Pratt & Whitney deploys BARB robot for jet engine bearing assembly in Connecticut

Pratt & Whitney's First Steps Toward Automated Jet Engine Assembly

During a recent tour of RTX-owned Pratt & Whitney's jet engine assembly plant in Middletown, Connecticut, TWZ observed a largely quiet production line following a major push to complete outstanding deliveries by the end of the second quarter on July 1. However, one machine remained steadily at work: the Bearing Automation Robotic Builder, or BARB.

BARB was completing assembly processes for the #2, #5, and #6 bearings on the company's commercial 1100G engine — a geared turbofan (GTF) engine powering several Airbus and Embraer fleets.

A Cautious Approach to Automation

While robotic assembly machines are common in factories producing cars and electronics, Pratt & Whitney's assembly lines remain largely human-dependent. This is partly due to the exacting nature of jet engine production, which requires carefully policed logbooks tracking every step to ensure error-free processes.

Throughout the factory floor, "Foreign Object Debris" bins remind workers to keep areas clear of loose materials — from stray threads to gum wrappers. Even small debris can become deadly if ingested into a jet intake. Company staff emphasized that ensuring a machine could operate error-free across a range of conditions was a time-consuming and critical prerequisite for embracing automation.

The BARB Robot

BARB — fitting the mold of a classic factory robot with its upright stance and long yellow arms — is the product of a $20 million investment in automation. It represents a modest first step toward integrating automation more fully throughout jet engine assembly, both on the civilian side and in the more complex military engine business on a parallel production line in the same facility.

According to Ted Sluis, vice president and manager of Product Delivery Centers at Pratt & Whitney, BARB arrived in Middletown around late 2024 but only came online this spring after extensive testing. The testing ensured the robot's cameras and sensors could reliably identify parts and consistently perform the correct operations.

"There is a visual inspection aspect of it, and when we were doing the initial trials of the parts, we were using scrap parts," Sluis said. "But the scrap parts were old, and we went to make production parts on it, those were new and shiny. The vision system started having issues because it wasn't used to shiny parts; it was used to like the old parts … little things like that, that we had not anticipated. And so a lot of learning meant that it took us all the way through last year, into the beginning of this year to get it to where it could repeatedly get through the entire cycle without a person intervening to do something."

Bearing Assembly Details

According to public production and training manuals, the 1100 engine — assembled in a horizontal position — has seven total bearings requiring assembly:

• #2 bearing: A ball bearing that supports the front of the low-pressure (LP) rotor, which extracts energy to power the engine fan and reaches maximum speeds above 10,000 RPM
• #5 and #6 bearings: Rear roller bearings

Sluis explained that engine assembly involves bearing sub-assembly, including the bearing, housing components, and affiliated seals and covers.

"So it's a handful of parts that you have to get put together into a sub-assembly," he said. "With the types of operations that we're doing, different parts have different clearances. And so to get them to go together, you have to heat one part and cool another part, and you have to orient those in the right way, press them together, let it normalize, inspect it to make sure that it actually meets the right dimensional requirements."

Integrating Automation into Record-Keeping

In the traditional engine assembly process, a mechanic would sign a record at every stage verifying the prescribed action had been completed in the correct order. Integrating the assembly robot into the record-keeping process has been another deliberate effort, Sluis said.

"If a person is doing that work, they would be signing with their badge all the different sequences to say 'I completed this work.' In this case, the mechanic is basically signing, saying, 'I provided the parts to the machine, the machine is tracking, I did this, I did this, I did this,' and that's going to be part of the engine build record. The mechanic signs, saying, 'I received the assembly from the automation machine, and I'm going back to the normal process.'"

Early Results

While the approach to integrating automation into an exacting assembly process has been small-scale to start, Sluis said the benefits in efficiency have been immediately clear — with an 80% reduction in "touch time." Reporters visited the production line on July 1.