RTX unit Pratt & Whitney completes preliminary design review of engine upgrade

(Reuters) - RTX Corp's Pratt & Whitney said on Monday it has completed the preliminary design review for an engine upgrade to increase durability and performance in all three variants of the F-35 fighter jet.

The F-35 jet is manufactured by Lockheed Martin Corp, accounting for about 27% of the company's sales.

RTX received full funding from the U.S. government in March for its F135 engine core upgrade (ECU), which will modernize the F-35's propulsion system.

"Upgrading the F-35's propulsion system to ECU is a critical step toward ensuring the F-35 remains the world's premier air dominance fighter," Pratt & Whitney said.

The U.S. government had cleared Pratt & Whitney in February, allowing the company to resume deliveries of its F-135 engine for the F-35 fighter jet, after a halt was put in place in December following the discovery of a safety concern.

In May, the Department of Defense also resumed accepting F-35 jet deliveries from Lockheed Martin, after a brief halt starting late March due to a dispute over who would cover the costs related to fixing a production error discovered in 2017 that had caused corrosion.

(Reporting by Ananta Agarwal in Bengaluru; Editing by Krishna Chandra Eluri)