Saratov Airlines Antonov An-148 Crash – February 11, 2018

On February 11, 2018, Saratov Airlines Flight 703, operated by an Antonov An-148, crashed shortly after takeoff from Moscow’s Domodedovo Airport. The flight was en route to Orsk in the Ural Mountains and crashed approximately 80 km southeast of Moscow, near the village of Argunovo. Tragically, all 71 people on board—65 passengers and six crew members—were killed in the crash.

Aircraft Overview and Design

The Antonov An-148 is a regional twin-engine jet designed for short-haul routes, primarily within Russia and surrounding areas. This aircraft type was designed to operate in harsh weather conditions, making it a reliable option for flights in cold and icy environments. However, like all aircraft, it relies on critical systems to ensure safe operation, including the pitot-static system, which provides crucial airspeed and altitude information to the pilots.

Sequence of Events Leading to the Crash

Flight 703 departed from Domodedovo Airport at 14:21 local time, and the aircraft climbed normally for the first few minutes. Weather conditions were cold, with light snow reported at the airport. Approximately five minutes into the flight, the aircraft’s altitude was recorded at 6,200 feet before it began a sudden and steep descent. Radar data showed that the aircraft was descending rapidly before disappearing from the radar at around 14:27, just six minutes after takeoff.

Eye-witnesses reported seeing the aircraft plummet into the snow-covered field near Argunovo, with no signs of distress from the flight crew being communicated prior to the crash. The impact was catastrophic, and there were no survivors.

Investigation and Preliminary Findings

The Russian Interstate Aviation Committee (IAC) was tasked with investigating the crash. Early analysis of flight data and cockpit voice recorders indicated that the aircraft experienced unreliable airspeed readings, likely due to icing of the pitot tubes. Pitot tubes are essential for measuring the dynamic pressure of the air, which is then translated into airspeed readings. These instruments are vulnerable to icing, especially in cold weather conditions, and are typically equipped with heating elements to prevent blockages.

In the case of Flight 703, it was found that the pitot-static heating system may not have been activated by the crew, leading to a blockage in the pitot tubes due to ice accumulation. As a result, the flight crew received conflicting airspeed indications from their instruments. One pilot’s display showed an over-speed warning, while the other’s indicated a dangerously low airspeed. These discrepancies led to confusion in the cockpit and improper control inputs as the pilots struggled to interpret the data.

Pilot Response and Human Factors

The investigation revealed that the flight crew did not follow the established procedures for dealing with unreliable airspeed indications. In such situations, pilots are trained to rely on basic flight instruments, such as the attitude indicator, and apply a standard pitch and power setting to maintain safe flight while troubleshooting the issue. However, the crew’s response was delayed, and their attempts to regain control were ineffective.

Human factors, such as stress and confusion in the face of conflicting data, likely played a significant role in the outcome of this flight. The flight crew’s limited experience with managing such a scenario may have contributed to their inability to maintain control of the aircraft.

Technical and Engineering Analysis

The Antonov An-148, like many modern aircraft, is equipped with multiple redundant systems to ensure safety even in the event of a system failure. However, the failure of the pitot-static system highlights a critical vulnerability in aviation: reliance on accurate airspeed data for safe flight. The pitot-static system is designed to provide this information, and when it becomes unreliable, it is crucial that pilots follow standard operating procedures to manage the situation effectively.

The design of the An-148’s pitot-static system is similar to that of other regional jets, with multiple pitot tubes providing input to the aircraft’s flight control computers. These systems are usually equipped with heating elements to prevent icing, but if these heaters are not activated, the tubes can become blocked, leading to erroneous airspeed readings.

Weather and Environmental Conditions

The weather at the time of the crash was cold, with light snow reported at Domodedovo Airport. While the conditions were not extreme, they were sufficient to cause pitot tube icing if the heating system was not activated. Icing of pitot tubes is a well-documented hazard in aviation, and it has been implicated in several other accidents over the years, including the 2009 crash of Air France Flight 447 over the Atlantic Ocean.

Given the known risks of pitot tube icing in cold weather, it is standard practice for pilots to activate the pitot tube heaters before takeoff. In this case, it is believed that the heaters were either not activated or malfunctioned, leading to the unreliable airspeed indications.

Lessons Learned and Safety Recommendations

The Saratov Airlines Flight 703 crash underscored the importance of adhering to standard operating procedures, particularly in the case of unreliable airspeed indications. Following this tragedy, the Russian aviation authorities and the airline industry at large took steps to reinforce pilot training on how to handle such scenarios. These measures include:

1. Enhanced Training for Unreliable Airspeed Events: Pilots are now required to undergo additional training on how to respond to unreliable airspeed situations, with a focus on maintaining control of the aircraft using basic pitch and power settings while troubleshooting the issue.

2. Increased Monitoring of Critical Systems: Airlines have been urged to implement more rigorous pre-flight checks of critical systems, including the pitot-static heating system, to ensure they are functioning properly before takeoff.

3. Improved Communication Protocols: The importance of clear communication between the flight crew and air traffic control has been emphasized, particularly in emergency situations where conflicting data may lead to confusion.

4. Review of Pitot-Static System Maintenance: Maintenance procedures for pitot-static systems have been reviewed to ensure that any issues are identified and rectified during routine inspections. This includes ensuring that pitot tube heaters are functioning correctly and that there are no blockages in the system.

Conclusion: The Importance of System Redundancy and Crew Preparedness

The crash of Saratov Airlines Flight 703 serves as a tragic reminder of the importance of system redundancy and crew preparedness in aviation. While the failure of the pitot-static system was the primary technical cause of the crash, the crew’s delayed response and failure to follow standard procedures contributed to the disaster.

In aviation, even the most advanced systems are not immune to failure, and it is essential that pilots are trained to handle such situations with confidence and clarity. The lessons learned from this accident have led to important changes in training and maintenance practices, helping to prevent similar incidents in the future.

As a result of the investigation into this crash, the aviation industry continues to prioritize the safety of passengers and crew, with a focus on ensuring that all systems are functioning properly and that pilots are equipped to handle any challenges that may arise during flight.