|**EARNINGS PER SHARE**                             | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
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|**Earnings Per Share [Abstract]**                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
|EARNINGS PER SHARE                                 | NOTE J: EARNINGS PER SHARENet income per common share attributable to L3Harris common shareholders (“EPS”) is computed by dividing earnings to L3Harris common shareholders less earnings allocated to participating securities, if applicable, by the weighted-average number of common shares outstanding for the period. Net income per diluted common share attributable to L3Harris common shareholders (“diluted EPS”) incorporates potential dilutive common shares, primarily consisting of employee stock options and restricted and performance share unit awards, into the weighted-average number of common shares outstanding.The weighted-average number of common shares outstanding used to compute basic and diluted EPS are as follows:Quarter EndedThree Quarters Ended(In millions)September 29, 2023September 30, 2022September 29, 2023September 30, 2022Basic weighted-average common shares outstanding189.3191.3189.6192.2Impact of dilutive share-based awards0.8—1.01.8Diluted weighted-average common shares outstanding190.1191.3190.6194.0The antidilutive impact excluded from diluted EPS for the quarter ended September 29, 2023 was immaterial. Diluted EPS excludes the antidilutive impact of 2.0 million weighted-average share-based awards outstanding for the three quarters ended September 29, 2023 and 1.9 million and 0.3 million weighted-average share-based awards outstanding for the quarter and three quarters ended September 30, 2022, respectively.
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|(In millions)                                      | September 29, 2023                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
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|Basic weighted-average common shares outstanding   | 189.3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
|Impact of dilutive share-based awards              | 0.8                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
|Diluted weighted-average common shares outstanding | 190.1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    

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