Issue Number 3 : July 1992
by Perry Thomas
It is an anomaly that most air carrier companies do not allow their flight crews to cancel their IFR flight plan or fly on a VFR flight plan, but do allow their flight crews to accept the visual approach. In accepting a visual approach, the pilot rejects the historic and hallowed protection of the air traffic control system and assumes the responsibility to "see and avoid" other traffic.
The controller statement "You are cleared for the visual approach" is a welcome pronouncement for flight crews. There is an anticipated lessening of the workload, a quicker and more relaxed end to the flight. Yet many of the reports received at the ASRS detail unexpected and unwanted occurrences for pilots flying the visual approach" -- such as the following wrong airport landing incident.
Given the potential for error such as this wrong airport approach and landing, why conduct visual approaches at all? Who benefits from visual approaches? Well, there are advantages for flight crews and controllers alike.
When pilots cross-check the visual with available electronic navigation, there is often a reduction in the level of navigation effort required; in addition there is a greater degree of flexibility in the planning and execution of their approach. Tighter sequencing, and what is often a more direct route to the airport translates into a reduction in flight time and fuel burn. At smaller or more remote airports where "full" approaches would otherwise be conducted, these savings may be considerable.
For controllers, a visual approach is an essential tool in the effort to maximize traffic flow (especially at busier airports). Visual approaches dramatically reduce controller workload -- ATC's IFR separation requirements are eliminated and the pilot assumes the burden for maintaining adequate separation.
The visual approach, intended to benefit everyone, frequently results in pilots experiencing exactly the opposite effect. Visual approach incidents reported to the ASRS frequently cite confusion, with resultant stress on the flight crews. There are a variety of performance errors revealed in ASRS reports.
While I paint with a broad brush, bear in mind that my negative impressions of the numerous serious hazards inherent in the visual approach have been gathered from reading and analyzing hundreds of ASRS reports on visual approaches, where the results of the visual approach produced unwanted results.
The Wrong Objective
Many reports indicate that airports or runways are either misidentified, or in some cases, lost after initial (and correct) recognition.
- "I called for slats, flaps, gear down, and landing check. While turning final for the runway, we both commented 'This isn't right,' at which time the Approach Controller called saying 'Pull up, you're looking at XXX [wrong airport].' "
And in another incident, the First Officer reports: "At 500 feet AGL the Captain realized we were lined up with the wrong runway. I called [out, saying] I was going around."
Too often the traffic that the flight crew agrees to follow cannot be identified. In some instances, the flight crew visually acquires the traffic, only to lose it through distraction or other problems.
- "While we were on a right downwind ... Approach asked us if we had the air carrier widebody (which we were following), in sight. We answered that we did. After we turned onto a right base for Runway 24R, Approach changed our Runway to 24L. I subsequently put the new runway into the FMC and the ILS into the ... [navigation] radio. Approach then called out small commuter traffic which I acknowledged. I then asked the Captain where the widebody was because I had lost him in the ground clutter after tuning the ILS...."
Misidentification of the required traffic is also a problem, particularly at busier airports.
- " ... [the Controller] asked us 'Do you have the ... [aircraft] ... at your 11 o'clock?' We responded we had the traffic. The traffic eventually passed our 9 o'clock. The Captain started his turn to base...."
Traffic that was following this reporter's flight queried the reporter's perceived early turn to base, and the reporter's error was then discovered:
- " ... it's really easy to pick out the wrong aircraft like we did...."
Visual approaches to parallel runways are especially rich incident-producing events; it seems logical that it is more difficult to maintain visual contact with parallel traffic than traffic you may be following to a single runway. A constant flow of reports to ASRS on flawed visual approaches highlights the hazards of losing sight of close proximity traffic.
- "As Captain, I had the airport in sight out the copilot's window as we were on base leg. As we approached downtown I overshot final, resulting in being lined up closer to the left runway than to the right runway. [The] Tower Controller advised we were encroaching on south complex airspace. He also advised we were close to another air carrier ... on final for the south complex. [The] Controller asked us if we had [the] air carrier ... in sight. We did not. In spite of good visibility, [the] air carrier [aircraft] was difficult to see in the background of buildings. We had to transmit several times to the Controller in order to sight and identify the traffic."
And in another parallel approach incident ...
