One photo shows why Boeing had to shut down production of its grounded 737 Max

• Striking photographs show almost 100 fuselages of Boeing 737 Max planes sitting useless at a Kansas factory parking lot.
• The pictures, taken at the HQ of supplier Spirit Aerosystems in Wichita, Kansas, illustrate the problem with Boeing's production line while the 737 Max is grounded.
• Until the planes are cleared to fly, Boeing has a growing backlog of planes under construction which it isn't able to deliver.
• On Monday, the aerospace giant took the embarrassing step of halting production indefinitely, while it hopes the FAA will clear the plane to fly once more.
• Visit Business Insider's homepage for more stories.

A striking set of photographs shows the fuselages of almost 100 Boeing 737 Max planes sitting unused at a Kansas factory - a vivid illustration of the problems that led the company to suspend production of the plane.

The images were taken by Reuters at the headquarters of Spirit Aerosystems in Wichita, Kansas. Spirit is one of the hundreds of companies in the Boeing supply chain which help produce the finished product.

The photo shows Boeing's snarled production line, which was getting ever more clogged as the company continued to build planes which are not yet legal to fly, or even to deliver to their customers.

The planes can't fly because they remain grounded by regulators around the world after two fatal crashes which killed more than 300 people between them.

The 737 Max has now been grounded for nine months, significantly longer than many in the industry predicted.

Similar images have shown completed 737 Max planes spilling over into the Boeing employee parking lot in Renton, Washington.

On Monday, Boeing admitted that its strategy of still building planes that can't fly was no longer sustainable, and said it would freeze the production line in the new year. It is not clear when it will be restarted.

Spirit Aerosystems has the capacity to produce around 50 fuselages for the Max per month, and employs around 13,000 people in Wichita. It is the city's biggest employer.

Spirit Aerosystems earns 80% of its revenue from Boeing, according to data provided to Business Insider by Bloomberg.

An extended production slowdown could have significant impacts on its bottom line. Other companies in the supply chain are facing similar problems.

While Boeing has said that it has no immediate plans to lay off or furlough staff who work on the 737 Max while production is stopped, there are fears that suppliers will have no choice.

Boeing has the ability to absorb the costs of paying idled workers, but many of its smaller suppliers likely do not.

As Boeing halts production of the Max, it is likely to stop paying suppliers such as Spirit Aerosystems to save on costs.

In this scenario, according to a Reuters report, furloughs - where staff are put on temporary unpaid leave - are almost inevitable at Spirit Aerosystems, while lay offs are also a possibility.

"No way can they keep going," one source told Reuters.

The 737 Max has been grounded worldwide since the crash of Ethiopian Airlines Flight 302, the second of two fatal crashes involving the jet within five months.

Boeing is awaiting a recertification for the 737 Max from the Federal Aviation Administration (FAA), before it can return the plane to the skies, but that is unlikely to happen until some time in 2020.

The FAA has refused to commit to a time line for the plane's return, instead repeatedly saying the plane would return when "ready."

The FAA even acknowledged in November that its staff was facing pressure to approve the plane soon, but that it would ignore all factors except safety in deciding when the plane can come back.