English query re question format with auxiliary verbs

Hi there - when we convert a past simple sentence to a question using 'did', 'did' takes the past tense and the main verb is a straight participle. For example, 'He ate the apple' becomes 'Did he eat the apple?'

Where we convert a present perfect sentence like 'he has eaten the apple', to a question, the format of both the auxiliary and main verb stay as is: 'has he eaten the apple?' Why does the structure not change to "had he eat the apple?' This is the format we use with the auxiliary 'to do'. !