Martin Chalk, of the European Cockpit Association, said the rules needed to be modernised
Airline pilots are demonstrating across Europe because they say long flying hours are "putting lives at risk".
European air crew unions argue current rules that govern how long they can fly for are unsafe, with fatigue a factor in 15% of accidents.
The European Aviation Safety Agency says it is still considering a scientific report on the issue.
In Brussels the protesters handed out fake boarding passes to the public, carrying health warnings.
Industrial action by pilots is outlawed in the UK, and British airports were unaffected by Monday's action.
In a demonstration outside the European Commission building in Brussels, TV pictures showed dozens of uniformed pilots and air crew holding placards and handing out flyers calling for a change in working conditions.
About 60 pilots demonstrated at Amsterdam-Schiphol airport in the Netherlands, the AFP news agency reports.
The rules are already in force in some EU countries, but are due to come into force in the UK in 2012.
This is a defining moment in how passengers will be protected
Jim McAuslan, British Airline Pilots Association
Pilots and air crew have complained that their working conditions have deteriorated as the airline industry looks to cut costs.
The British Airline Pilots Association (Balpa) said many leaflets would be handed out across Europe by the protesters.
The general secretary of Balpa, Jim McAuslan, said he feared that attempts by the EU to standardise working conditions by 2012 would put more pressure on pilots.
He said: "Only fatigue experts understand the impact on a body of flying through so many time zones, having consecutive early starts and late duties and all the other factors that make up a pilot's life".
Mr McAuslan told the BBC that while EU law meant a pilot could work up to 14 hours a day, scientists believe they should not exceed 13 hours.
"Anything over that increases the risk of an accident by five and a half times," he said.
"When that's brought home to the public, I hope the public will put pressure on the regulator to say 'you mustn't do this - you must listen to what science has been saying'."
Safety is 'top priority'
The President of the European Cockpit Association, Capt Martin Chalk, warned that "unless the EU acts now on information it already has, that it commissioned and that was delivered to it a year ago - unless it acts on that, unfortunately the safety levels we currently enjoy would be damaged".
Pilots claim long duty hours are putting passengers in danger
He was speaking to BBC Radio Five Live on Monday.
A UK Department for Transport spokesman insisted that safety would not be compromised by the new rules.
He said: "The European Aviation Safety Agency is in the process of considering the responses to its consultation on a first draft of rules establishing flight and duty time limits.
"While these are unlikely to be finalised until some time in 2011, we are confident they will maintain the same high level of safety as the current rules.
"The safety of passengers and crew is our top priority and we will not allow this to be compromised."
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