Earlier this month the world awoke to the news that hairline cracks had been found on older third-generation Boeing 737 aircraft. Now that engineers have had time to assess the damage and go over fleets with a fine-toothed comb, we can see which airlines have had to ground 737 aircraft.

What is the issue?

During a regular inspection of an older Indonesian Sriwijaya Air Boeing 737-800 with over 30,000 flight cycles, engineers discovered pickle fork cracks. The pickle fork refers to the part of the aircraft that attaches the main fuselage of the plane to its wing structure, playing a key role in maintaining and managing the integrity of the aircraft.

As it is rather alarming that an aircraft might have cracks along its body, the FAA and Boeing decided to do a full inspection of all the Boeing 737 NG (Next Generation, or known as the third generation 737, the series before the Boeing 737 MAX) aircraft with over 30,000 flight cycles.

"Safety and quality are Boeing’s top priorities. Boeing notified the FAA of this issue and has been actively engaged with our 737NG customers globally in a plan to support the required inspections." - Boeing Statement

Whilst this led to a few more groundings, the situation didn't heat up until airlines started to do their own inspections on aircraft with below 30,000 cycles. In fact, one or two Boeing 737 NG aircraft with only 22,500 cycles were discovered to have the issue.

Thus a range of different airlines are now grounding 737 NG aircraft, as they move them into servicing by Boeing trained technicians.

Which airlines have had to ground aircraft?

So far we know the following airlines have had to ground 737 aircraft after discovering pickle fork cracks.

Qantas currently has three Boeing 737-800s grounded but has said they have finished inspecting the rest of their fleet. Rival Australian carrier Virgin Australia has said none of their 737 fleet is affected by this issue.

Korean Air has been ordered by the South Korean Ministry of Land, Infrastructure, and Transport (MOLIT) to ground five of their aircraft with the cracks. They were quickly followed by three from Jin Air, and one from Jeju Air.

But it seems that the cracks problem is also present in European carrier Ryanair, with the airline taking two 737s out of action for repairs.

In the USA, Southwest, the biggest operator of the type in the world, has had to ground two of their aircraft. Gol, the Brazillian carrier, has not fared so well, having to ground 11 aircraft for this issue.

There might be a few other airlines affected by the issue, but so far that's all the airlines that have been reported.

"Just over 1,000 airplanes have reached the inspection threshold, with less than 5 percent having findings that will need repair. However, we are not providing a list of customers impacted."

What do you think? Will these airlines be able to make do in the meantime? Let us know in the comments.