Turkish Airlines Flight 634 crashes near Diyarbakır Airport, Turkey, killing the entire crew and 70 of the 75 passengers.
Overview of Turkish Airlines Flight 634
Turkish Airlines Flight 634 was a routine scheduled domestic passenger service operated by Turkish Airlines, the national flag carrier of Turkey. The flight originated from its primary operational hub, Istanbul Atatürk Airport (which has since closed for commercial passenger flights, replaced by Istanbul Airport), and was bound for Diyarbakır Airport (DIY) in the southeastern region of Turkey. This particular flight, carrying a total of 80 occupants, tragically concluded on the evening of 8 January 2003.
The Ill-Fated Flight and Accident Sequence
At approximately 20:19 Eastern European Time (EET) – corresponding to 18:19 Coordinated Universal Time (UTC) – the aircraft operating Flight 634, a British Aerospace Avro RJ100, encountered severe difficulties during its final approach to Diyarbakır Airport. The Avro RJ100, a four-engined regional jet known for its robust short-field performance and quieter operation often favored for regional routes, was attempting an Instrument Landing System (ILS) approach. However, it was later revealed during the investigation that the ILS glide slope component at Diyarbakır was unserviceable at the time of the accident. Amidst exceptionally poor weather conditions, primarily dense fog and extremely limited visibility, the aircraft descended below the minimum decision altitude without sufficient visual reference to the runway or its surrounding environment.
Tragically, the aircraft struck the ground approximately 900 metres (equivalent to about 3,000 feet) short of the runway threshold. Following this initial impact, the aircraft collided with an elevated slope, a geographical feature located just beyond the initial point of contact, causing significant structural damage and rapid deceleration. This catastrophic sequence immediately led to a post-crash fire, consuming much of the wreckage and intensifying the tragedy.
Casualties and Survivors
The severity of the impact and the ensuing post-crash fire resulted in a devastating loss of life. Out of the 80 individuals on board, which included both passengers and the full complement of flight and cabin crew, 75 tragically perished in the accident. This grim toll included both of the flight's highly experienced pilots, who were among the fatalities. Miraculously, five occupants survived the crash, albeit with serious injuries, a rare occurrence given the forces involved and the subsequent fire. These survivors received immediate medical attention following rescue efforts.
Official Investigation and Probable Causes
The comprehensive investigation into Turkish Airlines Flight 634 was meticulously conducted by the Turkish Directorate General of Civil Aviation (DGCA), the authoritative body responsible for aviation safety oversight and accident investigation within Turkey. The inquiry thoroughly analyzed critical evidence, including data from the aircraft's flight recorders (the Cockpit Voice Recorder and Flight Data Recorder), detailed eyewitness accounts, and prevailing meteorological information to pinpoint the factors contributing to the tragedy. The final report identified several critical probable causes and contributing factors, offering vital insights for future aviation safety enhancements:
- Continuation of Unstable Approach in Adverse Weather: The flight crew persisted with their approach despite encountering severe fog and very low visibility conditions, which rendered a stable and safe approach virtually impossible. Crucially, visual references required for landing were not established at or above the minimum decision altitude.
- Failure to Execute a Mandatory Go-Around: Despite clear indications that the approach was becoming unstable and that the aircraft had descended below decision height without visual contact with the runway, the flight crew did not initiate a mandatory go-around procedure. A go-around is a fundamental safety protocol designed to abort an unsafe landing attempt and allow the aircraft to climb away for another, safer approach.
- Unserviceable Airport Infrastructure: A significant contributing factor was the non-operational status of the Instrument Landing System (ILS) glide slope at Diyarbakır Airport at the time of the accident. While the localizer (providing horizontal guidance) was reportedly functioning, the absence of vertical guidance from the ILS significantly increased the difficulty of performing a precise manual approach in the challenging weather conditions.
- Deficiencies in Crew Resource Management (CRM): The investigation highlighted shortcomings in crew resource management, particularly concerning effective communication and coordination between the two pilots in the cockpit. These deficiencies may have impaired their ability to collectively assess the escalating risks and make timely decisions to abort the hazardous approach.
- Loss of Situational Awareness: There was a significant loss of situational awareness by the crew regarding the aircraft's precise position relative to the ground and their height above the runway threshold, particularly in the prevailing low visibility conditions.
Key Takeaways and Impact on Aviation Safety
The tragic accident of Turkish Airlines Flight 634 served as a stark reminder and underscored several critical aspects of aviation safety, particularly concerning flight operations in challenging weather conditions and the absolute necessity of adhering to standard operating procedures. The findings of the investigation reinforced the paramount importance of strict adherence to go-around policies when an approach is deemed unstable, the critical role of robust crew resource management training, and the absolute necessity of ensuring that essential airport navigation aids are fully operational and meticulously maintained, especially at airfields prone to adverse weather conditions. This accident, like others before and since, contributes invaluable data to the evolving understanding of human factors, operational safety, and technological requirements in commercial aviation, continuously driving improvements in pilot training methodologies, air traffic control protocols, and airport infrastructure development globally to prevent similar occurrences.
Frequently Asked Questions About Turkish Airlines Flight 634
- When and where did Turkish Airlines Flight 634 crash?
- Turkish Airlines Flight 634 crashed on 8 January 2003 at approximately 20:19 EET (18:19 UTC) during its final approach to Diyarbakır Airport in southeastern Turkey.
- What type of aircraft was involved in the accident?
- The aircraft involved in the accident was a British Aerospace Avro RJ100, a four-engined regional jet airliner.
- How many people died in the Turkish Airlines Flight 634 crash?
- Out of 80 occupants on board, 75 people tragically died in the crash, including both pilots. There were five survivors.
- What were the primary causes of the Turkish Airlines Flight 634 accident?
- The primary causes were determined to be the flight crew's decision to continue an unstable approach in severe fog and very low visibility, their failure to execute a go-around, and the unserviceable Instrument Landing System (ILS) glide slope at Diyarbakır Airport, coupled with deficiencies in crew resource management.
- What is an Avro RJ100 aircraft?
- The Avro RJ100 is a British-built, four-engined regional jet airliner. It is part of the Avro RJ series, commonly used for short-haul flights and known for its operational capabilities at smaller airports and relatively quieter performance compared to older jets.