All UK airports have now relaxed the restrictions on hand luggage introduced in the wake of Thursday's alert over a possible terror plot.
Airport restrictions on hand luggage have now been relaxed
The new guidelines - which allow one item of hand luggage the size of a laptop computer bag - were delayed until Tuesday at Heathrow and Gatwick.
Most airports have reported business as usual, while 45 flights were cancelled at Heathrow, the worst-affected.
Airport operator BAA has said searches mean delays are likely to continue.
Meanwhile, a senior policeman has criticised calls for screening of passengers for likely terrorist types.
Metropolitan Police Chief Superintendent Ali Dizaei said such a move could create an offence of "travelling whilst Asian".
Passengers had been banned from taking anything into aircraft cabins except travel documents, baby food and certain medicines, all of which had to be carried in clear plastic bags.
The bag they can now take should be no bigger than 45cm x 35cm x 16cm (17.7 × 13.7 x 6.2 inches), including wheels, handles, and side pockets.
But people are still not allowed to take in any liquids apart from baby milk and baby food, and prescription medicines.
BAA said anyone travelling over the next few days should allow extra time for their journey.
The airport operator has come under fire from several airlines who have been highly critical of the way it has managed its airports during the upheaval.
British Airways has said it may sue BAA, but Virgin Atlantic called on BAA, airlines and the government to sit down and discuss who should "pick up the cost" of the terror alert.
BA boss Willie Walsh has attacked BAA's management, saying it had "no adequate plan" to deal with the emergency.
He told the Daily Mirror that the resulting queues resembled a "bad dream at Disneyland".
Paul Charles, from Virgin Atlantic, talking about the situation at Heathrow and Gatwick, said: "The delays are less and the queues are less. It is clear some of the measures put in place are working.
"There is no doubt that the picture is better from a passenger perspective."
He said Virgin Atlantic was running a normal service, adding that it had been a frustrating few days "because we have been forced to cancel a handful of flights we would otherwise be running normally".
On Tuesday, a total of 45 flights were cancelled at Heathrow - one Jet Airways flight and 44 British Airways. Of BA flights, this includes four long-haul services, 21 short-haul and 16 domestic flights.
On Monday, the majority of flights got away on time, said a BAA spokeswoman.
At Gatwick 11 flights have been cancelled - all on BA domestic routes - while at Stansted there have been eight cancellations of Ryanair flights.
Elsewhere, airports including Birmingham, Newcastle, Manchester, Edinburgh and Glasgow were reporting business was mostly back to normal after the less stringent measures were introduced on Monday.
The Times reports that transport officials are considering "passenger profiling", where airlines identify people who, on grounds of such things as conduct or appearance, they believe could pose a risk to security.
They are then subjected to more questioning or greater surveillance.
Metropolitan Police Chief Superintendent Ali Dizaei said intelligence might be able to shed light on people's travel history, where they bought tickets, and the persistency of travel.
But he told BBC Two's Newsnight: "It becomes hugely problematic when it's based on ethnicity, religion and country of origin. I don't think there's a stereotypical image of a terrorist."
BAA's Tony Douglas said the airline industry had faced a "national security challenge" on an "unprecedented scale" in the past few days.
He said the situation was becoming more stable, with improved punctuality of flights at Heathrow and fewer cancellations.
But police at Gatwick have said there has been an increase in thefts from passenger baggage in transit during the recent security alert.
Eight passengers on outbound flights reported items stolen from bags in the hold since the increased security measures began, compared with just one theft over the same period last year.
There have also been 52 reported thefts from inbound flights over the last five days, compared to 16 at the same time last year.
Meanwhile, police investigating the suspected plot to blow up transatlantic flights have found a handgun and a rifle in searches.
Police are continuing to search woodland near High Wycombe, while officers have also carried out searches at two internet cafes 18 miles away in Slough.
Thames Valley Police said extra officers had now been drafted in to guard against any "misguided backlash" in Slough.
Twenty-three people are in custody in connection with the suspected plot. Their detentions will be reviewed by a district judge on Wednesday.
The UK security threat level was raised to "critical" last week amid fears of a plot. On Monday it was downgraded to "severe", meaning an attack is now considered highly likely but not imminent.