Europe's Airbus has ordered immediate repairs to 6,000 of its widely used A320 jets in a sweeping recall affecting more than half the global fleet, threatening upheaval during the busiest travel weekend of the year in the U.S. and sparking disruption worldwide.

The fix mainly involves reverting to earlier software, but it must be done before the planes can fly again, according to a bulletin to airlines seen by Reuters. Several airlines said the repairs could cause flight delays or cancellations.

Here is a list of major disruptions flagged by airlines as of 6:20 p.m. ET (2320 GMT):

American Airlines

The world's largest A320 operator said some 340 of its 480 A320 aircraft would need the fix. It said it mostly expected the updates to be completed by Saturday with about two hours required for each plane.

Lufthansa

The German airline expects a small number of flight cancellations or delays over the weekend, as it would take a several hours per aircraft to implement the measures prescribed by Airbus. Avianca

Colombian carrier Avianca said the recall affected more than 70% of its fleet, inevitably causing "significant" operational disruptions over the next 10 days. Avianca has closed ticket sales for travel dates through December 8.

Wizz Air

Some of Wizz Air's aircraft require the software update, the airline said, adding it has immediately scheduled the necessary maintenance to ensure full compliance with the mitigation. As a result, some flights over the weekend may be affected.

British Airways

Three of the British carrier's short haul A320 aircraft are impacted and it does not expect any operational impact.

easyJet The airline said it has completed the software update on many aircraft which require them. It plans to operate the flying programme normally on Saturday.

Air France

The airline cancelled 35 flights on Friday following Airbus's communication.

Air New Zealand

The airline said all its A320neo aircraft will be get a software update before operating their next service, which would disrupt a number of its flights on Saturday. It also expects a number of cancellations to services.

Air India

The airline said Airbus' directive will result in a software/hardware realignment on a part of its fleet, leading to longer turnaround time and delays to operations.

Air India Express

Air India's low-cost subsidiary said while most of its aircraft would not be impacted, the guidance applies to operators worldwide, leading to delays and cancellations.

IndiGo

The Indian budget carrier said it was proactively completing the mandated updates, and that some flights may see "some slight schedule changes" as it works through the "precautionary updates".

Volaris

The Mexican airline said the Airbus update will cause delays and flight cancellations for the next 48 to 72 hours.

Latam Airlines

The update applies to a limited number of Latam aircraft from affiliates in Colombia, Chile and Peru. Aircraft operating with affiliates in Brazil and Ecuador are not subject to this notice.

Turkish Airlines

The company said eight A320 aircraft will be returned to service after it completes the required actions. "All our operations continue safely and without interruption," it said.

Viva

The Mexican airline said its fleet will be affected by Airbus software update, but no time frame has yet been determined for when aircraft will be ready to fly again.

Delta Airlines

The U.S. carrier expects any operational impact from Airbus' directive to be limited.

Aer Lingus

The Irish carrier said a limited number of aircraft are impacted, and the airline is taking steps to complete the required software installation. It expects there will be no significant operational disruption.

United Airlines

The airline, which operates A320 family jets, said it was not impacted by the Airbus announcement. Azul SA

Brazilian airline Azul said none of its A320 jets were included in the Airbus recall.