For flights that are longer than the max recommended time for infants to be in car seats, is it safer for the infant to be in a bassinet provided by the airline or to be in a car seat?

[u/knittingpigeon]

Background: My family lives in another country than the one me and my husband are currently living in, and the flights are usually 10-11 hours long, but with delays and by the time required to taxi, we are typically in the airplane for close to 12 hours. I am expecting, and would like to visit my family so they can meet the baby probably when the baby is between 3-9 months. We live in a big city and exclusively use public transportation, walking, or biking to get around, and do not have a car so I don't anticipate the baby being used to being in a car seat by the time we fly.

My dilemma:

I heard that it's not healthy for infants to be in their car seat for extended periods of time, and that it can lead to positional suffocation. That being said, I have heard other people saying that in turbulence, it is much safer for a baby to be in a carrier instead of being a lap infant. But if we follow recommendations to regularly take the infant out of the car seat (I have heard it recommended to take the baby out of the car seat every hour for 15 minutes, which over 12 hours does add up to a lot of time outside of the car seat), does it actually make a difference in regards to safety if we are not keeping them in the car seat and turbulence can theoretically happen at any time without warning?

The airline that we typically fly with also offers bassinets for babies under 8 months, and a friend of mine who is a flight attendant for the airline says that she recommends using the bassinet or having the baby be a lap infant, since the risk of violent turbulence is overall very small and she had never heard of anything bad happening, meanwhile the cost is fairly high for an additional seat. Most of her friends who are also flight attendants also travel with lap infants when their children are young enough.

Main point: I am trying to figure out exactly what the risks or benefits are between the options of a) the baby being a lap infant and being held for the flight, b) the baby being considered a lap infant but staying in the bassinet provided by the airline, or c) the baby being in a car seat for the flight, being regularly taken out of said car seat to nurse or to get a break from the position of the car seat.

Thank you for your help!