that found they often misunderstand basic terms and procedures for this procedure. A lack of understanding of these crucial factors when maneuvering an aircraft close to the ground in marginal weather conditions can lead to tragedy.

Basic terms such as circling approach, visual approach, circle to land, and visual maneuvering often are misunderstood by pilots. Likewise, there is a general lack of understanding regarding flying a circling approach procedure. As an example, pilots are confused on when to begin the circling maneuver, what direction to turn, when to descend from the minimum descent altitude/height to the touchdown zone, and how to properly fly a go-around from a circling approach.

Another FSF study highlights the dangers of flying a circling approach. These procedures are inherently riskier than a straight-in approach and should be flown only as a last resort. Risks include penetrating obstacle clearance limits either during the approach or subsequent go-around, a loss of control in-flight event either during the approach or go-around, or colliding with another aircraft in the air or during a wrong surface landing.

Straight-in approaches are 25 times safer than a circling approach; adding vertical guidance (an ILS glideslope or VNAV path) increases the safety margin by another eight times. For these reasons, operators will either prohibit or place restrictions on circling approaches.

The FAA’s Instrument Procedures Handbook urges caution when attempting a circle-to-land maneuver: “Circling approaches are one of the most challenging flight maneuvers in the National Airspace System (NAS), especially for pilots of Category C and Category D turbine-powered transport category airplanes. The maneuvers are conducted at low altitude, day and night, and often with precipitation present affecting visibility, depth perception, and the ability to adequately assess the descent profile to the landing runway.”

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Furthermore, AIM 5-4-2(f) states, “Circling may require maneuvers at low altitude, a low airspeed, and in marginal weather conditions. Pilots must use sound judgment, have an in-depth knowledge of their capabilities, and fully understand the aircraft performance to determine the exact circling maneuver since weather, unique airport design, and the aircraft position, altitude, and airspeed must all be considered.”

In business aviation, access to second or third-tier airports creates a Catch 22 situation. The ability to serve “close-in” or remote airports is a huge benefit to passengers, but often these airports do not have the approach capability of larger airports. Operators and pilots must weigh the risks associated with flying something other than a straight-in approach and determine if it is worth the risk of flying a circling approach.

In a recent accident, preliminary reports suggest that the pilots of a midsize business jet—a Category C aircraft—lost control in-flight during a circling maneuver. On July 26, 2021, a Bombardier Challenger 605 aircraft crashed near the Truckee-Tahoe Airport (KTRK) in Truckee, California. Both pilots and four passengers were killed in the crash.

The NTSB preliminary report sets up the event as a routine flight from Coeur d’ Alene, Idaho, to Truckee. As the aircraft passed over northwest Nevada, the flight became more complicated when ATC began to issue descent instructions and advised the flight crew to expect the RNAV (GPS) approach to Runway 20 at KTRK due to ATC flow control “constraints.” The flight crew accepted the approach and requested to circle to Runway 11 (a longer runway) for landing performance considerations.

At that time, the weather at KTRK was reported as variable winds at three knots, a 3,500-foot ceiling, and five miles of visibility, with smoke from nearby forest fires. Runway 11 circling approach minimums for a Category C aircraft at KTRK include an MDH of 1,796 feet and visibility of three statute miles. Visibility at the time of the accident reportedly had dropped to four statute miles.

Approaching KTRK, the flight crew was instructed by ATC to hold at ALVVA—the initial approach fix—due to preceding traffic on the approach. After one turn in the holding pattern, ATC cleared the flight crew for the approach, canceled radar services, and instructed them to contact the KTRK tower.

At the LUMMO fix, approximately 10 nm north of Runway 20, the flight crew “checked in” with the tower. The tower controller offered either a left downwind to Runway 29 or Runway 11; the flight crew announced that they would make a right turn and reported Runway 11 in sight. ATC then cleared the flight to land on that runway. There were no further radio transmissions from the aircraft.

Witnesses near the crash site reported seeing the aircraft at a low altitude and in an abnormal flight path to Runway 11. Others noted the aircraft in a nose-down attitude in a steep left turn—“banking erratically”—just before impact.

A preliminary flight path reconstruction indicates the aircraft overshot the final approach course to Runway 11 and crashed short of the runway.

The crew did have other options. In addition to the RNAV (GPS) approach to Runway 20, KTRK has a straight-in RNAV (GPS) approach to Runway 11; that approach would have offered a much higher safety margin than attempting the circling approach maneuver.

Circling approaches are not an instrument approach in the traditional sense. A circling approach is the visual segment conducted after an instrument approach and terminates in either a landing or an instrument missed approach.

