Pakistani authorities have indicated that an Airbus A320 crew required supplementary oxygen after climbing towards cruise altitude, having previously believed a pressurisation problem was resolved.

The Fly Jinnah aircraft had been operating a service from Lahore to Karachi on 24 May.

French investigation agency BEA, citing its Pakistani counterparts, states that the aircraft had departed but stopped climbing at 8,000ft owing to a “pressurisation indication”.

But the crew subsequently requested to continue climbing, it says, reporting that the problem had been resolved and that the aircraft was able to reach 36,000ft.

Fly Jinnah Airbus-c-Fly Jinnah

Source: Fly Jinnah

Fly Jinnah is a joint venture set up by Air Arabia and the Pakistani conglomerate Lakson Group

As it passed 23,000ft, however, both the captain and first officer felt “dizzy and drowsy”, says BEA, with a sense of being lethargic.

The two pilots “immediately” put on oxygen masks, it adds.

BEA says one of the cabin crew members “passed out” before regaining consciousness after administration of supplementary oxygen, while the other cabin crew on board felt unwell.

The aircraft climbed to 27,000ft before the crew, 100nm out of Lahore, reported a pressurisation problem, requesting to descend and return to Lahore.

BEA says the aircraft landed safely with no injuries to the occupants. It identifies the aircraft involved as AP-BOV, a CFM International CFM56-powered twinjet originally delivered to Air Arabia in 2011.

Air Arabia is a partner in Fly Jinnah, a joint venture which commenced operations in 2022.