The Lemon Fool

TAA
Try Another Airline

TACA
Take A Chance Airways

TNT
Tomorrow Not Tonight

TWA
Travel With Alcohol
Try Walking Across
Try With Another

United
Usually Not Inclined To Eliminate Disasters

USAir
Underwater Seats Available In Rear

UTA
Unlikely To Arrive
Unable To Ascend

Virgin
Very Interesting Ride: Going Into Nymphos

I wondered what you might write for TACA as the saying I heard was a tad racist.

Take A Chance Airways though might live up to my memory. I obtained free flights to Miami after assisting closing a sticking door. Later on in the news, the flight had crash landed on the banks of the Mississippi.

Fortunately it wasn't due to the door issue.

When we eventually arrived in Miami airport we were both nearly arrested. Her because she insisted she had come from the UK and me "crossing the line" at immigration trying to explain that we had come from Mexico not the UK on this particular journey.

I could see the build up of security as she was quizzed and unclipping of holsters as I tried to move forward to explain the misunderstanding.

Customer service of THY - Turkish Airlines (flag carrier) - was rumoured to stand for They Hate You.

TAP - Take another plane.

I was expecting the old chestnut.

Man on TWA flight asked, "Would you like some TWA coffee?"

"I'd prefer some TWA tea."

I seem to remember ALITALIA standing for “Always Late In Takeoff and Always Late In Arrival”.
Possibly apocryphal or possibly not.