Those amazing falcon wing doors on the Tesla Model X were almost a disaster

Tesla launched the Model X SUV last September and wowed the public with exotic "falcon wing" doors.

But according to a lawsuit the automaker filed on Wednesday, the doors weren't working just a few months before the Model X was revealed.

In the complaint, filed in the US District Court Northern District of California, Tesla alleges that a parts supplier misrepresented its ability to engineer the doors.

Tesla is seeking to prevent Alabama-based Hoerbiger Automotive Comfort Systems LLC from demanding further payment for the services its rendered to Tesla.

Tesla is also asking for damages, legal fees and a declaration that it didn't breach any contracts when it severed its relationship with Hoerbiger last year. Tesla says it paid Hoerbiger about $3 million for the prototypes.

"We were forced to file this lawsuit after Hoerbiger decided to ignore their contracts with us and instead demanded a large sum of money to which they are not entitled," A Tesla spokesperson told Business Insider in an email. "We will vigorously prosecute this case."

Hoerbiger declined to comment on the lawsuit.

The Tesla Model X is the third vehicle and the first SUV to emerge from the Palo Alto, California-based automaker, after the Roadster and the Model X sedan.

Although the prototype for the X debuted on February 9, 2012, the production version of the $80,000 electric SUV didn't launch until the end of September 2015.

Falcon wings

The falcon wing doors are unique in the automotive industry. They can open up and over the car, using a series of electric motors as well as a series of sensors that allows the doors to detect their surroundings and avoid hitting other vehicles or the ceiling of a garage.

According to the complaint, Tesla contracted Hoerbiger in February 2014 to produce a prototype hydraulic system to open and close the doors. The automaker claimed that the system Hoerbiger delivered was no where near production quality.

"Although Hoerbiger had represented it could produce a production-ready hydraulic actuation system, Hoerbiger failed to deliver a product that met Tesla's specifications or that fulfilled Hoerbiger's promises," Tesla alleges in the complaint. "On numerous occasions, Tesla notified Hoerbiger of the multitude of defects with its product. While Hoerbiger insisted it could fix the problems, Hoerbiger failed to do so."

The complaint also alleged that the Hoerbiger could not produce a system that could function up to Tesla's standards.

For example, the system was prone to overheating, which caused it to shut down- making the doors inoperable-when Tesla stress-tested a prototype vehicle. The doors also did not open with the speed or symmetry that Tesla required, including when a prototype vehicle was parked at an incline or when the system was exposed to extreme temperatures. Hoerbiger's doors also "sagged" beyond Tesla's specified tolerance levels. Furthermore, the product persistently leaked oil, both internally and externally, which, as Hoerbiger acknowledged, was entirely unacceptable, negatively impacting performance as well as leaving unsightly markings and stains inside the vehicle. In sum, Hoerbiger's prototype never came close to fulfilling the promises made by Hoerbiger. Ultimately, the deficiencies in Hoerbiger's product made it an unworkable engineering solution for the Falcon Wing doors of the Model X.

Tesla cut ties with Hoerbiger in May 2015 and redesigned the doors with electric motors just four months before the launch of the production cars.

As a result, the company claims it:

"Incurred millions of dollars in damages, including, but not limited to (i) costs of re-tooling the entire vehicle in order to support a different engineering solution, (ii) costs that were sunk into testing the Model X vehicle that embodied the Hoerbiger hydraulic part, (iii) premium payments that Tesla needed to pay a new supplier to provide alternative electromechanical parts within TESLA'S timeline for production, and (iv) costs associated with the business disruption within Tesla's sourcing, engineering, and business teams caused by Hoerbiger's inability to fulfill its promises."