In first class sit the senior bankers, the privatisation consultants, the big names in oil, and the systems analyst from British Aerospace who flies the route so often that the grateful airline has upgraded him. In club class sit the footsoldiers of the British export boom that in 1994 sent £1.5bn worth of products and services to the kingdom: the sales wallahs, the middle managers, the computer engineers, and the odd diplomat or senior army officer.
At the back of the plane are the less privileged who are returning to join the 30,000-strong British community in Saudi Arabia - nurses, engineers, oilmen, English teachers, children returning from boarding schools, and the occasional taciturn fellow, rugged and with short hair, who reveals nothing of substance about his activities.
"People come to the kingdom for one reason," observed a senior banker in Riyadh. "Money." Tax-free, with accommodation often thrown in, school fees paid for the children of the lite, and a high net income even for modest earners, the Saudi expatriate package remains attractive. Its Islamic society imposes stern restrictions - women may not drive, for example - but compensates with a safe, remunerative environment.
At its best, the deal is summed up by a British executive in Riyadh: "Put in five years here, try to stay off the booze, play a lot of sport and come home with the mortgage paid off and the private education looked after. You can't do that in Croydon any more." At its worst, life can still resemble the ghastly colonial parody described by the author Jonathan Raban in the 1970s - saloon bar bores droning on about the salutary effects of sharia law on petty offenders while, as the illicit drink takes effect, "the locals" are more and more firmly put in their place.
With a quarter of the world's proven oil reserves beneath its sands, Saudi Arabia is likely to stay a profitable market for years to come. Britain's investment there is vast, its rewards prolific, its historical connection unrivalled, its secret diplomacy shrewd, its understanding of the monarchy profound. How ironic, therefore, that a tawdry domestic imbroglio such as the Jonathan Aitken affair should cast a shadow over this apparent success story.
BRITISH adventurers have always been attracted to Arabia. In the early years of the cen- tury they roamed its deserts in caravans and armies. They bankrolled its monarchs and put down rebellions. Cartographers mapped the boundaries of nations hitherto known only by tribe and faith. Civil servants made them sacrosanct by treaty. It began with T E Lawrence: "We went into the main lodging, to the gaping window sockets of its eastern face, and there drank with open mouths of the effortless, empty, eddyless wind of the desert ... `This,' they told me, `is the best.' "
Purity, manliness, dignity and honour - such were the buttresses of the myth. But history teaches another version, one of scheming, venality, wounded pride and broken promises. In relations between Britain and the Arabian peninsula, one tradition is intertwined with the other.
In the First World War, the British encouraged a revolt by tribes along the eastern shores of the Red Sea. The holy cities of Mecca and Medina had slumbered for generations under Ottoman Turkish rule, unbothered by the clash of European empires. But Turkey had made an alliance with Germany; there were fears of the Berlin-to-Baghdad railway; strategists worried about the route to India and the Suez Canal. The uprising led by Lawrence and Sherif Hussein of Mecca routed the Turks. General Allenby's subsequent Palestine campaign broke the Ottoman empire.
In theory, Arabia was free. In practice, it became a tribal cockpit. Britain, to the disgust of Lawrence, played power politics, making concessions to the French in Syria and confining his friends from Mecca to present- day Jordan. By the 1920s Britain had conceded domination over Arabia to Sherif Hussein's rival, Abdul Aziz bin Abdul Rahman bin Faisal Al Saud.
Abdul Aziz founded the House of Saud and his 11th son, Fahd, is king today, aged 74 and in indifferent health. Abdul Aziz owed his success to the prowess of arms and an alliance with the Ikhwan, fierce fundamentalist tribesmen from the interior around Riyadh. As he conquered Saudi Arabia bit by bit, British officials argued over whether to grant him the mandate of heaven. The details are of little relevance today, but the methods of British influence remain highly pertinent.
The British knew how to exercise power cloaked in deference, a technique summed up by Lawrence's friend Ronald Storrs. "We deprecated the Imperative, preferring the Subjunctive, even the wistful Optative mood," he recalled. British officials "advised" their client rulers, "inspected" their finances and "guided" their policies.
