Circling approaches are the most dangerous of all approaches, especially when flown at night or in marginal weather conditions. As an extension of an instrument approach, a circling approach is the “visual segment of an approach” often flown at low altitude, low airspeed, and with no lateral or vertical guidance to a runway. Accepting a clearance to fly a circling approach is risky business and there is no room for error.
Since 2008, according to the National Transportation Safety Board (NTSB), there have been 10 major accidents involving Part 91 and Part 135 aircraft flying a circling approach. On average, that is one fatal accident every 18 months, where an aircraft either loses control or impacts terrain while attempting a circling approach.
According to a Flight Safety Foundation study, a straight-in instrument approach is a much better alternative and is 25 times safer than a circling approach; adding vertical guidance to an approach will increase the safety margin by another eight times.
For reasons unknown, other than convenience or “operational flexibility,” some operators and pilots of business aircraft continue to accept the risk of flying a circling approach, while other operators take a much more conservative route and either prohibit them or place restrictions on circling approaches.
In March 2023, following a series of business jet accidents, the NTSB issued a safety alert (NTSB Safety Alert Number 84) that cautioned pilots of the complexities and risks associated with flying a circling approach. The NTSB advises pilots to “know the risks, before conducting a circling approach, to be sure that it is the best and safest option, and to brief the approach, plan its execution and acknowledge your own limitations.”
Prior to the publication of the NTSB safety alert, the FAA cautioned pilots of the dangers of flying a circling approach in its Instrument Procedures Handbook and in the Aeronautical Information Manual (AIM).
The Instrument Procedures Handbook states, “Circling approaches are one of the most challenging flight maneuvers in the NAS, especially for pilots of Category C and Category D turbine-powered transport category airplanes. These 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.”
The AIM 5-4-20(f) further cautions, “Circling may require maneuvers at low altitude, at 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 its safety alert, the NTSB highlights three recent fatal accidents involving business jets flying circling approaches. In each case, the flight crews of the accident aircraft followed a disastrous script that was eerily similar to the cautions published earlier by the FAA.
Circling mishaps
In May 2017, the pilots of a Learjet 35A, on a Part 135 repositioning flight, stalled and crashed while attempting a circle-to-land approach at New Jersey's Teterboro Airport (KTEB). The weather at the time was daytime VMC with strong northwesterly winds at 19 knots gusting to 29 knots.
The flight crew had been cleared for the ILS Runway 6 approach, circle to Runway 1 at KTEB. ATC issued this approach clearance 50 nm from the airport; this approach clearance is a common practice at KTEB to accommodate traffic flow.
Unfortunately, the pilots never briefed the approach and due to a series of procedural deviations and errors had difficulty becoming established on the approach. Twice during the approach, ATC reminded the pilots of the final approach fix (FAF) altitude—the aircraft subsequently crossed the FAF “hundreds of feet” high.
Rather than beginning the circling maneuver at the FAF, as instructed by ATC, the aircraft continued toward Runway 6 at an altitude higher than required. Approximately one mile from the end of Runway 6, the crew began the circling maneuver toward Runway 1. At this point, they were too high and too close to Runway 6 to align with the landing runway. The flight crew continued to maneuver towards the runway, but the airspeed decreased during the turn, and the aircraft stalled and crashed one mile short of Runway 1. Both pilots were fatally injured in the crash.
The NTSB found that “The flight crew had multiple opportunities to recognize and discontinue the unstabilized approach, most notably during the circling segment of the approach. Their lack of situational awareness could have been prevented by briefing the approach and following ATC instructions to become established on the approach and safely maneuvering to land.”
In another crash, in July 2021, the pilot of a Bombardier Challenger 605 lost control during a circling maneuver near the Truckee-Tahoe Airport (KTRK) in Truckee, California. Both pilots and four passengers were killed in the crash.
As the aircraft neared KTRK, ATC advised the crew to expect the RNAV (GPS) Runway 20 at KTRK due to ATC flow control “constraints.” The flight crew originally planned the RNAV (GPS) 11 approach but accepted the approach to Runway 20 and then requested to circle to Runway 11 (a longer runway) for landing performance considerations.
At the time of the accident, the weather was reported as 4 miles visibility (with smoke), a broken cloud layer at 2,300 feet agl, and wind from the west at 11 knots gusting to 16 knots. The visibility was reported to further decrease to as low as 3 miles as the aircraft approached the airport.
Approximately 10 nm north of Runway 20, the flight crew “checked in” with the tower. The tower controller offered either a left downwind for Runway 29 or Runway 11. The flight crew reported Runway 11 in sight and began a right turn to enter the left downwind for Runway 11. Next, the aircraft continued to circle past the extended centerline of Runway 11 and entered a nose-down attitude in a steep left turn, and crashed short of the airport.
