Whenever an aircraft is grounded due to a maintenance issue, it quickly becomes a major headache for the airline and its passengers.
Of course, if you're a carrier like American Airlines with more than 900 aircraft, or even a Qantas with 125, there is a fair chance a replacement is soon found. In the meantime, the ripple effect soon engulfs lots of disgruntled passengers, and the Twitterverse quickly lights up.
So please spare a thought for Air Vanuatu, a small but vital airline located in the beautiful South Pacific Ocean, around two and a half hours flying from Brisbane, Australia.
It has one Boeing 737-800 in its fleet of four aircraft, which it uses on international flights from Vanuatu to Auckland in New Zealand and Brisbane, Sydney and Melbourne in Australia.
The aircraft is now grounded in Vanuatu as the airline waits for the parts it needs to get the 737 airborne again.