A preliminary investigation into a plane crash near Dubai airport that killed all four people onboard in May has found that the plane was flying too close to a larger aircraft.
The small Diamond DA62 aircraft, which crashed on May 16, likely lost control because of turbulence caused by flying too close behind a Thai Airways Airbus A350- 900 jet, the UAE’s General Civil Aviation Authority (GCAA) said in a report.
Three Britons and a South African, who were employed by UK-based Flight Calibration Services, were killed after the plane crashed into a nature reserve near Mushrif Park, about 5km south of the airport.
The aircraft was carrying out checks as part of the southern runway refurbishment project at Dubai International airport.
According to the investigation, the DA62 was at a distance of 3.7 nautical miles (nm) from the Airbus jet, which was flying the approach to runway 30R.
“When the DA62 levelled off after turning onto final at an altitude of approximately 1,100 feet and at an airspeed of approximately 130 knots, it rolled slightly but was recovered after nine seconds,” the report said.
“Seven seconds later, the aircraft abruptly rolled to the left until it became inverted and it then entered a steep dive. The aircraft impacted the ground approximately 3.5 nm from the runway 30L threshold. The impact was not visible to the runway approach camera,” it added.
The GCAA stated that observations of previous approaches during the same calibration flight indicated that the DA62 “consistently” followed the Airbus jet at distances which were “below the specified minimum separation, and less than the distances discussed during the pre-departure meeting”.
“The radar monitor recording indicated that there was an air traffic control (ATC) inconsistency in advising the DA62 of the expected occurrence of hazards caused by wake turbulence from traffic on approach to the parallel runway 30R,” the report said.
“Based on these observations, the investigation believes that there is sufficient reason to issue a prompt safety recommendation to re-emphasise to pilots and air traffic controllers the importance of maintaining a minimum safe distance and issuing essential traffic information such as advising aircraft of the expected occurrence of hazards caused by wake turbulence,” the GCAA advised.
The Diamond DA62 plane was a seven-seat twin-engine aircraft. It was not fitted with a cockpit voice recorder or flight data recorder since it is not a regulatory certification requirement for an aircraft of its size.
The GCAA said it is now in the process of publishing a safety decision containing mandatory requirements for ensuring that ATC procedures are developed, implemented and maintained for issuing essential traffic information, including the advice to aircraft of the expected occurrence of hazards caused by turbulent wake.
A safety decision is also being prepared to ensure standardised procedures are in place for the management of unusual or abnormal aircraft operations, including calibration flights.