According to the NTSB, “the flight crew had many options available to them that would have increased the likelihood of executing a stabilized approach and successful landing, such as: requesting the approach they originally planned for, briefing the approach they accepted, or performing a missed approach procedure.”
Five months after the Challenger accident in KTRK, a Learjet 35A struck the powerlines and crashed near Gillespie Field (KSEE) in El Cajon, California while performing a circling approach at night in deteriorating weather conditions. The weather at the time of the accident was 3 miles of visibility and a broken cloud layer at 2,000 feet agl.
This flight was operated as a Part 91 repositioning flight that originated at the John Wayne/Orange County Airport (KSNA) in Santa Ana, California. After a short flight, the flight crew initiated the GPS Runway 17 approach and were cleared to land on Runway 17. Shortly afterward, the pilot requested to land on Runway 27. The controller instructed the pilot to overfly the airport and enter left traffic for Runway 27R and cleared the aircraft to land.
ADS-B data indicated that the aircraft overflew the airport at 407 feet agl and then began a climbing turn to align with runway 27R. The aircraft struck power lines and impacted the ground about a mile from the end of the runway. Both pilots and two flight nurses were fatally injured.
"Follow SOPs and industry best practices for stabilized approach criteria, including a normal glidepath, specified airspeed and descent rate, landing configuration (flaps, gear, etc.), appropriate power setting, landing checklists, and a heading that ensures only small changes are necessary to maintain runway alignment. Guidance and tips that, in most cases, the approach should be stabilized by 1,000 ft in instrument conditions or 500 ft in visual conditions. If the approach becomes unstabilized at any time after that, go around.”
The NTSB noted that: “Instead of attempting a landing from an unstable approach in poor visibility, the flight crew could have initiated a missed approach procedure and attempted a landing to a different runway or diverted to another airport due to the weather.”
NTSB Identifies the Problem
Circling approaches, according to the NTSB (and as demonstrated in these accidents), are problematic for the following four reasons:
- Circling approaches can be riskier than other types of approaches because they often require maneuvering at low altitude and low airspeed during the final segment of the approach, increasing the opportunity for loss of control or collision with terrain. These risks are heightened when conducting circling approaches in marginal or reduced visibility conditions and increased focus is required.
- While circling approaches might be necessary to accommodate traffic flow at airports, or are advantageous due to wind conditions, pilots sometimes do not evaluate the risks of these approaches fully before accepting them, which can result in unstabilized approaches.
- Often, circling approaches do not allow for stabilized approach criteria to be met. Approaches should be stabilized by 1,000 feet height above touchdown (HAT) in instrument conditions, and by 500 feet HAT in visual conditions.
- When circling approaches are conducted in IMC, transitioning from instruments to ground references can cause the “illusion of high speed” if the instruments are not properly monitored.
Operators are encouraged to establish, publish, and adhere to stabilized approach criteria; these criteria may restrict or prohibit an operator from circling approaches.
NTSB Safety Alert Number 77 – March 2019, titled “Stabilized Approaches Lead to Safe Landings,” recommends operators to, “Follow SOPs and industry best practices for stabilized approach criteria, including a normal glidepath, specified airspeed and descent rate, landing configuration (flaps, gear, etc.), appropriate power setting, landing checklists, and a heading that ensures only small changes are necessary to maintain runway alignment. Guidance and tips that, in most cases, the approach should be stabilized by 1,000 ft in instrument conditions or 500 ft in visual conditions. If the approach becomes unstabilized at any time after that, go around.”
Pilot and Organizational Takeaways
The NTSB safety alert on circling approaches is aptly titled “Know the Risks!” Pilots must fully understand the risks involved when flying a circling approach and use sound judgment before accepting a clearance to fly a circling approach. Is it your best option?
Consider your personal experience, proficiency, and other limitations when planning to fly a circling approach. Is the weather close to minimums? Is it nighttime? Are you familiar with the airport and terrain surrounding the airport? Again, there are other options such as requesting a straight-in approach to a different runway or diverting to a more suitable airport.
From an organizational perspective, “know the risks!” Circling approaches present both a safety risk and a liability risk. The safety risk is well-defined; a straight-in approach is 25 times less risky than a circling approach.
The liability risk is less defined. There is an argument where an operator will say, “A circling approach is a legal procedure that has been certified by the FAA (or other authority).” Another point of view will argue that a circling approach will allow access to second and third-tier airports, which provides a marketing advantage. All interesting points, but at the end of the day ask yourself and your legal counsel this question: Does the “operational flexibility” of flying a circling approach outweigh the liability if there were an accident?