Every now and then a character leaps from the pages of this history whose integrity is less conspicuous than his buccaneering spirit. One such is Harry St John Philby, father of the future Soviet spy Kim. His story contains familiar resonances. He found favour with Abdul Aziz and obtained commercial concessions from him. He embraced Islam and was rewarded with further influence. His role was historic: he was the first to discover the riches to be garnered by introducing foreign businessmen to Saudi royalty. In the process, he helped the United States to take over from Britain as the predominant foreign power in Saudi Arabia. The reason was oil.
"I HEREBY find that the defence of Saudi Arabia is vital to the defence of the United States." So decreed President Franklin D Roosevelt in his executive order 8926 of 18 February 1943. Ten years had passed since Philby's commercial intrigues had borne fruit. For just £35,000, the Standard Oil Company of California won the first oil concession from Abdul Aziz in 1933. With incredible insouciance, the British minister, Andrew Ryan, had advised the Saudi monarch to accept, and in 1937 oil gushed from well No 7 in the Dammam dome. Arabia would never be the same again.
The Second World War vastly increased American links with the kingdom. Britain, bankrupt and over-extended, could no longer compete. Behind Churchill's back, Roosevelt arranged a meeting with Abdul Aziz on an American warship in the Great Bitter Lake at the Suez Canal. When the austere Saudi monarch went to meet Churchill at a hotel, the British prime minister cast aside the deferential arts recommended by Ronald Storrs and told Abdul Aziz that while he understood his adherence to the precepts of Islam, "my rule of life prescribes as an absolutely sacred rite smoking cigars and also the drinking of alcohol before, after and if need be during all meals and in the intervals between them". Churchill proceeded to conduct a three- hour discussion while puffing cigars and draining glasses of whisky. The king was not impressed.
Such are the small slights by which serious disadvantage in dealing with Saudi Arabia may flow. From the 1950s until 1973, the US never looked back. Aramco became the dominant oil company, the US became the guardian of Saudi security and the Wilson government wound down the old imperial presence east of Suez.
"I ALWAYS regretted, even at the time, the decision of Ted Heath's government not to reverse the Wilson government's withdrawal of our forces and the severing of many of our responsibilities east of Suez," writes Margaret Thatcher in her memoirs. "The West cannot pursue a policy of total disengagement in this strategically vital area."
In Mrs Thatcher's era, the tide had turned against exclusive American interests in the Arab world. Richard Nixon's support for Israel in the 1973 Arab-Israeli conflict led Saudi Arabia to embargo oil sales to the US, ending the West's long post-war expansion. And in 1979, the fall of the Shah of Iran completed the destruction of American prestige in the region. Meanwhile, Britain had quietly rebuilt its standing in the Gulf. "We did so," recalls a former ambassador, "in a rather understated but effective way. We didn't, of course, preach to them about human rights or democracy. That would have been quite inappropriate and, anyway, quite ineffective."
British SAS units fought a covert war for the Sultan of Oman. British officers and security experts vanished from the books of the Ministry of Defence to reappear as "advisers" to sheikhdoms and emirates up and down the Gulf. Arms contracts formed the bulwark of the export effort. There were occasional embarrassments, as when the public learnt of a British sale of manacles and leg irons to one emirate. But, by and large, British business and influence expanded, free from political questioning.
All that changed with the Gulf war of 1991, when the British armed forces found themselves fighting to liberate Kuwait and defend Saudi Arabia. There was outrage when a hitherto uninterested public discovered that Britain had helped to arm Iraq. The spotlight then turned on the whole network of weapons dealers, financiers and middlemen who had profited from British trade with Saudi Arabia from the mid-1970s to the present day.
