Passengers on a recent LOT Polish Airlines flight reported "snapping for air like fish" after an inflight air conditioning issue. According to The Aviation Herald, the aircraft promptly returned to the ground without casualties. Here's what we know...

What happened?

On Friday 31st January 2020, a LOT Polish Airlines 737-800 was completing flight LO-234 when it ran into difficulties. Whilst flying conditions on the journey between Brussels and Warsaw weren't out of the ordinary, there was something going on in the cabin.

After climbing to FL100, the crew became aware that there was something wrong with the air conditioning system in the cabin. The exact details of the fault are currently unknown and we are awaiting further comment from LOT Polish.

However, we can deduce that the air conditioning was not functioning correctly since passengers reported the cabin being hot. Additionally, it appears as though passengers were also gasping for air. The report from The Aviation Herald said:

"Passengers reported they were snapping for air like fish, and it was hot."

Where is the aircraft now?

After realizing the issues, the crew decided to return to Brussels where it had taken off. Aircraft SP-LWB landed back on runway 25L in Brussels Airport 40 minutes after departure. The plane was disembarked without passenger or crew injury and remained on the ground in Brussels.

SP-LWB stayed in Brussels Airport for 16 hours before it flew back to Warsaw, completing flight LO-9006. It then remained on the ground in Warsaw for a further eight hours. It is unclear whether the air conditioning issues were fixed in Brussels or in Warsaw.

How serious is an air conditioning fault?

On the face of it, air conditioning problems might not seem so serious, however, that couldn't be further from the truth. An aircraft air conditioning system is more of a user-friendly phrase to describe a number of different systems working together to control the airflow within an aircraft.

When the air conditioning seems to be at fault, this will more likely refer to an issue with the "pack" or Pneumatic Air Cycle Kit. Whilst the pack is responsible for the regulation of temperature within the aircraft, it also deals with pressurization. And this is where serious issues can occur.

If there are issues with the pack, there might be issues with temperature and pressure within the cabin. Now whilst there are two packs on every aircraft, gambling with fate is not the best way to go when you're so high in the sky.

For that reason, crews will divert aircraft to the ground for the safety of all of those on board rather than relying on the integrity of a single pack. This could have been what forced LOT Polish Airlines to return to Brussels Airport.

LOT Polish's 737-800 fleet

Whilst it's unclear what will happen to SP-LWB, LOT Polish has a fairly robust fleet of aircraft to fall back on. It currently has 92 aircraft seven of which are 737-800.

LOT Polish's 737-800 aircraft are not particularly new although they are comparatively young to the likes of its 737-400 fleet which boasts an average age of 23 years. The 737-800s are just 13.1 years old on average and began entering the fleet three years ago from May 2017. According to Planespotters, SP-LWB was one of the first to arrive in May 2017 and the fleet continued to grow until September 2019.

Have you ever experienced an air conditioning fault during a flight you were on? Let us know in the comments.