So great is the urge to flee poverty in their home countries, that migrants are willing to risk their lives at 30,000ft at temperatures well below freezing for the chance of a better life.
To try to stem the trend, refugee experts called yesterday for tougher action on the plight of stowaway migrants, especially those who are increasingly falling prey to traffickers in the face of tightening asylum rules in European Union countries.
Claude Moraes, director of the Joint Council for the Welfare of Immigrants, said he estimated that the number of clandestine entrants was rising because of an increase in the activities of traffickers prepared to cash in on human misery.
Mr Moraes and Louise Williamson, director of the children's division at the Refugee Council, both warned that the problem of stowaways - including unaccompanied children - could only worsen as EU countries put up higher barriers against would-be asylum-seekers. Ms Williamson said: "We have to look at the whole question of just how difficult it is to get to this country legally."
She went on to dispute the suggestion made on Sunday that a young person seeking to flee his country alone was a rarity.
While most were not stowaways, in the year ending March 1995, the council received 361 referrals from unaccompanied young people from 40 countries, 87 of whom were 14 or under, she said. The next year there were 626 referrals, 112 of whom were 14 or under.
The 12-year-old found in the Jumbo jet on Saturday will not be the last to risk life to escape political or economic privations at home. Ground staff at Gatwick airport found the boy's mutilated body after a British Airways 747 arrived from Nairobi, Kenya, on Sunday morning. He was crushed by the front wheel, which retracts after take-off.
The death follows political unrest in Kenya in the past few weeks, culminating in the death of Solomon Muruli, a student leader.
Earlier this month, the body of Vijay Saini was found in Richmond, south- west London, after he froze to death in the landing gear bay of a BA flight from Delhi, India.
His brother, Pardeep, managed to survive temperatures as low as minus 60C in another wheel arch and is at present having his asylum application considered.
It is not in dispute that some stowaways will be "economic" migrants rather than genuine refugees fleeing a war situation.
But Mr Moraes said: "There has been an increase in the numbers of stowaways who would in the past have had a case."
He said that he had received reports from agricultural areas in Kent and East Anglia that illegal immigrants were being exploited as cheap seasonal labour. The prospects for most stowaways appears bleak, however. Sniffer dogs trained to detect human odour are routinely employed at Britain's south coast ports and those not detected can face horrible deaths.
At least 11 African men have recently died in the holds of ships, either from dehydration or the effects of pesticide. Last September, a Russian stowaway froze to death in the luggage hold of an Aeroflot flight to Rome.Reuse content