How the plane window broke during a flight from Thessaloniki

Ryanair (Malta Air) flight FR1879 from Thessaloniki to Memmingen, Germany, was flying over North Macedonia when one of the aircraft’s windows broke.

A loud bang was heard, followed by cabin decompression. The oxygen masks dropped, while passengers tried to hold back the man sitting next to the broken window, whose upper body had been pulled partly outside the cabin.

An aircraft window is designed not to break

What we see as an airplane window is actually made up of three different layers of durable acrylic material.

• The outer layer comes into contact with the external environment and is designed to withstand the enormous pressure difference between the air inside the cabin and the outside atmosphere at high altitude.
• The middle layer contains a tiny hole known as a “breather hole”, which balances the pressure between the cabin and the space between the windows.
• The inner layer absorbs damage, scratches and accidental impacts from passengers, protecting the middle window layer.

What could break through all three layers of protection — something that happens extremely rarely and almost always in the cockpit?

A crack developing during flight or a manufacturing defect, as Captain Lim Khoy Hing, who has more than 25,000 flight hours in his career, has explained on his website.

The relevant aviation safety authorities have launched an official investigation to determine exactly what happened to flight FR1879, with the initial report stating that there was a serious engine failure. However, according to British media reports, the cause was the detachment of part of the engine.

How an engine failure caused the aircraft window to break

Argus reported that during the aircraft’s initial climb, while it was flying over North Macedonia, a serious mechanical failure occurred in the right engine.

A metal fragment or a piece of the damaged engine casing detached, was propelled at extremely high speed and struck the window with great force, causing it to break and separate. In other words, it was an external violent impact that destroyed the entire structure.

Brussels Signal added that because the aircraft was flying at high altitude (approximately 16,400 feet), the hole created caused air to escape violently from inside the cabin to the outside, resulting in the oxygen masks dropping — an automatic response when cabin pressure falls.

The massive decompression caused the air to “pull” a 61-year-old Serbian passenger who was seated next to the broken window, leaving his head and shoulders outside the cabin.

His wife and other passengers reacted immediately and saved him.

The pilots immediately implemented the emergency protocol, carrying out a rapid descent from 16,000 to 6,000 feet in order to reach an altitude where the air is breathable without masks, with the aircraft returning for a safe landing at “Makedonia” Airport.