It was inevitable that Jonathan Aitken's name should come up. A small coterie of British political and business figures enjoys influence with the Saudi royal family. Successive ambassadors to Riyadh have nurtured the relationships developed by generations of well-schooled Foreign Office Arabists. But there exists in Saudi dealings with Britain and America an undiscovered hinterland of private patronage, reciprocal understandings and individual business arrangements. Among this group there is a feeling that the Aitken affair, coming after the entreprenurial adventures of Mark Thatcher, risks converting embarrassment into damage for Britain.
The reason is that Saudi Arabia is no longer the complacent financial cornucopia that the young Aitken first visited. The House of Saud has witnessed the Iran-Iraq war, an attempted revolution in Mecca, Saddam Hussein's invasion of Kuwait, Scud attacks on Riyadh, another war in neighbouring Yemen and the growth of political fundamentalism at home. These events have exacted a fearful cost - the Gulf war alone cost £37bn - and the monarchy can no longer buy the allegiance of its subjects.
Previous scandals over Saudi Arabia - the Death of a Princess television row in 1980, for example - merely touched on cultural sensitivities that could, with time, be assuaged and in any case appeared only in the Western media. The difference now is that the British weapons deals with Saudi Arabia, in particular the £20bn Al-Yamamah arms-for-oil barter contracts, go right to the heart of the debate within Saudi society itself. Whereas, in 1980 the inhabitants of Riyadh could live in ignorance of the outside world, censorship has today broken down.
Saudi Arabia has no liberal, secular opposition. But there is a determined group of fundamentalists which believes in a pure Islamic state without kings and princes. From London, an exiled group sends daily faxes of propaganda and news to sympathisers, among them some of the business and religious lite. Few in Britain realise that the costs of the Al-Yamamah arms project arouse great resentment, even in the Saudi establishment. "Let's face it," said one senior Saudi, "we're being coerced to buy weapons we will never be able to use properly for a price we can't afford in exchange for your promise to come and defend the place if we really get into trouble. If you want our protection, then buy our weapons. That's it. It amounts to blackmail." These sentiments were expressed by a man of utter loyalty to his king. But they are echoed with vengeful spite by the fundamentalists, who see in the Aitken and Thatcher stories a God- given opportunity to savage a "corrupt" monarchy and berate the infidel at the same time.
Said Aburish, an Arab author whose recent book on the House of Saud was banned in the kingdom, says that there are four traditional methods by which arms barter deals can generate profit for a favoured few. "First, there are direct percentage commissions paid to the agent," he says. "Then they can understate or overstate the value of oil to skim off a percentage of the amount to be exchanged for the goods. After that comes the `offset' programme where Saudi companies provide services or goods, charging the Saudi government whatever they like. Finally there is the money to be made in subcontracting, building barracks or providing food for personnel. Fortunes are made like this."
In the oil boom years, few Saudis cared about the vast wealth accruing to a small group. That has changed, reflecting new tension between the profligate and the parsimonious, between cosmopolitanism and rigour, between indulgence and piety. These are deep-buried conflicts, but war and economic austerity have brought them to the surface.
SO WHAT, in all this, are British interests in Saudi Arabia today? Are they, as so often depicted by the Foreign Office, the lifeblood of an anaemic domestic arms industry? Or should Britain's interests perhaps be more broadly defined? Certainly not all of those on tonight's Boeing 767 flight are en route to peddle weapons or trade in influence.
Thousands of Britons have brought worthwhile commercial, cultural, medical and teaching skills to a kingdom that in their parents' time was remote and obscure. And thousands of Saudis study in Britain, follow the BBC World Service and appreciate and admire this country.
ONE thing should be clear. The struggle for Saudi Arabia's future is of vital importance to the West.British policy is too critical to be subordinated to the interests of any one individual, family or firm, however well-connected. Mr Aitken - and, no doubt, Mark Thatcher - feel they acted in a manner above reproach. But taxpayers, and the parents of our servicemen, are entitled to believe that if the Government is once again called to take decisions of life or death involving this vast country, its members should do so in a climate of impartiality.
A little more of Ronald Storrs, and a little less of Harry St John Philby, is the least we should expect.