A visual approach is an effective tool that air traffic control (ATC) utilizes to maximize aircraft traffic flow and reduce controller workload. For pilots, the greatest benefit of flying a visual approach is that it allows for tighter sequencing between aircraft, which equates to less time in the air and a reduction in fuel burn.
According to a recent issue of the NASA Aviation Safety Reporting System’s (ASRS) Callback newsletter, “Many pilots consider a visual approach to be less demanding than instrument approaches flown in poor weather conditions…But visual approaches can present a number of hazards, particularly when localizer and glideslope indications are not used to backup visual impressions.”
For many reasons, a visual approach is much more complex than perceived by pilots. According to another NASA report, there is a dark side to the visual approach. In this study, “Problems with Visual Approaches: The Visual Trap,” it states, “The visual approach is intended to benefit everyone, but frequently results in the pilots experiencing the opposite effect. NASA ASRS reports frequently cite confusion with added stress to the flight crews (when flying a visual approach).”
This added stress is the result of the burden of traffic separation being transferred from the air traffic controller to the pilot. According to the FAA ATC handbook, “A visual approach is an ATC authorization for an aircraft on an IFR flight plan to proceed visually and clear of clouds to the airport of intended landing.” Once cleared for a visual approach, pilots must see and avoid other aircraft.
NASA ASRS is a repository of great reports by well-intended pilots who have fallen into the visual approach trap. From those reports, several hazards have been identified—each filled with important lessons learned for the rest of us.
Common Visual Approach Hazards
Visual approach at night. One of the greatest lessons learned through the NASA ASRS reporting system regarding visual approaches is to always back up the visual approach with all available course (lateral) and glideslope (vertical) guidance—ideally an instrument approach procedure—and especially at night.
Likewise, it is recommended, if flying a visual approach, to join the final approach course outside of the final approach fix at or above an appropriate charted altitude. This will help with runway alignment and aid in approach stability. Seconds saved are not worth the added stress of flying a short approach.
Personally, I will not accept a visual approach to any airport at night unless there is both lateral and vertical guidance to the runway. This assures terrain clearance and proper guidance to the runway.
In mountainous terrain, at night, it is recommended to fly an instrument approach and not accept a clearance to fly a visual approach.
Wrong surface landing. Certainly embarrassing and logistically challenging, one of the greatest hazards is to land at the wrong airport, on the wrong runway, or on a taxiway. In these cases, most likely, the airport or runway is misidentified or lost after an initial correct identification.
Most landings at the wrong airport begin with a visual approach.
Traffic. Too often, reporters in the ASRS system mention the flight crew agreed to follow traffic that cannot be identified or is lost after visually acquiring the runway.
In some cases, the pilots visually acquire the traffic only to lose it through distractions, limited visibility, or other problems. Another issue is identifying the wrong traffic. This is more common at larger airports and those with parallel runways. Pilots must notify ATC if the preceding traffic is visually lost.
Wake turbulence separation. Pilots are required to see and avoid other traffic during a visual approach. In addition, pilots are responsible for wake turbulence separation. There is no requirement for ATC to provide wake turbulence separation to an aircraft on a visual approach.
According to the ATC handbook, “All aircraft following a heavy, or a small aircraft following a Boeing 757, must be informed of the airplane manufacturer and/or model.” Visual separation is not authorized when the lead aircraft is a super-category aircraft (Airbus A380 or Antonov AN225).
Pro tip: Pilots flying large or heavy aircraft with low approach speeds (at lower landing weights) should advise ATC of your planned approach speed—this will hopefully cue other aircraft behind you that your approach speed is low and in a slow-and-dirty configuration that your aircraft is producing some serious wake turbulence.
Landing without a clearance. Most incidents of landing without a clearance in the NASA ASRS database originated with a visual approach. Often, these aircraft touch down with their crews forgetting to obtain a landing clearance or switching to the tower frequency. Crews often cite complacency as a factor, while others point to an increase in workload or distractions.
Jumping the gun. Often in the anticipation of being issued a clearance for a visual approach—i.e. told by ATC to “expect a visual approach”—the flight crew jumps the gun and begins an early descent before receiving the actual visual approach clearance, leading to an altitude deviation.
Misused resources. Often the submitter of an ASRS report indicates that they were overly optimistic regarding their ability to see and identify traffic, airports, and runways and will reply inappropriately to ATC’s query, “Do you have the [blank] in sight?” Remember, if you call the “airport in sight,” you and your crew must see the runway or traffic.
Pilots are cautioned not to call the airport in sight if it is behind them—i.e. on an extended downwind flying away from the airport. Pilots are required to maintain visual contact with the runway and proper cloud clearance throughout the entire approach.
Flying—and briefing—the published missed approach procedure. Remember, a visual approach is not a standard instrument approach and has no missed approach segment. According to the ATC handbook, “An aircraft unable to complete a landing from a visual approach must be handled as any go-around and appropriate IFR separation must be provided until the aircraft lands or pilot cancels their IFR flight plan.”
A common error is for the pilot flying to brief the visual approach backed up by the ILS and continue to brief the published missed approach procedure. As the pilot monitoring, ask the flying pilot what their plan is in the event of a go-around or discontinued approach when flying a visual approach.
Recommendations
Authors of an early NASA report on visual approaches suggest that the best way to stay alive is to learn from others. As such, they developed a few practical, no-nonsense suggestions to reduce some of these hazards.
For all approaches:
- Review and brief all applicable visual and instrument charts before the approach—ideally prior to top-of-descent and discuss the plan to discontinue the approach or go-around.
- Do not identify the traffic in sight, airport in sight, or runway in sight unless you and the rest of your crew are certain of your identification.
- Keep traffic in sight. If you lose traffic, tell ATC.
- Ensure that at least one pilot monitors the flight path and navaids to aviate, navigate, and communicate.
- Use all available electronic navigation to back up the visual.
- If visual approaches are being conducted but you do not want a visual, insist on an ILS or other instrument approach—especially at night, in mountainous terrain, or at an airport that you are unfamiliar with. Bear in mind, however, that during your instrument approach, other aircraft in your proximity may be conducting a visual approach.
- Expect visibility to deteriorate and be reduced if you are descending into a smog/haze layer or into the sun during the turn to base and final. This may lead you to misidentify the runway to which you are cleared to land.
For parallel approaches:
- Be aware that parallel approaches mean that other traffic will be near your aircraft. These approaches require increased vigilance and the flight crew must maintain a careful traffic watch outside the aircraft.
- Be aware of overshooting the runway alignment and encroaching into the parallel runway’s approach path.
When To Expect a Visual Approach
ATC may provide a vector for a visual approach if the reported ceiling at the airport of the intended landing is at least 500 feet above the minimum vectoring altitude or minimum intercept altitude and the visibility is greater than three miles.
Furthermore, ATC may issue a clearance for a visual approach when the pilot reports the airport or runway in sight (at a tower-controlled airport) or the airport in sight (at a non-towered airport). The controller will resolve potential conflicts with other aircraft and ensure that the weather is VMC.
With this in mind, a visual approach is safe if pilots are aware of the potential pitfalls or gotchas. Every day, there are thousands of visual approaches that are well executed, flown safely, and don’t end with a submission to ASRS or an operator’s ASAP program.
Negative impressions of a visual approach presented here are based on reading NASA ASRS submissions from pilots where an approach ended poorly with an undesirable result. From those results, hazards are identified, and the rest of the aviation community can learn from these lessons to prevent future occurrences.
The opinions expressed in this column are those of the author and not necessarily endorsed by AIN Media Group.