Possibly birthing alone, partner working away, advice

My partner works fly in fly out, hes away for 5 weeks, home for 5 days (taken out 1 day to travel home and 1 day to travel back). This is hard, but is manageable, our son (not biological dad, but is dad none the less) is 4 adjusts reasonably well, although has his days and moments when he just wants dad home. Im now pregnant with second bub, biologically his first. Hes not due home again until a week after bub is due, if i go into labour before then, it could take a day alone to arrange flights and then the additional travel time, would no doubt mean that he will miss the birth. He seems so calm about the whole thing, "if i miss it i miss it" type attitude. I understand its out if his control due to his type of work. But i wont lie im a little crushed that there is a high possibility he could miss the birth and even more crushed that hes so unbelievably calm about it. Not really a question, more of a hormonal vent. With my first birth, biological father walked out early in the pregnancy and i was on my own with no support and it was so hard. Slightly terrified of the possibility of having to go through having another baby alone with just a bunch of strange nurses and doctors. It hadn't really hit me until recently now that ive only got a few weeks to go.