MOSCOW (Sputnik) – The Russian Kogalymavia (Metrojet) flight 9268 began a sharp descent soon after a "significant event," revised data released by FlightRadar24 indicated Tuesday.
"In normal cases, GPS altitude data must be requested from Air Traffic Control, but in this instance, we only see it in the data set after the flight has experienced a significant event and begun to descend rapidly," the company said.
While altitude data based on the US Global Positioning System (GPS) is not unusual, FlightRadar24 said "our receipt of it from this flight is."
The aircraft began descending at the speed of 3,584 feet per minute with increased vertical speed of negative 3,584 feet per minute at 04:13:15. By 04:13:18, its vertical speed was negative 8,384 feet per minute.
An unknown event that cut the plane’s vertical speed by more than half at an altitude of 29,750 feet occurred at 04:13:19. As the plane reached maximum descent of 24,960 feet, FlightRadar stopped processing altitude data at 30,670 feet at the descending altitude of 20,352 feet per minute.
The new data was released at the request of French and Egyptian investigative authorities.
The death of all 224 people aboard flight 7K9268, en route from the Egyptian resort of Sharm El-Sheikh to St. Petersburg early Saturday, is the largest civil aviation tragedy in Russian and Soviet history.