I have just booked business class award tickets for my cousin and his 3 daughters (aged 18, 20 and 21) from JFK to HKG to BKK. The 18 and 20 year old would like to know the minimum drinking age on Cathay Pacific flights (I assume that the 21 year old will not have an issue). Their father will be traveling with them and is not opposed to their having a glass of wine (but he would be sure they don't drink to excess). Does anyone know the official minimum drinking age on Cathay flights from JFK to HKG and from HKG to BKK?

Cathay flights is 18 for alcohol. I just don't remember if they have any restrictions while over US airspace. But then again I'm within the age group in which you are asking and have never been ask to produce ID on AA or CX flights.

HKG-BKK is definitely 18. JFK-HKG I think is probably 18 as well, but I am not 100% sure about this. I would suspect that once the aircraft is in the air, it follows the laws of its country of registration and for CX that means Hong Kong law.

I think possibly the only exceptions to this rule are on "domestic" flights operated by CX within US/Canada. For example, if you're flying from YVR-JFK on CX, then I don't know what the rules might be and maybe it's 21 (as you already "enter" the US in YVR itself).

However, really, whatever the official rules may say, if you look 18 they probably won't make a fuss about it (unless you do). Crew are trained to ensure that those who are intoxicated don't get any more alcohol.

I bet that cxcabincrew has a definitive answer to this, if he/she is reading this thread.

please advise full details of flights so we can all avoid this one as for sure it will end in tears

if you're going direct I cannot see why they dont serve to 18-21 upon takeoff. if you are bothered, call CX and ask (call HK, where they wont use their "common sense" in the US). I suppose they would serve the preflight drinks to them too, especially when dad's onboard.
The only time i had problems was on 1 of the HKG-LHR student carrier and they made me show passport (I was 18+ so there was no problems) other than that 1 flight, no problems at all.

Anyway, sometimes upon op-up I do drink far more than I should. (whoops) and I remember once my sister who was 15 then got offered drinks. So I guess if FA think they will be sensible, they'll be offered.

Thanks for all of your help -- the girls are most relieved. And sorry bizclassboy, in light of the fact that the girls are tall, thin, young and gorgeous, I will NOT be posting the flight info.

Now it has ended in tears I am heart broken you can always PM me MATEY ^

They won't even ask for age

they may check passport. from personal experience.

what is your personal experience exactly or is this a IMHO

In post #5 kaka describes his/her personal experience.

so a one off then nothing to worry about

Sorry to bring an old thread to the top, but I feel like that the OP's question wasn't fully answered.
[Searching the web as the father of an 18yo]

No.
You enter the US in JFK.

that post you're responding to is nearly three years old...