French investigators are recommending that the transmission time of flight-recorder locator beacons be increased to at least 90 days, to improve the chances of quickly recovering data following an air accident at sea.
Investigators want aircraft operating over the sea to be fitted with an additional underwater locator beacon - possibly transmitting on frequencies around 8.5-9.5kHz - and for studies to determine the practicality of mandatory regular transmission of basic flight parameters.
France's Bureau d'Enquetes et d'Analyses is also asking ICAO to look closely at the possibility of implementing deployable recorders.
The recommendations are contained in an update to the inquiry into the loss of the Air France Airbus A330-200, operating flight AF447 from Rio de Janeiro to Paris, over the South Atlantic on 1 June.
No firm conclusions have been established as to the cause of the accident, partly because neither the flight-data nor cockpit-voice recorder has been found.
In its update the French investigation agency Bureau d'Enquetes et d'Analyses states: "The investigation into the accident to AF447 confirms the importance of data from the flight recorders in order to establish the circumstances and causes of an accident, and to propose safety measures that are substantiated by the facts.
"As in other investigations it also brings to light the difficulties that can be encountered in localising, recovering and reading out the recorders after an accident in the sea.
"These difficulties raise questions about the adequacy of the means currently in use on civil transport aircraft for the protection of flight data with the technological possibilities and the challenges that some accidents represent."
BEA says that a working group aimed at addressing these concerns has found that underwater locator beacons - which currently need to transmit for 30 days - should have their transmission time, and range, extended. The group, which presented its findings to an ICAO panel last month, has also looked at transmission of data and installation of deployable recorders.