Systems rarely fail all at once. More often, they erode quietly and locally until pressure in one part of the operation obscures what is developing somewhere else.
Two issues have come into focus this week. The first is the continuing concern around fatigue in commercial air transport, alongside communication barriers that often receive less attention than they deserve. The second is the Newark approach incident involving a Boeing 767-400ER—a reminder that experienced crews can still find themselves outside their intended safety margins when workload, visual cues, aircraft geometry, and operational pressure interact.
This edition looks at that combination: fatigue and approach-path management as performance-shaping factors, rather than as evidence of individual carelessness.
The purpose is not to prejudge the Newark investigation or assign blame. It is to ask a more useful human-factors question: not simply what did the crew do?, but what conditions made the outcome possible and the actions understandable at the time?
That question sits at the heart of Sidney Dekker’s New View of human error and James Reason’s work on organizational accidents. It also aligns with the Human and Organizational Performance principle that failure is rarely explained adequately by the final action alone.
Scenario: Visual Approach Distortion at Newark
On May 3, 2026, United Airlines Flight 169, a Boeing 767-400ER, was approaching Newark Liberty International Airport’s Runway 29 when the aircraft struck a light pole associated with the New Jersey Turnpike. Debris subsequently struck a tractor-trailer. The aircraft continued to the runway and taxied to the gate; the NTSB preliminary report states that the investigation remains ongoing. (NTSB)
Runway 29 is substantially shorter than Newark’s principal parallel runways. That makes touchdown-zone management and stabilized-approach discipline especially important, although runway length alone does not establish why the aircraft descended as it did
The approach environment also matters. The available procedure provided lateral and vertical guidance only to a visual guidance point, after which the crew had to continue visually. That transition increases the importance of maintaining a disciplined cross-check between flight-path indications, outside references, airspeed, descent rate, and the runway environment. (NTSB)
NTSB-sourced diagram of the United 169 Newark approach: standard 3° glide path vs. actual descent trajectory, light pole strike point (~0.75 NM pre-threshold, ~19 ft AGL), and 767-400ER geometry factors under review.
Now picture the view from the flight deck. On a longer-fuselage aircraft such as the 767-400ER, the approach sight picture can differ from that of shorter 767 variants because the aircraft’s geometry, landing attitude, and visual relationship to the runway are not identical. The 767-400ER also uses redesigned, taller main landing gear. Those differences may be operationally relevant, but they should not be presented as the established cause of this event. (Airliners.net)
In low-light conditions, reduced external cues can make visual height and path judgments more demanding. But Newark occurred in daylight with good reported visibility, so night conditions should not be used to explain this particular approach. (NTSB)
A more defensible description is a progressive deviation below the intended vertical path. Informally, some pilots might call this “glide slope creep,” but the phrase is not an official finding in the NTSB preliminary report. It is better understood as a possible pattern in which small corrections, changing visual references, speed control, workload, and monitoring demands gradually reduce the available margin.
That interpretation remains a hypothesis, not a conclusion. The investigation must still determine how the approach developed, what cues the crew received, how those cues were interpreted, and why the aircraft continued toward the obstacle environment.
Human Factors Lens: Dekker’s New View and HOP Principles
The easy question after an approach excursion is: Why didn’t they go around?
It is also the wrong question to ask first.
A stronger starting point is: What made continuing the approach seem reasonable in that moment?
Causal-pathway diagram mapping systemic pressure, local performance factors, and operational drift in the Newark Runway 29 approach event (preliminary, subject to revision).
1. Local rationality and operational drift
From inside the operation, decisions often make sense locally. A short runway may increase concern about touchdown distance. A visual approach may create pressure to maintain the expected runway picture. A small deviation may initially appear recoverable. None of these factors, by itself, explains the event—but together they can create a pathway in which margin is gradually consumed.
That is the value of Dekker’s “local rationality” concept. It asks us to understand the conditions surrounding an action before judging the action itself.
The descent below the intended path may not have been one deliberate decision. It may instead have developed through a sequence of small adjustments: a correction for speed, a change in pitch, an attempt to preserve the runway picture, or an assumption that the deviation would be corrected moments later.
This is not an excuse. It is a way to investigate the system more effectively.
2. Fatigue as a performance constraint
Fatigue does not need to produce an obvious mistake to affect safety. It can reduce scanning quality, slow the recognition of developing deviations, weaken working memory, and make competing cues harder to reconcile.
That does not mean fatigue caused the Newark event. The available preliminary information does not establish that conclusion. It does mean fatigue belongs in the broader risk picture whenever an operation combines late-duty workload, visual approach demands, short-runway concerns, and the need for continuous monitoring.
Conklin’s HOP principles offer a useful reminder: error is normal, context influences behavior, and learning requires attention to the conditions in which work is performed.
The practical question is therefore not simply whether a crew was alert enough. It is whether the operation provided enough redundancy, monitoring, and recovery opportunity when attention and capacity were under pressure.
