Is it necessary to book a longer layover for this?
 

I'm zeroing in on a flight for us for next year between Vancouver, BC and Auckland, NZ. The flight there will be direct, but on the way back we will have to stopover in Sydney, Australia. Will we have to go through customs or anything in Sydney if it's just a stopover? I am wondering if we need to book a longer layover or not. Our choices right now are a 1.5, 2.5 or 3.5 hour layover.

By stopover (in Sydney) do you mean your flight just makes a stop and you continue on the same flight or do you mean have a connecting flight on the same or airline? If a "connecting flight" to a different airline will both flight be booked on one ticket or are will you have separate tickets for both flights. You need to clarify this as it will make a difference on procedures.

If it is just a stopover (i.e. continuing on the same plane with same flight number) you will deplane in Sydney, go through a quick passport check and the equivalent of a TSA security checkpoint and proceed back to the gate for the continuation of your flight. 1.5 hours will be more than enough time for this. Other scenarios may or may not need more time.

So this is what it says:

Our flight from AKL to SYD is Air Canada 6099 Operated by Air New Zealand

Our flight from SYD to YVR is Air Canada 34.

So different planes, but I guess the airline is the same, just operated by Air New Zealand for the 2nd part of the flight.

Doesn't really help when the flight times are not disclosed.

Here it is amended with the flight times:

So this is what it says:

Our flight from AKL to SYD is Air Canada 6099 Operated by Air New Zealand. We can either be on a 7AM-8:35AM, 8AM-9:35AM or 9AM-10:35AM flight

The layovers are then either 1hr 45min, 2hr 45min or 3 hr 45min layover.

Our flight from SYD to YVR is Air Canada 34.

So different planes, but I guess the airline is the same, just operated by Air New Zealand for the 2nd part of the flight.

No, not the same airline. You are flying 2 different airlines - an Air New Zealand flight (It's called a Code Share with Air Canada) from AKL to SYD and then connecting to an Air Canada flight from SYD to YVR.

Since you are transferring to an Air Canada aircraft from a Code Share partner (Air New Zealand you'll be issued your boarding passes for both flights when you check-in in AKL.

You will be considered"In transit" at SYD. Upon arrival in SYD you will deplane then go through a security checkpoint where they will inspect any carry-on luggage you may have (your checked lunge, if any" will be automatically transferred to your connecting flight).

You then proceed directly to the Departure Gate for your connecting flight. Since both your incoming and connecting flights are "International" they should be in the same terminal. When making your connection DO NOT leave the secure area. If your inbound flight is on time a 1:45 connection time should be more than adequate to make your Air Canada flight..

>>If your inbound flight is on time << Note the "If".

1:45 should be fine but me personally, I'd be much happier w/ 2:45.

The problem with trying to recommend an optimum connection time is you have to contend with Murphy's Law of Air Travel which every experienced traveler knows means if you have a short connecting time (say 1 hour) your inbound flight will be delayed, when the plane lands it will sit on the tarmac for a while because the arrival gate is occupied by another aircraft, you'll be seated in the rear of the aircraft and one of last to deplane, there will be extra long lines at the security checkpoint (if a necessary step) and the gate for your connecting flight will be at the far reaches of the airport. Meaning at best you'll have to sprint through the airport just barely getting to your departure gate seconds before the door is closed and at worst you miss your flight entirely.

By contrast, if you have a long layover (say 3 hours) you are virtually assured your inbound flight will arrive early, you'll be able to deplane within just a few minutes of arrival, the gate for your connecting flight will be less than 50' from your arrival gate and your connecting flight will end up boarding 30 minute late meaning you'll be sitting at the gate for 2:45 twiddling your thumbs.

None of this, of course, helps OP make a decision. So here's my bottom line:

1:45 should be doable

2:45 is very safe

3:45 is probably too long

Are you buying these on two separate tickets or are you buying them on one ticket. (If you buy them yourself on two tickets, you have no protections).

You should call Air Canada and ask if you will be in transit and what they recommend. Not people here who have never flown that route.

Or try posting on the Australia forums or on Flyer Talk. Hardly anyone comes on Fodors Air Travel.

What RoamsAround says is right. Take the 8AM flight or the earlier one an you should be fine. If you can't do either of those then take the later one.

Am assuming both flights are on the same ticket.

You sh/could look into what gates NZ and AC use at SYD and look at a terminal map. Looks like AC6099 is NZ103. Today, that flight and AC34 arrived/departed from T1.

Not that it matters, but I actually connected from an NZ flight AKL-SYD to international before (UA to LAX) and it was uneventful.

>>Am assuming both flights are on the same ticket.
Actually, that shouldn't matter.