A preliminary investigation report into the Emirates cargo plane that crashed into the sea at the airport will be released "within one month", the Air Accident Investigation Authority (AAIA) said, as the flight data recorders were retrieved.

The aircraft veered off the runway upon landing on Monday, killing two workers after sending their security patrol vehicle into the sea.

Salvage workers late on Friday retrieved the flight data recorder and cockpit voice recorder, commonly known as the "black boxes", from the aircraft wreckage.

"The professional team lifted the tail of the cargo aircraft... out of water around [10.41pm on Friday]," the Airport Authority said in a statement issued on Saturday.

The AAIA, an independent authority under the Transport and Logistics Bureau, said its probe "will take time".

"Following the successful recovery of the 'black boxes', the subsequent data processing, along with a thorough analysis and integration of other evidence, will take time," an AAIA spokesperson said in a statement.

"We will release a preliminary investigation report within one month and continue to conduct a thorough and rigorous investigation to determine the sequence of events and causes of the accident, as well as to propose safety recommendations to enhance aviation safety."

The bureau overseeing AAIA said the analysis involves reconstructing the sequence of events through the data retrieved, interviews with relevant personnel, laboratory findings, examination of the aircraft wreckage, aircraft operating procedures, aircraft system status and maintenance records, weather conditions, and other relevant factors, to prepare a report.

"Personnel from the National Transportation Safety Board of the United States and the Transport Safety Investigation Centre of Türkiye have arrived in Hong Kong, while experts from Boeing are also participating," the bureau added.

The ongoing salvage work also lifted one of the aircraft's engines and its landing gear out of the sea, the Airport Authority said, and the operation is expected to "last a few days".