Amid all the controversy and speculation surrounding the Flight 447 crash, Air France has sent a memo to its pilots informing them that speed measurement instruments will be replaced on all medium- and long-haul Airbus planes, AP reports.

For a few days investigators have been focusing on automated messages sent out during the plane’s final moments that indicate the jet may have been flying at an improper speed through bad weather. This suggests an issue with the plane’s speed reading instruments.

Flying at the correct speed is very important when going through a storm, especially one as severe as the one Flight 447 is thought to have encountered.

Meteorologists say the jet went through a storm with 100 mph updrafts that sucked up water from the ocean thousands of feet below. The damp air then rose up and froze quickly in the -40 F weather, causing major turbulence and possibly icing.

The airliner’s electrical systems then failed, and AP reports the plane most likely broke apart in air. It has been suggested that the plane’s speed readers may have been inadequate, and it was reportedly previously advised they be changed.

Air France will now replace the instruments, known as Pitot tubes, on all of its mid- and long-haul Airbus jets in the “coming weeks.” CNN reports the Pilots’ union claims Air France has said the sensors will be replaced within a few days.

The Alter union, a small union within Air France, is urging their pilots to wait until the tubes are replaced before flying their planes, CBC reports.

Pitot tubes are L-shaped and stick out from the wing or fuselage of the plane. “The pressure of the air entering the tube lets sensors measure the speed and angle of the flight, along with less vital information like outside air temperature” AP reports.

They are heated to prevent icing, though a theory suggests the Pitot tubes on Flight 447 were faulty, which could have caused them to ice over. Malfunctioning tubes would have fed incorrect speed readings to the plane’s computers, causing the plane to accelerate or decelerate dangerously.

A French agency investigating the crash has reports the plane’s pilots saw major turbulence and an inconsistency in speed readings before going down, according to Le Monde newspaper.

Air France Flight 447 crashed into the Atlantic last Monday just hours after taking off from Rio de Janeiro. All 228 passengers are believed to be dead. Thus far, sixteen bodies have been found.

Searchers are still looking for the flight’s cockpit recorders. Mini submarines will arrive this week to aid in the hunt.

Be sure to click here to follow the progress of the search for bodies, black boxes and pieces of the plane.