The Events Unfold

Journalist Christine Negroni meticulously outlines the events leading to the demise of Helios Flight 522, framing it within the context of one of aviation's greatest mysteries: the disappearance of Malaysia Flight 370.

The flight took off from Larnaca at 9:07 a.m. local time, but signs of trouble emerged shortly thereafter. According to Jake Hardiman from Simply Flying, just five minutes after takeoff, the cabin altitude warning alarm activated as the aircraft ascended past 10,000 feet. The crew dismissed the alarm, mistaking it for a routine takeoff warning, which was puzzling since the aircraft was no longer in the takeoff phase.

In reality, the plane was experiencing a loss of cabin pressure. By the time it reached an altitude of 18,000 feet, oxygen masks were deployed for both crew and passengers. Although the pilots reported an air conditioning issue shortly after, their subsequent communications became increasingly unclear.

Ground operations maintained contact with the crew for the last time 13 minutes into the flight. When engineer Alan Irwin inquired whether the pressurization panel was set to auto, Captain Hans-Jürgen Merten failed to respond meaningfully, instead asking about equipment cooling circuit breakers.

An investigation later revealed that the crew had succumbed to hypoxia, which is a lack of oxygen to the brain. The loss of cabin pressure was the primary cause, with the aircraft reaching 34,000 feet before it levelled off 16 minutes into the flight. The emergency oxygen masks provided only around 12 minutes of breathable air.

Hypoxia can lead to impaired judgment, which Negroni suggests explains Captain Merten's unusual responses during communication with ground control. The accident report indicated that once the aircraft entered Greek airspace, the pilots ceased responding to air traffic control. By 9:37 a.m., the plane was flying in circles over Athens on autopilot. In response, the Hellenic Air Force dispatched two F-16 fighter jets to intercept the aircraft, contemplating the need to take defensive action.

Initially, the fighter pilots suspected a terrorist attack, particularly in the post-9/11 climate. However, upon reaching the aircraft, they found the pilot's seat unoccupied, and the first officer unconscious in the cabin, with oxygen masks hanging in the passenger area.

A Flight Attendant's Brave Attempt

Despite the dire situation, hope was not entirely lost. Flight attendant Andreas Prodromou, only 25 years old, was one of the few individuals aboard who remained conscious due to hypoxia. He managed to locate a portable oxygen supply and made his way to the cockpit just before the plane's impact.

Prodromou faced the critical task of lowering the aircraft's altitude, which could have enabled the incapacitated pilots to regain consciousness. As a licensed commercial pilot, he possessed the knowledge necessary to potentially guide the plane to safety, despite lacking experience with the Boeing 737.

His girlfriend, Haris Charalambous, was also awake and assisted him in trying to control the plane. Prodromou signaled to one of the F-16s but was ultimately unable to regain control. Nevertheless, he managed to divert the aircraft away from Athens and toward the countryside. Unfortunately, the aircraft's engines flamed out due to fuel exhaustion.

Though he radioed five mayday calls seeking assistance, none were received—his radio had been set to the wrong frequency, communicating with Larnaca instead of Athens. The aircraft ultimately crashed into a hillside outside of Athens.

The Aftermath of the Crash

In the wake of the disaster, the Hellenic Air Accident Investigation and Aviation Safety Board identified three primary causes for the crash. First, the crew failed to recognize that the cabin pressurization mode selector had been left in the manual position during preflight inspections. Second, they did not acknowledge the warnings regarding cabin depressurization, including the deployment of oxygen masks and the cabin altitude warning horn. Lastly, the crew's incapacitation from hypoxia led to the aircraft continuing its flight on autopilot, culminating in fuel depletion and the eventual crash.

Since the pressurization selector was set to manual, the aircraft did not regulate the internal pressure. Sally Williams of The Guardian reported that Alan Irwin, the engineer responsible for inspecting the aircraft before takeoff, was blamed for this oversight. He had worked for Helios Airways for six months, ensuring the safety of three Boeing 737s.

Irwin, who had been in charge of the pre-flight checks, faced severe consequences following the accident. He was vilified in the media, lost his job, incurred substantial legal expenses, and experienced the dissolution of his long-term relationship. Following the investigation, Irwin was charged with manslaughter in April 2008, and by 2012, he was found guilty, alongside three Helios Airways officials. However, he successfully appealed the verdict in 2013, while the other officials did not.

The Case Against Boeing

While human error played a role, the reality of aircraft crashes often involves a multitude of contributing factors. The potential for systemic issues raises questions about what safeguards should be in place to prevent such incidents.

Boeing's warning horn was particularly problematic, as it could sound for both takeoff configuration and altitude warnings. This design flaw led the crew of Helios Flight 522 to misinterpret the alarm, mistaking it for a takeoff warning. In 2004, concerns were raised about this confusion by the director of NASA's Aviation Safety Reporting System.

Incidents of cabin pressure emergencies involving Boeing 737s were not isolated, with multiple serious events reported between 2000 and 2005. Boeing's inaction regarding the warning horn was criticized, particularly after the FAA mandated the installation of additional warning lights in 2011 to differentiate between warnings.

The accident report noted Boeing's failure to address prior pressurization incidents adequately. A safety assessment conducted by the FAA in 2006 effectively placed blame on Boeing, suggesting that the warning horn confusion was a significant contributing factor to the crash.

In July 2007, the families of eight Cypriots filed a lawsuit against Boeing for 76 million euros. The case was settled out of court.

Lessons Learned

The blame game that followed the crash served as a convenient narrative for Boeing, allowing the company to evade accountability for its role in the disaster. This approach has only grown less tenable in light of recent tragedies involving the Boeing 737 Max, highlighting the need for systemic changes in safety practices.

The distinction between the earlier Boeing 737 models and the Max is crucial, as the latter has recently been reintroduced into service after a lengthy grounding. The tragedy of Helios Flight 522 serves as a chilling reminder of the potential consequences of hypoxia and the need for improved safety protocols within the aviation industry.

Christine Negroni draws parallels between the Helios crash and the mystery surrounding Malaysia Airlines Flight 370, which may share similar causes.

Today, Irwin reflects on his experience, believing he was unfairly scapegoated for the tragedy. He has since transitioned into a career as a property developer. Unfortunately, it took Boeing six years to address the warning horn issue, a delay that raises significant concerns about the company's commitment to aviation safety.

The first video, titled "Mysterious 2005 Helios Airways Crash - Ghost Plane | Mayday: Air Disaster," delves into the eerie details surrounding the Helios Flight 522 crash.

The second video, "Helios Flight 522: How a Single Switch Killed 121 Passengers," explores the critical factors that led to the disaster, focusing on the implications of a single switch left in the wrong position.