US air safety regulators have cleared United Airlines to resume service on more than 50 Boeing 777 planes that were grounded over engine issues, a United executive said Tuesday.
### Instruction: What is the sentiment of this news? Please choose an answer from {negative/neutral/positive}
### Input: US air safety regulators have cleared United Airlines to resume service on more than 50 Boeing 777 planes that were grounded over engine issues, a United executive said Tuesday.
### Response: mildly positive