KATOWICE, POLAND — The Budapest-based budget carrier Wizz Air rescued one of its four Airbus aircraft stranded in Ukraine in a daring escape task that involved flying at a low altitude and turning off its transponder, tracking app Flightradar24 data suggests.

Four Wizz Air Airbus jets had been stranded in Lviv International Airport for seven months since Russia started a military campaign against Ukraine.

Flight tracking app Flightradar24 showed that an Airbus A320 flew from Lviv in western Ukraine to Katowice in neighboring Poland on Sept. 13 at 10,000 feet when it eventually reappeared on the radar as it entered Polish airspace after switching on its Mod 4C tracking system.

"Wizz Air confirms that, following an in-depth risk assessment and thorough preparation, one aircraft based in Lviv departed from Danylo Halytskyi International Airport and successfully landed in Katowice on Sept. 13, 2022," 

an airline spokesperson said.

Ukraine's airspace has been mostly closed to passenger jets since Russia's military operation over Ukraine. Flying at a low altitude may have helped the Wizz Air flight avoid being detected by radars or anti-aircraft missiles.

"But in all cases, the rescue operation of the Hungarian airline is irresponsible," 

a military aviation expert told Airlinerwatch.

"An aircraft flying with an off transponder could easily be identified as hostile from both sides and even be targeted by air defense systems because 10000 feet flight level is not low enough to hide from military radars." 

the expert added.

The airline didn't comment if it plans to rescue the remaining three Airbus planes that are still stuck in Kyiv International Airport. Compared to the Lviv operation, it shouldn't be an easy task since Kyiv has no border with a friendly territory as Lviv has with Poland.