RTX ▼ -0.6% - RTX Corporation $RTX - RTX's Pratt & Whitney completes F135 Engine Core Upgrade Risk Reduction Design Review RTX shares fell 0.6% today following news that the company's Pratt & Whitney division completed a design review for the F135 Engine Core Upgrade risk reduction effort. The move may reflect profit-taking despite the technical milestone, or investor caution ahead of further development and testing phases required before production implementation of the upgrade. 15-SEP-2026 07:01 AM ET