According to ICAO Doc 8168 PANS-OPS Vol 1–Flight Procedures, “A circling approach is an extension of an instrument approach procedure which provides for visual circling of the airport prior to landing.” JAR-OPS 1.435(a)(1) defines it as “a circling approach in the visual phase of an instrument approach to bring an aircraft into position for landing on a runway which is not suitably located for a straight-in approach.”

In other words, pilots fly a circling approach when they cannot land from a straight-in approach due to tailwinds, obstacles, other limitations, or to accommodate traffic flow for ATC. Circling approaches come in many different varieties, but what is confusing is that they are all classified as a “circling approach.”

Examples include a circling approach that becomes a VFR pattern due to winds or to accommodate ATC restrictions—in other words, to accommodate an orderly traffic flow in high-density airspace.

Common “circling VFR patterns” are Teterboro’s (KTEB) ILS Runway 06 circle to land Runway 01—this procedure separates KTEB traffic from Newark International and the major airports in New York City, namely LaGuardia and JFK. Another is Chicago Midway’s (KMDW) ILS Runway 31C circle to land Runway 22L, which provides space between traffic at Midway and Chicago O’Hare.

Other varieties include a circling approach that is really a straight-in to a specific runway. Classic examples include the old “checkerboard” approach to Hong Kong Kai Tak Airport’s Runway 13 and the iconic Canarsie “circling approach” to Runway 13 L/R at New York’s JFK International Airport. Both approaches were replaced by either an entirely “new” airport or RNAV GPS approach.

From the prior FSF survey, pilots often would misinterpret terms such as a circling approach, visual approach, circling to land, and visual maneuvering. Although a visual approach and circling approach are conducted by visual reference, there are some differences.

A visual approach, in general, is an approach by an IFR flight when either part or all the instrument approach is not completed, and the approach is executed in visual reference to the terrain—or, in the U.S., by following the preceding aircraft. Visual conditions are defined as maintaining VMC. In the event of a go-around or balked landing, the pilots will comply with ATC instructions.

In contrast, a circling approach, after initial visual contact, the basic assumption is that the runway environment must be kept in sight while at the MDA(H) during circling. If visual reference of the runway is lost while circling, the missed approach for the instrument approach must be followed.

Another common misconception is when to descend from the MDA(H), when to begin the circling maneuver, or what to do in the event of a missed approach. In general, a successful circling approach begins with a thorough briefing at cruise, if not before.

Understanding the approach category of the aircraft, the circling criteria (either TERPS or ICAO PAN-OPS or other), current weather conditions (to include ceiling, visibility, and winds), restrictions to circling (for example, at night or in a certain geographic area), and the missed approach procedure are paramount to a safe outcome.

In general, TERPS applies to airports in the U.S., territories in the Pacific region, or U.S. military bases. Otherwise, ICAO PAN-OPS applies. On Jeppesen charts, these criteria are displayed on the far-left margin or in the “minimums” boxes.

Of importance, the category of the aircraft is based on indicated airspeed (IAS) flown during the circling maneuver. Generally, this is 1.3 times stall speed (Vso) or the approach speed recommended by the OEM—often the higher of the two.

The most recent TERPS and ICAO PAN-OPS circling criteria “updates” account for elevation (for example, true airspeed) and wind up to a maximum of 25 knots. Approaches with the new larger circling minima are displayed on Jeppesen approach charts with a “C” in a black square.

Pilots must understand and plan to maneuver within the visual circling area to maintain the minimum obstacle clearance as prescribed for that category of aircraft. A common strategy to reduce the risk of maneuvering during a circling approach is to use the next higher category to increase the safety margins—meaning an approach Category C aircraft uses Category D minima. Likewise, pilots can use the aircraft’s flight management system to “draw” an appropriately sized circle around the runway to visualize the maneuvering area.

A final area of confusion for pilots is related to initiating a go-around from a circling approach. The correct response can be broken down into two steps. Prior to reaching the MDA, fly the published missed approach procedure; or after reaching the MDA, and beginning the circling maneuver, the missed approach begins with a climbing turn towards the airport and then rejoins the missed approach of the approach conducted prior to reaching the MDA. Of importance, first begin the climb, but always honor the lateral path of the missed approach procedure as published.

Circling approaches are an incredibly complex procedure. One of the best risk-mitigation strategies is to simply eliminate the hazard by flying a straight-in approach or, if available, an RNAV visual approach (for example, KEWR’s Stadium Visual).

