What is the maximum start time for the third to fifth engine starts on the ground?

For engine starts on the ground, the maximum start time for the third to fifth attempts is 90 seconds. This time limit is crucial because extending the start time beyond this threshold can risk engine or component overheating, contribute to fuel inefficiency, and potentially lead to engine damage. Following the specified time guidelines ensures that the engines operate within safe and efficient parameters. Adhering to the 90-second maximum for subsequent starts allows for proper cooling and necessary procedures to be undertaken between attempts, which helps maintain operational safety and reliability.