To have prolific British celebrity tweeter Stephen Fry on board a flight grounded by an engine fault less than a week after a labour dispute-related complete shutdown of services has to count as bad luck for an airline.

But Australian airline Qantas's public-relations week from hell showed the dangers of treating social media like Facebook or Twitter as one-way marketing channels.

In the last year or two, many companies have come to understand the value of monitoring social media channels to gauge public sentiment about their brands and services.

But few have yet succeeded in establishing an effective two-way conversation with their followers and those who comment online on their activities -- leaving themselves open to being the subject of discussion without taking part.

On Friday, Fry's 3.3 million Twitter followers (@stephenfry) likely learned before the media team at Qantas's Sydney headquarters that an engine fault had forced a London-bound A380 to divert to Dubai, when Fry tweeted: Bugger. Forced to land in Dubai.

As the hours passed and Fry's language got more colourful, particularly when he discovered his wallet was still on the plane, traditional media from London to Sydney leapt on the story, with Britain's Daily Telegraph newspaper describing the plane carrying 258 people as Stephen Fry's flight.

When you have got very influential people tweeting negatively about you, that is very unfortunate, said Alex Clough, a digital strategist at global communications consultancy Lewis PR.

But Clough and others said such situations can only become more common, and organisations need to take account of Twitter evangelists like Fry in their social media strategies.

He is one of these people who symbolises Twitter really ... so it makes sense for people to follow him around, see what he is up to, make sure he is happy, said University of East London education professor John Preston, who is researching the use of Twitter in disaster situations.

Qantas was roundly condemned for a failure to communicate with customers when it grounded its entire fleet last weekend, even asking its 70,000 stranded passengers not to ring its contact centre.

By Friday, it had recovered to the point of publicly engaging with Fry and other customers, tweeting: Mr. Fry, your wallet has been found and is on its way back to you at the terminal and Thanks for keeping your sense of humour.

However, as Clough pointed out: If you have got tens of thousands of people grounded ... you can't physically go and tweet every single one of them.

Paul Charles, founder and chief executive of London-based travel crisis communications consultancy Perowne Charles Communications, said: Qantas have certainly upped their game -- they have had to ... but there is a lot further to go.

FOUR-HOUR WINDOW

The global travel industry has had to learn fast since an ash cloud from an Icelandic volcano shut airports across Europe a year and a half ago, causing chaos among stranded customers.

That was a real warning to companies to get their act together before governments put into place legislation to force them to act, says Charles.

Bernhard Warner, co-founder of consultancy Social Media Influence, said the event was as much of a wake-up call to passengers as it was to the airlines.

Thanks to the Stephen Frys of the world, we suddenly did not have to live with the radio silence any more, he said.

The industry had received a warning two months before the Icelandic volcano erupted, when U.S. budget airline Southwest Airlines ejected film maker Kevin Smith from a flight for being too large to fit in his seat.

Smith unleashed a barrage of complaints about his treatment on his Twitter feed -- followed by 1-1/2 million people, some of whom shared their own experiences of rejection -- and Southwest eventually apologised publicly.

Such incidents made the industry realise Twitter and other social media sites were not one-way channels for marketing messages, and could bite back.

They realise now that they cannot just shove marketing messages down people's throats when the sky is falling in, Warner said.

As well as a sympathetic attitude, speed is essential when dealing with distressed passengers -- companies have about a four-hour window to win or lose the PR battle, London professor Preston said. If a company says a plane is stuck at an airport, that is too late. People are already sharing opinions about that by then.

You have got a really short window in which to source what is happening on the ground before people start emoting about it. People are looking for stuff then, their emotions going one way and another.

Most of the industry is still operating at a far lower level of sophistication, said PCC's Charles, giving Lufthansa's loss-making airline bmi, being sold to British Airways owner IAG, as an example.

At six o'clock in the evening on a Friday, they will actually tweet out: 'That is all from us, have a good weekend. See you on Monday,' he said.

(Editing by Dan Lalor)