Nation & World

Boeing's 737 MAX parts 'from all over the world,' including Rockwell Collins

Design contains fingerprints of hundreds of suppliers, including Rockwell Collins


Employees walk by the end of a 737 Max aircraft at the Boeing factory in Renton, Wash., in March.
Reuters Employees walk by the end of a 737 Max aircraft at the Boeing factory in Renton, Wash., in March.

The software at issue in two deadly crashes of Boeing 737 MAX jetliners runs on two identical computer processors tucked inside a small metal box the size of a toaster.

Boeing designed that software, known as the Maneuvering Characteristics Augmentation System, or MCAS.

But the lines of code underpinning this system and the physical box it runs on were programmed and built to Boeing’s specifications by Rockwell Collins, one of the hundreds of partners that Boeing relies on to assemble the 737 Max.

Rockwell Collins was purchased by United Technologies Corp. last year and now is part of Collins Aerospace, Cedar Rapids’ largest employer.

Boeing, meanwhile, is mired in legal risk as investigators home in on the MCAS as a key factor in two plane crashes that killed 346 people in Ethiopia and Indonesia.

This week, Boeing CEO Dennis Muilenburg acknowledged it was “apparent” that MCAS had been activated in both crashes after being fed erroneous data from sensors. The company said Friday it would decrease its 737 MAX production rate from 52 planes per month to 42.

Boeing’s 737 Max planes are the subject of congressional inquiries, a federal audit and a criminal probe by the U.S. Department of Justice.

The scrutiny already is spilling over to Boeing’s wide network of supply chain partners.


Minnesota-based Rosemount Aerospace, also owned by United Technologies and the maker of a sensor on the 737 Max, this week was sued by the family of an American victim of the Ethiopia crash, claiming the company was negligent.

“These parts are screwed together from all over the world,” said Mike Boyd, an aviation analyst with Boyd Group International. “You better believe that anybody who has so much as a fingerprint on this MCAS issue is getting a lawsuit.”

A list of more than 900 companies who contribute to the 737 Max was included in a settlement Indonesian airline Lion Air offered families of the victims of the October 2018 crash, according to documents reviewed by the Washington Post.

The airline offered about $91,000 in exchange for waiving their right to sue any of those companies, which included Boeing, engine makers GE and Safran and smaller makers of parts such as LED lights and electro-mechanical switches.

Rockwell Collins was on the list. According to communications between Boeing and 737 customers reviewed by the Washington Post, Rockwell built the 737 Max flight control computer and wrote the software code that contains MCAS, among other components of the plane.

United Technologies repeatedly declined to answer questions about Rockwell and Rosemount for this story.

Boeing spokesman Peter Pedraza said Rockwell Collins “has a deep legacy of expertise,” in aircraft electronics. “The aerospace industry globally functions by bringing expert suppliers of structures, systems and services together to develop and produce aircraft.”

Boeing is preparing a software fix that is designed to address the underlying problems with MCAS and has said it expects to have a solution ready “in the coming weeks.”


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As more aspects of commercial jets have become automated, Boeing and other manufacturers have come to rely more on the companies who build the computers and software code that power autopilot functions.

On a typical passenger flight, pilots manually taxi the jet and perform the takeoff, then turn the physical control of the plane over to the computer.

Rockwell won the contract to produce the flight control computer for 737 models in 2003.

Rockwell tasked hundreds of employees, including hardware and software engineers, with designing a new computer based on specifications provided by Boeing, according to two former Rockwell employees who worked on flight controls.

The computer this team created, used in several 737 models since then, relies on what’s called a “dual dual system,” which means it has two computers — each the size of large toaster — housing two processors apiece. The design is meant to ensure that if one processor malfunctions, the plane can seamlessly shift to another one with the exact same functions.

The hardware and software for a new plane’s computers can take more than three years to develop, the former Rockwell employees said. Boeing may spend roughly $200,000 for a flight control computer on a single new plane, estimates Chris Brady, a former 737 pilot who catalogs aircraft features and adaptations on his website, the Boeing 737 Technical Site.

Boeing is known to work closely with its software partners on flight control systems. Employees of Rockwell used to hold all their internal meetings before 10 a.m. local time because that’s when Boeing managers in Seattle usually would get into work and start calling to check their progress on the 737 computer, said one of the former employees.

It’s unclear how much direction Boeing gave Rockwell in the specific design of the MCAS and whether anyone at Rockwell raised concerns about the safety of the system.

Boeing typically would handle the process of certifying flight controls with regulators such as the Federal Aviation Administration after they are completed and added to the plane.


Rockwell also has provided free software upgrades to 737 owners — similar to Apple or Android’s periodic updates to smartphone operating systems. Notably, Rockwell issued a software update to 737 Max flight control systems on Jan. 25, which was designed to change MCAS functionality to improve its safety “when flap position failures are detected,” according to a notice Boeing sent customers about the changes.

This software update, which has not been previously reported, came three months after the Lion Air crash and about six weeks before the crash of Ethiopian Airlines Flight 302, raising questions about whether Boeing and Rockwell attempted to change the MCAS software as a result of the first accident and whether it obtained approval from regulators to do so.

Separately, Boeing submitted a proposed fix to the MCAS to the FAA on Jan. 21, the agency’s acting administrator said in a Senate hearing last week. It’s unclear how the proposed fixes may have differed from the software changes it made available to customers a few days later.

Boeing spokesman Pedraza said the two software updates were unrelated and referred to the Jan. 25 changes as a “standard service bulletin” to 737 operators.

A spokesman for Ethiopian Airlines declined to comment on whether the plane that crashed in March had received the Jan. 25 software update.

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