Disney to Narita timeframe

Hello. I have visited Japan before (for work) and will be returning (for work). I am taking two days after work is over to visit Tokyo Disney with my son.

We are staying at the Hilton Tokyo Bay. On Sunday, June 9, we have a 6:10 flight leaving Narita on American.

What is the best way to get to the airport and when should I do this?

We would like to visit one of the parks in the morning, before leaving for Narita. I see the bus schedule shows one bus leaving the Hilton at 13:09 and arriving at 14:20. If we take this one, we would have almost four hours in the aiport.

But, the next bus leaving the Hilton leaves at 14:44, and arrives at Terminal 2 at 15:50.

Is that enough time? Are these busses often late? I do not want to miss my flight, but I do not want to sit in the airport for four hours before a flight unless I really need to.

Or, should I plan on taking a train?

Thank you for your help!

ask American latest gate in time.

Bus 60min operate possible.
(no busy day and time)

we have a 6:10 flight leaving Narita on American.
one bus leaving the Hilton at 13:09 and arriving at 14:20. If we take this one, we would have almost four hours in the airport.

So, "6:10" is a typo, right? What is the correct time?

I do not want to miss my flight, but I do not want to sit in the airport for four hours before a flight unless I really need to.
Or, should I plan on taking a train?

If it is not easy to change flights on the day, you had better take trains or an early bus, I suppose.
From Maihama area to NRT there are various rail routes, though no direct train is available.

Hilton Tokyo Bay (13:15)
| {bus (weekends & holidays only)}
Maihama Station (13:45)
| {JR Keiyo Line}
(13:56) Minami-Funabashi (14:00)
| {JR Keiyo Line}
[Option A]
(14:06) Nishi-Funabashi: Track 1 or 2 (14:28)
| {JR Sobu Line}
(14:31) Track 2: Funabashi: Track 4 (14:40)
| {JR: Rapid}
(15:41) Airport Terminal 2.
[Option B]
(14:06) Nishi-Funabashi
: Transfer Gate:
Nishi-Funabashi (14:27)
| {Toyo Rapid}
(14:48) Toyo-Katsutadai: Exit Gate
| {short walk}
Entrance Gate: Katsutadai (15:00)
| {Keisei Main Line}
(15:29) Narita Airport Terminal 2.

I recommend you would ask a station attendant in Nishi-Funabashi (of JR-East) whether it would be OK to take trains for Narita Airport and get an advice if not.

Good luck!

I am sorry for my typo.

The flight leaves Narita at 18:10 (6:10 p.m.).