Since a circling approach at or near minimums is dangerous, another strategy is to divert to an airport with better approach capabilities.

Planning for a circling approach requires an extensive briefing to include aircraft configuration at specific points, level of automation to be used, a clear understanding of when the circling maneuver begins, and at what point it is safe to descend from the MDA(H). It also requires an exacting explanation of how to initiate the go-around from various points on the approach or during the circling segment of the approach.

Pilot, safety expert, consultant, and aviation journalist - Kipp Lau writes about flight safety and airmanship for AIN. He can be reached at stuart.lau3@gmail.com.

 

 

[GeeBee]

I am sure you got a few type ratings that say "Circling Approach-VMC Only" since the sim cannot faithful execute them and/or they are not in the training syllabus. Even light plane flying my circling minimums are basic 1000-3 unless the plate shows higher, then I ponder if I want to do it at all!

 

 

[N201MKTurbo]

Back in the 80s I had almost unlimited access to Frontier Airlines 737 sim. The circling approach was the only approach I never mastered. I must have tried it 30 times. I did it successfully about 5 times. Those aren’t very good odds. I would set the ceiling 100 ft above minimums. That means I had to be set up for the approach, when I broke out I had to reconfigure the plane for level flight, then make a couple of fairly steep turns while staying -0 +100 feet. You had to have the power settings nailed, there was no room for figuring it out on the fly. If there was any turbulence dialed in, all bets were off.

I asked a few airline pilots how they fly it and they have all said their airline won’t let them do circle to land approaches. I’ve done them in the Mooney  before, but never with 100 feet to work with, it was usually with many hundreds of feet and I was just flying the pattern for the most part.

[Mooneymite]

All the time I was with an airline, my type ratings did not include circling approaches.  The airline just didn't qualify us for them, so we either didn't land from them, or we reverted to a visual approach when the weather permitted.  However my post airline jet job required proficiency at circling approaches because of the diverse places we flew.  Training in the simulator, while FAA approved, was pretty much a scripted exercise.  Out on the road we did them frequently...very often at KTEB, but just as the article mentions, TRK was on the list. 

I suspect that the approval to fly "AR" (yeah, I know the nomenclature is changing hourly) GPS approaches will greatly diminish the number of circling approaches done in jets.

Good riddance!  Flying a missed approach out of a circling approach?  Who needs that kind of fun?

Edited November 26, 2021 by Mooneymite

[GeeBee]

Oh. TRK, loads of fun. Ran a flight department that had a daily trip into there. We even had our own de-icing truck.

 

 

[Marc_B]

According to the FAA Instrument Flying Handbook, "The circling minimums published on the instrument approach chart provide a minimum of 300 feet of obstacle clearance in the circling area. [Figure 10-12] During a circling approach, the pilot should maintain visual contact with the runway of intended landing and fly no lower than the circling minimums until positioned to make a final descent for a landing. It is important to remember that circling minimums are only minimums. If the ceiling allows it, fly at an altitude that more nearly approximates VFR traffic pattern altitude. This makes any maneuvering safer and brings the view of the landing runway into a more normal perspective."

https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/media/FAA-H-8083-15B.pdf

We have several VOR approaches up here in Northern CO that I'd train with working on my instrument rating that mostly come in at an oblique angle to the airport not lined up with anything in particular.  The hardest part was avoiding VFR traffic as we "meshed" with the pattern.  For me personally, turning a circling approach into an approach to a VISUAL traffic pattern flown at TPA in visual flight conditions makes WAY more sense safety wise.  

Marc.

[PT20J]

I think it is good to remember that a circling approach at minimums is low altitude scud running. 

Personally, given adequate runway length, I will accept up to a ten knot tail wind before opting for a circling approach when the weather is at or near minimums. I will not fly a circling approach at an unfamiliar airport unless VFR, and I will not fly a circling approach at night at any airport unless VFR.

Skip

[Immelman]

As with so many things it depends...

My home airport, if I fly the approach to minimums/the missed approach point, requires circling and that is very common due to the nature of the local marine stratus. I've done it so many times it is second nature.

Now going to an unfamiliar area... terrain? Obstacles? At night? Yikes... In a transport!!? Those factors complicate things immensely.

In the B1900 they did train us to circle using the VOR-13 into JFK (lead in lights) which was kind of bogus, but it "checked the box". Doing it for real in the airplane was a real challenge. And that was a very pilot-friendly airplane. In a larger jet transport with high maneuvering and approach speeds, where things go really well if you're where you need to be, and not so well if you're more than a little off... no thanks.