- " ... Approach gave us our co-approach [traffic] ... on the Tiptoe visual (we were on the Quiet Bridge) at about 20 miles out. I clearly saw him and figured we would be landing approximately together, he on 28L and us on 28R! At about 3 miles to go to the high span, on course but high, Bay [Approach] switched us to Tower. I changed frequency, looked back out and our co-approach [traffic] ... was crossing my course 30 degrees off my heading, about 1,000 feet lower. He passed to our right. We stopped our descent and slowed to keep him in sight! He then wrapped it up in a left turn back to the [left] runway."
The reporter concludes with this admonishment:
"There is a time for basic airmanship and see and avoid -- it is all the time!"
Landing Without Clearance
Most incidents of landing without clearance reported to ASRS are out of visual approaches --flights touch down with their crews having neglected to request their landing clearance. Reporters often cite complacency as a factor; others point to changes or increases in workload.
- "While on initial approach we were held at a high altitude longer than desirable. Due to the steep descent path required to successfully complete the approach, our workload was increased. Due to the increased demands on us -- because of the steep approach -- we failed to contact the tower before landing."
Too Quick Off the Mark
Flight crews may tend to "anticipate" a clearance when asked if they can accept a visual. Frequently reported are altitude deviations when the flight crew agreed they could accept a visual approach and then immediately started to descend -- before the controller said the magic words that cleared them for the visual approach.
- "The First Officer was flying and overshot his turn to the radial -- which was our clearance. [The] Approach Controller asked if we had the airport in sight, to which I replied 'affirmative,' although the First Officer did not see it. (Emphasis added.) [The] Approach Controller then said, 'Cleared for the Quiet Bridge visual.' The First Officer keyed ... [on] the word 'visual,' and started descent while I was attempting to program the FMC for the approach. [The] Controller advised [us that] we had busted our altitude."
Many incidents reported seem to indicate that flight crews are overly optimistic regarding their ability to see and identify traffic, airports and runways, and often reply inappropriately to the query "do you have ________ in sight?"
Electronic navigation is frequently ignored or abandoned.
It appears from what I read in ASRS reports, and from my own experience, that we all -- all categories of pilots -- have at one time or another (even frequently) succumbed to enticement, and accepted visual approaches when it was not timely or appropriate to do so. Why do otherwise sane and sensible pilots consistently fall into "The Visual Trap?"
I must conclude that the primary motivation, aside from the desire of the flight crew to cooperate with the ATC system and the controller in expediting other traffic, is to expedite arrival of their own particular flight.
One of our better ways of learning how to stay alive in the flying game is to profit from the unhappy experience of others. Here are a few practical, no-nonsense suggestions from these same reports that should reduce some of the hazards.
For All Approaches
- Review and brief all applicable visual and instrument charts before the approach;
- DO NOT identify traffic in sight, airport in sight, or runway in sight, unless you are certain of your identification, and your flight deck mates concur;
- Keep your traffic in sight; if you lose your traffic, tell ATC;
- Ensure that at least one pilot monitors the gauges and radios to "aviate, navigate, and communicate;"
- Use all available electronic navigation to back-up the visual;
- If visual approaches are being conducted but you don't want a visual, insist on an ILS or other instrument approach. 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, (and possibly the setting or rising sun), during the turn to base and final. This may lead you to misidentify the runway to which you are cleared.
For Parallel Approaches
- Be aware that parallel runway approaches means that there is likely to be other traffic close at hand. There may be a significant increase in flight deck workload -- unless the flight crew briefs and prepares themselves to the maximum extent possible. Safety in visuals will be enhanced by close coordination between flight crew members, and by maintaining a careful traffic watch outside the aircraft;
- Beware of overshooting runway alignment and encroaching into the parallel runway's approach path;
- Beware the dangers of "The Visual Trap."
In putting together the information for this article, I have borrowed extensively from Captain William P. Monan's NASA Contractor Report (Number 166573) entitled "Cleared for the Visual Approach -- Human Factors in Air Carrier Operations." Captain Monan's report covers all aspects, pro and con, of visual approaches and it should be required reading for all thoughtful pilots who may be concerned about visual approaches.
|Reproduction and redistribution of ASRS Directline articles is not only permitted--it is encouraged. We ask that you give attibution to ASRS Directline, to the Aviation Safety Reporting System (ASRS), and of course, to the authors of each article.|