Actually, we aren't going on an airplane any time soon much to H's chagrin. Every time he hears the one pass over, the campaign starts:
'Eh, eh,' he eloquently suggests.
'Oh, H. You'd like to go on a plane?'
'I DO. I DO.' H screeches, as if finally you've comprehended his most fervent desire.
'Well H, we'll be visiting Lala and Grandpa in Minnesota this Christmas and we'll take an airplane.'
H listens thoughtfully and then suggests, 'Wake?'
'Yep, you'll have to wake 57 more times before we go.' This satisfies him.
H is developing a sense of time but it's focused on the future.