[ohdub]

In the last year or two, most of the approaches in my area have had the circling minimums removed from the approaches. I assume it's because of the unnecessary risk when the other runways have approaches as well.

[Ragsf15e]

In the military circling is definitely restricted based on airframe and mission.  In fighters, they’re banned.  I suppose you could shoot a straight in if the weather was high enough for a normal 1500’ pattern, cancel when vmc, and then circle to another runway, but a traditional circling approach is not authorized.  In basic training in T-6s, we did teach daytime only circling, but not night.

I definitely agree it can be used in some specific cases to get to a normal pattern, but it should be used very cautiously and in a known environment.

[ilovecornfields]

I completely agree that circling is dangerous. That’s why I do straight-in approaches wherever I go (20 times safer, right?). I’ve found it’s really helpful at busy uncontrolled airports during the weekend because instead of doing all that dangerous low level maneuvering near the ground I just advise I’m on the RNAV for a 20 mile final. People seem to understand that means I’m #1 for the runway because I’ll often see those guys give me the #1 sign after I land. Thanks for sharing that article.

[cliffy]

KTRK is the only airport I ever told an owner that I wouldn't take him to at night. Stand on the ramp in daylight and look around all quadrants and you might have the same opinion, especially in a jet. Too old and NO bold :-)  

Did the JFK 13 Lead In Lights many times in 727s and 757s. It was OK even at mins.  

"A mans got to know his limitations!"   (Dirty Harry)

[midlifeflyer]

19 hours ago, Marc_B said:

landing. It is important to remember that circling minimums are only minimums. If the ceiling allows it, fly at an altitude that more nearly approximates VFR traffic pattern altitude

That seems so obvious, doesn't it? I'd no sooner fly at MDA unless I had to than takeoff and make a turn on course on a VFR day at 400 AGL with 6 others in the pattern. If we're talking VFR, the idea of circling being dangerous sounds silly.

But the discussions on the safety of circling approaches aren't based on a good VFR day. They are based on being at both ceiling and visibility minimums with a 0 temperature/dew point spread where a a change in conditions and the need to find one's way back to the MAP while in the soup can happen in an instant.

[MB65E]

Isn’t TRK closed at night anyway now?

My ATP Checkride was night, JFK vor 4L circle 31R. Fun times! 
 

The obstacle clearance rings have changed a few times in the past thus crating some confusion. 2.3nm currently for CAT D. They are now teaching adding 50ft to the MDA. Confusing part for me was the Missed approach during the circle if you went IMC. Most of the time/all is a turn to the center of the airport! Or assigned heading. 
Wouldn't want to fly one in the Mtns at night either. 

-Matt

[N201MKTurbo]

I just checked my logbook and I've landed at Truckee 4 times. All I remember is it is always bumpy and its in a hole. I have only landed there day VFR.

Oh, and the FBO had loaner bicycles.

Edited November 28, 2021 by N201MKTurbo

[GeeBee]

2 hours ago, MB65E said:

Isn’t TRK closed at night anyway now?

My ATP Checkride was night, JFK vor 4L circle 31R. Fun times! 
 

The obstacle clearance rings have changed a few times in the past thus crating some confusion. 2.3nm currently for CAT D. They are now teaching adding 50ft to the MDA. Confusing part for me was the Missed approach during the circle if you went IMC. Most of the time/all is a turn to the center of the airport! Or assigned heading. 
Wouldn't want to fly one in the Mtns at night either. 

-Matt

The curfew at KTRK is voluntary. 

You add 50' because you now have DA, no more dive and drive. The 50' is the go around allowance so you don't descend below MDA on a constant angle descent and subsequent go around.

[RobertGary1]

20 hours ago, GeeBee said:

The curfew at KTRK is voluntary. 

You add 50' because you now have DA, no more dive and drive. The 50' is the go around allowance so you don't descend below MDA on a constant angle descent and subsequent go around.

Because the acs tolerance is -0/+100 we teach students to fly jt 50 above MDA. Not for safety but because busting a checkride for going 1 foot low isn’t fun. 