3. Why “just be more careful” is not a strategy
A resilient system does not depend on perfect visual judgment under pressure. It creates multiple opportunities to detect and correct deviation:
clearly defined stabilized-approach criteria;
explicit callouts for airspeed, vertical path, and sink rate;
disciplined monitoring of outside references and flight instruments;
clear go-around triggers;
approach briefings that identify runway, obstacle, and visual-illusion risks;
reporting and review systems that detect recurring patterns
The aim is not to eliminate human variability. It is to ensure that normal variability does not easily become an unrecoverable event.
“Be more careful” is not a control. It is an aspiration.
Safety Legacy and Industry Evolution
Approach instability and visual illusions have influenced many of the protections now embedded in commercial aviation. These protections are not based on the assumption that crews will never misjudge a situation. They are based on the recognition that humans can misperceive, become overloaded, or continue with a plan longer than intended.
Safety domain | Operational development |
|---|---|
CFIT defenses | Terrain-awareness and warning systems provide an additional layer when aircraft position and terrain or obstacle clearance become unsafe. |
Stabilized-approach criteria | Operators define acceptable limits for speed, descent rate, configuration, alignment, and vertical-path deviation, together with go-around requirements. |
Flight-data monitoring | FDM and FOQA programs can identify recurring low approaches, unstable approaches, high sink rates, and runway-specific patterns before they become accidents. |
Fatigue-risk management | FRMS approaches treat fatigue as an operational risk influenced by schedules, circadian disruption, workload, and recovery—not simply as an individual responsibility. |
Threat and error management | TEM encourages crews to identify threats early, monitor how they develop, and preserve recovery options throughout the approach. |
These layers are most effective when they work together. A warning system cannot replace a stabilized approach. A stabilized-approach policy cannot compensate for an unclear briefing. A fatigue program cannot succeed if crews believe that reporting fatigue will be treated as a personal weakness
Safety is built through overlapping defenses, not through one perfect safeguard.
Practical Takeaways for Flight Operations
If you fly the line or train the people who do
Treat visual guidance as one cue, not the only cue. Cross-check the runway picture against available vertical-path indications, airspeed, descent rate, configuration, and stabilized-approach criteria.
Brief the visual segment specifically. Identify the point at which electronic guidance ends, the expected visual references, the runway length, nearby obstacles, and the exact conditions that will trigger a go-around.
Do not normalize a slowly developing deviation. A small deviation that is not corrected promptly is still a developing threat, particularly when airspeed or sink rate is also moving away from target.
Make the go-around decision operationally easy. The crew should not need to prove that the approach is unrecoverable before discontinuing it.
Use standard callouts as safety barriers. Callouts should not be treated as ritual. They should provide the crew with a shared, timely picture of the aircraft’s energy state and flight path.
If you run the safety program
Map geometric and procedural traps. Review short runways, visual approaches, displaced thresholds, obstacle environments, unusual approach transitions, and routes that frequently combine night operations with high workload.
Use flight-data monitoring to look for drift. Search for trends in low approaches, unstable approaches, excessive sink rates, late configuration changes, and go-arounds that occur later than expected.
Treat fatigue data as an operational signal. Repeated fatigue reports may indicate roster design, night-turnaround pressure, inadequate recovery time, or cultural barriers to reporting.
Examine the transition from instruments to visual references. The highest risk may not be the final few seconds before touchdown. It may be the point at which the crew moves from a structured instrument picture to a less constrained visual one.
Protect the decision to go around. A go-around should be understood as a normal risk-control action, not as evidence of poor performance.
Avoid premature causal certainty. Preliminary reports are valuable because they establish facts and guide further inquiry. They are not final explanations.
Reflection and Further Reading
Operational reflection
How effectively does your flight-data-monitoring program identify gradual deviations below the intended vertical path on visual approaches, particularly when the aircraft remains technically controllable and the deviation develops slowly?
Systemic reflection
When fatigue reports increase, does the safety-management system treat them as isolated personnel issues—or as evidence that scheduling, workload, recovery, and communication systems may need attention?
Stay in the Loop
Safety is not the absence of mistakes. It is the presence of enough capacity, information, monitoring, and recovery options to prevent an ordinary mistake from becoming an extraordinary outcome.
When fatigue reports rise, visual approaches repeatedly generate unstable-path trends, or crews find themselves relying on a runway picture that no longer matches the instruments, those signals should not be dismissed as noise.
They are early warnings.
The goal of safety leadership is to notice them while there is still time to redesign the conditions that produce them.
Further reading
EASA, Article 89 Report on Aviation Safety and Socio-Economic Factors in Commercial Air Transport.
NTSB, preliminary report on United Airlines Flight 169 and the Newark approach incident. (NTSB)
Sidney Dekker, The Field Guide to Understanding Human Error, 3rd edition.
Todd Conklin, Better Questions: An Introduction to Human and Organizational Performance.
Operator guidance on stabilized approaches, threat and error management, and fatigue-risk management.