Lounge Access whilst traveling
 

I'm AA Sapphire and need someone with experience to help prevent me from looking like a fool at LHR T3.
OneWorld lounge rules state:

The following exceptions apply:

American Airlines and Qantas offer programmes enabling customers to pay to gain access to their lounges. These programmes are not part of the oneworld agreement, and members of these programmes are not entitled to access lounges under the oneworld agreement.

So, this means if I'm flying in coach through LHR as an OW sapphire, I have free access to Admirals, whilst a business class ticket on BA connecting to AA would give me access to Admirals and Galleries but not the CX lounge in T3.

Is this correct? Thanks all.

Sapphires are allowed access to any oneworld Business lounge, regardless of class of travel. So you can "lounge shop" around the network however you please, as long as you see the Sapphire gemstone outside of the lounge.

The exception you mention is only applicable to people who pay for an annual Admirals Club (or Qantas Club) membership and do not hold a top tier status with a oneworld member. Those people would only be entitled to access at those AA/QF lounges as stipulated in those programmes, and would not be entitled to access, say, a CX lounge.

Are you sapphire or emerald?

Sapphires (via AA) get access to Business Class OW lounges when traveling on OW flights on long haul international itineraries on day of travel.

Emerald (via AA) get access to Business and FIRST Class OW lounges when traveling on OW flights on long haul international itineraries on day of travel.

AA earned emeralds and sapphires do not get lounge access on itineraries that are solely within North American/Caribbean region (flights to/from Mexico City being the sole exception).

Are you AAdvantage Platinum (Oneworld Sapphire) or AAdvantage Executive Platinum (Oneworld Emerald)?

Simple Admirals Club membership won't get you into anything other then an Admirals Club.
AAdvantage Platinum will get you into any oneworld business lounge, regardless of cabin, unless it is a flight within North America.
AAdvantage Executive Platinum will get you into any oneworld business or first lounge, regardless of cabin, unless it is a flight within North America.

An Executive Platinum at LHR can get into any accessible oneworld operated lounge, when traveling on a oneworld flight.

As long as you hold a Business Class ticket , you are allowed into any lounge irrespective if you hold Sapphire or not. If you are in coach, you just show your Sapphire card to any lounge you want access at T3 - the exception is the CX lounge.. Though you are allowed access, CX has right to refuse you entry if they are running full and you're not on their flight.

Thanks all. My typo was the emerald. My final situation will be a OW sapphire with a 4.5 hour layover coming off AA in J connecting to BA J on a T3 departure. So for a shower and brekky I guess its BA to start and a go at CX for a change of scenery. AA is nothing special, I know.

Might not help but...
I normally have a morning BA arrival into T5 and an afternoon or evening flight out of T3. I tend to go through immigration and use the BA arrivals lounge in T5 (shower, breakfast), then get the train over to T3 and use the lounges there.

There is the AA arrivals lounge in T3...

^^

Plus the AA lounge will give you the neat drink tickets since you're on Intl travel, which means you get a champagne breakfast.

As connecting, you can't use BA Arrivals lounge. Use the CX lounge instead.

Wait, I thought Advantage Plat/EXP can you get you lounge access to ONEWORLD lounges when you travel domestically, you're just barred from admirals clubs. This doesnt happen very often, but for airports where you can get to the oneworld lounges from the terminal you're in, you can use them? am i wrong?

You are wrong, alas. EXP/Plat on a domestic itinerary would not have access to the Terraces Lounge in ATL or Houston, eg. (or PHL, IAD, SEA)