This representational image shows a silhouette of an aircraft in flight. — Pexels/File

• Boeing 737 lost contact during flight from Sharjah: sources.
• Aircraft makes sudden U-turn before rapid descent.
• Aviation authorities activate emergency response.

KARACHI: A cargo aircraft has gone missing approximately 155 nautical miles west of Karachi after losing contact, the Pakistan Airports Authority (PAA) said in a statement on late Tuesday.

The search for the cargo aircraft has widened significantly, with the Pakistan Navy and Air Force now deploying additional ships and aircraft to the search zone, sources said.

The Pakistan Navy has dispatched the warship PNS Zulfiqar to join the search and rescue effort, while a Pakistan Air Force Saab surveillance aircraft is also taking part in the operation, according to sources. A Navy ATR aircraft has flown out from Turbat to assist, joining the wider search from the air.

PNS Hunain has also been dispatched to the affected area to take part in the search and rescue operation, sources said.

Commercial vessels operated by the National Shipping Corporation have likewise been deployed to help scan the waters, sources added, bringing together military and civilian resources in the hunt for the missing plane.

Search teams have yet to report any sign of wreckage or further contact with the five crew members on board.

The missing aircraft is a 27-year-old Boeing 737 operated by a Pakistani cargo company, said aviation sources adding that contact with the aircraft was lost at 9:32pm during its flight from Sharjah to Karachi.

Flight tracking data showed the aircraft, flight TA1732, was cruising normally at an altitude of 35,000 feet and a speed of 790 kilometres per hour at 9:17pm when it encountered unusual circumstances.

The data indicated that the aircraft abruptly made a U-turn before entering a rapid descent.

Within five minutes, it had lost approximately 34,000 feet of altitude, eventually dropping to 1,100 feet while slowing to 211 kilometres per hour before disappearing from radar, FlightRadar data showed.

The PAA confirmed that the cargo plane went missing after reporting a malfunction in its navigation system while airborne.

The Area Control Centre (ACC) immediately provided guidance to the crew following the report, it added.

The pilot of the missing cargo aircraft did not issue a Mayday distress call before contact was lost, an air traffic controller told Geo News, adding that the crew may not have had time to do so given how quickly the emergency appears to have unfolded.

Following the incident, the Rescue Coordination Centre was activated immediately to coordinate response and search efforts, a PAA spokesperson said.

In 2010, a Russian cargo aircraft carrying eight people crashed in a residential area of Karachi shortly after taking off from the city’s airport.

The aircraft was heading to Khartoum in Sudan when it went down, killing all those on board.

The crash sparked fires in nearby buildings and triggered a large-scale rescue operation. The aircraft lost contact with air traffic control minutes after departure, according to officials at the time.