It all started in the late 1990s when, after briefly helping Subrato Roy with Sahara Airlines, Radia set up Crownmart, an aviation consultancy, which did business with Singapore Airlines.
Around the same time the government wanted to sell 40 per cent in Air India.
Singapore Airlines decided to bid for the stake with the Tata group.
In order to work out the details of the partnership, it sent Radia to meet Tata.
She was given 20 minutes but the meeting went on for two hours.
Tata has never spelt out what he liked in her, but Radia talks confidently and comes across as well-informed and energetic.
The Air India divestment never happened. But Tata, impressed by her knowledge of the aviation business, offered her to take up the public relations mandate of his group.