The pilots of a plane that crashed last month in Pakistan, killing 98 people, were pre-occupied by the coronavirus crisis and tried to land with the aircraft's wheels still up, according to initial official reports released Wednesday.

The Pakistan International Airlines (PIA) plane crashed into a crowded residential area on May 22 after both engines failed as it approached Karachi airport for a second landing attempt, killing all but two people on board, and a child on the ground.

The preliminary report outlines the flight's chaotic final minutes and a bizarre series of errors compounded by communication failures with air traffic control.

Investigators found the plane was at more than twice the correct altitude when it first approached the runway, and the tower advised the pilots to circle for a more gradual descent, the report states.

But, instead of going around, the pilots attempted to land anyway -- even though they had raised the landing gear.

Air traffic control saw the Airbus A320's engines scrape the runway with a shower of sparks, but did not tell the cockpit.

The badly damaged engines failed as the plane turned to attempt a second landing.

Pakistan's aviation minister Ghulam Sarwar Khan told parliament the pilots had been discussing the coronavirus as they attempted to land and had disengaged the craft's autopilot.

"The pilot and co-pilot were not focused and throughout they were having a conversation about corona. The [virus] was on their minds. Their families were affected and they were having a discussion about it," Khan said.

"Unfortunately the pilot was overconfident," the minister added.

Khan also pointed to a troubling review of pilot credentials that is bound to reverberate through the country's airline industry.

He said a probe last year found that 262 of Pakistan's 860 active pilots had fake licenses or had cheated on exams -- including an unspecified number of PIA pilots.

The crash investigation team, which included officials from the French government and the aviation industry, analysed cockpit data and voice recorders.

Pakistan's deadliest aviation accident in eight years came days after domestic commercial flights resumed following a two-month coronavirus lockdown.

The deadly crash of a Pakistan International Airlines plane last month has been blamed on human error in an initial report on the disaster The deadly crash of a Pakistan International Airlines plane last month has been blamed on human error in an initial report on the disaster Photo: AFP / Rizwan TABASSUM

According to the report, the plane had been on the ground for 46 days during that time.

But it was "100 percent fit for flying, there was no technical fault", Khan said.

Qasim Qadim -- a spokesman for the Pakistan Airline Pilots Association -- called the investigation's findings "mind-boggling".

"How could it happen? It just baffles me," he said.

"The greatest pilots with the best records have made mistakes. Humans make mistakes."

The report did not name the pilots, but a senior PIA official told AFP the captain was Sajjad Gul.

Gul joined the airline 25 years ago and had racked up 17,000 hours of flying experience, including 4,500 hours on A320s, the official said.

Many passengers were travelling to spend the Muslim holiday of Eid al-Fitr with loved ones.

Buildings were torn apart after the plane's wings sliced through rooftops, sending flames and plumes of smoke into the air.

Khan said three people on the ground were injured, saying for the first time that a young girl later died.

A full report is expected to be released at the end of the year, with advanced analysis of the aircraft wreckage still ongoing.

Pakistan has a chequered military and civilian aviation safety record, with frequent plane and helicopter crashes over the years.

In 2016, a PIA plane burst into flames after one of its two turboprop engines failed while flying from the remote north to Islamabad, killing more than 40 people.

The deadliest air disaster in Pakistan was in 2010 when an Airbus A321 operated by private airline Airblue crashed into the hills of Islamabad as it came in to land, killing all 152 people on board.

An official report blamed the accident on a confused captain and a hostile cockpit atmosphere.

PIA, one of the region's leading airlines until the 1970s, now suffers from a sinking reputation due to frequent cancellations, delays and financial troubles.

It has been involved in numerous controversies over the years, including the jailing of a drunk pilot in Britain in 2013.