Whether or not the black boxes from Air France flight 447 are found, the crash has shown that new technology is needed to record a flight's last moments in real-time, an aviation expert argues.

Former Air Canada chief executive and ex-head of the International Air Transport Association, Pierre Jeanniot helped pioneer flight data recorders 40 years ago but now says the "black boxes" are obsolete.

"Technology has evolved," Jeanniot told AFP.

"Real-time data transmission from the cockpit by satellite is a lot less costly than it was ten years ago. It is now possible to transmit everything directly during the flight if there is a problem."

Jeanniot said an automatic system for data transmission of flight information by satellite exists and should now become the norm in the industry.

It would put an end to painstaking searches like the one taking place off the coast of Brazil for AF 447's flight recorders, and allow investigators to reconstruct events in only a few clicks of a mouse.

"The plan would begin to transmit data only from the time that a malfunction occurs," said Jeanniot.

"The system can be programmed so that in the event of a serious malfunction, it transmits all data and cockpit communications non-stop. It's quite simple."

The new advanced technology would eliminate the need for costly and often futile searches for black boxes at the bottom of the ocean or deep in the jungle, using helicopters, submarines and mobilising rescue teams.

"Through satellite transmission, everything can be collected instantly. We can know exactly where the aircraft has dropped," Jeanniot said.

More importantly, the valuable data would help grieving families.

"Can you imagine how hard it is for families to be left not knowing what happened for months, some times years?" he said.

A small Toronto-based firm StarNav is developing the state-of-the-art system to provide the real-time connection between the aircraft and the ground, said Jeanniot.

As the data would only be monitored in the event of a problem, most of the flights would not be transmitting anything at all, and there would be no risk of overloading the satellite linkups, said Jeanniot.

Airline companies and governments must now show a willingness to support a shift toward improved and safer technology, said the aviation expert.

"We must draw lessons from every accident," he said.

The head of the Air France pilots' union, Gerard Arnoux, said modern planes were already transmitting data by satellite and that this was the "absolutely intelligent thing to do."

But the head of a smaller pilots' union, France Alter, said the system raised confidentiality issues.

"With the black boxes, if there is no problem on the flight, everything remains in the recorder," said Christopher Presenti.

"But if everything is being recorded, the voice of pilots who are talking about their lives or other matters, what do you do with this information and how can you be sure that the airline is not going to gain access to it?"