European safety officials have ordered checks on certain Airbus speed sensors supplied by U.S. manufacturer Goodrich, weeks after clamping down on alternative equipment from France's Thales.
Potentially faulty speed readings from sensors made by Thales are at the center of investigations into the crash of an Air France A330-200 jet in the Atlantic on June 1.
In an airworthiness directive dated September 22, the European Aviation Safety Agency said there had been reports of loose fittings on a number of Goodrich sensors, known as pitot probes.
This could be the result of mis-torque...at equipment manufacturing level, the Cologne-based agency said.
If not corrected, such a problem could lead to an air leak and false speed readings, according to the public document.
The Goodrich sensors were designed for the A330 and A340. The company was not immediately available for comment.
A spokeswoman for EASA, a European Union safety agency, said the problem would be relatively easy to address and services were unlikely to be severely disrupted.
An Airbus spokesman said the checks affected a limited batch of sensors and these had been tracked down through their serial numbers. The number of airlines and aircraft affected was not immediately available.
It is the first time Goodrich sensors have come under the spotlight since the Air France crash highlighted the occasional fragility of systems used to measure an aircraft's speed.
All 228 people on board were killed when Air France flight AF447 crashed en route from Rio de Janeiro to Paris.
Investigators revealed inconsistent speed readings from the three Thales sensors on board the doomed Air France A330, but have said it is too early to say exactly what caused the crash.
Since the crash several other incidents involving speed sensors have come to light, but French investigators attribute this in part to extra zeal in reporting momentary glitches that would otherwise pass almost unnoticed and never get reported.
Pitot probes take pressure readings from which computer systems calculate an aircraft's speed, but they are vulnerable to icing or anything else that interrupts the air flow.
Without accurate speed data, pilots can accidentally fly the plane too fast, putting pressure on its structure, or too slowly, causing it to stall.
EASA last month banned the particular model of Thales sensor installed on the crashed jet and restricted the use of a newer Thales model to just one per aircraft. The move meant that at least two sensors must in future come from Goodrich.
Goodrich is the standard supplier of sensors for the Airbus A330 and A340. Thales makes the only approved alternative.
The EASA spokeswoman said it had acted over the quality of a batch of sensors leaving the Goodrich factory but not over their design. In the case of Thales probes, safety officials had been more worried about their inherent resistance to bad conditions.