[Ibra]

On 11/28/2021 at 6:12 PM, MB65E said:

Confusing part for me was the Missed approach during the circle if you went IMC

Fun fact, past MAPt, one is no longer in hands of approach designers for protection while going missed in IMC, with tailwind things go fast in a Mooney, my easy way to stay within design limits is to use MDA from higher aircraft categories 

The other fun fact, is that no one knows where one should exactly descend bellow MDA to land on opposite threshold during a CTL, I have heard every colour & taste on this one: from as early as in downwind or base leg to not before straight-in final and on visual descent angle 

If one adds mix of today avionics for navigation guidance Approche:GPS+ILS+CTL then Missed: GPS+VOR, the circling thing will just keep giving 

Edited November 29, 2021 by Ibra

[201er]

1 hour ago, Ibra said:

with tailwind things go fast in a Mooney, my easy way to stay within design limits is to use MDA from higher aircraft categories 

The category is for the speed you are flying and not the aircraft you are flying. A Skyhawk might just make it into category B in a descent if it were to really try 

At least in a Mooney you have choice to fly in Category A, B, C, or maybe even D if ATC demands you keep the speed up!

[Ibra]

4 minutes ago, 201er said:

The category is for the speed you are flying and not the aircraft you are flying

Yes I find it hard to keep Mooney under 91kts indicated, it comes out of ILS like a bullet 

[aviatoreb]

I did the circling approach yesterday - RNAV 24 into my home airport Potsdam.  Winds were favoring (slightly) Runway 6.  Of course it was like 4000 ft ceilings and I was on IFR simply because I was coming out of the clouds after crossing the adirondacks.  But I did the circling because I was on the approach, and joined the normal pattern altitude thinking of what it would be like at an unfamiliar airport and lower since pattern is well higher than circling mins.  I think with 6 kts down the runway 6 so tail wind for runway 24 and 3700 ft I would more likely proceed with landing 24 (and being a rural airport there is rarely other traffic to deal with in proper IFR conditions - at least none that aren't talking).  Or - as I have done several times, I head over to Massena - 2 runways including an ILS for lower mins - and take the Uber home 25 min by land.

Edited November 29, 2021 by aviatoreb

[jaylw314]

3 hours ago, Ibra said:

The other fun fact, is that no one knows where one should exactly descend bellow MDA to land on opposite threshold during a CTL, I have heard every colour & taste on this one: from as early as in downwind or base leg to not before straight-in final and on visual descent angle 

Isn't the wording something like "when you can make a normal approach to landing"?  Not that that's terribly specific or anything...

[GeeBee]

8 hours ago, RobertGary1 said:

Because the acs tolerance is -0/+100 we teach students to fly jt 50 above MDA. Not for safety but because busting a checkride for going 1 foot low isn’t fun. 

Not quite for the 50' add on. It is as I described to prevent decent below MDA on the go-around.  It is called DDA for CDA approaches as defined in AC120-108

https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_120-108.pdf

 

"Derived Decision Altitude (DDA). Pilots must not descend below the MDA when executing a missed approach from a CDFA. Operators should instruct their pilots to initiate the go-around at an altitude above the MDA (sometimes referred to as a DDA) to ensure the aircraft does not descend below the published MDA. Operators conducting approaches authorized by operations specification (OpSpec) C073, Vertical Navigation (VNAV) Instrument Approach Procedures (IAP) Using Minimum Descent Altitude (MDA) as a Decision Altitude (DA)/Decision Height (DH), may use MDA as a DA."

 

[Hank]

3 hours ago, GeeBee said:

Not quite for the 50' add on. It is as I described to prevent decent below MDA on the go-around.  It is called DDA for CDA approaches as defined in AC120-108

https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_120-108.pdf

 

"Derived Decision Altitude (DDA). Pilots must not descend below the MDA when executing a missed approach from a CDFA. Operators should instruct their pilots to initiate the go-around at an altitude above the MDA (sometimes referred to as a DDA) to ensure the aircraft does not descend below the published MDA. Operators conducting approaches authorized by operations specification (OpSpec) C073, Vertical Navigation (VNAV) Instrument Approach Procedures (IAP) Using Minimum Descent Altitude (MDA) as a Decision Altitude (DA)/Decision Height (DH), may use MDA as a DA."

That's more of a problem with the big iron. When I go to WOT / 2700 in my little Mooney, it goes UP right away!

Yes, I practiced circle to land with my CFII, and demonstrated one under the hood on my Instrument check ride . . . But do one for real, low ceiling, poor visibility? I'd rather go somewhere else. 

[RobertGary1]

26 minutes ago, Hank said:

That's more of a problem with the big iron. When I go to WOT / 2700 in my little Mooney, it goes UP right away!

Yes, I practiced circle to land with my CFII, and demonstrated one under the hood on my Instrument check ride . . . But do one for real, low ceiling, poor visibility? I'd rather go somewhere else. 

Unless I’m at 200 feet on the ils in the fog. Then sometimes I may be a little slow on the throttle.