Pakistan International Airlines is referring to evidence of a “technical fault” on the Airbus A320 which crashed while attempting to land at Karachi.

Air-ground communications from flight PK8303 reveal that the crew tried to execute a go-around while conducting an ILS approach to runway 25L, following a service from Lahore on 22 May.

But the crew subsequently seemed unable to hold the required altitude and then informed air traffic control that they had “lost engines”.

Pakistan’s federal minister for aviation, Ghulam Sarwar Khan, says an “immediate inquiry” has been ordered to “ascertain the facts related to the crash”.

PIA says the crew reported a “technical fault” and that, shortly afterwards, contact was lost.

“Details of what the actual technical fault was can only be established once [an] inquiry is started and critical aircraft parts and evidence from the site is recovered and analysed,” it says.

But PIA states that preliminary information points to an “uneventful flight” up to the final approach, during which the crew contacted controllers and provided an “arrival report with everything normal”.

The radio communications show the crew reported being “comfortable now” – although the reason for this declaration is unclear – and that the aircraft was descending through 3,500ft for 3,000ft and established on the ILS for 25L.

But after confirming again to controllers that the aircraft was established in the ILS, and receiving landing clearance, the crew’s next radio transmission appeared to feature the sound of a background chiming.

The pilots then informed controllers that they were conducting a go-around and wanted to make another attempt to carry out the ILS approach.

But after instructing the crew to turn left on a heading of 110° and climb to 3,000ft, the controller informed that the aircraft was “dropping altitude” to 2,000ft – at which point the pilot asked for 2,000ft instead.

Even after having this altitude approved, the crew appeared to be having problems, telling the controller that the aircraft was “now maintaining…trying to maintain”.

The controller then queried why the aircraft appeared to be turning left, to which the crew responded: “We have lost engines.”

Shortly afterwards the crew transmitted a ‘mayday’ distress signal and the controller told them that both runways were available for landing. Communications were archived by LiveATC.

Video images circulating on social media purported showing the aircraft’s final moments indicated that it descended into a built-up area with a high nose attitude and its landing-gear deployed.

At least one photograph, claiming to show the jet prior to the crash with its landing-gear retracted, indicates that the ram-air turbine – located on the left underside of the central fuselage – was deployed. Ram-air turbine power enables critical systems to function in the event that primary power sources are unavailable.

The same image also appears to show underside damage to both engines, the nature and origin of which is unclear. The status of the undercarriage during the first approach has not been confirmed.

Airbus has formally identified the aircraft involved as AP-BLD, a CFM International CFM56-powered jet, and indicates that 91 passengers and eight crew members were on board.

It stresses that it has “no confirmed information concerning the circumstances of the accident”.

But it states that the aircraft (MSN2274) entered service in 2004 and had been operating with PIA since 2014.

Airbus adds that the aircraft had accumulated about 47,100h over the course of 25,860 cycles.

The Pakistan civil aviation authority says the aircraft had undertaken eight flights since 21 March, when domestic and international flights were suspended in response to the coronavirus outbreak. It adds that the jet underwent an A-check in March.

Pakistani investigators are heading the inquiry, but technical support will be provided by Airbus through the French investigation authority BEA. PIA and CFM are also assisting the probe.