Pakistan-registered cargo plane missing off Karachi coast after navigation problem

A Pakistan-registered Boeing 737 cargo plane with five crew members on board lost contact with air traffic control on Tuesday night after reporting a navigational system problem on its way to Karachi, Pakistani aviation authorities said.

Early flight data indicated the 27-year-old converted freighter operated by K2 Airways possibly crashed into the sea southwest of Karachi after a series of sharp altitude changes before a steep final descent, according to flight-tracking service Flightradar24.

Authorities have launched a coordinated search and rescue operation at sea through various agencies to locate the missing plane, Pakistan Airports Authority said on Facebook.

K2 Airways said it was cooperating with the Pakistan Civil Aviation Authority and other government agencies.

"We continue to pray, earnestly, for the safety of our colleagues," the aircraft operator said on Facebook.

Boeing did not immediately respond to requests for comment.

The plane reported a navigational system issue at 9:18 pm Pakistan Standard Time (1618 GMT) while flying toward Karachi, the airport authority said.

Local air traffic control tried to guide the aircraft, but three minutes later radar systems showed the plane descending rapidly, and communication was lost, the authority said. The flight was about 155 nautical miles (287 km) west of Karachi at the time, according to the statement.

Flightradar24 tracking data showed chaotic final minutes as the plane plunged about 5,000 feet in less than a minute, surged back some 6,000 feet in just 30 seconds, before a catastrophic dive from 36,550 feet.

The last transmitted data point placed the aircraft at 1,100 feet above sea level, with a vertical rate of minus 22,400 feet per minute - about 400 kilometres per hour - an extremely steep and abnormal rate of descent.

"Anytime you see something extreme like that, it catches your eye, but it is too soon to say what any of it means without more information," said Anthony Brickhouse, an aerospace safety consultant.

The missing aircraft is part of Boeing's decades-old 737 family but is two generations older than the 737 MAX version that was involved in a recent safety crisis. It uses engines made by CFM International, jointly owned by GE Aerospace and France's Safran.

The 737-400 was first delivered as a passenger plane to Russia's Aeroflot in 1999 and was converted to a freighter in 2012, according to Flightradar24.

It is K2 Airways' only aircraft and entered into service with the carrier in 2024. Before the last flight, it had not flown since June 28, according to Flightradar24 data.

If casualties are confirmed, the incident would be the first fatal crash in Pakistan since 2020, when a Pakistan International Airlines Airbus A320 came down short of the runway in Karachi, killing 97 people after pilots were distracted discussing the coronavirus before a failed landing attempt.