The two crashed 737 MAX aircraft did not have security features for which Boeing charged a surcharge

It is one of the most used strategies by the world's leading aerospace manufacturers. Instead of selling a single version of their models to all their customers, They offer different types of optional devices, upgrades, for those who ask for a lot of money.

Some aggregates are aesthetic or serve to improve comfort. But others are tools that can contribute to flight safety.

The major airlines are willing to spend large sums to get the most complete versions, but Some low-cost ones, such as the Indonesian Lion Air, usually opt for standard versions, which include all the minimum requirements established by the air authorities.

The Boeing 737 MAX that crashed in Indonesia and Ethiopia lacked two safety devices for which the manufacturer has charged a supplement, as indicated The New York Times. One of the tools is the angle of attack indicator, which displays sensor readings that record if the nose of the plane is too high and automatically lowers it, one of the potential keys to both tragedies. The other aggregate, called light of disagreement, is activated if these sensors disagree..

According to the New York newspaper, as part of the reforms undertaken by Boeing, its 737 MAX to contain the crisis triggered by accidents, the light of disagreement should be incorporated into the standard version. The angle of attack indicator would always be optional.

US Congress to Hold First Boeing 737 MAX Accident Hearing Next Week in the presence of representatives of the manufacturer and the transport authorities. In addition, the FBI has joined the investigation, reported the US media.

The Republican Senator Ted Cruz convened for 27 March at the hearing of the Subcommittee on Aviation and Space, which will be attended by three transport officials, including the head of the Federal Aviation Administration (FAA).

Cruz wants to hold a second hearing to interview Boeing officials, as well as pilots and other members of the sector, according to a statement released Wednesday.

More than 300 people died in two accidents with two 737 MAX 8 aircraft shortly after takeoff, the first flight of a Lion Air aircraft in Indonesia in October and the last of Ethiopian Airlines this month.

The Department of Transportation is investigating the treatment of aircraft certification by Boeing and the FAA. especially the new flight stabilization system known as MCAS (Maneuverability Enhancement System), which was involved in the Lion Air accident in October. The FBI badists the authorities in this investigation, informed USA Today.

Pilots complained that they had not been informed of the new system, which can force the nose into the plane if it gets a wrong reading from a sensor, giving the impression that the plane may be destabilizing.

The committee will hear FAA Acting Chief Daniel Elwell next week. and Calvin Scovel, chief investigator of the Department of Transport, and Robert Sumwalt, chairman of the National Transportation Council.

The FAA announced on Wednesday that it would be reviewing the information on the Ethiopian Airlines black boxes as soon as they are available.

"Understanding the circumstances that contributed to this accident is fundamental for developing new actions and for the return to service of the aircraft"said the FAA.