Aircraft are expensive. With the cost of a new A380 coming in at $444 million USD list price, airlines are incredibly reluctant to ever take an aircraft out of service. But, throughout history, airlines have either been forced to write off an aircraft (sometimes even brand new) or in some special cases, spent millions of dollars more than the aircraft is worth to not write it off.

What does 'written off' mean?

Before we dive into the specifics of what it takes for an airline to write off an aircraft, we first need to understand what the term 'written off' means.

There are two major terms in the aviation industry:

• Hull loss - The aircraft has been destroyed, is no longer flight worthy and cannot be repaired
• Written off - The aircraft has been extensively damaged and the cost of repairs would be more than the aircraft is worth

Specifically, if an aircraft is split in two and its parts spread over a runway then its likely that this is a hull loss. But if an aircraft is damaged through use, an incident or just requires extensive maintenance, airlines might choose to just write off the aircraft and replace it with a (sometimes cheaper) new aircraft.

However... it also depends on who is paying for these repairs. If an aircraft was grounded due to a fault (such as the Boeing 737 MAX groundings) would the airline actually pay for the aircraft being written off? Or would the manufacturer? Depending on insurance, it is possible that the aircraft will be rebuilt, recertified, repainted and back in the skies on someone else's dime.

There have been some incidences where an airline has straight up had to write off an aircraft; Etihad had to give up on a brand new Airbus A340-600 (Tail number F-WWCJ) after the test pilot ran it into a wall at the Airbus factory. The forward section of the aircraft actually split off and the whole aircraft had to just be scrapped.

Do airlines always write off aircraft?

There are some times, however, where airlines have chosen to do anything but write off an aircraft.

In 1999, Qantas QF1 was landing at Bangkok airport during a heavy rainstorm, when it overshot the runway. According to the crash report, it was a combination of pilot error, low visibility, problems with the flaps and the aircraft hydroplaning on the wet runway. The Boeing 747-400 overshot the runway, collapsing its nose and right landing gear and damaging two of its engines. Fortunately, beyond the runway was an empty golf course (due to the rain) and no one was seriously injured.

By all accounts, the entire Qantas Boeing 747-400 was a write-off. It would cost Qantas more than the book value of the aircraft to get in back in the sky. But there is something worth more to Qantas than money, and that's its reputation for never losing an aircraft.

Thus Qantas footed the bill for the incident, spending the cost of a brand new Boeing 747 to get their older one back in the sky. The Boeing 747-400 in question, tail number VH-OJH, would go on to serve the airline until September 2012 (essentially another 13 years!).

What do you think? Should airlines write off aircraft? Let us know in the comments.